Microbiology with Diseases by Taxonomy Chapter 22 Answers

Microbiology with Diseases by Taxonomy Chapter 22 Answers

Microbiology with Diseases by Taxonomy Answers

Microbiology with Diseases by Taxonomy Chapter 22 Answers 1CM
Following concept map describes systemic mycoses.
microbiology-with-diseases-by-taxonomy-chapter-22-answers-1cm

Microbiology with Diseases by Taxonomy Chapter 22 Answers 1CT
The fungi and the spores produced by them are present almost everywhere in the environment- air, water, soil and on or in most of the multicellular organisms. However, their omnipresence due not cause diseases in human beings, though most of human beings experience mycosis at least once in life time. Fungi are so omnipresent that environmental contact to opportunistic fungal pathogens is not avertible.
Opportunistic fungi are present everywhere, but they lack the genes for virulence and cannot infect health individuals. The fungi exist as harmless residents in the environment.
However, the opportunistic pathogens attack and cause people with compromised immunity.
Many of the fungal pathogen enter through the same portals and lead to similar symptoms. This leads to difficulty in diagnosis. Diagnosis on the fungal infections only based on clinical symptoms is not recommended as some of the symptoms are very common among the fungal infections. Hence the detection of fungal pathogens is relied upon the following methods:

  1. Direct microscopic examination of fresh specimens
  2. Confirmatory isolation on solid media
  3. Serological tests for host antibody

The ubiquitous nature of the fungi makes it difficult to control. And since majority of the fungi present more or less similar kind of clinical symptoms the diagnosis of fungal infections is also challenging.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 1FB
Dimorphic fungi exist in two forms:
The fungal species are existed in different types of environments and different types of physical forms. Here, the dimorphic fungi is shows the dimorphism on physical structure based on the temperature difference in their living conditions.
(a) In the environment where the temperature is below 300C, this fungi grows as mycelial form composed of hyphae.
(b) In the human hosts where the temperature is at 370C it grows as spherical yeast forms.
mycelial forms , yeast forms.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 1M
Please find below the correct options for the diseases with the manner in which fungi enter the body.
A. Inhalation:
The fungi enter the body through the respiratory tract via inhalation. A large number of fungi are inhaled on a daily basis by everyone. Microorganisms that attack the typical healthy respiratory tract have established specific mechanisms to avoid destruction by alveolar macrophages and to overcome muco-ciliary defenses. Following are the examples of the fungi that invade the body via inhalation. Hence the correct option is A) Aspergillosis, Coccidioidomycosis, Cryptococcosis, Histoplasmosis
B. Contact:
The fungi enter the body through the skin via dermal contact. Majority of microorganisms penetrate through breaks in the skin, which could be through superficial pricks, burns, wounds, and diabetic and pressure related foot infections. Following are the examples of the fungi that invade the body via inhalation. Hence the correct option is B) Candidiasis
C. Trauma:
The fungus is introduced directly into the host blood stream through mechanical injury or accidental injury. Trauma plays a significant role in causing fungal infection. Fungal pathogens introduced through trauma gains entry and launch themselves in the cornified layers of macerated or traumatized skin. Hence the correct option is C) Chromoblastomycosis, Dermatophycosis, Mycetoma, Sporotrichosis
D. Ingestion:
The fungus is introduced through the digestive tract via ingestion. Ingestion can occur via smoking or eating with contaminated hands or in unhygienic work areas. Hence the correct option is D) Hypersensitivity reactions, Mushroom poisoning

Microbiology with Diseases by Taxonomy Chapter 22 Answers 1MC
A fungus that can infect or causes disease in both healthy and immunocompromised patients is known as a true pathogen.
a. True pathogen:
True pathogen infects or causes disease in healthy individuals, irrespective of the immune status. True pathogenic fungi include Histoplasma capsulatum, Coccidioides immitis, Blastomyces dermatitidis, and Paracoccidiodies brasiliensis. Hence, this option is correct.
b. An opportunistic pathogen:
Opportunistic fungi on the other hand lack genes for proteins that help in colonizing body tissues, and therefore these fungi infect individuals with compromised immune system. Opportunistic fungi include Candida albicans and Pneumocystis Pneumonia. Hence, this option is incorrect.
c. A commensal organism:
A commensal organism lives in association within or on the other organism. Commensalism is a relationship in which one organism is benefited without causing any effect to the other organism. Hence, this option is incorrect.
d. A symbiotic organism:
A symbiotic organism lives in a close and prolonged association of a different organism belonging to same or a different species. In this association the organisms does not necessarily benefit each other. Hence, this option is incorrect.
Hence, the correct option is (a) a true pathogen is the fungus that is capable of infecting both immunocompetent and immune comprised individuals.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 1MTF
Fungi along with the spores they produce are Omni-present. They are found in the atmosphere, in soil, and in water. The fungal infections are acquired through inhalation, trauma, or ingestion. The fungal infections are generally not contagious. Epidemics of fungal infection do occur due to mass exposure to the environmental source of fungi, but not as result of transmitting from person to person.
Very rarely the fungi spread from one person to another. Dermatophytes are the group of fungi which are contagious.
Hence, the given statement, fungi are generally not transmitted from person to person is TRUE.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 1SA
The majority of the antifungal fungal drugs are toxic to human cells, due to the similarities between fungal and human cells. Human cell membranes and fungal membranes both contain sterols. The sterols are act as primary membrane target for anti-fungal agents. The human cell membrane contains cholesterol as sterol molecule; the fungal membrane contains Ergosterol as sterol molecule. Hence, all the antifungal agents like amphotericin B specifically target the ergosterol in fungal cytoplasmic membranes.
The side effects of using long term anti-fungal agents include headache, gastrointestinal upset, anemia, rashes, and serious damage to liver and kidney.
Though “amphotericin B” is considered as gold standard among the antifungal agents and this drug have more side effects and toxicity to the human beings. Amphotericin is usually prescribed after other antifungal antibiotics failed to treat the symptoms. Therefore, amphotericin B is used only in the treatment of life-threatening fungal infections.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 2CT

  • Certain true fungal pathogens exhibit dimorphism –
    • Mycelial form that grows in the environment
    • Yeast form that grows in the human host
  • Dimorphism indicates that environmental cues are prompting changes in gene expression in fungal pathogens.
  • The mycelium mostly lives in soil and contamination happens when the human host breathes in mycelial or conidia that transform into the yeast form within the host lung.
  • This capability to shift between mycelial and yeast forms is vital for the establishment of the infection.
  • Because dimorphism exhibited by the fungal pathogen is obligatory for its capability to cause infection, the biochemical routes and the genes accountable for activating this course could be the main emphasis to develop new antifungal agents, which could be more efficient and specific.
  • Characterization of the genes being expressed in the pathogenic yeast phase ascertains functions crucial to pathogenesis that in turn may be targeted by chemical equivalents of their metabolic intermediates.
  • The most prominent difference between mycelial and yeast forms is the cell wall polysaccharide. 1,3-ß-glucan is found in mycelia and 1,3-a-glucan is found in yeast forms.
  • Either the conditions in the host cell or specific antifungal agents targeting the 1,3-a-glucan present in the yeast cell wall can be utilized as targets for designing new anti-fungal agents
  • The antifungal agent can be designed effectively to target fungal pathogen in its active form within the host.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 2FB
True pathogen infects (or) causes disease in healthy individuals, irrespective of the immune status. True pathogenic fungi include Blastomyces dermatitidis, Coccidioides immitis, Histoplasma capsulatum, and Paracoccidiodies brasiliensis.
Blastomyces dermatitidis, Coccidioides immitis, Histoplasma capsulatum, and Paracoccidiodies brasiliensis.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 2MC
Tricophyton rubrum is the fungi where the mode of transmission is from person to person.
a. Blastomyces dermatitidis :
In humans, this fungus is transmitted via inhalation of the airborne fungal spores. These fungal spores in soil become airborne during the occupational and recreational activities and thereby get inhaled. Hence, this option is incorrect.
b. Coccidioides immitis infection is caused by inhalation of the fungal spores/particles. Hence, this option is incorrect.
c. Tricophyton rubrum is a dermatophyte and is commonly known as athletes’ foot, ringworm, or jock itch. It is transmitted from person to person through their skin. Hence, this option is correct.
d. Aspergillus fumigtus:
Aspergillus fumigatus belongs to genus Aspergillus, and is among the most common Aspergillus species to cause infection in individuals with compromised immune system. The transmission of fungal spores to the human host is through inhalation.
Hence, the correct option is (c) Tricophyton rubrum is the fungus that is generally spread from person to person.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 2MTF
Fungal infections are difficult to treat due to the following reasons:

  1. Biochemical ability:
    Fungi generally possess the biochemical ability to resist T-cell mediated immune responses.
  2. Biochemical similarity:
    The majority of the antifungal fungal drugs are toxic to human cells due to the similarities between fungal and human cells. Human cell membranes and fungal membranes both contain sterols, a primary membrane target for anti-fungal agents. The only difference seen in the composition of membrane is the presence of ergosterol in the fungal cell in place of cholesterol in human cells. However, cholesterol and ergosterol are not distinct enough to prevent the damage to human tissues. Hence, all the antifungal agents have some extent of side effect.

Hence, the given statement, on the whole, fungal infections are relatively easy to treat is FALSE..
On the whole, fungal infections are relatively DIFFICULT to treat.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 2SA
The superficial mycoses are generally confined to the outer layers of skin, nails, and hair, and do not attack living tissues. These superficial fungi are known as dermatophytes. Dermatophytes are capable of producing extracellular enzymes known as keratinizes, which are able to hydrolyze keratin. This has enabled the superficial mycoses to dwell on the outer layers.
The dermatophytes causing infections in humans have diverse natural sources and means of transmission:

  • Anthropophilic – Related with humans. Transmission from one man to another via close contact or through polluted items.
  • Zoophilic – Related with animals. Transmission to man via close contact with animals (cats, cows, dogs) or with polluted items.
  • Geophilic – These fungi are generally found in the soil and are spread to man via direct exposure.

Since these sources of infection are very common and also since the superficial mycoses are limited to the outer layers it is very difficult to determine the exact source. The symptoms produced by the fungal pathogen are similar and cannot be differentiated based on the source. Identifying the exact species of dermatophyte and cause of infection are crucial for appropriate treatment of the patient and also control of the source.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 3CT

  • Reducing fungal growth in and on foods can aid in reducing usage of fungal toxins.
  • By means of utilizing fungicides in fields where crops are grown can decrease the extent of fungi growing alongside the crops and consequently reduce the extent of fungal spore contamination when the crops exist in the field.
    • Growth of fungal resistant variations of growing plants;
    • Control field contamination of fungi by planting crops;
    • Expending preservatives and fungicides against fungal growth;
  • Washing with cleansers or detergents after crop, cooking or radiation can decrease fungal growth on foods during storage.
  • All the above stated precautions can be applied worldwide, however toxic fungi with distinct geographic dispersals might require precise precautions bespoke to local conditions.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 3FB
The majority of the antifungal fungal drugs are toxic to human cells due to the similarities between fungal and human cells. Human cell membranes and fungal membranes both contain sterols, a primary membrane target for anti-fungal agents.
The only difference seen in the composition of membrane is the presence of ergosterol in the fungal cell in place of cholesterol in human cells. Hence, all the antifungal agents target the ergosterol in fungal cytoplasmic membranes. Hence, the correct answer is Ergosterol.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 3MC
Identification of true fungal pathogens should be done by various screening methods like Gomori methenamine silver (GMS), microscopic examination, and serological testing. The identification of true fungal pathogen cannot be done by clinical symptoms alone.
a. Growth at 250C and 370C to show dimorphism :
Culturing the sample on Sabouraud dextrose agar for observation of colonies, and microscopic examination of yeast cells, mycelia, or mold spores. Microscopic examination for identification dimorphic forms exhibiting growth at 250c and 370c. This technique aids in identification of true fungal pathogen. Hence, this option is incorrect.
b. GMS staining of infected tissues:
Gomori methenamine silver (GMS) staining on the tissue sections to stain fungal cells black. GMS staining is widely used for diagnosis of fungal infections. This technique is recommended for identification of true fungal pathogen. Hence, this option is incorrect.
c. Serological testing involves measuring antibody in the serum and identification of antigens in the blood, secretions or tissue by the way of various immune-chemical techniques. It is transmitted from person to person through their skin. This technique is widely used for the identification of true fungal pathogen. Hence, this option is incorrect.
d. Clinical symptoms alone :
Diagnosis on the fungal infections only based on clinical symptoms is not recommended as some of the symptoms are very common among the fungal infections. Appropriate diagnosis of the causative agent is first step to effectively treat fungal infections. Hence, this option is correct.
Hence, the correct option is (d) clinical symptoms alone is not used to detect and identify true fungal pathogens.
Accurate diagnosis of fungal agents involves:

  1. Direct microscopic examination of fresh specimens
  2. Confirmatory isolation on solid media
  3. Serological tests for host antibody

Microbiology with Diseases by Taxonomy Chapter 22 Answers 3MTF
Dermatophytes are the fungi that transmit from person to person and thrive only on skin, nails, and hair. Dermatophytes use keratin as a source of their nutrition and therefore colonize only on dead tissue.
Systemic mycoses on the other hand are contracted from the environment. These fungi spread across different geographical locations and cause pulmonary infections when the spores are inhaled. Systemic mycoses have the ability to spread beyond the lungs.
Hence, the given statement, Dermatophytes are always contracted from the environment is FALSE.
SYSTEMIC MYCOSES are always contracted from the environment.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 3SA
Superficial fungal infections are difficult to diagnose, and are often mistaken for other disorders, such as psoriasis or eczema. Fungal infections are usually analyzed on the basis of clinical appearance. Nevertheless, the antifungal or steroid reaction of a dermatosis may be utilized in the diagnosis, so it is significant that suitable investigations are initiated before administering any form of treatment, which often comprises an anti-fungal or a steroid cream. This approach will permit the diagnosis to be reevaluated if preliminary treatment is ineffective.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 4CT

  • The blood supply is not direct to the nail beds, thus attributing to its slow growth rate.
  • No direct blood supply also substantiates the fact that antifungal agents reach very slowly/or sluggishly to the nail beds and thus need a continuous level of medication over an extended period of time.
  • Treatment over an extended period the will allow the antifungal agent to infiltrate to the site of the infection.
  • Hence owing to the poor blood supply to the nail beds, Onychomycoses are both difficult to treat, and are generally require treatment with oral antifungal agents for long periods of time.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 4FB
Black piedra forms hard, black nodules, while white piedra produces soft, gray to white nodules.
Piedra is a characteristic hairy fungal disease is also called trichsporosis. The black piedra is caused by the single fungal species called Piedraia hortae.
The white piedra is caused due to the infection by several fungi, the nodules contains anthroconidia and yeast cells and hairy shafts. Hence, the correct answer is BLACK ,WHITE.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 4MC
Though amphotericin B is gold standard for treating fungal infections, it is extremely toxic to humans and most clinicians. Therefore, it is prescribed only for systemic infections.
a. Dermatophyte infections:
Dermatophyte infections are caused due to the fungus that infects skin, nails, and hair. These fungi have the ability to obtain required nutrients from the keratin. Majority of the infections are treated with topical application of the antifungal agents. Depending of the fungi causing the infection and severity, oral treatment will include itraconizole, terbinafine, or griseofulvin. Hence, this option is incorrect.
b. Malassezia infections:
Malassezia infections are naturally occuring on the skin surfaces of humans and animals. Melassazia infections are treated with ketoconazole or selenium disulfide containing shampoos. Other treatments include miconazole, coal tar, zinc pyrithione (ZPT), tea tree oil, or ciclopirox olamine medicated shampoos. Hence, this option is incorrect.
c. Systemic infections:
A systemic disease affects a number of tissues and organs, or infects the body as a whole via infection in the blood stream. Amphotericin B is the gold standard for treatment of systemic infections. Though it is toxic for human cells, in case of systemic infections where the intensity of the infection is severe, it is prescribed as the treatment option. Hence, this option is correct.
d. Black piedra:
Black piedra is fungal hair infection where soft black nodules form on hair shafts. Terbinafine is the antifungal agent used for treating black piedra. Hence, this option is incorrect.
Hence, the correct option is (c) systemic infections are treated with amphotericin B, though it is extremely toxic to humans.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 4MTF
Chromoblastomycosis and Phaeohyphomycosis are cutaneous and subcutaneous mycoses that look similar and are caused by dark-pigmented ascomycetes. Both the infections are caused due to traumatic introduction of the fungi into the skin. Lesions produced due to this infection may be far-reaching and can spread internally.
Hence, the given statement, Chromoblastomycosis and Phaeohyphomycosis are both caused by dark-pigmented ascomycetes is true.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 4SA
The fungi and fungal spores are present almost everywhere in the environment- air, water, soil and on or in most of the multicellular organisms. However, their omnipresence doses not always cause the diseases to human beings, some fungal species are have beneficiary effects.
Majority of the fungal infections are not contagious and hence do not spread from one infected person to another. Opportunistic fungi are present everywhere, but they lack the genes for virulence and cannot infect health individuals. The fungi exist as harmless residents in the environment.
The Opportunistic fungi like Aspergillus, Candida, Cryptococcus, pneumocystis, Mucor.
These fungal organisms associated with the other pathogenic infections like viral, increases the rate of disease condition.
However, the opportunistic pathogens attack and cause people with compromised immunity. In AIDS patients the immunity is at very low level. Hence, they become very good targets for the opportunistic pathogens to thrive on. The clinical manifestations of these fungi in AIDS patients are odd and pose challenge for the physicians to treat them. With the growing number of AID patients, opportunistic fungal infections have become significant cause of human disease and death.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 5CT
Following are the factors that contribute to the pathogenicity of Cryptococcus infections:
(a) Polysaccharide capsule:
Provide a poorly immunogenic surface and protect the bacteria from antibodies and phagocytosis. The polysaccharide capsule contains mannose, glucuronic acid, and sugar molecules with O-acetyl side chains.
The presence of polysaccharide layer on the bacterial surface provides the gelatinous nature, this nature help to pathogen to escape from the phagocytic cells. These carbohydrate molecules act as great virulence factors.
(b) Ability to produce melanin:
The ability of the yeast to produce melanin it is a pigment molecule, which further prevents phagocytosis. These species weakens the central nervous system.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 5FB
Sporotrichosis is caused by dimorphic ascomycete Sporothrix schenckii, which is commonly known as rose-garderner’s disease. Sporotrichosis is a sub cutaneous infection that is limited to arms and legs and it occurs mostly via thorn pricks and wood splinters.
The Sporotrichosis mainly attacks the skin (sub cutaneous), lungs (pulmonary) and joint bones.
This disease mainly affects the people, who worked near the gardens and farms, and they mostly grow in immune compromised individuals. Hence, the correct answer is SPOROTHRIX SCHENCKII.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 5MC
Ringworm is a superficial fungal infection caused by dermatophyte.
a. Helminth:
Helminths are parasitic worms that cause a range of transmittable diseases. The infections caused by helminth parasites include Elephantiasis, Bilharzia, Ascariasis, Trichuriasis, and hook worm. Hence, this option is incorrect.
b. Dermatophyte:
Ringworm or dermatophytosis is a fungal infection of the skin in humans, domesticated animals such as sheep, cattle, and pets such as cats. Ring worm is caused by a dermatophyte. Hence, this option is correct.
c. Dimorphic fungus:
Dimorphic fungi have the ability to exist as hyphal or filamentous form and yeast forms. Infections caused by dimorphic fungi include coccidioidomycosis, paracoccidioidomycosis, candidiasis, and blastomycosis. Hence, this option is incorrect.
d. Commensal fungus:
Commensal fungi are the group of fungi, which neither benefit nor harm to the host. Commensal fungi do not generally cause any infections. Hence, this option is incorrect.
Hence, the correct option is (b) dermatophyte is the causative agent of ring worm.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 5MTF
Sporotrichosis, commonly known as rose gardener’s disease is a sub cutaneous infection that is restricted to arms and legs. This fungus resides in solid and contracts humans by means of wood splinters or thorn pricks.
Hence, the given statement, Sporotrichosis is always caused by traumatic introduction of fungi beneath the skin is true.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 5SA
Following is the differentiation between mycotoxicosis and mycetismus.
(a) Mycotoxicosis:
Mycotoxins are toxins produced by fungi. Mycotoxicosis is caused by consuming mycotoxins; the fungus itself is not present in this case.
The Mycotoxins are chemical molecule they are poisonous in nature. Some, examples of Mycotoxins include Aflatoxins, which are produced by the Aspergillus species and ergot alkaloids synthesized by the Claviceps species.
(b) Mycetismus:
Mycetismus is a specific type of mycotoxicosis, caused by consuming the fungus. Mycetismus is commonly known as mushroom poisoning and is caused due to ingestion of toxic mushrooms. The deadliest mushroom toxin is produced by Amanita phalloides.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 6CT
Though subcutaneous mycoses cause lesions around the skin at the site of inoculation, following are some characteristics that will help in in distinguishing one kind of sub cutaneous fungi from another:

  • Differentiated by the presence of pigments golden brown are developed by Fonsecaea while brown pigments are caused due to Cladophiolaphora.
  • Differentiated by exhibiting dimorphic forms, whether it exists in the form is yeast (e.g. Sporothrix) or myeclial forms (Madurella and Pseudoallescheria).
  • Differentiated by geographic location, region in which the infection was developed can also be beneficial in determining the causative agent.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 6FB
Cryptococcus neoformans is the primary species causing crytococcoses. Humans are infected via inhalation of spores (or) dried yeast aerosols from the droppings of the birds.
Hence, the correct answer is Cryptococcus neoformans.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 6MC
Aspergillus niger exhibits characteristic of opportunistic fungi and hence is a typical example of opportunistic fungus
a. Piedraia hortae :
Piedraia hortae is superficial mycoses, which causes black piedra. Piedraia hortae is found in Southeast Asia and throughout Central America. The infection caused is restricted to the superficial surfaces of the hair and skin. These infections are non-destructive and of cosmetic significance only. Hence, this option is incorrect.
b. Histoplasma capsulatum :
Histoplasma capsulatum is an ascomycete and causative agent of histoplamosis. Histoplasma capsulatum is classified as a true fungal pathogen, which means that it is capable of infecting immune competent individuals. Hence, this option is incorrect.
c. Fonsecaea pedrosoi :
Fonsecaea pedrosoi is the causative agent of the disease chromoblastomycosis. The mode of infection is through traumatic introduction of the fungi under the skin, usually by splinters or thorns. Though this fungus is prevalent across all regions, the occurrence of this disease is very low. Hence, this option is incorrect.
d. Aspergillus niger :
Aspergillus niger spores are found almost everywhere and human beings are routinely and constantly exposed to them. This kind of exposure is a normal part of the human condition and in general does not cause any adverse health effects. But, under favorable conditions like immune-comprised individuals, it can lead to systemic diseases. Aspergillus niger is less probable to cause human disease than some other Aspergillus species. But, in case of inhalation, large amounts of spores it can turn detrimental. Hence, this option is correct.
Hence, the correct option is (d) Aspergillus niger which has the characteristics of classical opportunistic fungus.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 6MTF
Coccidioidomycosis is caused by Ascomycete Cocidioides immitis, which is found exclusively in the country southwestern United States (Nevada, Texas, Arizona, New Mexico, and California) and also in Mexico. Few other regions where Cocidioides immitis is found include Central and South America.
Therefore, the possibility of Coccidioidomycosis occurring beyond the Western Hemisphere is limited.
Hence, the given statement Coccidioidomycosis does not occur normally outside the Western Hemisphere is TRUE.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 6SA
A. General area where Blastomycosis is endemic
microbiology-with-diseases-by-taxonomy-chapter-22-answers-6sa
B. General area where Coccidiodomycosis is endemic
microbiology-with-diseases-by-taxonomy-chapter-22-answers-6sa1
C. General area where Histoplasmosis is endemic
microbiology-with-diseases-by-taxonomy-chapter-22-answers-6sa2

Microbiology with Diseases by Taxonomy Chapter 22 Answers 7CT

  • Health care providers have restricted possibilities to attempt to slow the increasing incidence of opportunistic fungal infections because of the omni-present nature of fungi and the difficulty in reducing the rate of increase of immunocompromised individuals.
  • Adapting stringent hygienic techniques can lessen the occurrence of fungi and spores.
  • Following some measures like filtration of air supplies in hospitals can reduce incidence of fungal infections.
  • Restricted prescription of immunosuppressive medications in the treatment can lessen patient susceptibility.
  • Using the least invasive procedural option can reduce nosocomial fungal infections that can be caused due to open surgeries.
  • Educating patients about sources and threats of infection may also aid in prevention of certain infections.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 7FB
Opportunistic fungi lack genes for proteins that help in colonizing body tissues; therefore these fungi infect individuals with compromised immune system. Opportunistic fungi include:
The Candida, Aspergillus, Cryptococcus, Pneumocystis and Mucor .

