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Penicillin was considered a "miracle drug" for all of the following reasons EXCEPT
A) it was the first antibiotic.
B) it does not affect eukaryotic cells.
C) it inhibits gram-positive cell wall synthesis.
D) it has selective toxicity.
E) it kills bacteria.
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A) it was the first antibiotic.
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A drug that inhibits mitosis, such as griseofulvin, would be more effective against
A) gram-positive bacteria.
B) gram-negative bacteria.
C) fungi.
D) wall-less bacteria.
E) mycobacteria.
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C) fungi.
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Most of the available antimicrobial agents are effective against
A) viruses.
B) bacteria.
C) fungi.
D) protozoa.
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B) bacteria.
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Antimicrobial peptides (AMPs) frequently work by
A) inhibiting protein synthesis.
B) disrupting the plasma membrane.
C) complementary base pairing with DNA.
D) inhibiting cell-wall synthesis.
E) hydrolyzing peptidoglycan.
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B) disrupting the plasma membrane.
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In what way are semisynthetic penicillins and natural penicillins alike?
A) Both are broad spectrum.
B) Both are resistant to penicillinase.
C) Both are resistant to stomach acids.
D) Both are bactericidal.
E) Both are based on β-lactam.
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E) Both are based on β-lactam.
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Which one of the following antibiotics is NOT bactericidal?
A) aminoglycosides
B) cephalosporins
C) polyenes
D) rifampins
E) penicillin
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C) polyenes
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Which one of the following does NOT belong with the others?
A) bacitracin
B) cephalosporin
C) monobactam
D) penicillin
E) streptomycin
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E) streptomycin
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Which of the following antimicrobial agents has the fewest side effects?
A) streptomycin
B) tetracycline
C) penicillin
D) erythromycin
E) chloramphenicol
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C) penicillin
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Which of the following drugs does NOT act by competitive inhibition?
A) ethambutol
B) isoniazid
C) streptomycin
D) sulfonamide
E) trimethoprim
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C) streptomycin
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Which of the following methods of action would be bacteriostatic?
A) competitive inhibition with folic acid synthesis
B) inhibition of protein synthesis
C) injury to plasma membrane
D) inhibition of cell wall synthesis
E) competitive inhibition with DNA gyrase
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B) inhibition of protein synthesis
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Which of the following antibiotics is recommended for use against gram-negative bacteria?
A) polyenes
B) bacitracin
C) cephalosporin
D) penicillin
E) polymyxin
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E) polymyxin
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Which of the following antimicrobial agents is recommended for use against fungal infections?
A) amphotericin B
B) bacitracin
C) cephalosporin
D) penicillin
E) polymyxin
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A) amphotericin B
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More than half of our antibiotics are
A) produced by fungi.
B) produced by bacteria.
C) synthesized in laboratories.
D) produced by Fleming.
E) produced by eukaryotic organisms.
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B) produced by bacteria.
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To date, most of our natural antibiotics have been found to be produced by members of what genus?
A) Streptomyces
B) Bacillus
C) Penicillium
D) Paenibacillus
E) Cephalosporium
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A) Streptomyces
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Which of the following is mismatched?
A) Ehrlich – "magic bullet" theory
B) Fleming – initial identification of penicillin’s effect on gram-positive microbial growth
C) Florey and Chain – identification of Penicillium as the producer of penicillin
D) Kirby and Bauer – disc-diffusion method
E) None of these is mismatched.
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C) Florey and Chain – identification of Penicillium as the producer of penicillin
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Which compound would be the most useful to treat candidiasis?
A) uracil
B) thymine
C) flucytosine
D) guanine
E) penicillin
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C) flucytosine
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Which of the following antibiotics are used to treat fungal infections?
1. aminoglycosides
2. cephalosporins
3. griseofulvin
4. polyenes
5. bacitracin
A) 1, 2, and 3
B) 3 and 4
C) 3, 4, and 5
D) 4 and 5
E) All of these antibiotics are used to treat fungal infections.
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B) 3 and 4
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Which of the following antibiotics does NOT interfere with cell wall synthesis?
A) cephalosporins
B) macrolides
C) natural penicillins
D) semisynthetic penicillins
E) vancomycin
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B) macrolides
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The antimicrobial drugs with the broadest spectrum of activity are
A) aminoglycosides.
B) chloramphenicol.
C) penicillin G.
D) macrolides.
E) tetracyclines.
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E) tetracyclines.
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Which of the following statements is FALSE?
A) Fluoroquinolone inhibits DNA synthesis.
B) Acyclovir inhibits DNA synthesis.
C) Amantadine inhibits the release of viral nucleic acid.
D) Interferon inhibits glycolysis.
E) Azoles inhibit plasma membrane synthesis.
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D) Interferon inhibits glycolysis.
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Protozoan and helminthic diseases are difficult to treat because
A) their cells are structurally and functionally similar to human cells.
B) they replicate inside human cells.
C) they do not have ribosomes.
D) they do not reproduce.
E) they have more genes than bacteria.
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A) their cells are structurally and functionally similar to human cells.
