Microbiology with Diseases by Taxonomy Chapter 10 Answers
Microbiology with Diseases by Taxonomy Answers
Microbiology with Diseases by Taxonomy Chapter 10 Answers 1CM
The following concept map can be generated when describing antimicrobial resistance:
Microbiology with Diseases by Taxonomy Chapter 10 Answers 1CT
Cocktail is a combination of several antiviral drugs, which are used to treat AIDS (acquired immune deficiency syndrome) and are more effective than using a single agent. This is because the HIV (human immune deficiency virus) will mutate or change a lot. So, using single drug can be effective against one mutation. By using cocktail of drugs it is easy to attack the virus at different points in the life cycle of virus and the patient compliance in taking the medicine is improved.
There are different sites of inhibition like:
- Inhibition at viral fusion into the cell.
- Reverse transcriptase enzyme inhibition.
- Protease enzyme inhibition.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 1L
Aminoglycosides: are amino modified sugars that changes shape of 30S sub-unit causing incorrect pairing of transfer Ribonucleic acid or tRNA anticodons with messenger Ribonucleic acid or m RNA codons. Hence, the correct answer is Aminoglycosides.
Antisense nucleic acids: blocks ribosome attachment to messenger Ribonucleic acid or mRNA.
Hence, the correct answer is Antisense nucleic acids.
Chloramphenicol: blocks enzymatic activity of the 50S subunit and preventing the formation of peptide bonds between amino acids. Hence, the correct answer is Chloramphenicol.
Lincosamides or macrolides: they bind to 50S subunit and blocking proper m RNA movement through ribosome. Hence, the correct answer is Lincosamides or macrolides.
Tetracycline: It is an antibiotic produced from a genus of actinobacteria, known as streptomyces. It block docking site of transfer Ribonucleic acid or tRNA. Hence, the final answer is Tetracycline.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 1MC
- For the effective treatment of diseases that are infectious. The physicians must be familiar with the specificity of effectiveness, about the pathogen. To access the microbial efficacy variety of test are included, like diffusion test. Hence, the option (a) is incorrect.
- Dilation susceptibility test includes Kirby-Bauer test. The test reveals the action of effectiveness of most of the drugs towards the particular pathogen. Moreover, the zone of inhibition is greater than the drug-soaked disk of petri plate. The effectiveness of the drug is known. Hence, the option (b) is correct.
- When drug act on number of pathogens of different types, it is said to be spectrum of action. Moreover, drugs acting on specific kinds of pathogens that are causing disease are called narrow-specific drugs. In addition, drugs that are effective to various kinds of pathogens are called as broad-spectrum drugs. Hence, the option (c) is correct.
- Diffusion and dilution tests that expose pathogens to antimicrobials are designed to determine, which drug is most effective and determines the amount of drug to use against particular pathogens. Hence, the correct option is (d) both (b) and (c).
Microbiology with Diseases by Taxonomy Chapter 10 Answers 1SA
The important characteristics of ideal chemotherapeutic agent are:
Explanation
An ideal chemotherapeutic agent is readily available, inexpensive, non-toxic, and non-allergenic. Moreover, they are chemically stable and selectively toxic against pathogens. No drug has all these qualities.
There are generally 5 ways, which chemotherapeutic agents damage or kill bacterial pathogens. They include cell wall synthesis inhibition, protein synthesis inhibition, nucleic acid synthesis inhibition, cell membrane disruption, and inhibit metabolites produced in the bacteria.
The following ways are shown how chemotherapeutic agent disrupts pathogen:
- Antibiotics inhibit the synthesis of bacterial cell walls. Those structures are thought to interfere with the bacterial enzyme that catalyzes the transpeptidation reaction, which forms peptidoglycan links in the cell wall.
- Antibiotics stop protein synthesis by binding to bacterial ribosome, as well as other components of protein synthesis. Thus, halts the processes like transcription or translation.
- Antibiotics inhibit synthesis of nucleic acids in two ways. One way is inhibiting DNA polymerase and DNA helicase, which halts replication. Another way is inhibiting RNA polymerase to stop transcription
- Antibiotics interfere with bacteria’s cell membrane by binding to the cell membrane to disrupt the structure and permeable capabilities.