Microbiology with Diseases by Taxonomy Chapter 22 Answers 7MC
Subcutaneous infections are contracted through trauma and these infections remain localized.
a. Inhalation and remain localized:
Systemic mycoses caused by opportunistic fungi are caused due to inhalation. The infections resulting from this group of fungi remain localized. Examples include aspergillosis and candidiasis. Hence, this option is incorrect.
b. Inhalation and become systemic:
Systemic mycoses caused by opportunistic fungi are acquired through inhalation. These infections start as general pulmonary infection that then spreads throughout the body via blood. Examples include histoplasmosis and blastomycosis. Hence, this option is incorrect.
c. Trauma and remain localized:
Subcutaneous mycoses are common soil saprobes living on dead organisms. But the infections produced by them are not as common as superficial mycoses since contamination requires traumatic introduction of fungi via the dead outer strata of skin into the deeper living tissue. Examples include chromoblastomycosis and phaeohyphomycosismycosis. Hence, this option is correct.
d. Trauma and become systemic:
Mycetoma is caused by filamentous fungi that attack traumatized skin. Lesions appear as blisters. The systemic form spreads to muscles and bones. Hence, this option is incorrect.
Hence, the correct option is (c) trauma and remain localized is applicable to subcutaneous infections.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 7MTF
The most common antibacterial drugs, their mode of action is to inhibit cell wall synthesis and repair. The anti-bacterial drugs derived from penicillin G, are broad-spectrum drugs that target both gram-negative and gram-positive bacteria.
Apart from the cell wall synthesis inhibition, some drugs have effect on the DNA synthesis, metabolic process and protein synthesis. The few examples of antibacterial drugs include rifamycin, sulfonamide, aminoglycosides, and tetracycline antibiotics.
The broad-spectrum antibacterial drugs have relatively low toxicity to humans because they target only the bacterial cell wall.
Hence, the given statement ‘’treatment of individuals with broad-spectrum antibacterial agents is a predisposing factor for opportunistic fungal infections” is TRUE.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 8FB
Oral candidiasis (or) thrush is caused by Candida. This infection is seen occurring amongst the immuno-compromised individuals. Hence, the genus causing thrush is CANDIDA.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 8MC
The term “dermatophyte,” refers to the fungal pathogen that grows in or on the skin. The term is indicative of the location on which the fungus thrives.
a. Pathogenicity:
Pathogenicity refers to the potential capability of certain species of fungal or microbial species to cause an infection or disease. Hence, this option is incorrect.
b. Where a fungus grows:
The term “dermatophyte,” which refers to the fungal organism that nurtures in or on the skin. The term is indicative of the location on which the fungus thrives. Hence, this option is correct.
c. Method of spread:
Method of spread indicates the mode in the spread of the infection, for example, from person to person, through environment, through aerosol, etc. Hence, this option is incorrect.
d. Pigmentation:
Pigmentation refers to the discoloration of the skin. It is caused due to fungal infections. Hence, this option is incorrect.
Since dermatophyte refers to the location or site on which the fungus grows, the correct option is (b) where a fungus grows.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 8MTF
Opportunistic fungi lack genes for proteins that help in colonizing body tissues, and therefore these fungi infect individuals with compromised immune system. Candida albicans is among the opportunistic fungi that can infect only individuals with compromised immune system.
The individual had a compromised immune system, because the person infected with the serious illness causing organisms like viruses. These viruses have the strong antigenic nature; they ultimately reduce the immunity level of the affected individual. Once the immunity level is reduced, the patient is susceptible of the other opportunistic infections.
Candida albicans generally causes localized opportunistic infections but can become systemic, particularly in the Imnuocompromised.
Hence, the given statement “Candida albicans generally causes localized opportunistic infections but can become systemic, particularly in the immunocompetent” is FLASE.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 9FB
Pneumocystis was formerly considered as a protozoan. Its morphological and developmental characteristic resembles those of a protozoan. However, based on rRNA sequence analysis and based on biochemical characters it has been now classified into fungus. The Pneumocystis is an opportunistic pathogen; it causes the diseases to an imnuo compromised individual.
Hence, the correct answer is Protozoan and Fungus.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 9MC
Subcutaneous mycoses that may demonstrate respiratory and cerebral forms is Phaeohyphomycosis.
a. Chromoblastomycosis:
infection occurs as small, scaly, itchy, and painless lesions of the surface of the skin due to fungal growth in subcutaneous tissues close to the location of inoculation. Hence, this option is incorrect.
b. Mycetoma:
causes infections on skin, fascia, and bones of hands or feet. It does not cause infections in respiratory tract and in cerebrum. Hence, this option is incorrect.
c. Phaeophyphomycosis:
colonizes in the nasal passages and sinuses in patients susceptible to allergies and in those suffering from AIDS. Phaeohyphomycosis can also cause brain infections in AIDS patients. Hence, this option is correct.
d. Sporotrichosis:
The infections caused by these fungi are limited to arms or legs. Hence, this option is incorrect.
Hence, the correct option is (c) Phaeohyphomycosis which is the subcutaneous mycoses that may possibly show respiratory and cerebral forms.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 9MTF
There are two categories of fungal agents:
True fungal pathogen:
True pathogen infects are causes disease in healthy individuals, irrespective of the immune status. True pathogenic fungi include Paracoccidiodies brasiliensis, Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides immitis.
Opportunistic fungi:
Opportunistic fungi on the other hand lack genes for proteins that help in colonizing body tissues, and therefore these fungi infect individuals with compromised immune system. Opportunistic fungi include Candida albicans and Pneumocystis Pneumonia extra.
In AIDS patients the immunity of the patients is at very low level. These conditions are favorable for fungal infections; especially the opportunistic fungi. Therefore, AIDS patients generally are prone to and suffer from fungal infections. The first line of treatment for AIDS patients is through anti-fungal agents.
Hence, the given statement “relapse of fungal diseases is common in AIDS patients” is TRUE.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 10FB
The useful mycotoxins are classified as ergo alkaloids and these are produced by some strains of ascomycete Claviceps. Hence, the correct answer is Claviceps.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 10MC
Coccidiomycosis is the systemic mycosis that is found in the deserts of the southwestern United States.
a. Blastomycosis:
Blastomycosis infection is caused by ascomycete Blastomyces dermatidis, which is prevalent in southeastern United States north to Canada. This infection has also been reported from regions of Latin America, Africa, Asia, and Europe. Hence, this option is incorrect.
b. Coccidioidomycosis:
Coccidiomycosis is caused by Coccidiodes immitis found predominately in the southwestern United States (Arizona, California, Nevada, New Mexico, and Texas) and northern Mexico. Small, focally widespread areas also exist in semiarid parts of Central and South America. Coccidiomycosis can be recovered from desert soil, rodent burrows, archeological remains, and mines. Hence, this option is correct.
c. Histoplasmosis:
Histoplasmosis is caused by Histoplasma capsulatum. Histoplasma capsulatum is widespread in eastern United States along the Ohio River Valley and also seen in regions of Africa and South America. Hence, this option is incorrect.
d. Paracoccidioidomycosis:
Paracoccidiomycosis is caused by Paracoccidiodes brasiliensis found predominately in the damp and cool ranging from southern Mexico to regions of South America, especially in Brazil. Hence, this option is incorrect.
Hence, the correct option is (b) Coccidioidomycosis which is systemic mycoses that is widespread to the deserts of the southwestern United States.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 10MTF
Fungi and their spores are dispersed everywhere in the environment- in water, in air, in soil and on or in most multicellular organisms including animals and plants. However, fungal infections and allergies are not very common. Majority of the fungi being opportunistic, infect only immune compromised individuals and very rarely true pathogens cause infections. Not everyone is prone to allergies to fungal elements.
Hence, the given statement, almost everyone has allergies to fungal elements, is FALSE.
3 – 10% of individuals have allergies to fungal elements.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 11MC
a. Blastomyces dermatitidis:
B. dermatitidis is a dimorphic fungal pathogen, exhibiting filamentous and yeast forms. It survives in filamentous form in the soil, which produces spores directly on the wall of the hyphae. When inhaled the spores cause infection in humans and animals. At the elevated temperature of 37°C in a host, the spores transition to pathogenic yeast form. Hence, the option (a) is incorrect.
b. Histoplasma capsulatum:
Histoplasma capsulatum exhibits unique dimorphism and undergoes significant development stages depending on the temperature.

  1. At 25°C, H. capsulatum exhibits a filamentous mycelia form.
  2. At 37°C, H. capsulatum exhibits a yeast form.
    Hence, the option (c) is incorrect.

c. Paracoccidioides brasiliensis:
Paracoccidioides brasiliensis is thermally dimorphic fungus. At 25°C, exhibits filamentous form and at 37°C, transforms to yeast form. Hence, the option (d) is incorrect.
d. Coccidiodes immitis :
Coccidiodes immitis grows as mycelium and produces sturdy chains of asexual spores called arthroconidia. The arthroconidia germinate into new mycelia in the atmosphere. However, if inhaled arthroconidia germinate in the lungs to produce parasitic form called a spherule. Thus, spherule stage is parasitic form exhibited by Coccidiodes immitis when arthroconidia spores are inhaled. Hence, the correct option is (b) Coccidiodes immitis exhibits a spherule stage when it infects humans.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 12MC
a. Chromoblastomycosis:
Chromoblastomycosis is a chronic mycosis of skin and dermal tissue, initiated by traumatic introduction of a specific group of dermatophyte. For Chromoblastomycosis, fungus has been introduced into the individual by traumatic means. The infection is not specific to AIDS patients, but can be seen in any individual who happen to encounter the fungus. Hence, the option (a) is incorrect.
b. Blastomycosis :
B lastomyces dermatitidis is a causative agent for blastomycosis. The fungus lives in association with decomposing organic matter and damp soil. Infection is caused, due to inhalation of airborne, microscopic fungal spores. Blastomycosis is seen occurring in individuals who are otherwise healthy, but is more common among people with low levels of immunity. Individuals have to come in contact with the spores, and upon inhalation will contract blastomycosis. Hence, the option (b) is incorrect.
c. Piedra:
The source of infection in black piedra is from the soil. Moreover, white piedra exist in soil, air, water, vegetable matter, sputum, and body surfaces. Transmission is by way of shared hair brushes and combs. Piedra infections are caused due to opportunistic fungi, which are not commonly seen in AIDS patients. Hence, the option (d) is incorrect.
d. Candidiasis:
Candidiasis is infection or disease caused by various species of the genus Candida albicans, which is capable of infecting all the tissues. Moreover, Candida albicans is commensal and exists as normal gut flora living in human mouth and gastrointestinal tract. Candida albicans is truly an opportunistic fungus, as it infects nearly all the individuals as soon as the immunity of the host is compromised.
Following are some of the infections caused:

  • Oral candidiasis is very rare in healthy individuals, but occurs at about 5% of the newborns.
  • Candidiasis is seen in at least 10% of the adults with a weak immune system.
  • Candidiasis affects nearly anyone suffering from AIDS.

Candida albicans exists as commensal where the host immunity is compromised and is turned into opportunistic pathogen. Candidiasis is seen in almost all terminal AIDS patients. Thus, candidiasis is the most commonly occurring fungal infection in nearly all the terminal AIDS patients.
Hence, the correct option is (c) Candidiasis is the fungal infection, which is seen in nearly all terminal AIDS patients.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 13MC
a. Invasive medical procedures:
Invasive medical procedures include surgery, insertion of medical implants, catheterization, etc. Surgical insertions introduce fungal spores and provide a site for fungal colonization. However, infections are avoided by following correct antisepsis and medical procedures by medical personnel. Hence, the option (a) is incorrect.
b. Chronic illness such as diabetes:
In case of chronic illness like diabetes the immunity of the patients is dysfunctional or compromised. Fungal infections in the cases can be avoided by taking proper medication to check the levels of sugar and keeping oneself free from injury. Hence, the option (c) is incorrect.
c. Short-term treatment with antibacterial agents:
Short term treatment with antibacterial agents will lead to infections, caused by opportunistic fungal pathogens. This can overcome by adopting complete and broad spectrum antibiotics. Hence, the option (d) is incorrect.
d. AIDS :
Opportunistic fungal infections infect individuals with low immunity levels. In AIDS (acquired immunodeficiency syndrome) patients the immunity is compromised and forms good basis for opportunistic fungi to attack. Even the commensal fungi like Candida cause infections to AIDS patients. Individuals infected with AIDS can face detrimental health threats from “opportunistic” fungal infections, which take the advantage of hosts’ compromised immune system. Moreover, person suffering from AIDS is likely to be infected by over 20 opportunistic infections. Therefore, AIDS is considered to be a predisposing factor for acquiring fungal infections. Thus, Patients suffering with AIDS are at high risk and invariably contract fungal diseases.
Hence, the correct option is (b) AIDS is a predisposing factor that leaves a patient with a maximum long-term risk of contracting a fungal infection.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 14MC
a. Type II hypersensitivity is referred as cytotoxic hypersensitivity. In type II hypersensitivity, antibodies produced by immune reaction bind to antigens on patient’s cell surfaces. Moreover, other form of type II hypersensitivity is known as antibody-dependent cell-mediated cytotoxicity (ADCC). Type II hypersensitivity mostly facilitated by antibodies of IgM or IgG classes. Thus, phagocytes and K cells play a role in ADCC. Hence, the option (b) is incorrect.
b. Type III hypersensitivity is referred as immune complex hypersensitivity. Type III hypersensitivity arises when antigen-antibody complex are not effectively cleared by accumulation of native immune cells, giving rise to an inflammatory reaction and desirability for leukocytes. The reaction may be pathogenic mechanism of infections caused by several microorganisms. Hence, the option is incorrect. Hence, the option (c) is incorrect.
c. Type IV hypersensitivity:
Type IV hypersensitivity is also known as delayed type hypersensitivity, as it takes two to three days for the reaction to develop. Unlike other types, type IV hypersensitivity is not antibody mediated but instead is a type of cell-mediated response. Very rarely, fungal allergens trigger type III hypersensitivities. Hence, the option (d) is incorrect.
d. Type I hypersensitivity:
Type I hypersensitivity is also known as immediate hypersensitivity. Type I hypersensitivity is an allergic reaction triggered by re-exposure to a specific type of antigen known as an allergen. Exposure to allergen may be by consumption, inhalation, inoculation, and direct contact. In type 1 hypersensitivity the antibody is IgE. Fungal allergens trigger type I hypersensitive reactions in which immunoglobulin E binds the allergens, stimulating reactions such as hay fever, asthma, eczema, etc. Thus, fungal allergens trigger type I hypersensitive reactions in which immunoglobulin E binds the allergens, stimulating reactions such as hay fever, asthma, eczema, etc.
Hence, the correct option is (a) type I hypersensitivity reactions is stimulated due to fungal allergens.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 15MC
a. Production of destructive enzymes:
Cryptococcus neoformans does not produce any destructive enzymes. The pathogenicity of Cryptococcus neoformans is due to the presence of capsule. Moreover, it has the ability to produce melanin and organism’s predilection for the central nervous system. Hence, the option (a) is incorrect.
b. Infection of immune cells:
Cryptococcus neoformans does not cause any infection to the immune cells. The pathogenicity of Cryptococcus neoformans is due to capsule, its ability to produce melanin and the organism’s predilection for the central nervous system. Hence, the option (c) is incorrect.
c. Variation of surface antigens to avoid immune system recognition:
The surface antigens are not present in Cryptococcus neoformans. The pathogenicity of Cryptococcus neoformans is due to capsule, its ability to produce melanin and the organism’s predilection for the central nervous system. Hence, the option (d) is incorrect.
d. Production of a capsule :
The pathogenesis of Cryptococcus neoformans is due to the following characteristics:

  1. Presence of a phagocytosis-resistant capsule around the yeast form
  2. Ability to produce melanin, which also aids in inhibiting phagocytosis
  3. The organism’s predilection for the central nervous system

Hence, the correct option is (b) production of capsule attributed to the pathogenic feature of Cryptococcus neoformans.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 16MC
a. Blindness :
Cryptococcus infection in AIDS patients led to meningitis and cutaneous cryptococcosis. There is no evidence of blindness cause Cryptococcus infection in AIDS (acquired immunodeficiency) patients. Hence, the option (a) is incorrect.
b. Cutaneous infection :
Cryptococcus infection in AIDS patients led to meningitis and cutaneous cryptococcosis. However, meningitis is most commonly occurring as compared to cutaneous infection. Hence, the option (b) is incorrect.
c. Pneumonia :
Cryptococcus infection in AIDS patients led to meningitis and cutaneous cryptococcosis. There is no evidence of the pneumonia caused Cryptococcus infection in AIDs patients. Hence, the option (d) is incorrect.
d. Meningitis :
In AIDS patients the most common manifestation of Cryptococcus infection is meningitis. The second most common manifestation is cutaneous cryptococcosis.
Hence, the correct option is (c) meningitis is the most common occurrence of the Cryptococcus infection in AIDS patients.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 17MC
Aspergillosis is the name specified to varied range of infections, caused by infection of the genus Aspergillus. Aspergillosis progresses mainly in immunocompromised individuals. Hence, the option (a) is incorrect.
Dermatophytosis is also known as ringworm. It is caused by closely linked group of fungi, known as dermatophytes. Dermatophytes are fungi that cause infections in hair, skin, and nail due to their ability to utilize keratin, as a nutrient source. Hence, the option (b) is incorrect.
Mycetoma is a chronic subcutaneous infection caused by fungi and actinomycetes. This infection is an outcome of granulomatous inflammatory response in deep dermis and subcutaneous tissue. Moreover, it can be spread to underlying bone. Hence, the option (c) is incorrect.
Zygomycosis are opportunistic fungal infections, affected by genera of fungi classified in the division Zygomycota, especially Rhizopus or Absidia. Rhizopus is the classic bread mold causes Zygomycosis.
Hence, the correct option is (d) zygomycosis is caused by bread mold.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 18MC
Inhalation of fungal allergens:
Mycetismus is fungal poisoning, caused by consumption of certain species of mushrooms. The mode of infection in this case is due to ingestion and not due to inhalation of fungal allergens. Example of fungal infections, caused due to inhalation of Histoplasmosis and Coccidioidomycosis. Hence, the option (a) is incorrect.
Traumatic inoculation of fungi beneath the skin:
Mycetismus is fungal poisoning, caused by consumption of certain species of mushrooms. The mode of infection in this case is due to ingestion and not due to traumatic introduction of fungi beneath the skin. Example of fungal infection caused, due to inhalation of chromoblastomycosis. Hence, the option (c) is incorrect.
Close contact with infected individuals:
Mycetismus is fungal poisoning, caused by consumption of certain species of mushrooms. The mode of infection in this case is due to ingestion and is not contracted due to contact with infected individual. Example of fungal infection is caused due to close contact with infected individuals like, candidiasis and ringworm. Hence, the option (d) is incorrect.
Ingestion of mushrooms:
Mycetismus is caused by eating mycotoxic mushrooms. Mycetismus is fungal poisoning, caused by consumption of certain species of mushrooms (fungal organisms). It is also called as mushroom poisoning. However, in most cases occurs when untrained individuals pick and consume wild mushrooms.
Hence, the correct option is (b) ingestion of mushrooms is the mode of infection in mycetismus.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 19MC
Amanita muscaria, commonly known as the fly amanita or fly agaric, is a poisonous basidiomycete fungus. Moreover, Amanita muscaria produces two hallucinogenic toxins – ibotenic acid and muscimel. However, Amanita phalloides is most toxic fungus in comparison to Amanita muscaria. Hence, the option (b) is incorrect.
Psilocybe cubensis, commonly known as magic mushrooms, cubes golden tops, gold caps or boomers. Psilocybe cubensis produces hallucinogenic psilocybin. However, the toxin is not less toxic to phalloidin and alpha-amanitin produced by Amanita phalloides. Hence, the option (c) is incorrect.
Claviceps purpurea is an ergot fungus that nurtures on the ears of rye and related cereal crops. Claviceps purpurea produces mycotoxins that are considered beneficial. Hence, the option (d) is incorrect.
Amanita phalloides: The most deadly mushroom toxin is produced Amanita phalloides, which is commonly called as “death cap” mushroom. The mushroom contains two related polypeptide toxins:

  1. Phalloidin, which disrupts the cell structure by binding irreversibly binding actin within cells
  2. Alpha-amanitin, obstructs mRNA synthesis

Hence, the correct option is (a) Amanita phalloides which produces more poisonous mycotoxin.

