BMS 127 Ch. 10 Antimicrobial Drugs

Question 0

In the Kirby-Bauer susceptibility test, the presence of a zone of inhibition around disks containing antimicrobial agents indicate:

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.

Answer 0

a. that the microbe does not grow in the presence of the agents.

Question 1

Diffusion and dilution tests that expose pathogens to antimicrobials are design to:

a. determine spectrum of action of a drug.
b. determine which drug is most effective against a particular pathogen.
c. determine the amount of a drug to use against a particular pathogen.
d. both b and c

Answer 1

d. both b and c

Question 2

What is the key to successful chemotherapy?

Answer 2

selective toxicity

Question 3

Which of the following statements is relevant in explaining why sulfonamides are effective?

a. Sulfonamides attach to sterol lipids in the pathogen, disrupt the membranes, and lyse the cells.
b. Sulfonamides prevent the incorporation of amino acids into polypeptide chains.
c. Humans and microbes use folic acid and PABA differently in their metabolism.
d. Sulfonamides inhibit DNA replication in both pathogens and human cells.

Answer 3

c. Humans and microbes use folic acid and PABA differently in their metabolism.

Question 4

Cross resistance is:

a. the deactivation of an antimicrobial agent by a bacterial enzyme.
b. alteration of the resistant cells so that an antimicrobial agent cannot attach.
c. the mutation of genes that affect the cell membrane channels so that antimicrobial agents cannot cross into the cell’s interior.
d. resistance to one antimicrobial agent because of its similarity to another antimicrobial agent.

Answer 4

d. resistance to one antimicrobial agent because of its similarity to another antimicrobial agent.

Question 5

Multiple-drug-resistant microbes:

a. are resistant to all antimicrobial agents.
b. respond to new antimicrobials by developing resistance.
c. frequently develop in hospitals.
d. all of the above.

Answer 5

c. frequently develop in hospitals.

Question 6

Which of the following is most closely associated with a beta-lactam ring?

a. penicillin
b. vancomycin
c. bacitracin
d. isoniazid

Answer 6

a. penicillin

Question 7

Drugs that act against protein synthesis include:

a. beta-lactams
b. trimethoprim
c. polymyxin
d. aminoglycosides

Answer 7

d. aminoglycosides

Question 8

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 in antiviral drugs can be used to stop viral replication.
d. Drugs containing protease inhibitors retard viral growth by blocking the production of essential viral proteins.

Answer 8

a. Macrolide drugs block attachment sites on the host cell wall and prevent viruses from entering.

Question 9

PABA is

a. a substrate used in the production of penicillin.
b. a type of beta-lactamase.
c. molecularly similar to cephalosporins.
d. used to synthesize folic acid.

Answer 9

d. used to synthesize folic acid.