- Antibiotics block the metabolic processes of bacteria antimetabolites. They interfere with the processes by acting as a strong competitive inhibitor to various enzymes.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 2CT
Penicillium is a mold belongs to fungus. Penicillin secreted by the Penicillium acts against bacterial cell wall and toxic to the bacteria, but not to fungus. The cell wall of bacteria is made up of peptidoglycan; penicillin blocks the formation of peptidoglycan. Fungus is a eukaryote and doesn’t contain peptidoglycan. So, penicillin cannot act against Penicillium. By this way Penicillium escapes the effects of penicillin it secretes.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 2MC
- For the effective treatment of diseases that are infectious. The physicians must be familiar with the specificity of effectiveness, about the pathogen. To access the microbial efficacy variety of test are included, like diffusion test. In Kirby-Bauer susceptibility test, the presence of a zone of inhibition around disks containing antimicrobial agents indicates that the microbe does not grow in the presence of the agents. Zone of inhibition is greater and the drug is effective. So, the Kirby-Bauer susceptibility test does not depend upon the microbe that grows well in the presence of agents, smallest amount of the agent that inhibit microbe growth, and minimal amount of an agent. Hence, option ‘b’, ‘c’, and ‘d’ is incorrect.
- Dilation susceptibility test includes Kirby-Bauer test. The test reveals the action of effectiveness of most of the drugs towards the particular pathogen. Moreover, the zone of inhibition is greater than the drug-soaked disk of petri plate. The effectiveness of the drug is known. Zone of inhibition is a clear region where bacteria do not grow. It is measured as the diameter of the clear region, if larger the zone of inhibition, the more effective the drug is. Hence, the correct option is (a) that the microbe does not grow in the presence of the agents.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 2SA
Difference between narrow spectrum and broad spectrum drugs:
Explanation
When drug act on number of pathogens of different types, it is said to be spectrum of action. Moreover, drugs acting on specific kinds of pathogens that are causing disease are called narrow-specific drugs. In addition, drugs that are effective to various kinds of pathogens are called as broad-spectrum drugs. For the effective treatment of diseases that are infectious. The physicians must be familiar with the specificity of effectiveness, about the pathogen. To access the microbial efficacy variety of test are included, like diffusion test.
Narrow spectrum: The drugs works against few kinds of pathogens, but not to all pathogens.
For example, polymyxin act against gram negative bacteria and penicillin can act only on gram positive bacteria.
Broad spectrum: The drugs work against different kinds of pathogens.
For example, tetracycline acts against gram negative and gram positive bacteria.
Hence, broad spectrum antibiotics are more effective when compared with narrow spectrum antibiotics. It is not desirable to use the drugs regularly because these may cause secondary infections.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 3CT
Bacillus licheniformis secretes bacitracin, which is an antimicrobial agent that inhibits cell wall formation. Bacillus licheniformis escapes the effects of its own bacitracin because they are resistant to it. This resistance prevents entry of bacitracin into the cell. Those bacteria which lack alanine-alanine cross-bridges are naturally resistant to this drug.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 3MC
- For the effective treatment of diseases that are infectious. The physicians must be familiar with the specificity of effectiveness, about the pathogen. To access the microbial efficacy variety of test are included, like diffusion test. Hence, the option (b) is incorrect.
- The effectiveness of the drug is known. Zone of inhibition is a clear region where bacteria do not grow. It is measured as the diameter of the clear region, if larger the zone of inhibition, the more effective the drug is. Hence, the option (c) is incorrect.
- When drug act on number of pathogens of different types, it is said to be spectrum of action. Moreover, drugs acting on specific kinds of pathogens that are causing disease are called narrow-specific drugs. In addition, drugs that are effective to various kinds of pathogens are called as broad-spectrum drugs. Hence, the option (d) is correct.
- Selective toxicity refers to the ability of a chemotherapeutic agent to inhibit or kill a pathogen, while causing little or no harm to the host. It is expressed in two terms:
- Therapeutic dose or the amount of drug to treat a disease.
- The amount of drug in which it becomes toxic for the host.
- The key to successful chemotherapy is selective toxicity against microbes and harmless to humans.
Hence, the correct option is (a) selective toxicity.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 3SA
Drug Z destroys NAM part of cell structure:
Explanation
Peptidoglycan is a complex compound that is a key component of the cell wall of bacteria. It is is made up of long sugar (glycan) groups that are attached to amino acid chains. These glycan chains are made of N-acetylmuraumic acid (NAM) and N-acetylglucosamine (NAG). The amino acid chains are covalently cross-linked to one another creating a layered structure of amino acids and sugars; hence, the name peptidoglycan. Peptidoglycan provides the structural support, for the cell wall.