Microbiology with Diseases by Taxonomy Chapter 22 Answers 20MC
The number of fungi in the environment is rising:
Fungi have a universal distribution, and breed in a wide range of habitats, including extreme climates. The fungi are present almost everywhere – atmosphere, water, soil, etc. Human beings are in contact with fungi in their day to day lives. However, the fungi are able to cause disease in individuals with compromised immune system. Increase in the number of mycoses cannot be justified to increase in the number of fungi in the environment. Hence, the option (a) is incorrect.
Fungi have become more pathogenic:
The pathogenic characteristics of fungi have evolved along the development of anti-fungal agents. Fungi have developed mechanisms to become resistance to anti-fungal agents. However, the advancement in medicine allowed treating the drug resistant fungi. Hence, the option (c) is incorrect.
Fungi are developing a tendency to be spread from person to person:
Majority of the fungi is opportunistic in nature. However, true fungal pathogens can infect healthy individuals. The fungal infections are majorly through ingestion, inoculation, and inhalation of the spores. Very few species of the fungi like dermatophytes have the tendency to spread from person to person. Hence, the option (d) is incorrect.
The number of immunocompromised individuals in the population is rising:
Opportunistic mycoses do not usually infect individuals with strong immune system, as the fungi lack genes for virulence factors to make them aggressively invasive. Moreover, opportunistic mycoses are restricted to individuals with compromised immune system. This is because of increase in the number of AIDS (acquired immunodeficiency syndrome) patients and number of mycoses worldwide cases that has been on rise.
Hence, the correct option is (b) the number of immunocompromised individuals in the population rising is the prime cause, for increase in number of mycoses worldwide.

Microbiology with Diseases by Taxonomy Chapter 20 Answers

Microbiology with Diseases by Taxonomy Chapter 20 Answers

Microbiology with Diseases by Taxonomy Answers

Microbiology with Diseases by Taxonomy Chapter 20 Answers 1CM
The following concept map describes completely about Escherichia coli. This includes the toxins liberated by the bacterium as well as about its transmission and the infection caused by it.
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Microbiology with Diseases by Taxonomy Chapter 20 Answers 1CT
The boy’s death could have resulted from meningitis, which is caused by Neisseria meningitidis. This bacterium is transmitted via droplets and spreads among people living in close contact, especially in dormitories, day cares, immediate family members etc. the symptoms of this disease include abrupt headache, sore throat, fever, vomiting, and convulsions. In this case, the boy has complained about sudden head ache and since he attends day care, which is a crowded place, there are more possibilities of contracting meningitis.
The day care workers are not to be blames for the boy’s death. Meningococcal meningitis progress very rapidly and may cause death within 6 hours of the initial symptoms. The day workers have alerted the boy’s mother at the appropriate time. The hospital staff is partially responsible for the boy’s death.
The boy has been the administration of penicillin, which might have triggered shock due to release of large amount of toxic lipid A resulting from killing many bacteria at a time. The options generally adopted for treating meningitis include intravenous administration of ceftriaxone and cephalosporin.
Following steps should be taken to protect the other children at the day care facility:

  1. Prophylactic treatment with ceftriaxone, ciprofloxacin, or rifampin for all children and workers at the day care.
  2. Vaccination for children above two years against the strains A, C and Y.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 1L
microbiology-with-diseases-by-taxonomy-chapter-20-answers-1l

Microbiology with Diseases by Taxonomy Chapter 20 Answers 1M
Escherichia coli is the most common coli form that is most widely studied. E.Coli causes non-nosocomial urinary tract infections, fatal hemorrhagic colitis, gastroenteritis and hemolytic uremic syndrome. Hence the correct option is C) Gastroenteritis.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 1MC
Lipid A is among the common virulence factor to all genera within Enterobacteriaceae. Lipid A is specific to gram-negative bacteria and is present in cell wall. When released into patient’s blood it triggers vasodilation, shock, fever, blood clots throughout the body, and disseminated intravascular coagulation (DIC).
a) Affects the formation of blood clots in the host:
Lipid A which is specific to gram negative bacteria and is present in cell wall. When released into patient’s blood it triggers vasodilation, shock, fever, blood clots throughout the body, and disseminated intravascular coagulation (DIC). Hence, this option is correct.
b) Causes these bacteria to be oxidase positive:
Microorganisms that are oxidase positive are aerobic. The oxidase positive microorganisms are capable of utilizing oxygen as a terminal electron acceptor during respiration. Oxidase positive generally means that the bacterium contains cytochrome c oxidase and can hence utilize oxygen for energy production with an electron transfer chain. Hence, this option is incorrect.
c) Triggers the secretion of a protease enzyme to cleave IgA in mucus:
Viral DNA sequences in a patient’s blood or other tissues can be identified by genetic screening. Moreover, it can identify the disease even before the patient show any symptom. Hence, this option is incorrect.
d) Enables the bacteria to ferment glucose anaerobically:
The process of synthesizing a polypeptide chain from an RNA template is called as translation. After this, post-translational modifications take place to make the polypeptide chains into active proteins. Hence, this option is incorrect.
Hence, the correct option is a) genetic fingerprinting, which is the technique that involves the production of a distinct pattern of DNA fragments on a gel.
Hence, the correct choice is Lipid A present in outer membranes of Gram-negative bacteria affects the formation of blood clots throughout the body in the host.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 1SA
Antimicrobial drug is not prescribed to treat diarrhea patient:
Explanation
The treatment of Diarrhea comprises of treating the patient with electrolyte and fluids replacement. Since, diarrhea is self-limiting expulsion of the organism from the body. It is more effective on administering antimicrobial agents. Besides, treatment of diarrhea with antimicrobial agents can worsen the prognosis. However, results in killing many bacteria, which will lead to the release of large amounts of lipid A and turn toxic.
Hence, in this case the treatment prescribed by the physician in treating the patient with diarrhea is appropriate. Prescribing fluid replacement is a right measure. Thus, administering antimicrobial drugs will worsen the patient’s condition.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 2CT
One important reason for the better response of the gram-positive bacteria to that of gram-negative bacteria is the structure of the outer membrane. Below outlined are the differences observed:
Gram negative bacteria:

  • Presence of outer membrane
  • High lipopolysaccharide (LPS) content
  • High lipid and lipoprotein content
  • Single and thin peptidoglycan layer
  • The cell wall is 70-120 Armstrong thick two layered
  • Highly resistant to physical disruption, dyes, and drying

Gram positive bacteria:

  • Absence of outer membrane
  • Very little or no lipopolysaccharide (LPS) content
  • Low lipid and lipoprotein content
  • Multilayered peptidoglycan layer
  • The cell wall is 100-120 Armstrong thick two layered
  • Low resistance to physical disruption, dyes, and drying

Gram-negative bacteria are more resistant against antibodies than gram-positive bacteria, because of their impenetrable cell wall. The outer membrane of gram- negative bacteria protects it from several antibiotics, dyes, and detergents that would usually destruct the inner membrane or peptidoglycan. The outer membrane provides gram-negative bacteria resistance to penicillin and lysozyme.
Hence, the gram-positive bacteria respond to treatment of antimicrobial drugs and thereby the fatality rates in case of gram-positive bacteria are low.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 2M
Klebsiella pneumonia is the causative bacterium for pneumonia which often involves damage of alveoli and the producing of bloody sputum.
This bacterium mostly grows in the respiratory tracks and digestive system of the humans and some animals. It is also associated with the several diseases like urinary tract infections and wound infections. Hence, the correct option is F) Pneumonia.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 2MC
The only genus of Gram-negative cocci that causes significant disease in humans is Neisseria.
(a) Pasteurella :
It is a nonmotile, Gram-negative coccobacillus. It causes zoonotic infections in humans. It causes significant diseases in animals. Hence, this option is incorrect.
(b) Salmonella :
It is a genus consisting of motile, Gram-negative bacilli. Hence, this option is incorrect.
(c) Klebsiella :
It is a nonmotile, Gram-negative coccobacillus. It is usually present in the respiratory tract of humans. The common disease that it causes is pneumonia. Hence, this option is incorrect.
(d) Neisseria :
It is a pathogenic Gram-negative coccus. It regularly causes disease in humans. The significant diseases that it causes in humans are gonorrhea and meningitis. Hence, this option is correct.
Hence, the correct option is (d) Neisseria. The only genus of Gram-negative cocci that causes significant diseases in humans is Neisseria.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 2SA
Distinction between pathogenicity of coliforms, non-coliforms, and pathogenic enteric bacteria:
Explanation
Pathogenicity of enterobacteriaceae:
Lipooligosaccharides:
Composed of three antigens- a core polysaccharide called the common antigen, O-polysaccharide, and Lipid A, which trigger vasodilation, fever, and other symptoms when released into the blood.
Fimbriae:
Fimbriae along with proteins are called adhesins, which enable the bacteria to attach themselves to the human cells.
Polysaccharide capsule:
Provide poorly immunogenic surface and protect the bacteria from antibodies and phagocytosis.
Siderophores:
Capture iron and make it available to the bacteria.
Hemolysins:
Lyse red blood cells by releasing nutrients such as iron.
Exotoxins:
Cause a variety of symptoms, such as diarrhea.
Type III secretion system:
The complex structure is composed of 20 different polypeptides, synthesized by several pathogenic enteric species.

  1. Coliforms: Coliforms are defined as facultative anaerobic or aerobic, rod shaped, Gram-negative bacteria, and ferment lactose. The most common coli form pathogens are Serratia, Escherichia, Klebsiella,Hafni, Enterobacter, and Citrobacter.
    Pathogenicity:

    • Fimbriae along with proteins called adhesins enable the bacteria to attach themselves to the human cells.
    • Exotoxins: Cause a variety of symptoms such as diarrhea.
  2. Non-coliforms: Non-coliforms are opportunistic pathogens that ferment lactose. Noncoli form opportunists include Proteus, Morganella, Providencia, and Edwarsiella.
    Pathogenicity:

    • They produce IgA-degrading protease, which functions to cleave secretory IgA, which is released by host in an initial response to infection.
    • Non coli forms produce three unique flagellin genes, which recombine and form novel flagella adept of deceiving the host’s defenses.
    • These forms produce fimbriae along with proteins called adhesins enable the bacteria to attach themselves to the human cells.
    • Another mechanism is the urease-mediated stone formation. Urease and hemolysin damage the host epithelial cells.
  3. Truly pathogenic enteric bacteria: These are non-lactose-fermenting bacteria and include three important pathogens – Salmonella, Shigella, and Yersinia.
    Pathogenicity:

    • These bacteria synthesize type III secretion systems by which they introduce proteins to rearrange the cytoskeletons of eukaryotic cells, induce apoptosis or inhibit phagocytosis.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 3CT
Based on the characteristics and biochemical test result, the causative agent is Shigella dysenteriae. This is non-motile, Gram-negative, urease negative, lactose negative and does not produce hydrogen sulfide gas. This bacterium produces a diarrhea inducing enterotoxin, and causes severe dysentery called shigellosis. Shigella dysenteriae can spread from person-to-person; especially it spreads very quickly among children and homosexual men.
Children can be infected by consuming ingesting bacterium through contaminated hands and also by in taking of infected food. Due to the tendency of this species to spread from person to person, it can easily contract other children in the vicinity of the infected individual or child.
The official should increase the hygiene in the community and follow effective procedures for sewage treatment. The officials can also treat the children in the community with oral antimicrobial drugs such as ciproflaxin, cephalosporin, etc., to inhibit the spread of the Shigella to close contacts of the patient.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 3M
Proteus mirabilis is associated with urinary tract infections in patients. This microorganism, releases a large amount urease in the bladder, which cause the breakdown of urea into ammonia and carbon dioxide.
Thus produced ammonia increase the pH levels of urine in the bladder and in the kidney, such that ions that are normally soluble at the acidic pH of urine will start to precipitate. These precipitations are formed around the bacterial cells to form infection induced kidney stones composed of calcium phosphate (or) magnesium ammonium phosphate. Hence the correct option is D) Kidney stones.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 3MC
The bacterial cell having fimbriae, lipooligosaccharide and polysaccharide will be more virulent. Absence of any one of these will result in the decrement of its virulence.
(a) A cell with fimbriae and LOS:
The cell with fimbriae and lipoooligosaccharide will be virulent. Fimbriae help the bacteria to attach to the human cell. LOS displays antigenic diversity, which aids in the evasion of the host defense mechanism. Even though, there will be a chance of being targeted by the host defense mechanism due to the absence of the other virulent factor, polysaccharide. Hence, this option is incorrect.
(b) A cell with a polysaccharide capsule and lipooligosaccharide:
Polysaccharide capsule protects the bacteria from phagocytosis and antibodies. Lipooligosaccharide displays antigenic diversity. These will be helpful in evading host’s immune system. But to cause infection, the bacteria have to attach to the host cell. It is possible by the help of fimbriae, which are absent in this cell. Hence, this option is incorrect.
(c) A cell with fimbriae, lipooligosacchride and a polysaccharide capsule:
Fimbriae enable the bacteria to attach to the human cell. Lipooligosaccharide will display antigenic diversity. Polysaccharide capsule will protect the bacteria from phagocytosis and antibodies. This cell will be more capable in evading the host immune system. Hence, this option is correct.
(d) A cell with fimbriae but no capsule:
Fimbriae will help the cell to attach to the host cell. But due to the absence of capsule, this cell will be either phagocytized or will be attacked by the antibodies. Thus, this cell may be non-virulent. Hence, this option is incorrect.
Hence, the correct option is (c) a cell with fimbriae, lipooligosaccharide and a polysaccharide capsule. A bacterial cell with fimbriae, lipooligosaccharide and a polysaccharide capsule is most likely to be virulent.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 3SA
Antimicrobial agents are placed in eyes of babies, during birth:
Explanation
The treatment of Neisseria gonorrhea is complicated, due to the worldwide spread of gonococcal strains. Moreover, the strains are resistant to antibacterial treatments like penicillin, erythromycin, and aminoglycosides. Besides, chemical prophylaxis is ineffective in preventing Neisseria gonorrhea. Therefore, nurses place antimicrobial agents in the babies’ eyes at birth, as a prophylactic measure that successfully prevents ophthalmic disease.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 4CT
Majority of the cases reporting typhoid fever are associated with international travel. The risk of contamination is maximum for international travelers visiting families and friends in nations where typhoid fever is endemic, perhaps because they are unlikely than other travelers to seek pre-travel immunization and to observe safe drinking water and food practices.
Several years ago, the international travels and vacations were more in number during summer. This attributed to more number of typhoid cases during summers. However, the frequency of travel due to opening of trade and relations between many countries has increased drastically. The risk is higher for travelers who visit the most highly endemic areas, even for a shorter term. Hence, the numbers of cases with typhoid fever are being observed throughout the year.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 4M
Salmonella enterica, it comes under the serotype Typhi (S. typhi). This bacterium mainly causes fever known as typhoid. Human beings are the sole hosts for this microorganism. Infection occurs through intake of contaminated food (or) water contaminated with sewage containing bacteria from carriers. These carriers are often asymptomatic.
This bacterium once enters into the intestine reach to the blood stream; they are opsonized by the phagocytic cells, but not killed by them. These phagocytic cells carry bacterium into various organs like liver, spleen, and bone marrow extra.
After, they enter into these organs they effect on their regular functions and show several disease symptoms like fever, and loss of appetite. Hence, the correct option is B) Typhoid fever.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 4MC
Pelvic inflammatory disease (PID) is caused by Neisseria gonorrhoeae.
(a) PID is a severe type of diarrhea in which infection spreads from the intestines to the bloodstream:
PID is a sexually transmitted disease. It infects the uterus and uterine tubes. It is not diarrhea. Hence, this option is incorrect.
(b) PID can result from Neisseria infection:
PID is caused by Neisseria gonorrhoeae. It is a sexually transmitted disease. Hence, this option is correct.
(c) PID is more common in men than women:
PID is a sexually transmitted disease. It infects the uterus and uterine tubes and thus commonly occurs in women. Hence, this option is incorrect.
(d) Members of the family Enterobacteriaceae usually causes PID:
PID is sexually transmitted disease caused by Neisseria. Members of the family Enterobacteriaceae are neither sexually transmitted nor causes PID. Hence, this option is incorrect.
Hence, the correct option is (b) PID can result from Neisseria infection. The statement that PID can result from Neisseria infection is true.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 4SA
Meningococcal diseases are more frequent in college dormitories and military barracks when compared to population:
Explanation
The meningococcal infection is transmitted through respiratory droplets that transmit among people who live in close contact. The transmission is widespread among families, soldiers living in barracks, prisoners, and college students living in dormitories. This is because the groups of people live in crowded conditions. Therefore, statistics indicate that meningococcal disease is 23 times more prevalent in students living in dormitories, as compared to cases in general population.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 5CT
Stomach flu in fact refers to gastroenteritis or inflammation and irritation of the stomach and intestines. Gastroenteritis may be triggered by a virus, bacteria, parasites, or due to lactose intolerance. The symptoms of stomach flu or gastroenteritis include abdominal cramps, stomach pain, nausea, and diarrhea.
Following is the list of bacteria discussed in this chapter, which are good candidates for causing stomach flu:

  • Escherichia coli infection can cause significant problems. E. coli O157:H7 can cause complications in nearly 10% of infected individuals, for example, kidney failure in children (hemolytic-uremic syndrome), thrombotic thrombocytopenic purpura (TTP) in the adults and bloody diarrhea.
  • Salmonella is contracted by ingestion of bacteria present in contaminated water or food, and by handling reptiles or poultry that transmit the germs.
  • Shigella generally spreads from one person to another. Shigella may be contracted by ingestion of contaminated food, and drinking water, or playing or swimming in contaminated water.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 5M
Shigella flexineri are a group of bacteria that can causes dysentery. Shigella flexineri causes severe form of dysentery which is characterized by fever, diarrhea, purulent bloody stools and cramps.
Once, the Shigella is enters into the gastrointestinal tract it attaches to the Epithelial cells of colon. It triggers the process of endocytosis, enters into the epithelial cells. Than bacterium multiplies in the cytosol of epithelial cells, it invades into neighboring cells. Ultimately, they are enters into the blood stream. Leads to abnormalities on immune system, this result diseases. Hence, the correct option is E) Purulent bloody stools, cramps, fever, and diarrhea.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 5MC
The coliform bacterium that contaminates dairy products is Enterobacter.
(a) Bartonella :
It causes Bartonellosis in humans. It is transmitted by very small blood sucking sandflies. It doesn’t contaminate dairy products. Hence, this option is incorrect.
(b) Serratia :
It is a motile coliform. It will grow in and on the hospital supplies. It causes urinary and respiratory tract infections. Hence, this option is incorrect.
(c) Enterobacter :
It is a lactose fermenting coliform. It is generally present in the digestive and respiratory tracts of humans and animals. It contaminates the dairy products. Hence, this option is correct.
(d) Proteus :
It is noncoliform opportunistic bacteria. It cannot ferment latose. It belongs to the family Enterobacteriaceae. Hence, this option is incorrect.
Hence, the correct option is (c) Enterobacter. The coliform bacterium that infects the dairy products is Enterobacter.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 5SA
An alcoholic is susceptible to pulmonary disease:
Explanation
Chronic alcohol consumption weakens multiple acute cellular functions in the lung. Moreover, leads to increase vulnerability to serious complications from pulmonary disease. In contrast, metabolism of alcohol increases oxidation levels. Oxidation damage to the cells impairs the capacity of the lungs to eliminate fluid. Oxidation damage also leads to reduction in immune response.
Thus, alcoholics have poor ability to clear aspirated oral secretions from their lower respiratory tracts; hence, they are more susceptible to pulmonary diseases.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 6CT
The hunter is likely to be infected by Francisella tularensis. This bacterium is very small, strictly aerobic, and Gram-negative coccobacillus that causes a zoonotic disease called tularemia. Hunters and hikers are mostly likely to contract this infection. The symptoms caused by due to tularemia include- fever, chills, headache, sore throat, muscle aches, and nausea. These symptoms are not distinct as these symptoms are very commonly occurring in any bacterial infection.
Following are few methods in which a laboratory scientist distinguishes among species:

  • Francisella tularensis is a fastidious, facultative intracellular bacterium that needs cysteine for growth.
  • F. tularensis grows poorly at 28°C, slowly at 35-37°C. This is a useful feature in differentiating from Yersinia pestis.
  • Microscopic examination: Gram-negative bacteria, very small, pleomorphic, and poorly-staining.
    Culture characteristics:
    0 Exhibits poor growth on sheep blood agar.
    0 Characteristic metallic sheen on cysteine heart agar that contains chocolatized blood.
  • The sub species can be identified by noting the history of the patient. The four sub species exist in different regions and therefore can be differentiated based on the location.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 6M
Yersinia pestis causes bubonic plague and pneumonic plague. It is an extremely virulent and non-pathogenic bacterium and has major historic impact.
This bacterium contains several virulence factors like adhesins (antigenic proteins) and Type III secretory system.
The adhesins make the way of entry of bacterium into the host cells. The Type III secretory system used to inject the antigenic proteins into the phagocytic cells, these antigenic proteins triggers the apoptosis process in phagocytic cells. Hence, the correct option is (a) Bubonic plague.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 6MC
Capsules of pathogenic enteric bacteria are virulence factors because they protect the bacteria from phagocytosis and from antibodies.
(a) Capture iron from haemoglobin and store it in the bacteria:
Siderophores capture iron from haemoglobin. They make the iron available to the bacteria. Hence, this option is incorrect.
(b) Release haemolysins that destroy red blood cells:
Haemolysins release nutrients by lysing the red blood cells. Capsules don’t release haemolysins. Hence, this option is incorrect.
(c) Produce fimbriae that enable the bacteria to attach to human cells:
Fimbriae and adhesins help the bacteria to attach more tightly to the human cells. Fimbriae are not produced by capsules. Hence, this option is incorrect.
(d) Protect the bacteria from phagocytosis and from antibodies:
Capsules provide a poorly immunogenic surface. They protect the bacteria from phagocytosis and antibodies. Hence, this option is correct.
Hence, the correct option is (d) protect the bacteria from phagocytosis and from antibodies. Capsules of pathogenic enteric bacteria are virulent because they protect the bacteria from phagocytosis and from antibodies.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 6SA
Following are the six factors that facilitate the production of disease by Bordetella pertussis :
Explanation

  1. Bordetella pertussis causes infection by inhibiting the action of ciliated epithelial cells of trachea. Various toxins and adhesins facilitate the disease.
  2. The bacterium adhered to certain lipids in the cytoplasmic membranes of tracheal cells via two adhesins: filamentous hemagglutinin and pertussis toxin.
  3. Filamentous hemagglutinin also attaches to certain glycoproteins on the cytoplasmic membranes of neutrophils; thus, commencing phagocytosis of bacteria.
  4. Bordetella pertussis persists inside the phagocytosis, while dodging the immune system.
  5. The toxin produced by pertussis, produce more receptors for filamentous hemmagglutin that leads to bacterial adhesion and phagocytosis.
  6. Bordetella pertussis produces four toxins:
    a. Pertussis toxin, serves as both adhesion and a toxin. A portion of pertussis toxin obstructs metabolism of ciliated epithelial cells, resulting in increased mucus production.
    b. Adenylate cyclase toxin elicits increased mucus production and impedes leukocyte movement, endocytosis, and killing. The function provides protection, for bacterium at early stage of infection.
    c. Dermonecrotic toxin causes localized constriction and hemorrhage of blood vessels, which results in cell death and destruction of tissues.
    d. Tracheal cytotoxin at low concentrations prevents the movement of cilia on ciliated respiratory cells. At high concentrations, causes the discharge of the cells from lining of trachea.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 7CT
The rash would have been caused by infection caused bacteria Pseudomonas aeruginosa. Pseudomonas aeruginosa is present almost everywhere and can thrive in disinfectant solution as well. The bacterium has a number of virulence factors. It is an opportunistic pathogen and cannot cause disease in healthy individuals because it normally cannot penetrate the skin and mucous membrane and also it cannot evade the host’s other defense mechanisms.
It is difficult to treat Pseudomonas aeruginosa as this bacterium is resistant to a wide range of antibacterial agents, including antimicrobial drugs, disinfectant soaps, antibacterial dyes, and quaternary ammonium sanitizers. The resistance acquired by the bacterium is due to the presence of non-specific drug antiports that pump some types of drugs out of the bacterium. Pseudomonas also forms biofilm which resists the penetration of the antibacterial drugs and disinfectants.
Physicians thus resort to various combinations of beta-lactam, aminoglycoside, and fluoroquinole antimicrobials. In cases where this treatment is not affective, a drug called Polymyxin which is also toxin to humans is administered.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 7MC
Petechiae are small red or purple coloured spots formed on the body due to minor haemorrhage (breaking of blood vessels). The bacterium which is responsible for the formation of petechiae in a host is Neisseria meningitidis.
(a) Neisseria meningitidis :
It causes meningococcal disease, which is life-threatening when it invades blood or cerebrospinal fluid. When it invades blood meningococcal septicemia is caused. The lipopolysaccharides trigger shock, which results in blood coagulation in many organs. It also causes petechiae on the trunk and lower extremities. Hence, this option is correct.
(b) Escherichia coli 0157:H7 :
It causes urinary tract infections and blood infections in the host. It does not cause petechiae. Hence, this option is incorrect.
(c) Klebsiella :
It causes pneumonia, bacteremia, meningitis, wound infections and urinary tract infections. It does not cause petechiae. Hence, this option is incorrect.
(d) Proteus mirabilis :
It causes urinary tract infections in the host. It does cause petechiae. Hence, this option is incorrect.
Hence, the correct option is (a) Neisseria meningitidis. The bacterium that is responsible for the formation of petechiae in a host is Neisseria meningitidis.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 7SA
Pseudomonas present on moist environment cause less disease, due to less prevalent gram negative bacteria:
Explanation
Pseudomonads are Gram-negative, aerobic rod belonging to the bacterial family Gammaproteobacteria. Pseudomonads are not particular in their growth requirements and are ubiquitous. Moreover, they are found everywhere – in soli, decaying organic matter, in moist environment, and hot tubs. Although, it is present everywhere it causes less disease than other less prevalent Gram-negative as Pseudomonads are opportunistic pathogen, which means that it exploits some break in the host defenses and can initiate an infection in only immune-compromised individuals.
Additionally, pseudomonads are epitome among opportunistic pathogens of humans. The bacterium in majority of cases does not infect immune-competent or uncompromised tissues. However, it is capable of infecting any tissue whose defenses are compromised due to some reason. It causes urinary tract infections, bone and joint infections, dermatitis, respiratory system infections, soft tissue infections, gastrointestinal infections, systemic infections, bacteremia in patients with severe burns, in cancer patients, and AIDS (acquired immunodeficiency syndrome). All the above mentioned infections weaken and suppress the immune system; thereby, making it favorable for Pseudomonads to attack.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 8CT
Based on symptoms the bacterium which could have caused diarrhea in this case is Shigella dysenteriae. Shigella causes a severe form of dysentery known as shigellosis, which is characterized by cramps, fever, diarrhea, and bloody stools. The 21 month old child is infected by Shigella dysenteriae.
The treatment of shigellosis includes replacement of fluids and electrolytes. As a precaution, oral antimicrobial drugs such as ciproflaxin, cephalosporin, should be administered to close contacts of the patient to check the spread of Shigella.
The family can take precaution and improve their personal hygiene. They might consider not involving children in cleaning of the cages where the contamination levels are high.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 8MC
Haemophilus influenza b is the most common cause of meningitis in children.
(a) Meningitis in children:
It is caused by Haemophilus influenzae b. The children within the age of 3-18 months get infected to this disease. This is controlled by immunization. Hence, this option is correct.
(b) Upper respiratory flu:
Haemophilus influenzae does not cause flu commonly. It is seen in the upper respiratory tract only. The strain Haemophilus influenzae a causes this flu. Hence, this option is incorrect.
(c) Endocarditis:
It is the infection to the heart valves. It is caused by Coxiella burnetti, Haemophilus parainfluenzae or Haemophilus aphrophilus. It is not caused by Haemophilus influenzae. Hence, this option is incorrect.
(d) Genital chancroid:
It is sexually transmitted. It is a genital ulcer. It is caused by Haemophilus ducreyi. Hence, this option is incorrect.
Hence, the correct option is (a) meningitis in children. The pathogen Haemophilus influenza b causes meningitis in children within the age of 3-18 months.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 8SA
Number of reported cases of pertussis in United States has increased, since 1970:
Explanation
Bordetella pertussis is gram-negative, non-motile, and aerobic coccobacillus. It causes pertussis, which is commonly known as whooping cough. Bordetella pertussis has no environmental and animal reservoir. They are effective vaccines available, as prophylactic measure, which can prevent from the infection. However, the number of pertussis cases reported has increased in United States, since the 1970s. This is because of the refusal of the parents to immunize their children. Even though vaccinations are administered, the immunity whether acquired or natural against this pathogens lasts only for 10 years.
Hence, to eradicate pertussis Centre for Disease Control recommends immunization of children and also one dose of adults under the age of 65 with a dose of cellular pertussis vaccine.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 9MC
Typically mild of the following diseases is cat scratch disease.
(a) Brazilian purpuric fever :
It is caused by the bacterium Haemophilus influenzae. It results in sepsis in children. It is fatal in some cases. Thus, it is not mild. Hence, this option is incorrect.
(b) Bartonellosis :
It is caused by Bartonella bacilliformis. It is characterized by severe anemia, fever, muscle and joint pains, headache and chronic skin infections. It is a fatal disease. Hence, this option is incorrect.
(c) Pediatric meningitis :
Haemophilus influenza b causes meningitis in children within the age of 3-18 months. It is characterized by inflammation of subcutaneous tissue, infantile arthritis, and fatal epiglottis. It is not a mild disease. Hence, this option is incorrect.
(d) Cat scratch disease :
Cat scratch disease is commonly called as cat scratch fever. It is generally benign and transmittable disease. It is caused by the intracellular bacterium Bartonella henselae. It is not fatal. Thus the cat scratch disease is typically mild as compared to the other given diseases. Hence, this option is correct.
Hence, the correct option is (d) cat scratch disease. The typically mild disease of all the given diseases is cat scratch disease.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 9SA
Illness caused by Legionella pneumophila:
Explanation
Legionella is a bacterium, which is transmitted through aerosols that are produced by air conditioning systems. Moreover, the bacterium causes two types of diseases namely:
Legionnaires’ disease (legionellosis) and Pontiac fever.

  1. Legionnaires’ disease (legionellosis):
    Characterized by chills, dry non-productive cough, fever, headache, and pneumonia. The disease can be fatal in immunocompromised individuals, especially in heart and kidney transplants persons.
  2. Pontiac fever:
    The disease has all symptoms that are similar to legionellosis, except for pneumonia and is not fatal.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 10MC
The bacterium that causes infections in many burn victims is Pseudomonas aeruginosa.
(a) Moraxella catarrhalis :
It causes infections to the ear, eye, respiratory system, nervous system and joints in humans. It usually attacks the patients who have compromised immune system. Hence, this option is incorrect.
(b) Pseudomonas aeruginosa :
It can colonize any organ or system of the human body and cause infection to it. Pseudomonas infections are common in burn victims and cystic fibrosis patients. It develops nosocomial infections in almost two-third of the burn victims. Hence, this option is correct.
(c) Escherichia coli :
It causes urinary tract infections and blood infections in humans. It may be fatal in children and immune compromised adults. Hence, this option is incorrect.
(d) Bartonella bacilliformis :
It causes bartonellosis. It is often fatal. It is transmitted by very small sandflies. Hence, this option is incorrect.
Hence, the correct option is (b) Pseudomonas aeruginosa. The bacterium that causes infections in many burn victims is Pseudomonas aeruginosa.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 10SA
Coxiella burnetti is an aerobic, extremely small, obligate intracellular parasite that inhabits and reproduces in the acidic environment within phagolysosomes. Coxiella forms an internal, firm, resistant infective body, which is referred to as spore. The structure and function of this infective body or the spore is similar to the endospores of Gram-positive species. The infective body or the spore enables the bacterium to withstand extreme environmental conditions, such as desiccation and heat for years.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 11MC
Q fever is caused by Coxiella burnetti.
(a) For many years its cause was questio nable:
The cause of Q fever is unknown for many years. The pathogen causing this fever was not identified even after many years of its identification. The Q fever was named so as its cause was questionable for many years. Hence, this option is true of Q fever.
(b) It was first described in 1976 during an outbreak in Quincy, Massachusetts:
The pathogen Coxiella burnetti that causes Q fever was discovered in 1937. Before this discovery itself, the Q fever had been described. Hence, this option is false of Q fever.
(c) Researchers found it could be effectively treated with quinine:
Treatment of Q fever is very effective with antibiotics. The commonly used antibiotics to treat Q fever are doxycycline, tetracycline and chloramphenicol. Of these, oral doxycycline is preferred. Hence, this option is false of Q fever.
(d) The sharp spikes of fever on patients’ temperature charts resemble porcupine quills:
Sharp spikes of fever will not be formed on the patients’ temperature charts. Hence, this option is false of Q fever.
Hence, the correct option is (a) for many years its cause was questionable. This statement is true of Q fever as its cause is unknown for many years.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 11SA
The virulence factors that may cause disease in the Gram-negative anaerobes include outer wall membrane containing lipopolysaccharides, capsules, fimbriae, and proteases that degrade antibodies.

  • Outer wall membrane:
    It consists of lipopolysaccharides. The lipid A produced by Gram negative anaerobes has little endotoxin activity as compared to other Gram-negative bacteria.
  • Polysaccharide capsule and fimbriae:
    Capsule is involved in adhesion to the host cell, abscess development, and inhibits phagocytosis.
  • Metabolic by-products (for example, short-chain fatty acids):
    In case the bacterium is phagocytized, short-chain fatty acids produced during anaerobic metabolism restrict the activity of lysosomes, facilitating the bacteria to persist phagocytosis. This mechanism is considered as potentially relevant pathogenic mechanisms in anaerobic infections.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 12MC
The bile tolerant anaerobe is Bacteroides fragilis.
(a) Bacteriodes :
It is anaerobic bacteria. It is catalase positive and tolerant to bile. It can be cultured on bile-esculin agar, which differentiates aerobic and most anaerobic bacteria. Hence, this option is correct.
(b) Escherichia :
It is Gram-negative facultative anaerobe. It is a rod shaped bacteria. It causes urinary tract infections. It is sensitive to bile. Hence, this option is incorrect.
(c) Shigella :
It is Gram-negative facultative anaerobe. It is non-motile bacilli. It causes shigellosis in humans. It is sensitive to bile. Hence, this option is incorrect.
(d) Prevotella :
It is Gram-negative. It is an anaerobe. It causes respiratory tract infections. It is sensitive to bile. Hence, this option is incorrect.
Hence, the correct option is (a) Bacteriodes. The bile tolerant anaerobe in all the given anaerobes is Bacteriodes.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 12SA
Oxidase test is the single biochemical test result that distinguishes gammaproteobacteria in the family Enterobacteriaceae from gammaproteobacteria in the family Pasteurellaceae.
The oxidase test is a test used to determine if a bacterium yields certain cytochrome c oxidases.

  • Gammaproteobacteria of the family Enterobacteriaceae are oxidase negative.
  • Gammaproteobacteria of the family Pasteurellaceae are oxidase positive.

Microbiology with Diseases by Taxonomy Chapter 20 Answers 13SA
Rickettsia rickettsii is the causative agent of Rocky Mountain spotted fever, which is the most severe and prevalent among rickettsial illness. Rickettsia rickettsii is transmitted among humans and rodents (act as reservoir) by hard ticks in the genus Dermacentor through a process called transovarian transmission.
Transovarian transmission is a process in which male ticks infect female ticks during mating. The female tick spreads the bacteria to eggs forming in their ovaries. Rickettsia rickettsii is inactive or dormant in the salivary glands of the tick and gets activated only after the arachnids feed actively for several hours. The active bacteria are released from the tick’s salivary glands into the mammalian host’s circulatory system where they infect endothelial cells lining small blood vessels.

Microbiology with Diseases by Taxonomy Chapter 19 Answers

Microbiology with Diseases by Taxonomy Chapter 19 Answers

Microbiology with Diseases by Taxonomy Answers

Microbiology with Diseases by Taxonomy Chapter 19 Answers 1CM
Clostridium sp. is one of the most dangerous microbial strains, that could be potentially life threatening. It is highly important that persons should be properly immunized and vaccinated to prevent the after effects of Clostridium infection.
microbiology-with-diseases-by-taxonomy-chapter-19-answers-1cm

Microbiology with Diseases by Taxonomy Chapter 19 Answers 1CT
Key to identify genera of Gram-positive cocci:
Due to biochemical aspects of the microorganisms, the genera could be aligned in various groups. Each group can be sorted out with the occurrence of the gram-positive bacteria. So, the following key is built to represent the key to identify the genera of Gram-positive cocci:
microbiology-with-diseases-by-taxonomy-chapter-19-answers-1ct
Key to identify the Gram-positive bacilli:
Methodology to identify the gram-positive bacilli includes tests on endospore. If it is negative in the test, it is filamentous. If it is tested positive, it is strict anaerobe. In case of further tests on strict anaerobe, the positive test leads to the identification of clostridium and negative leads to the identification of bacillus.
In case of filamentous bacteria, the further test leads production of cold tolerated species and acid-fast bacteria. It continues till the identification of mycobacterium with positive test results and Nocardia with negative test results under Cords. The species, Corynebacterium is identified under snapping division.
microbiology-with-diseases-by-taxonomy-chapter-19-answers-1ct1

Microbiology with Diseases by Taxonomy Chapter 19 Answers 1M
Scaled skin syndrome is a characteristic feature of Staphylococcus species. It is a cutaneous disease. In scale skin syndrome, skin near the mouth reddens and spreads to other parts of the body. This would be followed by the formation of large blisters that contain clear fluid devoid of any bacteria. As a result of the infection, the outer skin gets peeled off within two days of incubation. It is only from the secondary infections the scale skin syndrome becomes more dangerous. Thus, it could be ascertained that Scale skin syndrome could be matched only with Stapylococcus, the causative organism.
Hence, the correct match for scale skin syndrome is (A) Staphylococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 1MC

  • Streptococcus sanguis are members those are primarily attached to the teeth causing dental caries. They are opportunistic pathogens. They can cause meningitis and endocarditis, but are hardly associated with food poisoning. Hence, option (a) is the incorrect choice.
  • Clostridium perfringens produces 11 different toxins, which are directly and indirectly involved in food poisoning. Though it causes food poisoning, it would last only for about 24 hours, being a benign disorder. Hence, option (b) cannot be the right choice.
  • Streptococcus pyogenes infect a host system only if the adapted immune system is too weak also when there is depletion in the normal competing microbiota. The organism is capable of causing scarlet fever, pyoderma, and rheumatic fever among others. Since they are highly opportunistic, they cannot be involved as a causative agent for food poisoning. Therefore, option (d) is incorrect choice.
  • Staphylococcus aureus is one of the more common causes of food borne diseases, which invade the human system from partially processed meats, custard pastries, potato salad, and ice cream. Symptoms of S. aureus include nausea, severe vomiting, diarrhea, headache, sweating, and abdominal pain. Thus, option (c) forms the right choice. Hence, the correct answer is option (c) Staphylococcus aureus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 1SA
Mycoplasma contains sterol in their cytoplasmic membranes. The presence of sterol aids in the maintenance of the osmotic pressure of the cell under different environmental conditions, though the cell lacks a rigid outer cell wall. This is the main reason why mycoplasmas were able to survive under different environments even though they lack a rigid cell wall.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 2CT
It should be only through the hospital worker that Methicillin-Resistant Staphylococcus aureus (MRSA) should have been spread. This is because MRSA has the ability to grow and colonize on the surface of the skin.
Due to this reason, the hospital worker should be highly precautious about the possible infection that he/she could transfer from one patient to another. It is highly advisable that the hospital personnel should aid the use of antiseptic solutions to ensure that he/she does not act as a vector for the transfer of infectious agent.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 2M
The term “Osteomyelitis” refers to inflammation of bone marrow. It occurs when a person is infected with the bacteria Staphylococcus aureus. These bacteria can infect persons either through a traumatic wound or through bacteremia. Upon infection, the condition leads to the inflammation of the bone marrow and the surrounding bone. Thus, it could be ascertained that osteomyelitis could be associated with the genus Staphylococcus. Hence, the correct match for Osteomyelitis is (A) Staphylococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 2MC

  • S. aureus do possess blood clotting enzyme that would ensure that once the cell is found inside the host, it is kept away from the immune system with help of the clot that surrounds the cell. But, this function does not have any impact in affecting the matrix of the host cell. Hence, option (a) becomes an incorrect choice.
  • Hyaluronic acid is a part of the cells of the host system that will not elicit an immune response. Hence, option (c) becomes incorrect.
  • S. aureus is not associated with necrotizing factors, but rather it is the Streptococcus pyogenes strain that produces the necrotizing agents, thereby destroying the host cells. This proves that option (d) is incorrect.
  • S. aureus produces the enzyme hyaluronidase, which would dissolve the cell wall of the matrix, as the major component of the cell wall of the matrix contains hyaluronic acid. This proves that option (b) is the right choice.
  • Thus, the right option is (b) S. aureus produces an enzyme that dissolves hyaluronic acid and thus enables it to pass between the cells.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 2SA
Mycobacterium avium-intercellulare was considered harmless and was found prevailing in the respiratory microbiota. The organism behaved as an opportunistic pathogen in patients suffering from human immunodeficiency virus infection, whose immune system is suppressed. Thus, the organism is said to have gained entry into the host system through contaminated food or water, due to the absence of both cell mediated and humoral immunity.
On entry, the organism is said to have behaved like a pathogen (more correctly an opportunistic pathogen). During acute infection stages, the organism is said to be well packed inside every cell giving almost about thousand microbes per milliliter. Thus, organism acts ultimately leading to multiple organ failure.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 3CT
Streptococcus pneumonia is supposed to be the agent causing pneumonia, which is capable of eliciting a fatal attack on age old people.
The causal organism of pneumonia could be restricted by the usage of antimicrobials including erythromycin and cephalosporin. Most of the organisms are still susceptible against penicillin as well.
Pneumovax, a vaccine could be incorporated into the old man in order to elicit an immune response against the organism Streptococcus pneumonia. This could be used as an option to put the old man in some sort of safety but at the same time it should be noted that to his age he is not supposed to develop a protective immunity against the organism.
No. The organism could deteriorate the health of old people and others who have contradicted other respiratory disease. At the same time, it cannot have a similar fatal symptomatic effect on younger populations.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 3M
Pharyngitis is also known as “strep throat” named after the genus Streptococcus, which is the actual causal agent. The condition is typically accomplished by the inflammation of the pharynx accompanied by fever, malaise, and headache. This makes sure that pharyngitis is caused by the organisms belonging to the genus Streptococcus. Hence, the correct match for Pharyngitis is (B) Streptococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 3MC