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Which of the following organisms would MOST likely be sensitive to natural penicillin?
A) helminths
B) Streptococcus pyogenes
C) penicillinase-producing Neisseria gonorrhoeae
D) Penicillium
E) Mycoplasma
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B) Streptococcus pyogenes
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Which of the following statements about drug resistance is FALSE?
A) It may be carried on a plasmid.
B) It may be transferred from one bacterium to another during conjugation.
C) It may be due to enzymes that degrade some antibiotics.
D) It is found only in gram-negative bacteria.
E) It may be due to decreased uptake of a drug.
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D) It is found only in gram-negative bacteria.
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Which of the following does NOT constitute an advantage of using two antibiotics together?
A) It can prevent drug resistance.
B) It lessens the toxicity of individual drugs.
C) Two are always twice as effective as one.
D) It allows treatment to be provided prior to diagnosis.
E) All of these are advantages of using two antibiotics together.
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C) Two are always twice as effective as one.
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Drug resistance occurs
A) because bacteria are normal microbiota.
B) when antibiotics are used indiscriminately.
C) against antibiotics and not against synthetic chemotherapeutic agents.
D) when antibiotics are taken after the symptoms disappear.
E) All of the answers are correct.
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B) when antibiotics are used indiscriminately.
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If you tested a 2nd strain of S. aureus with the same method and concentrations of drugs as indicated in Table 20.2, but you found that the zone of inhibition caused by drug D had dropped to 2 mm, what does this indicate?
A) The 2nd strain of bacteria is likely resistant to drug D.
B) The 2nd strain of bacteria is much more sensitive to drug D.
C) The experiment wasn’t conducted properly, and is giving inaccurate results.
D) There is no functional difference between how the 2 strains react to the drug.
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A) The 2nd strain of bacteria is likely resistant to drug
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Which of the following would be selective against the tubercle bacillus?
A) bacitracin – inhibits peptidoglycan synthesis
B) ethambutol – inhibits mycolic acid synthesis
C) streptogramin – inhibits protein synthesis
D) streptomycin – inhibits protein synthesis
E) vancomycin – inhibits peptidoglycan synthesis
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B) ethambutol – inhibits mycolic acid synthesis
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In the presence of penicillin, a cell dies because
A) it lacks a cell wall.
B) it plasmolyzes.
C) it undergoes lysis.
D) it lacks a cell membrane.
E) its contents leak out.
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C) it undergoes lysis.
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Lamisil is an allylamine used to treat dermatomycoses. Lamisil’s method of action is similar to that of
A) polymyxin B.
B) azole antibiotics.
C) echinocandins.
D) griseofulvin.
E) bacitracin.
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B) azole antibiotics.
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Niclosamide prevents ATP generation in mitochondria. You would expect this drug to be effective against
A) gram-negative bacteria.
B) gram-positive bacteria.
C) helminths.
D) Mycobacterium tuberculosis.
E) viruses.
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C) helminths.
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Which of the following statements about drugs that competitively inhibit DNA polymerase or RNA polymerase is FALSE?
A) They can potentially cause mutations.
B) They are used against viral infections.
C) They can affect host cell DNA synthesis.
D) They cause cellular plasmolysis.
E) They interfere with protein synthesis.
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D) They cause cellular plasmolysis.
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Which of the following does NOT affect eukaryotic cells?
A) antiprotozoan drugs
B) antihelminthic drugs
C) antifungal drugs
D) nucleotide analogs
E) semisynthetic penicillins
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E) semisynthetic penicillins
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Mebendazole is used to treat cestode infections. It interferes with microtubule formation; therefore, it would NOT affect
A) bacteria.
B) fungi.
C) helminths.
D) human cells.
E) protozoa.
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A) bacteria.
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Which of the following antibiotics causes misreading of mRNA?
A) aminoglycoside – changes shape of 30S units
B) chloramphenicol – inhibits peptide bonds at 50S subunit
C) oxazolidinone – prevents formation of 70S ribosome
D) streptogamin – prevents release of peptide from 70S ribosome
E) tetracyclines – bind with 30S subunit
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A) aminoglycoside – changes shape of 30S units
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The antibiotic actinomycin D binds between adjacent G-C pairs, thus interfering with
A) transcription.
B) translation.
C) cellular respiration.
D) plasma membrane function.
E) peptide bond formation.
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A) transcription.
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Use of antibiotics in animal feed leads to antibiotic-resistant bacteria because
A) bacteria from other animals replace those killed by the antibiotics.
B) the few surviving bacteria that are affected by the antibiotics develop immunity to the antibiotics, which they pass on to their progeny.
C) the antibiotics cause new mutations to occur in the surviving bacteria, which results in resistance to antibiotics.
D) the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal.
E) the antibiotics persist in soil and water.
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D) the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal.
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Which one of the following anti-protozoan drugs was a traditional Chinese medicine for controlling fevers, but which has also exhibited useful anti-malarial properties?
A) Quinacrine
B) Metronidazole
C) Miltefosine
D) Mebendazole
E) Artemisinin
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E) Artemisinin
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