Similarly, NAM is a component of bacterial cell wall, which is absent in human cell membrane. So, drug Z targets only NAM, which is present in bacteria and can be used in chemotherapy.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 4CT
Despite wide variety of known antibiotics less than 1% of drugs have practical value in treating the diseases. This is because the morphological characters for prokaryotes are similar and the drug targets for most of the antimicrobials are same. So, these drugs have both medical and commercial value in treating the variety of diseases.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 4MC
- Sulfonamides drugs are produced first produced in the form of dye. They are analogs of PABA, which are capable of binding to the enzyme irreversibly by forming dihydrofolic acid. They are specific to spectrum of action and effective against the bacteria, protozoa, and fungi; however the importance of the drugs is widespread. Hence, the option (a) is incorrect.
- Sulfonamides are effective because humans and microbes use folic acid and PABA differently in their metabolism. Sulfonamide is a structural analog of para-aminobenzoic acid, which is needed for nucleic acid synthesis in bacteria. Hence, the option (d) is incorrect.
- Sulfonamides are analogs in structure to PABA, which differs from humans. Thus, the drugs prevent the amino acids incorporation into polypeptide chains. Hence, the option (b) is incorrect.
- In humans PABA (para-amino benzoic acid) is not essential and folate should be taken from diet. So, the metabolic process involved in both human and microbes are different and the targets are different for antimicrobial agent to act.
Hence, the correct option is (c) humans and microbes use folic acid and PABA differently in their metabolism.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 4SA
Antimicrobial agents target on ribosomal sites of human cells and pathogens:
Explanation
Targets for antimicrobial agents differ in the ribosome subunits for both humans and pathogens. Pathogens have 70S ribosomes with 30S and 50S subunits and humans have 80S ribosomes with 60S and 40S subunits. Antimicrobial agents selectively targets bacterial protein synthesis in different steps. Due to this difference in the ribosomes of humans and pathogens there is no problem in the process of protein synthesis for humans. Moreover, it is safer to use antimicrobial agents even though mitochondria of humans contain 70S ribosomes with fewer side effects.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 5CT
The possible ramifications or complications for usage of antimicrobials against infections caused by the moths and butterflies are development of resistance to the infections. Over usage of such antimicrobials causes toxicity. Ciprofloxacin is generally used by moths and butterflies collectors, which is recommended by Lepidopterists society in 2000.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 5MC
Cross resistance takes place when the resistance to one chemotherapeutic agent confers resistance to similar drugs. Whereas, multiple drug resistant pathogens are resistant to many types of antimicrobial drugs. Thus, cross resistance does not include: the deactivation of an antimicrobial agent by bacterial enzyme, mutation of genes that affect the cell membrane channels, and alteration of resistant cells. Hence, the options (a), (b), and (c) are incorrect.
Cross resistance is defined as resistance that typically occurs when one antimicrobial agent may confer resistance to similar type of drugs. It generally occurs when drugs are similar in their structure. For example, resistance to one aminoglycoside drug like streptomycin can confer resistance to similar aminoglycoside drug. Hence, the correct option is (d) resistance to one antimicrobial agent because of its similarity to another antimicrobial agent.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 5SA
Antimicrobial agents produce resistant cells:
Explanation
Antimicrobial agents induce some enzymes, which can destroy the drugs and make the process slow or prevent the entry of drug. Moreover, it can alter the target of the drug, which can alter in metabolic chemistry, and pump the antimicrobial agent out of the cell before drug can act. Thus, according to these considerations antimicrobial agents produce resistant cell where drugs cannot act further.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 6CT
Gentamicin has wide range of activity against both gram positive and gram negative bacteria. Even though they cause deafness these are used for the treatment of pneumonia and is the better choice of drug to treat this disease. Gentamicin exclusion assay is carried out and the activity of drug against the disease is calculated; and is fixed to be as a better choice of drug for pseudomonas infection.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 6MC
- Multiple-drug-resistant pathogens are called as superbugs that are resistant to three to more against antimicrobial agents. Thus, multiple-drug-resistant microbes are not resistant to all antimicrobial agents, and do not respond to new antimicrobial agents. Hence, option (a) and (b) are incorrect.