  • Impetigo is a condition that is common among kids whose immune system is yet to be fully developed. Such a condition is a part of the cutaneous disease, thus making option (a) as the incorrect choice.
  • An infection of hair follicle in which the base of the follicle becomes red, swollen, and pus filled is termed folliculitis. The condition is a part of the cutaneous disease, thus making option (b) as the incorrect choice.
  • Carbuncle is formed as a result of merging of several furuncles. The furuncles are large boils surrounding the tissue, which is a painful nodular extension forming a part of the cutaneous disease. Hence, option (c) is the incorrect choice.
  • The toxic shock syndrome is a systemic disease caused through the infection of Staphylococcus aureus. The toxic shock syndrome toxin when produced by the organism in the wound area gets absorbed in to the blood, the systemic condition of staphylococcal toxic shock syndrome occurs. The condition is characterized by fever, vomiting, red rash, extremely low blood pressure, and loss of sheets of skin. Hence, option (d) is the right choice. Thus, the right answer is option (d) toxic shock syndrome.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 3SA
Lepromatous leprosy is said to be more virulent than tuberculoid leprosy. In lepromatous leprosy the organism multiplies in skin and nerve cells, thereby gradually destroying the cells leading to loss of facial features, digits, and other body structures. Tuberculoid leprosy, on the other hand, is the non-progressive form of the disease. But, the spots where the infection has occurred would remain affected showing characteristic features of the disease, which includes the loss of sensation at the spot of infection.
Upon infection, the host system responds well to Mycobacterium leprae through its cell mediated immune system, by killing the infected cells; it leads to the formation of lepromatous leprosy. At the same time, when there is a reduction in the cell mediated immune response in the host, it leads to lepromatous leprosy.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 4CT
No. Tetanus toxin cannot be used as an antidote to botulism toxin. Botulism toxin blocks the neural transmitter, acetylcholine producing flaccid paralysis. On the other hand, tetanus toxin interferes with the inhibitory signal that allows muscle contraction. The tetanus toxin cannot counter flaccid paralysis.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 4M
Scarlet fever is often associated with pharyngitis, which again is caused by the organism belonging to the genus Streptococcus. Pharyngitis is accompanied by scarlet fever, provided the infection as a result of the lyophilized strain of Streptococcus. It is after the onset of pharyngitis, the pyrogenic toxins would be released that would end up in forming rashes that begins from the chest and spreads across the body. This proves that scarlet fever is caused by the organism belonging to the genus Streptococcus. Hence, the correct match for scarlet fever is (B) Streptococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 4MC

  • S. aureus is the causative agent of bacteremia and pneumonia in adults, but not in neonatal. Hence, option (a) becomes incorrect.
  • S. epidermidis is a common skin microbe that is capable of infecting the host under accidental introduction into the system. They are hardly involved in infection of neonatal, thus making option (b) as the incorrect choice.
  • S. pyogenes spread from people to people via respiratory droplets, especially under crowded conditions such as those in classrooms. The presence of antibodies in the neonatal from the mother prevents the infection of the opportunistic pathogen that might develop a disease among the adults when there is a lack of competition from other inhabiting microorganisms in the host system. This makes option (c) as the incorrect choice.
  • Streptococcus agalactiae is the organism that is often associated with infecting neonatal. They are involved in bacteremia, meningitis, and pneumonia in 3 among 1000 newly born children. This makes sure that option (d) is the right choice. Thus, the right choice is (d) Streptococcus agalactiae.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 4SA
Mycobacterium tuberculosis would be transmitted via aerosol droplets from person-to-person. About 10 bacterial cells are required for establishing an infection in a person. The cells that escape from the infected person would have entered the person nearby by inhalation of the aerosols. Once the cell enters the host system they would be engulfed by the macrophages.
The macrophages would attempt to digest the pathogen through its enzyme, thereby exhibiting the antigen to the helper-T cells for further activation. But the organism that is being engulfed prevents the fusion of lysosomes with the phagosome, thus establishing a dwelling place for them to multiply without being invaded by the host immune system. The bacteria break the macrophage and then reach other macrophages and infect them.
If the businessman who is contradicted by the organism lacks knowledge about the usage of multi drug therapy, or when he does not take the requisite dose of antimicrobial drug, then he is susceptible to the whole effect of the disease. Also there is a chance that the organism might be a multi-drug resistant strain, which accounts for over 10% of death toll. This could be the reason behind the fatality due to infection with Mycobacterium tuberculosis that led to the death of the Canadian businessman.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 5CT
Cleaning of teeth could lead to removal of the soft tissue surrounding the teeth, which becomes a possible route for the microbes present in the oral cavity to enter into the blood stream. There is a greater chance that even pathogenic microbial strains could gain entry into the blood stream through these gateways. This is the main reason, blood from a person who has cleansed his teeth is refused to be donated.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 5M
Pyoderma is a confided pus producing lesion that is confined to a particular environment at the site of infection. Pyoderma is caused through the infection of Streptococcus. Infection can spread through infected fomites or through direct contact. The pus filled lesion when breaks becomes highly contagious, spreading the lesions. Thus, it could be ascertained that pyoderma is caused as a result of microbes belonging to the genus Streptococcus.
Hence, the correct match for Pyoderma is (B) Streptococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 5MC

  • Cutaneous anthrax is characterized by painless, solid, raised nodules ultimately leading to the killing of cells at these infection sites. These nodules then spread to form a painless, swollen, black, crusty ulcer known as eschar. They are a part of both humans, as well as animals, thus making option (a) as the incorrect choice.
  • Inhalation anthrax is rare among humans (and animals) and the infection spreads via inhalation of spores. This makes option (b) as the incorrect choice.
  • The three major clinical manifestations that could be caused as a result of Bacillus anthracis are cutaneous anthrax, inhalation anthrax, and gastrointestinal anthrax. This shows that option (d) is incorrect.
  • Gastrointestinal anthrax is the common phenomenon that affects the animals larger, which is highly rare among humans. It results in intestinal hemorrhaging and eventually death among animals. Thus, option (c) forms the right choice. Thus, the right option is (c) gastrointestinal anthrax.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 5SA
The botulism is a disease caused by the anaerobic, and endospore forming bacteria known as Clostridium botulinum. These bacteria produce the different types of toxins, which are protein in nature.
Botulinum toxins are mainly act on the synaptic clefts, Toxins inhibit the binding of the acetylcholine as a result nerve impulse is arrested. This process mainly affect the neuromuscular junction, therefore the muscle contraction is stopped.
Food stuffs suspected of containing botulism toxin are analyzed through subjecting life mice. Two portions of food one mixed with Clostridium botulinum antitoxin and the other without the antitoxin provided for two different sets of mice. If the mice that received the antitoxin survive, and the other mice that do not receive the antitoxin die, then botulism is confirmed.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 6CT
a) Actinomyces – is characterized by the pus containing bacteria, resembling fungal hyphae.
b) Staphylococcus – as a result of the multiple plane of division, where the cells are aggregated in the form of clusters.
c) Bacillus – Since the cells are not detached, they form as Streptobacillus. They are rod shaped.
d) Mycobacterium – the acid fast bacilli that found it tough to be stained by the gram- staining procedure.
e) Streptococcus – As a result of a single plane of division, the coccus are found growing in one dimension giving a chain like appearance.
f) Clostridium – the cells are characterized by the presence of endospores at one end of the cell to give a characteristic drum stick appearance.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 6M
Pharyngitis occurs as a result of infection with Streptococcus pyogenes. If it is left untreated, it leads to rheumatic fever. The complication is often associated with the inflammation of heart valves and muscles. This shows that rheumatic fever is caused as a result of the organisms belonging to the genus Streptococcus. Hence, the correct match for rheumatic fever is (B) Streptococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 6MC

  • Staphylococcus species is a human pathogen that is predominately found near the sebaceous glands. The very nature of the pathogenic status of the organism makes it susceptible to other temperatures and conditions. Hence, option (a) is incorrect.
  • Though Mycobacterium species is composed of mycolic acids and cord factor that aids in the pathogenesis, it could not help in the survival of the organism under harsh conditions. Thus it could be ascertained that option (c) is not the right choice.
  • Actinomyces species is an opportunistic pathogen, which is a bacterium, stating that it could thrive only when there is no competitive organism in the vicinity. Thus, it could be ascertained that option (d) is not the right choice.
  • Clostridium species is known to produce endospores that could be alive for years and could break into vegetative forms after a drought period. Thus, it could be ascertained that this organism could withstand vigorous temperature ranges.
  • Hence, option (b) should be the right choice. Thus, the right option is (b) Clostridium.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 6SA
Because infant botulism is often associated with the consumption of honey, parents are advised by the pediatricians not to feed their child with honey. This is because the infant under age one do not possess sufficient microbiota in their system to prevent the action of Clostridium botulinum, they are advised so.
The botulism is a disease caused by the anaerobic, and endospore forming bacteria known as Clostridium botulinum. These bacteria produce the different types of toxins, which are protein in nature.
Botulinum toxins are mainly act on the synaptic clefts, Toxins inhibit the binding of the acetylcholine as a result nerve impulse is arrested. This process mainly affect the neuromuscular junction, therefore the muscle contraction is stopped.
The botulism is a food borne disease; the Clostridium botulinum bacteria are present in the form of endospores. Ingestion of these spores through the food, they accumulated in the gastrointestinal tracts of children’s. Now these endospores compete with the other common microbiota present in the gastrointestinal tracts, for the food and shelter. Sometimes, it leads to the severe illness (or) death of the child’s.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 7M
It is due to some unknown reasons the strains of Streptococci that bound to antibodies are not removed from the circulation through the immune cells. Instead they are found accumulating in the glomeruli of the nephrons in the kidney leading to the condition Glomerulonephritis. This proves that Glomerulonephritis is caused as a result of organisms belonging to the genus Streptococcus. Hence, the correct match for glomerulonephritis is (B) Streptococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 7MC
Pathogenic strains including Staphylococcus species, Mycobacterium species, and Enterococcus species, are organisms where they tend to become resistant to antimicrobial drugs over a period of time. But as and when the antimicrobial drug becomes resistant to one drug, the microbes would be inactivated by other antimicrobial drug. This particular characteristic of microbes becoming resistant to antimicrobial drugs is a common phenomenon and hence all the options (a), (b), and (c) are correct. Thus, the right option is (d) all of the above.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 7SA
The mycoplasmas are smallest free living bacteria, their diameter ranging from 0.1 to 0.8 µm. These bacteria have special characters like, independent growth and reproduction. The mycoplasmas have low G + C content in their genome. Based on their rRNA analysis, genetically they are related to the gram positive category.
Gram stain is done mainly based on the differences in the characteristic features of the cell wall of the organism. While undergoing gram stain, the strains that take a purple color are said to be gram positive and the strains that takes pink color are said to be gram negative organisms. Mycoplasma are said to lack cell wall, which is the reason why it fails to retain the primary purple color, and ultimately taking up the pink color of the secondary stain.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 8M
Inflammation of the nasal sinuses through Streptococcus pneumoniae is termed ‘sinusitis.’ Infection with Streptococcus pneumoniae occurring after a viral infection in the upper respiratory tract leads to this condition. Pus production leads to inflammation and pain in the cavity. This proves that sinusitis is caused as a result of organisms belonging to the genus Streptococcus. Hence, the correct match for sinusitis is (B) Streptococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 8MC

  • Streptococcus pyogenes have no effect in support with the formation of pseudomembranous colitis. The organism is capable of causing pharyngitis, scarlet fever, toxic shock like syndrome, and rheumatic fever. Thus, it could be ascertained that option (b) is not the right choice.
  • Mycobacterium avium-intracellulare is an opportunistic pathogen that could establish themselves in immune-compromised patients infected with human immunodeficiency virus. It would have an adverse effect almost on every organ of the body. Therefore, the option (c) is incorrect.
  • Corneybacterium dipthriae causes the fatal disease diphtheria. The bacteria is said to infect the respiratory, gastrointestinal, urinary, and genital tracts. Thus, it could be ascertained that option (d) is not the right choice.
  • The disease Pseudomembranous colitis is caused by Clostridium difficile. Pseudomembranous colitis is characterized by the enlargement of sections of colon wall as a result of sloughing off. This would lead to the perforation of the colon walls leading to massive internal infection by fecal bacteria. The condition could also lead to the death. Hence, option (a) is the right choice. Thus, the right option is (a) Clostridium difficile.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 8SA
Pyrogenic toxins initiate the stimulation of macrophages and helper T lymphocytes to release cytokines that in turn stimulate fever, a widespread rash, and shock. Since they are formed near the end of blood capillaries characterized by rashness and dilation, they are also known as erythrogenic toxins.
Pyogenic toxins aids in the formation of pus filled lesion that usually occurs on the exposed skin of the face, arms, or legs. When the pus filled lesion breaks open, it forms a yellow crust.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 9M
Otitis media is another complication caused as a result of Streptococcal pneumoniae. The condition is characterized by the inflammation of the middle ear as a result of pus formation, which would be accompanied with pain. This proves that sinusitis is caused as a result of organisms belonging to the genus Streptococcus. Hence, the correct match for Otitis media is (B) Streptococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 9MC

  • Mycoplasmas are genus of microbes that characterized by the absence of cell wall. This shows that option (a) is right choice.
  • Since these organisms do not have a definitive cell wall around them, they tend to have a pleomorphic shape. This proves that option (b) is right choice.
  • Mycoplasmas contain sterols in their cell structure that provides the osmotic regulation for the microbe, preventing it from the stress caused as a result of osmotic pressure (since cell wall prevents the cell from being under pressure). This proves that option (c) is also right choice.
  • Thus, the right option is (d) all of the above.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 9SA
Staphylococcus aureus is normally found in areas where the moisture content is higher whereas Staphylococcus epidermidis is found generally occupying the outer skin or epidermis.
S. aureusis said to be more virulent, which is capable of producing a variety of disease conditions. S. aureusis mainly casus the food poisoning, cutaneous diseases like scaled skin syndrome syndrome, and systemic diseases like toxic shock syndrome extra.
Whereas tie latter cannot show its virulence unless it is left in an immunocompromised individual. This shows that S. epidermidis is an opportunistic pathogen and less virulent on compared with S. aureus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 10M
Anthrax is caused by the bacterium Bacillus anthracis. The organism produces toxins that would lead to apoptosis of the host cell. This makes the organism highly lethal and increases the chance of fatality. The three clinical manifestations of anthrax are gastrointestinal anthrax, cutaneous anthrax, and inhalation anthrax. Thus, it could be ascertained that anthrax is caused as a result of the organism belonging to the genus Bacillus. Therefore, the correct match for anthrax is (G) Bacillus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 10MC

  • Tuberculoid leprosy is a non-progressive form of leprosy. Patients whose cell mediated immune response is effective against Mycobacterium leprae are said to exhibit the condition. Thus, option (a) is not the right choice.
  • Arrhythmia is caused as a result of infection caused due to S. aureus. The condition is characterized by the attack of lining of the heart by the action of the microorganisms. Thus option (c) cannot be the right choice.
  • Tetanus is caused by the organism Clostridium tetani. The disease condition is characterized by the action of the toxin produced by the organism leading to locked jaw (a common characteristic feature of the disease). Thus the option (d) cannot be right choice.
  • Diphtheria is characterized by the formation of fluids that gets stored and thickens in to a pseudomembrane. This fluid is said to adhere so tightly to the tonsils, uvula, palate, pharynx, and larynx that cannot be dislodged without causing bleeding. Thus, option (b) becomes the right choice. Thus, the right option is (b) diphtheria.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 10SA
The anthrax is caused by the bacteria, known as Bacillus anthracis. It is a gram positive, rod shaped endospore forming bacteria. This, bacteria produce the different types of toxins, which are protein in nature.
The three types of anthrax diseases are:

  • Gastrointestinal anthrax
  • Cautious anthrax
  • Inhalation anthrax

The gastrointestinal anthrax is most commonly observed in animals, it causes severe intestinal hemorrhaging. The cautions anthrax is mostly evident in human beings, this diseases is painless and mainly damages the skin. The inhalation anthrax is rarely seen in human race, but it mainly affects the lungs.
The number of cases of anthrax reported between January 1976 and September 2001 was a meager 15 cases. Such is the rarity of the disease. Suddenly when scientists confronted with more than a dozen of cases with anthrax, it led to the suspicion that there is a possible terrorist attack during the period.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 11M
Myonecrosis is as a result of invasive infection of the bacterium Streptococcus. The infection is rendered life threatening. This disease condition is characterized by toxemia, failure of many organs and death of more than 50% of patients.
Therefore, the correct match for myonecrosis is (B) Streptococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 11MC

  • Mycoplasma lacks cytochrome that forms a part of many of the electron transport chain. Since cytochrome is not a part of the mycoplasma, option (a) is said to be the one which is absent in the mycoplasmal system. Hence, option (a) is said to be the right choice.
  • Sterols are present in the cytoplasmic membrane of the mycoplasma. The presence of sterols aids in the maintenance of the osmotic pressure of the organism, even though the cell lacks cell wall. Hence, option (b) becomes the wrong choice.
  • UGA codon is used as a stop codon in many other organisms, but the same codon codes for the amino acid tryptophan. Since this is a part of the organism, option (c) becomes the wrong choice.
  • The mycoplasmal rRNA (ribosomal ribonucleic acid) reveals that the organism is genetically related to gram positive organisms. Since the statement is true, option (d) becomes an incorrect option.
  • Hence, the right choice is option (a) cytochromes.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 11SA
Tetanus is caused as a result of the exposure of host to the produced tetanus toxin, known as tetanospasmin. The toxin is a potent neurotoxin released by the cells of Clostridium tetani.
The Clostridium tetani is a motile, endospore forming bacteria. This bacterium usually lives in the soil, dust, human and animal intestines.
Muscular contractions are said to be done by the action of acetylcholine. The skeletal muscles are arranged in opposite sides, with the joint facing each other. These two muscles are not actually in contact with each other, but they would come in contact with the help of the neurotransmitter, known as acetylcholine. When acetylcholine is passed through the ends of the muscles, muscle at the other end contracts.
Tetanospasmin is composed of two protein molecules, among which one is heavier while the other is a lighter molecule. The heavier molecule binds to receptor on a neuron’s cytoplasmic membrane. This leads to the endocytosis of the molecule, where it undergoes proteolytic cleavage releasing the lighter polypeptides.
The lighter polypeptides are transported to the central nervous system. These peptides, restricts the release of the neurotransmitter acetylcholine. With inhibition blocked it leads both the muscle to contract without any regulatory mechanism. This leads to the continuous contraction of the muscles, without relax.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 12M
Corynebacterium diphtheria is transmitted through respiratory droplets or through skin contact from person to person. It is an illness associated with upper respiratory tract. This disease condition is characterized by the symptoms including sore throat, localized pain, fever, pharyngitis, and oozing of fluid. This disease can be prevented using DPT (diphtheria-pertussis-tetanus) vaccine. Therefore, the correct match for diphtheria is (F) Corynebacterium.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 12SA
Mycolic acid is a typical waxy lipid that is found enclosing the Mycobacterium species. Mycolic acid is composed of chains of 60-90 carbon atoms. This is the main reason why they remain without being eliminated even though they encounter phagocytosis by the host immune cells. It also prevents the cell from being dehydrated when exhaled through aerosols. It is the Mycolic acid that prevents the cells from being eliminated and thus could be added as a virulence factor of the organism.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 13M
Leprosy is caused as a result of Mycobacterium leprae. There are two types of leprosy based on the immune response of the patient. Lepromatous leprosy is a highly progressive form of leprosy, which is found in patients with a weak cell-mediated immunity. Tuberculoid leprosy is the non-progressive form of leprosy, where the organism is stopped by the activity of the immune system. Thus, it could be ascertained that leprosy is caused by the organism belonging to the genus Mycobacterium. Hence, the correct match for Leprosy is (C) Mycobacterium.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 13SA
Mycoplasma are bacterial cell that lack a cell wall, hence they tend to become pleomorphic in shape. They are 0.1 µm to 0.8 µm in diameter. Since they lack cell wall, they possess the character of squeezing through bacterial filters which makes it look like a virus.
The distinctive difference between a virus and a mycoplasma is that mycoplasma does not require a live cell to replicate. Mycoplasma contains both functional RNA and DNA that virus lacks. These are some of the differences that differentiate the mycoplasmas from the viruses.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 14M
Dental caries are as a result of action of the bacterium Streptococcus viridans. They stick on to the dental surfaces through the presence of the insoluble polysaccharide, dextran. The presence of dextran allows viridans, as well as, other organisms to populate the area and cause dental plaque through microbial biofilms. Thus, it could be ascertained that the dental carries is caused as a result of the organisms belonging to the genus Streptococcus. Hence, the correct match for Dental caries is (B) Streptococcus.

Microbiology with Diseases by Taxonomy Chapter 19 Answers 15M
Acne is caused as a result of the action of Propionibacterium acnes. The organism causes 85% acne in adolescents and young adults. The organism could also act as an opportunistic pathogen when gained entry into the host. Thus, it could be ascertained that acne is as a result of the organism belonging to the genus Propionibacterium. Hence, the correct match for Acne is (E) Propionibacterium.

