BackWhat specific test for antimicrobial efficacy is shown? What does this test measure? Draw an oval to predict the size and shape of the zone of inhibition if the drug concentration on the strip were increased twofold.
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In a Kirby-Bauer susceptibility test, the presence of a zone of inhibition around disks containing antimicrobial agents indicates __________ .
a. That the microbe does not grow in the presence of the agents
b. That the microbe grows well in the presence of the agents
c. The smallest amount of the agent that will inhibit the growth of the microbe
d. The minimum amount of an agent that kills the microbe in question
Describe three types of microbes that are extremely resistant to antimicrobial treatment, and explain why they are resistant.
Which of the following statements is false concerning antiviral drugs?
a. Macrolide drugs block attachment sites on the host cell wall and prevent viruses from entering.
b. Drugs that neutralize the acidity of phagolysosomes prevent viral uncoating.
c. Nucleotide analogs can be used to stop microbial replication.
d. Drugs containing protease inhibitors retard viral growth by blocking the production of essential viral proteins.
Which class of surfactant is most soluble in water?
a. Quaternary ammonium compounds
b. Alcohols
c. Soaps
d. Peracetic acids
Which of the following is most closely associated with a beta-lactam ring?
a. Penicillin
b. Vancomycin
c. Bacitracin
d. Isoniazid
Given that both human cells and pathogens synthesize proteins at ribosomal sites, how can antimicrobial agents that target this process be safe to use in humans?
Which of the following antimicrobial properties would be the most crucial to consider in developing a new antimicrobial?
a. Selective toxicity
b. Ease of administration
c. Lack of drug interactions
d. Long half-life
e. The drug’s capacity to be bactericidal
Assume a bacterium makes beta-lactamase. Could you still use a glycopeptide drug to treat an infection caused by this bacterium? Explain your reasoning.
Why does a cell die from the following antimicrobial actions?
a. Colistimethate binds to phospholipids.
b. Kanamycin binds to 70S ribosomes.
Show where the following antibiotics work: ciprofloxacin, tetracycline, streptomycin, vancomycin, polymyxin B, sulfanilamide, rifampin, erythromycin.
A broad-spectrum drug is best described as
a. bactericidal against a wide range of species.
b. bacteriostatic against a wide range of species.
c. effective against a wide range of species.
d. empiric therapy.
e. selectively toxic.
Drugs that act against protein synthesis include ___________ .
a. Beta-lactams
b. Trimethoprim
c. Polymyxin
d. Aminoglycosides