- Multiple-drug-resistant microbes are resistant to three or more types of antimicrobial agents. Examples include multiple-drug resistant strains of Staphylococcus, Streptococcus, Enterococcus, Pseudomonas, Mycobacterium tuberculosis, and Plasmodium are resistant to two or more different types of antimicrobial agents. They develop resistance generally in hospitals. Hence, the correct option is (c) frequently develop in hospitals.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 6SA
Pathogen resistant strains are related to general development of persons:
Explanation
There are several methods to prevent development of resistance against antimicrobial drugs:
- Allow your body to defeat pathogen on their own, so that drug can be maintained in a patient’s body for long time. Moreover, destroys all sensitive cells and inhibit others for the body’s defense to defeat them.
- Using combination therapy with other antimicrobial agents. Some drugs enhance the effect of other drug in a process called synergism.
- Limit the use of antimicrobials to necessary cases, so that unwanted usage of drugs can be reduced.
- Using new generation drugs like second and third generation drugs, which are less resistant.
- Using full course of antibiotics.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 7CT
Pregnant and nursing women should not take tetracycline for sore throat infection because tetracycline is a broad spectrum antibiotic used to treat sore throat. It has mutagenic qualities, which can cause damage to the unborn child. It passes into breast milk and cause bone problems and teeth staining in nursing women. It causes a baby to be more sensitive to sunlight and increase the risk of fungal infections. Hence, the decision taken is a poor one.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 7MC
Vancomycin is a chemical compound, which has action on bactericidal agent and capable of killing bacteria. Thus, Vancomycin is an example of bactericidal agents that is capable of disrupting cell wall formation of Gram-positive bacteria. Thus, the option (b) is incorrect.
Bacitracin do not have beta-lactam ring in their structure. Moreover, blocks NAG and NAM transport from cytoplasm. Thus, the option (c) is incorrect.
Isoniazid is the most widely used drug in the treatment of tuberculosis. Its studies have shown that they inhibit a crucial enzyme in tuberculosis bacterium. A covalent adducts is formed between carbonyl of isoniazid and nicotinamide ring of the NAD molecule. Thus, the option (d) is incorrect.
Penicillin generally associates with beta-lactam ring. It is the functional portion of the drug, which shows antimicrobial activity by interfering the disruption of bacterial cell wall. Bacitracin, vancomycin, and isoniazid do not have beta-lactam ring in their structure. Hence, the correct option is (a) penicillin.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 7SA
Antiviral drugs are difficult to develop:
Explanation
Antiviral drugs or medicines will inhibit the lifecycle of virus. These medicines will make the virus less likely to replicate; thus, used to slow down the rate of infection. In addition, they also prevent the influenza virus from leaving the infected cell.
Furthermore, viruses generally utilize host cells enzymes and ribosomes for the metabolism and replication. They are present inside human cells; so, drugs have to penetrate human cells to act against viruses, which are harmful for human cells. Thus, antiviral drugs are difficult to develop as they destroy human cells.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 8CT
Acyclovir has replaced Adenosine arabinoside to treat herpes virus infection because Adenosine arabinoside is fatal to host cells, as they incorporate the drug into cellular DNA (deoxyribonucleic acid). It also causes anemia. Acyclovir is phosphorylated by virally coded kinase enzyme, which activates the drug.
Adenosine arabinoside is phosphorylated by cell-coded kinase enzyme, which activates the drug. Due to these adverse effects shown by adenosine arabinoside it is replaced with acyclovir. Acyclovir is a better choice because it inhibits both DNA and RNA (ribonucleic acid) synthesis and has no adverse effects like adenosine arabinoside.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 8MC
Aminoglycosides acts against protein synthesis. They irreversibly bind to 30S subunit of prokaryotic ribosomes, causing ribosome to mistranslate mRNA and stop the protein synthesis.
Beta-lactams inhibit bacterial cell wall, polymyxin destroys cytoplasmic membranes of susceptible cells, and trimethoprim interferes with the bacterial nucleic acid synthesis. Hence, the correct option is (d) aminoglycosides.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 8SA
Broad-spectrum drugs therapy causing unintended consequences:
Explanation
Broad-spectrum drugs have a wide range of effectiveness; they are effective against a wide array of pathogen types. While some are very effective, the types of drugs tend to have a lower therapeutic index, since they are, so broad and target a wide range of processes to disrupt in a pathogen. Additionally, broad-spectrum antibiotic can act against wide range of bacteria like both gram positive and gram negative bacteria. This may destroy or kill the normal gut flora, which reduces microbial antagonism leading to development of secondary or super infections.