Microbiology with Diseases by Taxonomy Chapter 18 Answers

Microbiology with Diseases by Taxonomy Chapter 18 Answers

Microbiology with Diseases by Taxonomy Answers

Microbiology with Diseases by Taxonomy Chapter 18 Answers 1CM
Immediate hypersensitivity:
Explanation
Type I hypersensitivity gives rise to allergies. Allergies result when allergens bind to IgE molecules that are already bound to mast cells and basophils. It causes the sensitized cells to degranulate and release histamines. As a result, it produces localized allergic reactions with clinical syndromes. The symptoms include hay fever, asthma and urticarial. Antihistamines are administered for asthma patients. In systemic allergic reactions, anaphylactic shock may occur. The specific treatment for anaphylaxis is epinephrine.
microbiology-with-diseases-by-taxonomy-chapter-18-answers-1cm
microbiology-with-diseases-by-taxonomy-chapter-18-answers-1cm1

Microbiology with Diseases by Taxonomy Chapter 18 Answers 1CT
The advantages of an individual that gain in making class E antibodies (IgE):
Explanation
IgE antibodies provide immunity against parasitic worms and protozoan parasite. Moreover, an allergen that triggers to IgE antibodies attaches to antigen binding sites. In addition, IgE antibodies are present on the mast cells and basophils, producing histamines and release into neighborhood.
Therefore, people exposed to internal parasites benefit from IgE antibody production. In rarely infected person, IgE antibodies are produced at low levels, in blood serum.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 1L
Graft types are named according to the relation between donor and the recipient. A graft is called an autograft when tissues are moved to a different location, within the same individual. A best example for autograft includes grafting of skin from one area of the body to another to cover a burns (or) use of a leg vein to bypass blocked coronary arteries.
Isografts are grafts transplanted between genetically identical individuals like siblings (or) clones. The MHC proteins are identical in these individuals. Thus Isografts are not rejected since they do not trigger immune response.
Allografts are grafts transplanted between genetically distinct members of the same species. The MHC proteins are not same in donor and recipient, it triggers strong type IV hypersensitivity reaction, which results in graft rejection.
Xenografts are grafts transplanted between individuals of different species. Since, the tissues of donor and recipient are extremely different, they trigger a rapid and intense rejection of graft, which is very difficult to suppress. Transplanting a baboon’s heart into a human is an example of xenograft.

  1. Autograft
  2. Isograft
  3. Allograft
  4. Xenograft

Microbiology with Diseases by Taxonomy Chapter 18 Answers 1M
Inflammatory mediators released from degranulating mast cells in type I hypersensitivity reaction causes allergies. When a sensitized individual’s contact with an allergen, many mast cells may degranulate simultaneously, releasing increased amounts of histamines and other inflammatory mediators into the bloodstream.
The chemicals released may exceed the body’s ability to adjust, resulting in acute anaphylaxis or anaphylactic shock. Thus, it could be ascertained that acute anaphylaxis could be associated with type I hypersensitivity. Hence, the given immune system complication matches with the option- A. Type I hypersensitivity.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 1MC

  • Immunoglobin A or (IgA) are secretory immunoglobulins found in mucous secretions like saliva, tears, and colostrum. It plays a major role in mucosal immunity. It does not mediate type-I hypersensitivity. Hence, the option (a) is incorrect.
    Immunoglobin M or (IgM) is the first antibody to appear in the primary immune response. It is commonly called natural antibody because it is formed in the blood even before primary immune response. It does not mediate type- I hypersensitivity. Hence, the option (b) is incorrect.
  • Immunoglobin G or (IgG) is the only immunoglobulin that crosses the human placenta and thus offers a passive protection to the newborn babies for about 6-9 months. IgG neutralizes toxins and viruses. IgG binds to bacteria, opsonizes them, thereby enhance their phagocytosis and elimination. It provides humoral immunity. It does not mediate type-I hypersensitivity. Hence, option (c) is incorrect.
  • Immunoglobin D or (IgD) has not been shown to have antibody activity and it does not mediate any functions attributed to immunoglobulins. IgD binds to basophils and mast cells and activates them to secrete antimicrobial factors to participate in respiratory immune defense. It does not mediate anaphylactic reaction. Hence, the option (d) is incorrect.
  • Immunoglobin E or (IgE) -antigen interaction on mast cells results in degranulation of the mast cells and inflammatory mediators are released. Histamines, kinens, proteases, leukotrienes, prostaglandins are the inflammatory mediators that triggers type I hypersensitivity reactions. IgE provides immunity against worms, protozoan parasites. The immunoglobulin class that mediates type I hypersensitivity is (e) IgE.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 1MTF
The given statement, “Cyclosporine is released by degranulating mast cells” is False.
Cyclosporine is an immunosuppressive drug, which involves treatment with antibodies against T cells or their receptors. Degranulating mast cells release histamines, kinins, proteases, leukotrienes, prostaglandins, and other inflammatory mast cells.
Hence, the correct statement is “Histamines, proteases, and kinins are released by degranulating mast cells.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 1SA
Acquired immunodeficiency syndrome was discovered in 1981, which emerged as a worldwide pandemic disease. AIDS is a syndrome; it is not a single disease. Syndrome is defined as a group of signs, symptoms, and diseases associated with a common pathology.
Several opportunistic (or) rare infections associated with a severe decrease in the number of CD4+ cells and a positive test showing the presence of HIV. The AIDS infection includes skin disease due to shingles and herpes. Disease of nervous system due to meningitis, toxoplasmosis, and cytomegalovirus, respiratory disease caused by tuberculosis, pneumocystis, histoplasmosis and coccidioidomycosis and disease of digestive systems such as chronic diarrhea, thrust, and oral hairy leukoplakia.
Kaposi’s sarcoma is a rare cancer of blood vessels in AIDS patients. AIDS results in dementia in final stages.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 2CT
Physician cannot use skin test to diagnose bacterial disease, similar to tuberculin reaction:
Explanation
A tuberculin response is mediated by memory T cells. It is a delayed type hypersensitivity reaction in which the skin of an individual is exposed to tuberculosis. Moreover, reacts to subcutaneous injection of a protein solution obtained from Mycobacterium tuberculosis. The resulting cell-mediated immune response generates memory T cells that persist in the body. However, other bacteria have unique antigens that trigger type IV hypersensitivity reactions. Immune responses to most of the bacterial infections are antibody mediated. Hence, physicians do not use skin tests to diagnose bacterial diseases.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 2M
Allergic contact dermatitis is a good example of type IV hypersensitivity reaction, which is T-cell mediated damage to chemically modified skin cells. The oil of poisonous ivy and related plants when rubbed against the skin, triggers cell-mediated immune response and results in intensely irritating skin rash called allergic contact dermatitis. Thus, it could be ascertained that allergic contact dermatitis could be associated with type IV hypersensitivity.
Hence, the given immune system complication matches with the option D. Type IV hypersensitivity.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 2MC

  • Histamines are the significant chemical released from mast cell. They are small molecules related to the amino acid histidine. Allergen binds to IgE molecule on sensitized mast cell. This binding triggers the sensitized mast cells to release the inflammatory chemicals. Inflammatory mediators mainly histamines are released from degranulated mast cells in type I hypersensitivity. Hence, the correct option is (c) histamine.
  • Immunoglobulins are glycoproteins formed in response to an antigen and react specifically with that antigen. It is not an inflammatory mediator released by degranulating mast cells in type I hypersensitivity. Hence, the option (a) is incorrect.
  • Complement is a heat-labile serum protein, in which, component involves in lysis of antigen by forming membrane attack complex. They are not mediators that cause allergic reaction. Hence, the option (b) is incorrect.
  • Interleukin are not the inflammatory mediators released by degranulating mast cells. They do not cause type anaphylactic or type I hypersensitivity. Hence, the option (d) is incorrect.
  • Prostaglandins are produced when allergens bind to IgE on mast cell, which activates other enzymes that trigger the production of leukotrienes and prostaglandis. They are not the major mediator released by degranulating mast cells in type I hypersensitivity. Hence, the option (e) is incorrect.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 2MTF
The given statement, “Type III hypersensitivity reactions may lead to the development of glomerulonephritis” is True.
In type III hypersensitivity reaction, excessive amounts of immune complexes are deposited in tissues, where they cause significant tissue damage. If large amount of immune complexes form in the blood stream, they may be filtered out by the glomeruli of the kidney, causing glomerulonephritis, which can result in kidney failure.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 2SA
Human population of approximately 85% carries Rh antigen, which is also found in rhesus monkeys. The Rh antigens are the second most common antigen, after ABO blood group. If Rh antigens are present on the surface RBC it is denoted as Rh+ve, vice versa.
If a woman is Rhve (negative) blood group carrying an Rh+ve (positive) fetus, the new born baby have risk of getting new born hemolytic disease. In which antibodies made by the mother against the Rh antigen may cross the placenta and destroy the fetus’s red blood cells.
“RhoGAM” administered to pregnant Rh-women may prevent this disease. If an Rh-positive blood group woman is carrying an Rh-ve (negative) fetus, the fetus doesn’t have the risk of new born hemolytic disease, in which no antibodies are produced which destroys the fetus’s red blood cells.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 3CT
Clinical consequences of autoimmune response to estrogen receptors:
Explanation
Systemic consequences are resulted when an autoimmune response is bound to estrogen. This is due to the presence of different cells producing estrogen receptors. There is reduction in fertility when any damage occurs to ovaries. Moreover, there is alteration in menstrual cycle in damaging the cells of endometrial. Since, the cells are involved in the growth of bone, which consists of receptors for estrogen there is impairment in remodeling.
Furthermore, the estrogen receptors in hypothalamus are targeted with high diversity and are not protected by blood-brain barrier. However, hypothalamus controls the regulation of endocrine functions. Thus, the estrogen receptors are targeted by an immune response that supports in fighting against estrogen-responsive cancers.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 3M
Systemic lupus erythematosus is an immune complex-mediated hypersensitivity reaction. It is a good example of type III hypersensitivity disease that affects multiple organs. Patients with generalized immunological disorder make antibodies against numerous self-antigens found in normal organs and tissues, giving rise to many different pathological lesions and clinical manifestations.
Development of self-reactive antibodies called autoantibodies bind to many autoantigens, especially the patient’s DNA (deoxyribonucleic acid). Thus, it could be ascertained that systemic lupus erythematosus could be associated with type III hypersensitivity.
Hence, the given immune system complication matches with the option C. Type III hypersensitivity.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 3MC

  • Rh antigen is present in 85% of human population, which is also found in rhesus monkeys. If an Rh-negative pregnant woman is carrying an Rh-positive fetus, the fetus may be at risk of hemolytic disease of the new born, in which, antibodies made by the mother go against the Rh antigen. This may result in destruction of the fetus’s red blood cells.
    Hence, the correct option (d) rhesus antigen.
  • Major Histocompatibility (MHC) protein plays a major role in grafting. If MHC antigens are similar in both donor and recipient, graft rejection will not occur. If MHC antigens are different, graft rejection occurs. MHC proteins are not the blood group antigens, which causes hemolytic disease of newborn. Hence, the option (a) is incorrect.
  • MN antigen is not blood group antigens. They do not cause hemolytic disease of the newborn. Hence, option (b) is incorrect.
  • The most important of the blood group antigens is the ABO group, which is largely responsible for transfusion reactions. Hemolytic disease of the newborn is caused by antibodies against Rh blood group antigen. Hence, option (c) is incorrect.
    Type II protein is not a blood group antigen. They do not cause hemolytic disease in newborn. Hence, option (e) is incorrect.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 3MTF
The given statement, “ABO blood group antigens are found on nucleated cells” is False.
ABO blood group antigens are present on surface of red blood cells. The most important of the blood group antigens is the ABO group, which is largely responsible for transfusion reactions. ABO blood group antigens are not found in nucleated cells.
Hence, the correct statement is “ABO blood group antigens are found on red blood cells.”

Microbiology with Diseases by Taxonomy Chapter 18 Answers 3SA
In allergic individuals plasma cells produce IgE in response to allergens. High levels of IgE are produced in only some allergic individuals. The main reason is exposure to environmental factors during infancy and childhood to high levels of indoor antigens such as cigarette smoke, dust mites, and molds. Hence, the sensitized individuals become hypersensitive.
Everyone is exposed to antigens in the environment, which triggers an immune response resulting in the production of IgG. But when cytokines from type II helper T lymphocytes activate the B lymphocytes in allergic persons, the B lymphocytes become turned into plasma cells, switches to IgE instead of producing IgG.
Following a sensitized individual’s contact with an allergen, many mast cells may degranulate simultaneously, releasing massive amounts of histamine and other inflammatory mediators into the bloodstream. The release of chemicals may exceed the body’s ability to adjust, resulting in anaphylactic shock.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 4CT
Defects in B-cells produce bacterial infections, while defects in T-cells produce viral disease:
Explanation
Antibody-mediated responses with extracellular bacteria are effective in fighting against bacterial infections. Moreover, some people suffer from bacterial diseases that lack B-cells. Additionally, immune responses of cell mediated fights effectively with pathogens like intracellular viruses. Thus, people who are devoid of T-cells will produce viral infections.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 4M
Allografts are grafts transplanted between genetically distinct members of the same species. Most grafts performed in humans are allografts. Since the MHC (major histocompatibility complex) proteins of the allograft are different from those of recipient. Allografts induce strong type IV hypersensitivity, resulting in graft rejection. Thus, it could be ascertained that allograft rejection could be associated with type IV hypersensitivity.
Hence, the given immune system complication matches with the option D. Type IV hypersensitivity.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 4MC

  • Farmer’s lung is one form of hypersensitivity pneumonitis, caused when immune complexes are deposited in the lung. It is a type III hypersensitivity reaction, occurs in farmers when they are chronically exposed to mold spores. This makes option (c) a type III hypersensitivity to mold spores.
  • A type I hypersensitivity reaction to grass pollen is an allergic reaction. It results from the release of inflammatory molecules such as histamine in response to the pollen grass allergen. Farmer’s lung is a type III hypersensitivity reaction. Hence, the option (a) is incorrect.
  • A type II hypersensitivity reaction results when cells are destroyed by an immune response. A significant example of type II hypersensitivity is incompatible blood transfusion and hemolytic disease of the newborn. Farmer’s lung is a type III hypersensitivity reaction. Hence, the option (b) is incorrect.
  • A type IV hypersensitivity reaction is also called delayed hypersensitivity or cell-mediated hypersensitivity; it is a T cell-mediated inflammatory reaction. Farmer’s lung is type III hypersensitivity. Hence, the option (d) is incorrect.
  • Farmer’s lung is a hypersensitivity pneumonitis resulting from a type III hypersensitivity to mold spores. Immune complexes are deposited in lung, where they cause significant tissue damage. Hence, the option (e) is incorrect.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 4MTF
The given statement, “the tuberculin reaction is a type I hypersensitivity” is False.
The tuberculin reaction is a good example of type IV or delayed type hypersensitive reaction, in which T cell-mediated inflammatory reaction takes 24-72 hours to occur. Protein extract of Mycobacterium tuberculosis is injected into the skin of an individual who has been infected with Mycobacterium tuberculosis.
A positive tuberculin test shows hard, red swelling of 10 nm in diameter. Tuberculin reaction is not an allergic reaction or type I anaphylactic hypersensitivity reaction.
Hence, the correct statement is “the tuberculin reaction is a type IV hypersensitivity.”

Microbiology with Diseases by Taxonomy Chapter 18 Answers 4SA
Graft types are named according to the relation between donor and the recipient. A graft is called an autograft when tissues are moved to a different location within the same individual. Foreign antigens are not expressed in autograft; hence they do not trigger immune response. A best example for autograft includes, grafting of skin from one area of the body to another to cover a burn area, (or) use of a leg vein to bypass blocked coronary arteries.
Isografts are grafts transplanted between genetically identical individuals like siblings or clones. The MHC proteins are identical in these individuals; hence the immune system of the recipient cannot differentiate, between the grafted cells and its own normal body cells. Thus Isografts are not rejected since they do not trigger immune response.
Allografts are grafts transplanted between genetically distinct members of the same species. In humans, most of the grafting performed is allograft. Since, the MHC proteins are not same in donor and recipient, it triggers strong type IV hypersensitivity reaction which results in graft rejection. Rejection of graft is suppressed, with immunosuppressive drugs.
Xenografts are grafts transplanted between individuals of different species. Since, the tissues of donor and recipient are extremely different, they trigger a rapid and intense rejection of graft, which is very difficult to suppress. Xenografts from matured animals are not commonly used in therapy. Transplanting a baboon’s heart into a human is an example of xenograft.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 5CT
The illness cause death in patients will combined immunodeficiency:
Explanation
AIDS is a syndrome with several opportunistic or rare infections, associated with several decrease in the number of CD4 cells.

  1. AIDS (acquired immunodeficiency syndrome) causes skin infections like shingles and herpes.
  2. Moreover, diseases of nervous system include meningitis, toxoplasmosis, and disease of the respiratory system, includes tuberculosis, pneumonia, histoplasmosis, and coccidioidomycosis.
  3. Furthermore, disease of digestive system includes diarrhea, thrush, and oral hairy leukoplankia, besides final stages results in dementia.
  4. In AIDS patients, a rare cancer is found in blood vessels called Kaposi’s sarcoma. Hence, persons with AIDS or combined immunodeficiency die due to opportunistic infections.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 5M
Acquired immunodeficiency syndrome (AIDS) is defined as the presence of several opportunistic infections or rare infections associated with a severe decrease in the number of CD4 cells and a positive test showing the presence of human immunodeficiency virus (HIV). This could be ascertained that AIDS is not a hypersensitivity reaction. Hence, the given immune system complication matches with the option E. Not a hypersensitivity.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 5MC
The tuberculin when injected into tuberculosis infected person, a red, hard swelling of about 10 mm or greater in diameter indicates positive tuberculin test. Inflammation reaches greater intensity within 24-72 hours and may persist for several weeks.

  • A patient infected with Mycobacterium tuberculosis when exposed to tuberculosis antigens shows positive tuberculin result. A positive tuberculin skin test indicates that a patient not immunized against tuberculosis (c) has been exposed to tuberculosis antigens.
  • A patient infected with tuberculosis, when exposed to a protein extract of the Mycobacterium tuberculosis, a red, hard swelling of 10 mm or greater in diameter indicates positive tuberculin test. Hence, option (a) is incorrect.
  • A positive tuberculin skin test indicates that a patient not immunized against tuberculosis, when injected with a protein extract of Mycobacterium tuberculosis shows a hard swelling of 10 mm or greater in diameter. It indicates that the patient is having tuberculosis infection. Hence, option (b) is incorrect.
  • A positive tuberculin test indicates that the patient is infected with tuberculosis; it is not that they are susceptible to tuberculosis. They already have the infection. Hence, option (d) is incorrect.
  • If the patient is infected with tuberculosis, a red hard swelling occurs in patient when injected with protein extract of Mycobacterium tuberculosis indicating positive tuberculin test. They are not resistant to tuberculosis. Hence, option (e) is incorrect.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 5MTF
The given statement, “Graft-versus-host disease can follow a bone marrow isograft” is False.
Surgical organ or tissue grafting can be made between genetically dissimilar individuals called as allograft. If it is not treated with immunosuppressive drugs, an organ donor’s cells attack the recipient’s body. Isograft is an organ or tissue graft made between genetically identical individuals.
Hence, the correct statement is “Graft-versus-host disease can follow a bone marrow allograft.”

Microbiology with Diseases by Taxonomy Chapter 18 Answers 5SA
Person producing large amount of IgE experience anaphylactic shock, instead of IgG:
Explanation
Immunosuppressive drugs play a major role in the success of modern transplantation. The four classes of immunosuppressive drugs include glucocorticoids, cytotoxic drugs, cyclosporine, and lymphocyte-depleting therapies.

