Controlling Microbial Growth in the Body
Which of the following is NOT a genus of an antibiotic-producing microbe?
A. Streptomyces
B. Penicillium
C. Bacillus
D. Streptococcus
The majority of antimicrobial agents are
A. antiprotozoan.
B. antihelminthic.
C. antibacterial.
D. antifungal.
All of the following are mechanisms of action associated with different types of cell wall inhibiting
drugs EXCEPT:
A. they dismantle existing peptidoglycan molecules.
B. they block the secretion of NAG and NAM from the cytoplasm.
C. they interfere with the formation of alanine-alanine crossbridges.
D. they prevent crosslinking between NAM subunits.
Which of the following cellular structures or molecules is most similar in both bacteria and humans?
A. cell wall
B. DNA
C. ribosomes
D. cell membrane
Tetracyclines inhibit which of the following?
A. nucleic acid synthesis
B. cell wall synthesis
C. metabolic pathways
D. protein synthesis
What is the reason that some drugs which inhibit protein synthesis in bacteria can also be harmful to
humans?
A. Some human cells have mutated ribosomes which are more susceptible to these drugs.
B. Some drugs are powerful enough to inhibit human cell protein synthesis as well as that of
bacterial cells.
C. Eukaryotic mitochondria have 70S ribosomes.
D. Humans and bacteria have very similar types of ribosomes.
What was the first practical antimicrobial agent to be widely used?
A. penicillin
B. vancomycin
C. arsenic compounds
D. sulfanilimide
Which of the following does NOT block the formation of folic acid in bacteria?
A. Dapsone
B. Trimethoprim
C. Sulfanilimide
D. Metronidazole
The bacterial enzyme DNA gyrase is a target of which of the following drugs?
A. aminoglycosides
B. quinolones
C. isoniazid
D. polymyxin
Why are viruses more susceptible to nucleotide analogs than their host cells?
A. Viruses replicate their nucleic acid more rapidly than host cells do.
B. Viral DNA polymerases incorporate nucleotide analogs into their DNA more readily than do
host cells.
C. Cellular DNA is not distorted by the presence of nucleotide analogs as is viral DNA.
D. Both A and B are correct.
E. Both B and C are correct.
All of the following drugs result in the disruption of fungal cytoplasmic membranes EXCEPT:
A. polymyxin.
B. turbinafine.
C. amphotericin B.
D. fluconazole.
Which of the following routes of administration of an antimicrobial drug produces the lowest blood
concentration of the drug?
A. intramuscular
B. oral
C. intravenous
D. All of these produce equally low blood concentrations.
Beta-lactamases are an example of which of the following mechanisms of resistance?
A. Alteration of a cellular receptor for an antimicrobial drug
B. Alteration of the cell's metabolism
C. Prevention of an antimicrobial drug's entry into the cell
D. Deactivation of an antimicrobial drug
Which of the following drugs does NOT inhibit protein synthesis by interacting with ribosomes?
A. fomiversan
B. chloramphenicol
C. streptomycin
D. erythromycin
Which of the following drugs interferes with nucleic acid synthesis?
A. amphotericin B
B. macrolides
C. amantadine
D. trimethoprim
Why is chemotherapy against Mycobacterium species so problematic?
A. They have ribosomes that are different from those of other bacteria.
B. They do not use sterols in their cell membranes.
C. They grow and reproduce very slowly.
D. There are no good drugs that can be used against Mycobacterium.
Which of the following is a reason to make semisynthetic derivatives of naturally-occurring antibiotics?
A. To make the drug more readily absorbed by the body.
B. To make the drug less susceptible to the activity of bacterial enzymes.
C. To make the drug more stable in the stomach.
D. Both A and C are correct.
E. A, B, and C are correct.
All of the following drugs inhibit protein synthesis EXCEPT:
A. streptomycin.
B. ciprofloxacin.
C. erythromycin.
D. chloramphenicol.
Which of the following types of antimicrobial drugs is also effective against rapidly dividing cancer
cells?
A. nucleotide analogs
B. inhibitors of cell wall synthesis
C. disrupters of the cell membrane
D. protein synthesis inhibitors
A patient develops a severe intestinal infection as a result of antibiotic therapy for a respiratory
infection. Which of the following is the best explanation for why this occurred?
A. The antibiotic has disrupted the normal microbiota of the intestine.
B. The patient is allergic to the antibiotic.
C. The microbe that caused the original infection has become resistant to the antibiotic.
D. The patient is showing signs of drug toxicity.