Thus, development of secondary infections is the unintended consequences that can arise from therapy.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 9CT
Amphotericin B is a polyene antifungal drug that is extracted from Streptomyces nodosus. This drug targets renal vasculature and make them constrict to reduce the glomerular filtration rate by more than half. There is an increase in creatinine is observed during the use of amphotericin B. So, it affects mainly kidneys rather than other parts in the body.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 9MC
Drugs that neutralize the acidity of phagolysosomes prevent viral coating. Moreover, nucleotide analogs act in deoxyribonucleic acid synthesis like nucleosides. They include antiviral products that can be used to stop viral replication. Thus, drugs containing protease inhibitors retard viral growth by blocking essential viral proteins. Hence, the options (b), (c), and (d) are the correct statements.
Macrolides contains macrocyclic lactone ring. It shows its action by binding to 50S subunit of prokaryotic ribosomes. Moreover, inhibits preventing in elongation of nascent protein. So, the statement macrolide drug that blocks attachment sites on host cell wall prevent viruses from entering, is false statement.
Hence the correct option is (a) macrolide drug that blocks attachment sites on the host cell wall and prevent viruses from entering.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 9SA
Similarities and differences between the following compounds:
Explanation
Polyenes:
The compounds disrupt cytoplasmic membrane in the cells and cause lysis to cells. The compounds associate with the molecules of ergosterol forming a pore through the fungal membrane, which leads to leakage of essential ions from the cells. For instance; Nystatin and Amphotericin B
Azoles:
The compounds inhibit the synthesis of ergosterol and disrupt cytoplasmic membrane. Hence, the cell membrane doesn’t remain intact and fungal cell dies; for instance, fluconazole, and ketoconazole.
Allyamines:
The compounds inhibit the synthesis of ergosterol; for instance, terbinafine.
Polymyxin:
The compounds disrupt lipid bilayer of cytoplasmic membrane in gram negative bacteria and are toxic to humans; for instance, Bacillus and polymyxa.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 10CT
Benzimidazole derivatives have many therapeutic uses including antifungal, antitumor, analgesics, antiviral, antiparasitic and antihistamine etc. These drugs act by inhibiting the microtubule formation and glucose uptake. Microtubules are formed by the polymerization of tubulin proteins. This polymerization is necessary for mitosis. During mitosis chromosome arranged on a metaphase plate are distributed equally to the two cells by the pulling action of microtubules. If the polymerization of microtubules is ceased, then mitosis cannot be completed.
The same microtubules constitutes the flagella, hence blockage of tubulin polymerization results in the dis-functioning or formation of impaired flagella.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 10MC
PABA is para-amino benzoic acid. It is structurally similar to sulfonamides. Moreover, PABA is required in the synthesis of nucleic acids like DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) of many organisms. During the process of degradation, most of the organisms convert PABA to dihydrofolic acid to tetrahydrofolic acid and then to folic acid. Folic acid is used as a coenzyme in the synthesis of purines and pyrimidines.
Since, PABA is required in the synthesis of nucleic acids like DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) of many organisms. Thus, it is not a substrate used in the production of penicillin; it is not a type of beta lactamase, and its molecular is not similar to cephalosporins
Hence the correct option is (d) used to synthesize folic acid.
Microbiology with Diseases by Taxonomy Chapter 10 Answers 10SA
Difference between antagonists and synergism:
Explanation
Antagonists:
These agents interfere with the other drugs or any attachment of viruses to the host. For example, penicillin’s act only against growing and dividing cells.
Synergism:
These agents enhance the effect of second drug, which is used in combination. For example, penicillin makes streptomycin molecule easier to enter bacteria for protein synthesis.
Drugs are classified as agonists, whereas some other drugs are classified as antagonists;
- Sumatripan is sold as Imitrex, which is an effective in treating migraine headaches. It acts as an agonist at the serotonin receptor. The effect of Imitrex prolongs the effect of serotonin.
- Ondansetron is sold as Zofran, acts on a subclass of serotonin receptors to inhibit nausea and vomiting. It is frequently prescribed to patients in chemotherapy. It acts as an antagonist at the receptors. The effect of Zofran blocks the response at the receptor.