  1. Glucocorticoids are corticosteroids, used as immunosuppressive agents for many years. Prednisone and methyl prednisolone are examples of glucocorticoids. The drugs suppress the response of T cells to antigen and inhibit T cell cytotoxicity and mechanism of cytokine production.
  2. Cytotoxic drugs inhibit cell division nonspecifically. Cyclophosphamide, azathioprine, mycophenolate mofetil, brequinar sodium, and leflunomide are examples of cytotoxic drugs. Cyclophosphamides cross-link daughter DNA molecules in mitotic cells, preventing their separation and blocking mitosis. It impairs both B cell and T cell responses.
  3. Azathioprine is a purine analog, which competes with purines during the synthesis of nucleic acids. Thus, blocks DNA replication and suppressing both primary and secondary antibody responses. Mycophenolate mofetil is a cytotoxic drug, which inhibits purine synthesis. Brequinar sodium and leflunomide inhibits pyrimidine synthesis to inhibit cellular replication.
  4. Cyclosporine drug is a polypeptide derived from fungi, preventing interleukins and interferon produced by T cells, thereby blocking Th1 responses. Cyclosporine acts on activated T cells. It is less toxic than the other nonspecific drugs. When the drug is given to prevent allograft rejection, only activated T cells attack the graft are suppressed.
  5. Lymphocyte-depleting therapies are used to reduce the adverse side effects of less specific immunosuppressive drugs. One of the techniques includes administering an antiserum called antilympocyte globulin, which is specific for lymphocytes. The modes of action of the therapies are, kills T cells nonspecifically, kills activated T cells, and IL-2 receptors are inhibited.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 6CT
Illnesses that cause death in patients when combines with AIDS:
Explanation
Tissues are different in pigs and humans where matching of tissue is not possible in xenografts. This is because different MHC (major histocompatibility) genes and proteins exist in pigs. Moreover, the xenografts have antigens that will be recognized as non-self.
In addition, Xenografts provoke rapid and intense rejection that is difficult to suppress. Therefore, xenografts require immunosuppressive therapy that leaves the recipient, deadly infections. Hence, xenografts from mature animals are not commonly used therapeutically.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 6M
The grafts are called transplants. The various organs like skin, liver, heart are transplanted within an individual (or) in between the un-related individuals.
There are several types of grafts are used in the transplantation:

  • Autografts (The grafts are transplanted within the individual)
  • Allografts (The grafts are transplanted between the genetically related species)
  • Isografts (The grafts are transplanted between the two genetically related individuals, for example twins )
  • Xenografts (the grafts transplanted between the different species. Those do not have genetic relatedness )

The main reason behind the graft rejection is the immunological reaction between foreign MHC complexes on the surface of host cells and recipient cells. The class I and II MHC proteins are involved in the graft versus host rejection.
When graft (donated) bone marrow T cells may consider the patient’s cells as foreign, mounting an immunological graft rejection against the recipient. It is a good example of type IV hypersensitivity. Thus it could be ascertained that graft-versus-host disease could be associated with type IV hypersensitivity.
6. Graft-versus-host disease (d) Type IV hypersensitivity.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 6MC

  • Systemic lupus erythematosus is a systemic autoimmune disease that affects multiple organs. It is also a type III hypersensitivity in which autoantibodies bind to many autoantigens, especially to the patient’s DNA. Hence, the correct option is (e) Systemic lupus erythematosus.
  • Autoimmune disease is production of autoantibodies or cytotoxic T cells against normal body components. Heart attack is not an autoimmune disease; it is caused mainly due to blockage in arteries. Hence, the option (a) is incorrect.
  • Acute anaphylaxis is caused when massive amounts of histamine are released from degranulating mast cells into the bloodstream. The result of chemicals may exceed the body’s ability to adjust. Autoantibodies ate not produced against normal body components in acute anaphylaxis. Hence, the option (b) is incorrect.
  • Farmer’s lung is one form of hypersensitivity pneumonitis, caused when immune complexes are deposited in the lung. It is a type III hypersensitivity reaction. It is different from autoimmune disease. Hence, the option (c) is incorrect.
  • Graft-versus-host rejection is transplantation of an organ or tissue from a donor to a recipient, in which, the donor tissues are considered as foreign, an immune response against them is elicited and the graft will be rejected. Hence, the option (d) is incorrect.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 7CT
Blisters of tuberculin reactions resemble blisters of ivy poison:
Explanation
Tuberculin skin test and oil of poisonous ivy comes under type IV or delayed type hypersensitivity reaction. They both trigger cell-mediated immune response. Tuberculin is mediated by the response of memory T cells. Additionally, an individual is infected with Mycobacterium tuberculosis, results in cell-mediated immune response to generate memory T cells. In tuberculin test, red, hard swelling, and inflammation reaches greater intensity within 24-72 hours. When the lesions developed are examined microscopically, it reveals infiltration of lymphocytes and macrophages.
Furthermore, oil of poisonous ivy is a highly reactive hapten that binds to any protein it contacts. It includes the proteins in the skin when anyone rubs the plant. The chemically modified skin protein is regarded as foreign, triggering a cell-mediated immune response, and resulting in an intensely irritating skin rash called allergic contact dermatitis. Thus, Tc cells destroy skin cells that become acellular, and fluid-filled blisters develop.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 7M
Milk allergy is caused due to adverse reaction, because of different biochemical constituents of the milk from any lactating animal. The milk allergy, it is a type I hypersensitivity reaction. The type I hypersensitivity occurs due to the allergens binds on IgE antibodies that coated on the mast cells and eosinophils.
Upon binding of allergens to the IgE antibodies on the mast cells causes the release of the histamines. These histamines are mainly, responsible for the allergic responses of an individual.
It is a potentially life-threatening condition. Thus it could be ascertained that milk allergy could be associated with type I hypersensitivity.
7. Milk allergy (a) Type I hypersensitivity.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 7MC

  • A graft is called an auto-graft when tissues are moved to a different location within the same individual. It will not trigger immune response because they do not express foreign antigens. Thus, when a piece of vein from a patient’s leg is transplanted to the same patient’s heart, it is said to be as auto-graft. Hence, the correct option is (b) an autograft.
  • Graft rejection is transplanting an organ or tissue from a donor to a recipient, in which the donor tissues are considered as foreign, an immune response against them is elicited and the graft will be rejected. By transferring a piece of vein from a patient’s leg to the same patient’s heart, the graft will not be rejected. Hence, option (a) is incorrect.
  • Allografts are grafts transplanted between genetically distinct members of the same species. Allografts typically induce type IV hypersensitivity reaction, resulting in graft rejection. Hence, option (c) is incorrect.
  • Type IV hypersensitivity reaction is also known as delayed hypersensitivity reaction in which T cell-mediated inflammatory reaction takes 24-72 hours to reach maximal intensity. It induces immune response, whereas autograft do not trigger immune response. Hence, option (d) is incorrect.
  • When cardiac operation is done for transplanting a piece of vein from a patient’s leg to the same patient’s heart it is called autograft. This will not trigger any immune response. The term cardiograft is not used in this condition. Hence, option (e) is incorrect.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 8M
Type III hypersensitivity is an immune complex mediated response. It can affect the lungs, causing a form of pneumonia called hypersensitivity pneumonitis. Individuals become sensitized, when minute mold spores are inhaled deep into the lungs, stimulating the production of antibodies.
A best example is farmer’s lung, which occurs in farmers chronically exposed to spores from moldy hay. Thus it could be ascertained that Farmer’s lung could be matched only with type III hypersensitivity.
8. Farmer’s lung- (c) Type III hyper sensitivity.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 8MC
Primary immune-deficiencies are associated with defects in adaptive immunity. Some children fail to develop lymphoid stem cells. As a result, they produce neither B cells nor T cells and cannot mount immune responses.

  • A deficiency of both B cells and T cells is most likely (d) a primary immunodeficiency.
  • A secondary immunodeficiency disease affects older individuals who normally have less effective cell-mediated immunity. This leads to increased incidence of both viral diseases and certain types of cancer. Hence, the option (a) is incorrect.
  • A complex immunodeficiency term is not generally used. Immunodeficiency diseases are basically of two types, primary and acquired or secondary immunodeficiency disease. Hence, the option (b) is incorrect.
  • An acquired immunodeficiency disease results from viral infections, which mainly affects older individuals who have less cell-mediated immunity. This also leads to cancer. Hence, the option (c) is incorrect.
  • An induced immunodeficiency term is not generally used. Basically immunodeficiencies are of two types, primary and acquired or secondary immunodeficiency disease. Hence, the option (e) is incorrect.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 9M
Allergens when inhaled may provoke type I hypersensitivity in the lungs, leading to severe difficulty in breathing known as asthma. The disease is characterized by wheezing, coughing, excessive production of a thick, sticky mucus, and muscle constriction in bronchi. Asthma is life threatening, which causes suffocation. Thus it could be ascertained that asthma could be associated with type I hypersensitivity.
The type I hypersensitivity is mainly due to the exposure to an allergen. The type I reaction occurred mainly due to release of the histamines, by the mast cells. These mast cells coated with the IgE antibodies.
The allergens responsible, for the asthma condition are bind on the IgE antibodies, upon binding sensitization takes place. This sensitization process leads to production of histamines responsible, for the inflammation.
9. Asthma – (a) Type I hypersensitivity.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 9MC
Acquired immunodeficiency syndrome (AIDS) is a condition marked by the presence of antibodies against Human Immunodeficiency Virus (HIV) in conjunction with certain opportunistic infections. In AIDS patient there will be severe decrease in the number of CD4 cells. It causes various diseases in skin, nervous system, digestive system, and dementia during final stages.

  • Infection with HIV causes (c) acquired immunodeficiency syndrome.
  • Immunodeficiency diseases are classified as primary immunodeficiency diseases, which are detectable near birth and develop in infants and young children, result from some genetic of developmental defect. Examples of primary immunodeficiency diseases include chronic granulomatous disease, in which a child’s neutrophils are incapable of killing ingested bacteria. Hence, option (a) is incorrect.
  • Hypersensitivity is said to be allergic reaction. Infection with HIV is not due to allergy. It is an immunodeficiency syndrome. AIDS is not a single disease but a syndrome which is associated with several opportunistic infections with a severe decrease in the number of CD4 cells. Hence, option (b) is incorrect.
  • Anaphylaxis is a type I hypersensitivity reaction which gives rise to allergies. HIV infection is not an allergic reaction; it is an acquired immunodeficiency syndrome. Hence, option (d) is incorrect.
  • Neither T- cells nor B-cells are produced in children and cannot mount immune responses. The resulting defect in the immune system causes severe combined immunodeficiency disease. HIV infection causes opportunistic infection, it is a syndrome. Hence, option (e) is incorrect.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 10M
Allergens when inhaled may provoke a response in the upper respiratory tract commonly known as hay fever. It is a type I hypersensitivity reaction which causes mild and localized disease. Hay fever is a local allergic reaction; the symptoms include severe nausea, throat and eye discomfort ness, loss of water through the eyes. Thus it could be ascertained that hay fever could be associated with type I hypersensitivity.
The type I hypersensitivity is mainly due to the exposure to an allergen. The type I reaction occurred mainly due to release of the histamines, by the mast cells. These mast cells coated with the IgE antibodies.
The allergens responsible, for the asthma condition are bind on the IgE antibodies, upon binding sensitization takes place. This sensitization process leads to production of histamines responsible, for inflammation in the respiratory track.
10. Hay fever – (a) the type I hypersensitivity.

Microbiology with Diseases by Taxonomy Chapter 18 Answers 10MC

  • To counteract various hypersensitivities, patients are administered with drugs like antihistamines, bronchodilators, glucocorticoids, and epinephrine. The hypersensitivities specifically counteracts the inflammatory mediators released by degranulating cells in type I hypersensitivity reaction. Hence, the correct option (e) All the above.
  • Antihistamines are administered to counteract histamine. Antihistamines are the drugs administered to counteract the inflammatory mediators released by degranulating cells. It is usually administered to asthma patients. Hence, the correct option is (a) antihistamine.
  • Bronchodilator counteracts the effect of inflammatory mediators in type I hypersensitivity reactions. Asthma patients are prescribed with inhalant containing glucocorticoids and bronchodilators to counteract the effect of mediators. Hence, the correct option is (b) bronchodilator.
  • Glucocorticoids along with bronchodilators are prescribed to counteract the effect of inflammatory mediators in asthma patients. Hence, the correct option is (c) glucocorticoid.
  • Epinephrine is the drug of choice prescribed for patients who suffer from severe type I hypersensitivities. The hormone epinephrine neutralizes the lethal effect of anaphylaxis by relaxing smooth muscle tissue in the lungs, contracting smooth muscle of blood vessels, and reducing vascular permeability. Epinephrine can be injected to patients before their allergic reactions become life threatening. Hence, the correct option is (d) Epinephrine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers

Microbiology with Diseases by Taxonomy Chapter 17 Answers

Microbiology with Diseases by Taxonomy Answers

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1CM
The concept map represented below describes about vaccines. Individuals can be protected against microorganisms by active immunization. Active immunization involves giving antigen in the form of live vaccine, killed vaccines, and toxoid vaccines.
microbiology-with-diseases-by-taxonomy-chapter-17-answers-1cm

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1CT
The disease prevalence and the mortality rate of infected persons are the factors determined. The disease prevalence, explains about the percentage of the disease in a particular population. The mortality rate is an indicator of the death percentage in a particular population per unit time. For example, if the disease causes death only infrequently and does not affect a majority of the population, approval of a vaccine that causes severe illness in 1% of the patients is not ethical.
The cost-benefit ration must be carefully examined in this situation. On the other hand, if the disease infects a large percent of the population, and has a significant mortality rate, a vaccine that causes 1% of patients to be seriously ill should be approved if it protects immunized individuals from contracting a potentially fatal infection.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1L
The fig 1L represents the following explanation:
Antibody is added to ELISA (enzyme linked immunosorbant assay) well. Excess antibody is removed by washing. Gelatin is added to cover any portion of the well, which is not covered by antibody. Moreover, antigen is added, followed by the addition of enzyme-labeled anti-antibodies to the well. The enzyme substrate is added to the well, giving a colored product. Therefore, the color is measured using spectrophotometer.
The chemicals in the picture, represented by artist’s conception of ELISA are, as follows:

  • Gelatin.
  • Substrate.
  • Antibody bound to micro well.
  • Color produced.
  • Enzyme-linked antibody.
  • Antigen in patient’s serum.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1M
Immunoglobulins induces rapid onset of immunity:
Explanation
Immunoglobulins are glycoproteins formed in response to an antigen and react specifically with antigen. The main function of immunoglobulin is protection of body against invading microorganisms. Moreover, immunoglobulins induces rapid onset of immunity. The protective role of antibody includes agglutination, precipitation, neutralization, opsonization, and phagocytosis. Thus, it could be ascertained that induces mainly an antibody response could be associated with immunoglobulin.
Thus, the statement, “induces rapid onset of immunity” matches to the term, “immunoglobulin”.
Hence, the correct option is D. Immunoglobulin.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1MC

  • Immediate immunity against tetanus is achieved if the patient receives antibodies against tetanus toxin. It is otherwise called antitoxins. It comes under passive immunotherapy, where preformed antibodies are administered to the patient. This makes option (d) as the right choice.
  • Attenuated vaccines of Clostridium tetani is an active immunization process in which immunity against tetanus will not be provided immediately. Hence, option (a) is incorrect.
  • A modified live vaccine comes under active immunization, which does not provide immediate immunity against tetanus. Hence, option (b) is incorrect.
  • Tetanus toxoid vaccines are modified using various chemical or thermal methods. These modified toxins can stimulate active immunity and the person cannot obtain immediate immunity against tetanus. Hence, option (c) is incorrect.
  • Subunit vaccines are developed using the antigenic fragments of microbes; it is safer to use subunit vaccines than to use live vaccines, which stimulate active immunity. Hence, option (e) becomes incorrect.
  • In order to obtain immediate immunity against tetanus, a patient should receive immunoglobulin against tetanus toxin (antitoxin). Hence, the correct answer is option (d) immunoglobulin against tetanus toxin (antitoxin).

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1SA
Contrast between Chinese practices of variolation with Jenner’s vaccination:
Explanation
In 12th century, the Chinese started variolation procedure. The children who were recovered from smallpox are not affected from the disease, the second time. They started the technique of infecting young children with particles of ground smallpox scabs from children who survived after mild disease. By adapting this technique, Chinese reduced the population’s overall morbidity and mortality from smallpox. Even though the technique is effective and successful, variolation caused death from smallpox in 1-2% of recipients and in people exposed to recipients. Hence, this procedure was outlawed.
In 1796, an English physician Edward Jenner demonstrated protection against smallpox, by inoculating crusts from a person infected with cowpox. Cowpox is related to smallpox, but causes very mild disease. The new technique was named as vaccination, since cowpox was also called vaccinia. The protective inoculum is called vaccine. Thus, for many years, vaccination against smallpox was widely practiced.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1TF
Passive immunotherapy is the administration of antiserum containing preformed antibodies that provides immediate immunity, but for a shorter time period. Passive immunotherapy does not provide prolonged immunity as in active immunization.
The passive immune therapy is mainly two types:

  • Natural acquired passive immunotherapy
  • Artificial acquired passive immunotherapy

Active immunization involves giving antigen in the form of vaccines, which provides prolonged immunity. The prolonged immunity is maintained with the help of memory B-cells.
Hence, the given statement, passive immunotherapy provides more prolonged immunity than active immunization is FALSE.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 2CT
False negative HIV test results are potentially more damaging than false positives. When a false negative result in a HIV patient, makes him believe that he is HIV negative, unknowingly he spreads the disease to others who are unaware of their risk.
A false negative result deprives the person of early interventions, which can increase their quality of life and perhaps extend their life. In a false positive result, the person becomes mentally stressed. The emotional trauma of a false positive can be considerable, but will fade when further testing demonstrates the person is not infected with HIV.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 2M
Subunit vaccine induces an antibody response:
Explanation
Subunit vaccines are a type of inactivated vaccines. They are produced by antigenic fragments of microbes. They are safer than live attenuated vaccines. Moreover, subunit vaccines are antigenically weak, so they are often administered with adjuvants. The vaccines are recognized by the immune system as exogenous antigens, they stimulate an antibody immune response. Thus, it could be ascertained that subunit vaccines could be associated by inducing an antibody response.
Thus, the statement, “induces mainly an antibody response,” matches to the term, “subunit vaccine”.
Hence, the correct option is C. Subunit vaccine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 2MC

  • Microbes in inactivated vaccines cannot reproduce, they do not present as many antigenic molecules to the body as do live vaccines; therefore, inactivated vaccines are antigenically weak. They are administered in high doses or in multiple doses, or incorporated with materials like adjuvants to increase antigenicity of the vaccine. This makes option (c) as the right choice.
  • In attenuated vaccines, virulent microbes are normally not used, instead the virulence property is reduced, but they are still active and the pathogens no longer cause disease. Pathogens in attenuated vaccine can reproduce, they presents many antigenic molecules to the body that stimulate an immune response. Attenuated vaccine type is not given with an adjuvant. Hence, option (a) is incorrect.
  • A modified live vaccine contains attenuated microbes. These vaccines cause very mild infections but no serious disease under normal conditions. Attenuated viruses in such a vaccine infect host cells and replicate. The vaccines contain active microbes; a large number of antigen molecules are available to stimulate immune response. Modified live vaccine type is not given with an adjuvant. Hence, option (b) is incorrect.
  • Immunoglobulins are raised in our body when exposed to an antigen. They are not incorporated with materials like adjuvants. Hence, option (d) is incorrect.
  • An agglutinating antigen clumps with antibodies specific to it. It does not come under vaccine type and they are not incorporated with adjuvants. Hence, option (e) is incorrect.
  • Therefore, the correct answer is option (c) a chemically killed vaccine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 2SA
Advantages and disadvantages of attenuated vaccine:
Explanation
Attenuated vaccines are live vaccines in which pathogens are weakened, so that they no longer cause disease. The process of reducing virulence is called attenuation. This is done by rising numerous generations of viruses in tissue culture, until they lose the ability to produce disease. Modified live vaccines cause mild infections, but no serious disease under normal conditions. Similarly, attenuated viruses in a vaccine infect host cells and replicate the infected cells to process endogenous viral antigens. As a result, modified live viral vaccines trigger a cell mediated immune response. Individuals vaccinated with modified live vaccine can infect around them, providing contact immunity.
Hence, attenuated vaccines can be hazardous because modified microbes may retain enough residual virulence to cause disease in immunosuppressed people. Pregnant women should not receive live vaccines because of the danger that the attenuated pathogen will cross placenta and harm the fetus. During the year 2000, polio epidemic has occurred in which reversion of an attenuated live virus in oral polio vaccine is formed to virulent poliovirus. Thus, live polio vaccine was no longer used to immunize children in United States.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 2TF
Attenuation is the process of reducing virulence. It is done by rising numerous generations of the culture. The process of inactivating (or) killing is different from attenuating, since killed vaccines cannot replicate, revert, and mutate (or) retain residual virulence. They are safer than attenuated vaccines. It is not standard to attenuate killed virus vaccines. Hence, the given statement, It is standard to attenuate killed virus vaccines is FALSE.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 3CT
It is important that a serologic test reach the market at a reasonable cost. A costly serologic test is little used, no matter how reliable (or) important the results. Health management organizations usually reject expensive tests out of hand, and people who have no health care coverage generally do not have the means to pay.
The less technical skill a test requires the better. A serologic test that is difficult to conduct will produce unreliable results more frequently due to human error. Automation is important for tests that are done frequently, and in large quantities. A person may become bored (or) distracted; a machine does not. Efficient and reliable results are provided by a machine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 3M
Attenuated viral vaccine induces cell mediated immunity:
Explanation
In attenuated viral vaccine, attenuated viruses infect host cells and replicate. Moreover, the infected cells process endogenous viral antigens. As a result, modified live viral vaccines trigger a cell mediated immune response, dominated by type 1 helper T cells (Th1) and cytotoxic T cells (Tc). Since, modified live vaccines contain active microbe, large number of antigen molecules are available to stimulate an immune response. Thus, it could be ascertained that induction of cell-mediated immunity could be associated with attenuated viral vaccine.
Therefore, the statement, “induces well cell-mediated”, matches with the term, “attenuated viral vaccine.”
Hence, the correct option is A. Attenuated viral vaccine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 3MC

  • Vaccinia virus is widely used in attenuated live vaccine. It is administered subcutaneously. It includes poxvirus which causes small pox in humans. Vaccine developed against small pox is done by repeated sub-culturing of small pox antigen. The virulent property is removed and the antigenic property alone will be present. This makes option (b) as the right choice.
  • Coronavirus can be a cause from severe common cold to SARS. Vaccine developed for coronavirus are mostly inactivated viral vaccine. To date, live attenuated vaccine has not been evaluated. Hence, option (a) is incorrect.
  • Influenza virus causes flu disease. The vaccine developed against influenza is inactivated subunit vaccine in which only the antigenic fragment of influenza virus is used for vaccine preparation. This makes option (c) incorrect.
  • Till now no proper vaccine has been developed against retrovirus. Attenuated live vaccination method cannot be applied to develop retroviral vaccine. Hence, option (d) is incorrect.
  • Myxovirus is a group of viruses that cause influenza, mumps, and certain other disease. Killed virus is injected intramuscularly using adjuvant and this is given as vaccine. Therefore, option (e) is incorrect. Hence, the correct answer is option (b) vaccinia virus.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 3SA
Advantages and disadvantages of passive immunotherapy and active immunization:
Explanation
Protection is required by passive immunotherapy with preformed antibodies, during immediate protection. Since, preformed antibodies are removed rapidly from the blood; memory B cells are not produced. Protection is temporary and the recipient becomes susceptible again.
Active immunization provides long-term protection that is capable of restimulation to produce memory cells. When active immunization is initiated before any exposure to Clostridium tetani has occurred, active immunization using tetanus toxoid develops, long-lasting protection that is readily available upon exposure to toxin.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 3TF
HIV infection cannot be diagnosed using a single serological test, since retroviral antigen modifies its epitope often. AIDS is not a single disease, it is a syndrome, and it causes opportunistic infection in patients. Many antibodies against HIV antigen will be produced in AIDS patients, so there are several chances of misinterpretation.
The various test used in the HIV diagnosis are ELISA (Enzyme linked imnuo sorbent assay), Western blotting, Antigen tests, Nucleic acid based tests and CD4-T cell count extra.
The ELISA is a common detective test, where Western blotting is termed as conformation test for HIV. The CD4- T cell test used to know the diagnosis of patient at what stage of disease.
Hence, the given statement, one single serologic test is inadequate for an accurate diagnosis of HIV infection is TRUE.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 4CT

  • In addition to blood serum, the body fluids that may be used for immune testing include urine, saliva, cerebrospinal fluid, sputum, semen, and vaginal secretions. On occasion breast milk might also be used.
  • The urine contains all the catabolic products of the human systems. The estimation of these catabolic products gives indirect information about the primary metabolic compounds and the enzyme activity associated with that particular primary metabolic compounds.
  • The CSF is used for the diagnosis of the fatal bacterial, fungal and viral meningitis disease. The parameters studied in the CSF analysis are the amount of glucose, proteins and WBC analysis.
  • The sputum samples are analyzed for the lung disease caused, by some bacterial species like Tuberculosis.
  • The vaginal secretion is collected for the analysis Sexually transmitted diseases (STD). The STD includes syphilis and HIV.
  • The breast milk is not commonly used, for the clinical diagnosis. It is analyzed, for the detection of lactose in tolerance condition.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 4M
Adjuvants increases antigenicity:
Explanation
Adjuvants are substances that increase effective antigenicity of inactivated vaccine. Moreover, adjuvants are often combined with whole agent vaccines or subunit vaccines. Additionally, adjuvants are chemicals added to increase the ability to stimulate active immunity. Thus, it could be ascertained that increases antigenicity could be associated with adjuvant.
Therefore, the statement, “increases antigenicity,” matches with the term, “adjuvant.”
Hence, the correct option is B. Adjuvant.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 4MC

  • If antigen is excess the amount of precipitate declines. If antigen is too excess than antibody, there will not be any precipitation development. Maximal precipitation does not occur in antigen excess zone. Hence, option (a) is incorrect.
  • When there is excess antibody, each antigen molecule is covered with many antibody molecules, preventing extensive cross-linkage and thus precipitation occurs. Immune complexes are small and soluble if the antibody is excess. Hence, option (b) is incorrect.
  • Maximal precipitation occurs only when there is equal concentration of antigen and antibody. Precipitin line does not occur just by adding antigen to the antibody. Hence, option (d) is incorrect.
  • When an unknown concentration of antibody is added to the antigen, precipitation does not occur. Maximal precipitation occurs only when there is equal concentration of antigen and antibody. Hence, option (e) is incorrect.
  • When the reactants are in optimal proportion, the ratio of antigen to antibody is such that cross-linking and lattice formation are extensive. Thus when antigen and antibody are at equivalent concentration, maximal precipitation occurs. This makes option (c) as the right choice.
  • Hence, the correct answer is option (c) antigen and antibody, are at equivalent concentrations.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 4SA

  • Precipitation tests are one of the simplest serologic tests, which rely on the fact that when antigens and antibody are mixed in proper proportions, they form huge, insoluble, and lattice-like complexes called precipitates.
  • Precipitation tests are often performed in clear gels this is called “immunodiffusion.” In immunodiffusion technique, the antigen and antibody are placed in wells that diffuse out through the agar, where they meet in optimal proportions, and a line of precipitation forms.
  • Another type of precipitation reaction is called “radial immunodiffusion.” In this technique, antigen in solution diffuses from a well into agar, which contains a known concentration of specific antibodies. The diameter of the ring of precipitate that forms around the antigen in the well is directly proportional to the concentration of antigen in the well.
  • Not all antigens are soluble proteins that can be precipitated by antibody. Because of their multiple antigen-binding sites, antibodies can also cross-link particle. Such as whole bacteria (or) antigen-coated latex beads causing agglutination.
  • “Agglutination” involves the clumping of insoluble particles, whereas precipitation involves the aggregation of soluble molecules. Agglutination reactions are easy to visualize and interpret with the unaided eye.
  • Agglutination reaction is caused by “IgM antibodies,” more efficiently than IgG. Hemagglutination is a type of agglutination reaction, used to determine blood type in humans.
  • Another use of agglutination is in a type of test that determines the concentration of antibodies in a clinical sample. The amount of these antibodies, called the titer, is measured by diluting the serum in a process called titration.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 4TF
Enzyme-linked immunosorbent assay (ELISA) has become a test of choice for many diagnostic procedures, such as determination of HIV infection. They are a family of simple serologic tests that can be automated efficiently and read easily, either by direct observation (or) by machine.
The ELISA technique mainly employed in three different methods: Indirect method, sandwich method, competitive method. In these methods the ultimate color product measured by using a spectrophotometer machine. The formed color product is proportional to the antibody present in the serum.
Hence, the given statement, ELISA is very easily automated is TRUE.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 5CT
Cross-reactive antibodies occasionally produce false positive results, when they are used in serological assays. Since, antigens from different sources are similar enough that antibodies reactive to one antigen will also react with the other antigen. Hence, serological test might give a false positive result.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 5M
Subunit vaccine uses antigen fragments:
Explanation
Subunit vaccines are a type of inactivated vaccines. They are produced from antigenic fragments of microbes. However, subunit vaccines are safer than live attenuated vaccines. Thus, it could be ascertained that subunit vaccines could be associated with uses antigen fragments.
Therefore, the statement, “uses antigen fragments,” matches with the term, “subunit vaccine.”
Hence, the correct option is C. Subunit vaccine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 5MC

  • Anti-antibodies are antibodies directed against other antibodies. An anti-antibody is used as secondary antibody to bind with primary antibody bound to an antigen. Hence, option (a) is incorrect.
  • If antibody is not agglutinating then there is no use of using an anti-antibody, because it cannot go and bind to primary antibody. They would be washed off. Hence, option (b) is incorrect.
  • An antibody does not activate complement. Anti-antibody is not used when an antibody does not activate complement. Hence, option (c) is incorrect.
  • When antigen is insoluble, anti-antibodies are not used to make it soluble. Anti-antibodies bind only to primary antibody. Hence, option (d) is incorrect.
  • It is possible to make an antibody that is directed against the antigen binding site of another antibody. This type of antibody is called anti-antibody, which is similar in structure to the original antigen.
  • They both recognize the same antibody. This makes option (e) as the right choice. Hence, the correct answer is option (e) the antigen is an antibody.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 5SA
Human chorionic gonadotropin is a hormone that is released during the early days of pregnancy. The HCG hormone act as biological marker used for the detection of pregnancy.
This hormone is produced only by an embryo (or) fetus. Increased levels of this hormone are found in all pregnant women. Immunochromatographic assay are faster and easier method used for pregnancy testing, which tests for human chorionic growth hormone.
The pregnancy test can be done by taking both urine and serum as samples. This test uses a monoclonal antibody that is specific for the ß sub unit of human chronic gonadotropin.
These monoclonal antibodies detect the enzyme labeled human chronic gonadotropin, and give the products either in color (or) luminescent form.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 5TF
A variation of the ELISA is the western blot test, which is used to detect antibodies against multiple antigens in a mixture. Western blot tests are currently used to verify the presence of antibodies against HIV in the serum of individuals, who are antibody-positive by ELISA. Compared to other tests, western blot tests can detect more types of antibodies and are less subjected to misinterpretation.
The western blotting involves the various techniques, like Electrophoresis, blotting, and ELISA. We can use the western blotting test for the diagnosis and confirmation of infection with HIV and diagnosis of Lyme disease. Hence, the given statement, ELISA has basically replaced the western blot test is FALSE.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 6CT
A test to distinguish between B cells and T cells makes use of antibodies against surface antigens common to all B cells (BCR or other B cell specific molecule) and (or) to T cells (TCR, or other T cell specific molecule).
For example, a fluorescent molecule covalently attached to the constant region of antibodies specific for TCR, added to the mixture of lymphocytes and viewed with a fluorescence microscope. It would illuminate T cells only. The T cells are made visible because of the fluorescent molecule attached to them.
If the test requires both cell types be seen at the same time, two differently colored fluorescent dyes could be used, one on T cells specific antibodies, and the other on the B cell specific antibodies. As long as the antibody concentration is too low for agglutination and no complement factors are present, the T and B cells will not be killed in the process.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 6M
Attenuated viral vaccine uses attenuated microbes:
Explanation
Attenuation is the process of reducing virulence. The most common method for attenuating viruses involves rising for numerous generations in tissue culture cells, until the viruses lose the ability to produce disease. However, attenuated viral vaccines contain attenuated microbes, which cause mild infections, but do not have serious disease under normal conditions. Additionally, attenuated viruses in a vaccine infect host cells and replicate; the infected cells then process endogenous viral antigens. Thus, it could be ascertained that attenuated microbes could be associated with attenuated viral vaccine.
Therefore, the statement, “uses attenuated microbes,” matches the term, “Attenuated viral vaccine.” Hence, the correct option is A. Attenuated viral vaccine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 6MC

  • An anti-antibody test is used to measure the concentration of a specific human antibody. Antibodies directed against other antibodies are called anti-antibodies. Hence, option (a) is incorrect.
  • A complement fixation test is a complex assay used to determine the presence of specific antibodies in an individual’s serum. The test can detect the presence of small amounts of antibody. Hence, option (b) is incorrect.
  • A soluble antigen reacts with antibody to form huge, insoluble, lattice-like complexes called precipitin. Precipitation occurs when antigens are antibodies are in proper proportions. Hence, option (c) is incorrect.
  • An agglutination test involves clumping of particulate antigen with antibody. Many different proteins in serum cannot be analyzed by agglutination test. Hence, option (d) is incorrect.
  • An immunodiffusion test is used to indicate exposure to complex mixture of antigens. When multiple antigens and antibodies are placed in a well, multiple lines of precipitation show antigen-antibody combinations. This makes option (e) as the right choice. Hence, the correct answer is option (e) an immunodiffusion test.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 6SA
Herd immunity is the protection, provided all individuals in a population due to the inability of a pathogen to effectively spread, when a large proportion of individuals of more than 75% are resistant. It is important that patients follow the recommended immunization schedule, not only to protect themselves but also to provide society with herd immunity. Herd immunity only applicable to the diseases which shows contagious patterns.
Pathogens in the attenuated vaccines are weakened so that they no longer cause disease, though they are still alive (or) active and can provide contact immunity in unimmunized individuals who are associated with immunized people.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 7CT
Three ways of genetic recombinant techniques used to develop safer and effective vaccines:
Explanation
Genetic recombinant vaccines provide more effective, cheaper, and safer vaccines. They have been made to improve new vaccines, against pathogens that have been difficult to protect. Using recombinant method, the virulent genes are deleted selectively from pathogen, producing an irreversibly attenuated microbe that cannot revert to virulent pathogen.
The technique used to develop safer and effective vaccines are:

  1. The genetic recombinant technique is used to produce large quantities of pure viral or bacterial antigens in vaccines. In this process, scientists isolate the gene that codes for an antigen and insert it into a bacterium, yeast, or other cell, which expresses the antigen.
  2. Hepatitis B vaccine is manufactures using recombinant yeast cells. Alternatively, a genetically altered microbial cell or virus may itself be used as a live recombinant vaccine.
  3. Another innovative method of immunization involves injection not of antigens, but instead of DNA that codes for antigen. For example, the DNA coding for a pathogen’s antigen can be inserted into a plasmid vector, which is then injected into the body.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 7MC

  • In direct fluorescent antibody test, the serum used is not inactivated by heat. Instead, the sample containing suspected antigen is flooded directly with labeled antibody. Hence, option (a) is incorrect.
  • The serum containing suspected antigen is flooded with fluorescent dye labeled antibody. If the suspected antigen is specific to labeled antibody, it fluoresces when observed under fluorescent microscope. The serum is not labeled with fluorescent dye, instead antibodies are labeled. Hence, option (b) is incorrect.
  • Direct fluorescent antibody test are performed to determine specific antigen when labeled antibodies are flooded over it. It requires a fluorescent dye. Hence, option (c) is incorrect.
  • A direct fluorescent antibody test does not require heated plasma. Here, antigen is directly flooded with fluorescent dye labeled antibodies. Hence, option (d) is incorrect.
  • Fluorescent labeled antibodies are those chemically linked to a fluorescent dye. The test can be direct and indirect fluorescent antibody tests. In direct fluorescent antibody tests, tissue sample containing suspected antigen are flooded with labeled antibody and observed under fluorescent microscope. If suspected antigen is present, it fluoresces. This makes option (e) as the right choice.
  • Hence, the correct answer is option (e) antibodies against the antigen.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 8CT
Difference between toxoid vaccine and attenuated vaccine:
Explanation
The following table depicts the difference between toxoid vaccine and attenuated vaccine:
microbiology-with-diseases-by-taxonomy-chapter-17-answers-8ct

Microbiology with Diseases by Taxonomy Chapter 17 Answers 8MC

  • ELISA is abbreviated as Enzyme-Linked Immunosorbent Assay. It uses enzyme labeled antigen-antibody, which binds to antibodies attached to the antigen of interest. The intensity of color indicates positive test when the enzyme labeled antigen-antibody reacts with its substrate. This makes option (a) as the right choice.
  • ELISA is abbreviated as Enzyme-Linked Immunosorbent Assay. Instead of a dye, enzyme is used which reacts with substrate to produce a colored product. a radioactive anti-antibodies are not used in ELISA. Hence, option (b) is incorrect.
  • Complement is not used in ELISA test. Only enzyme labeled antibody is used which reacts with antibody-antigen complex and produces color. Hence, option (c) is incorrect.
  • In ELISA test the well is coated with performed antigen which reacts with sample containing antibody against the specific antigen. Antigen-antibody labeled with an enzyme was added later. Hence, option (d) is incorrect.
  • Antibody present in the sample reacts with antigen, which is already coated in well. When Antigen-Antibody labeled with an enzyme reacts with substrate then Ab binds to Ag, and produces color. An enzyme is labeled with antigen-antibody and not with antibody present in sample. Hence, option (e) is incorrect.
  • Thus, the correct answer is option (a) an enzyme-labeled anti-antibody.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 9CT
Health organizations promote breast feeding of newborns to provide natural immunity.
Explanation
Breast feeding is very important for newborns. There are specific and innate immune factors present in mother’s milk to provide specific protection against pathogens in infants. In addition, immune factors in milk provide protection against microbial infections such as Haemophilus influenzae, Streptococcus pneumoniae, Vibrio chlorae, Escherichia coli, and rotavirus.
Hence, health organizations promote breast feeding of newborns because mother’s milk provide natural immunity to baby.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 9MC

  • Direct fluorescent antibody test is performed to determine the presence of suspected antigen, which is specific to labeled antibody. When flooded with fluorescent labeled antibody to tissue sample containing suspected antigen, fluorescence indicate that antigen is specific to labeled antibody. This makes option (b) as the right choice.
  • Direct fluorescent antibody test is used to detect the presence of suspected antigen. The fluorescent labeled antibody gives fluorescence, if the labeled antibody is specific to antigen. Haemagglutination is the clumping of red blood cells. Hence, option (a) is incorrect.
  • Direct fluorescent antibody test is used to detect the presence of tissue sample containing specific antigen. It is not done to detect the presence of antibody. Hence, option (c) is incorrect.
  • Complement is a heat-liable serum protein. In complement fixation test, we detect the presence of specific antibodies in an individual’s serum. Hence, option (d) is incorrect.
  • Antigen-antibody complexes are not precipitated in direct fluorescent antibody test, instead they fluorescence since we label antibody with a fluorescent dye. When this labeled antibody binds to specific antigen it fluoresces. Hence, option (e) is incorrect. Hence, the correct answer is option (b) specific antigens.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 10CT
Contrast between hemagglutatination tests with viral hemagglutination inhibition test:
Explanation
The below table depicts the differences between hemagglutatination tests with viral hemagglutination inhibition test:
microbiology-with-diseases-by-taxonomy-chapter-17-answers-10ct

Microbiology with Diseases by Taxonomy Chapter 17 Answers 10MC

  • Agglutination test is done to detect pregnancy and to diagnose salmonellosis, brucellosis, gonorrhea, rickettsial infection, mycoplasma infection, yeast infection, typhoid fever, meningitis caused by Hemophilus. Hence, option (a) is incorrect.
  • Hemagglutination inhibition is performed to diagnose viral infections like influenza, but it is not used to detect rabies virus in the brain of a dog. Hence, option (b) is incorrect.
  • Virus neutralization is performed to diagnose infections by specific strains of virus, but not specifically to detect rabies virus in the brain of a dog. Hence, option (c) is incorrect.
  • Western blot is performed to verify the infection HIV and to diagnose lyme disease. Hence, option (d) is incorrect.
    • Direct immunofluorescence test is performed to detect rabies virus in the brain of a dog. The fluorescent dye labeled antibody binds to specific antigen in tissue sample and it fluoresces. This makes option (e) as the right choice. Hence, the correct answer is option (e) direct immunofluorescence.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 11CT
Medical personnel have eliminated the problem by switching on to inactivated polio vaccine:
Explanation
Attenuated oral polio vaccine (OPV) is very effective, as it causes clinical poliomyelitis, for every 1 in 2 million recipients or close contacts. However, attenuated viruses occasionally cause disease. It is not only found in fetuses and immunosuppressed patients, but also in healthy children and adults. Hence, medical personnel have eliminated the problem by switching on to inactivated polio vaccine (IPV).

Microbiology with Diseases by Taxonomy Chapter 17 Answers 11MC

  • The virulence of the pathogen is reduced so, that the pathogen no longer causes disease. Attenuation is the process of reducing virulence by raising them for numerous generations in tissue culture cells until the virus loses the ability to produce disease. This makes option (a) as the right choice.
  • Attenuation is the process of reducing virulence. It is not a necessary step in vaccine manufacture. Hence, option (b) is incorrect.
  • A thin scraping from recovered children is injected into deliberately infecting young children, this procedure is called variolation. It is different from attenuation procedure. Hence, option (c) is incorrect.
  • Adjuvants are substances that enhance antigenicity. Adjuvants are entirely different from attenuation since, attenuation is done to reduce virulence of a particular pathogen. Hence, option (d) is incorrect. Attenuation is (a) the process of reducing virulence.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 12MC

  • An anti-antibody is an antibody often labeled with an enzyme that binds to primary antibody. Antiserum is different from antibody because antiserum binds to antigen, which triggers immune response. Hence, option (a) is incorrect.
  • An inactivated vaccine (or) killed vaccine is where the antigen is killed and given as vaccine, which provides immunity to that particular antigen. Antiserum is different from inactivated vaccine, since it is produced in our body against particular antigen. Hence, option (b) is incorrect.
  • Antiserum is blood serum containing polyclonal antibodies. Monoclonal antibodies are secreted by clones originated from a single plasma cell. Scientists have overcome the limitations of antisera by developing monoclonal antibodies. Hence, option (c) is incorrect.
  • An antiserum is the liquid portion of blood which is otherwise called as “immune serum.” Antisera are typically collected from human blood plasma when exposed to an antigen. Antiserum contains polyclonal antibodies; they are particularly effective against pathogens which are capable of evading the immune system. This makes option (d) as the right choice.
    An antiserum is (d) the liquid portion of blood used for immunization.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 13MC

  • Hybridomas are developed by fusing myeloma cells and antibody-secreting plasma cells. Each hybridomas divides continuously to produce clones of itself, and each clone secretes large amounts of a single antibody molecules. These identical antibodies are called monoclonal antibodies because they are secreted by clones originating from a single plasma cell. This makes option (a) as the right choice.
  • Monoclonal antibodies are identical antibodies secreted by clones of single plasma cell. Each clone secretes large amount of a single antibody molecules. This makes option (b) as the right choice.
  • Hybridomas are maintained in tissue culture to produce the antibodies needed for passive immunotherapy. Monoclonal antibodies are used to treat newborns infected with respiratory syncytial virus. Thus, monoclonal antibodies can be used for passive immunization. This makes option (c) as the right choice.
  • Monoclonal antibodies are produced by fusion of myeloma cells with plasma cells results in hybridomas, the source of monoclonal antibodies. They are identical antibodies secreted by clones of single plasma cell. Monoclonal antibodies produced are used in passive immunization. This makes option (d) as the right choice. Monoclonal antibodies (d) all the above.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 14MC

  • Attenuation is the process of reducing virulence. This process used in the vaccine production. It is not the study of antibody-antigen interactions in blood. Hence, option (a) is incorrect.
  • Agglutination tests involve the clumping of insoluble antigenic particles by antibodies. Hence, option (b) is incorrect.
  • Precipitation test involves mixing of soluble antigens with antibody in proper proportions, they form huge, insoluble, and forms lattice-like complexes called precipitates. Hence, option (c) is incorrect.
  • Serology is the study and use of immunological tests to diagnose and treat disease and to identify “antibody-antigen interactions” in the blood. This makes option (d) as the right choice. The study of antibody-antigen interaction in the blood is (d) serology.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 15MC

  • Anti-human antibody antibodies are not found in immunocompromised individuals. Immunocompromised individuals are susceptible to various diseases since their immunity will be low. Antibodies against human antibodies are called anti-human antibody antibodies. Hence, option (a) is incorrect.
  • Direct fluorescent antibody tests identify the presence of small amount of antigen in patient’s tissue. Labeled antibody is flooded over the antigen and examined under fluorescent microscope. Hence, option (b) is incorrect.
  • When purified human antibodies are injected into a rabbit stimulate the rabbit to produce rabbit antibodies against the human antibodies. Such antibodies directed against other antibodies are called anti-antibodies. Hence, anti-human antibody antibodies are formed by animals reacting to human immunoglobulins. This makes option (c) as the right choice.
  • ELISA is a simple test that can be readily automated and read by machine. These tests are among the most common serologic tests used. It is not an alternative method for anti-human antibody antibodies. Hence, option (d) is incorrect. The correct answer is option (c) formed by animals reacting to human immunoglobulins.