Question 1

An official from an international health agency predicts that if all countries enacted legislation to only sell antibiotics with a prescription, then the rate of antibiotic resistant would ʺgrind to a halt.ʺ Do you agree? Explain.

Accepted Answer

The answer of An official from an international health agency...

Question 2

Use of antibiotics in animal feed leads to antibiotic-resistant bacteria because

Accepted Answer

A)  the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal. 
B)  bacteria from other animals replace those killed by the antibiotics. 
C)  the antibiotics persist in soil and water. 
D)  the antibiotics cause new mutations to occur in the surviving bacteria, which results in resistance to antibiotics. 
E)  the few surviving bacteria that are affected by the antibiotics develop immunity to the antibiotics, which they pass on to their progeny.

Question 3

Protozoan and helminthic diseases are difficult to treat because

Accepted Answer

A)  their cells are structurally and functionally similar to human cells. 
B)  they replicate inside human cells. 
C)  they do not reproduce. 
D)  they have more genes than bacteria. 
E)  they do not have ribosomes.

Question 4

Which of the following antibiotics causes misreading of mRNA?

Accepted Answer

A)  tetracyclines  bind with 30S subunit 
B)  aminoglycoside  changes shape of 30S units 
C)  chloramphenicol  inhibits peptide bonds at 50S subunit 
D)  oxazolidinone  prevents formation of 70S ribosome 
E)  streptogamin  prevents release of peptide from 70S ribosome

Question 5

Which of the following antimicrobial agents is recommended for use against fungal infections?

Accepted Answer

A)  polymyxin 
B)  bacitracin 
C)  amphotericin B 
D)  cephalosporin 
E)  penicillin

Question 6

Which of the following antibiotics is NOT bactericidal?

Accepted Answer

A)  polyenes 
B)  cephalosporins 
C)  penicillin 
D)  aminoglycosides 
E)  rifampins

Question 7

Penicillin was considered a ʺmiracle drugʺ for all of the following reasons EXCEPT

Accepted Answer

A)  it was the first antibiotic. 
B)  it has selective toxicity. 
C)  it does not affect eukaryotic cells. 
D)  it kills bacteria. 
E)  it inhibits gram-positive cell wall synthesis.

Question 8

Which of the following methods of action would be bacteriostatic?

Accepted Answer

A)  competitive inhibition with folic acid synthesis 
B)  competitive inhibition with DNA gyrase 
C)  injury to plasma membrane 
D)  inhibition of protein synthesis 
E)  inhibition of cell wall synthesis

Question 9

Table 20.2
The following results were obtained from a disk-diffusion test for microbial susceptibility to antibiotics. Staphylococcus aureus was the test organism. $$\begin{array} { | l | l | } 
\hline  { \text { Antibiotic } } & \text { Zone of Inhibition } \
\hline \mathrm { A } & 3 \mathrm {~mm} \
\hline \mathrm { B } & 7 \mathrm {~mm} \
\hline \mathrm { C } & 0 \mathrm {~mm} \
\hline \mathrm { D } & 10 \mathrm {~mm} \
\hline
\end{array}$$
-In Table 20.2, the most effective antibiotic tested was

Accepted Answer

A)  A. 
B)  B. 
C)  C. 
D)  D. 
E)  The answer cannot be determined based on the information provided.

Question 10

Can you determine both MIC and MBC from an E-test? Explain.

Accepted Answer

The answer of Can you determine both MIC and MBC...

Question 11

Phage therapy has been used in the past as an antiviral treatment.

Accepted Answer

A) True 
 B)False

Question 12

Which of the following does NOT affect eukaryotic cells?

Accepted Answer

A)  antifungal drugs 
B)  semisynthetic penicillins 
C)  antiprotozoan drugs 
D)  antihelminthic drugs 
E)  nucleotide analogs

Question 13

More than half of our antibiotics are

Accepted Answer

A)  synthesized in laboratories. 
B)  produced by Fleming. 
C)  produced by eukaryotic organisms. 
D)  produced by fungi. 
E)  produced by bacteria.

Question 14

Which of the following would be selective against the tubercle bacillus?

Accepted Answer

A)  streptogramin  inhibits protein synthesis 
B)  ethambutol  inhibits mycolic acid synthesis 
C)  vancomycin  inhibits peptidoglycan synthesis 
D)  bacitracin  inhibits peptidoglycan synthesis 
E)  streptomycin  inhibits protein synthesis

Question 15

Table 20.2
The following results were obtained from a disk-diffusion test for microbial susceptibility to antibiotics. Staphylococcus aureus was the test organism. $$\begin{array} { | l | l | } 
\hline  { \text { Antibiotic } } & \text { Zone of Inhibition } \
\hline \mathrm { A } & 3 \mathrm {~mm} \
\hline \mathrm { B } & 7 \mathrm {~mm} \
\hline \mathrm { C } & 0 \mathrm {~mm} \
\hline \mathrm { D } & 10 \mathrm {~mm} \
\hline
\end{array}$$
-In Table 20.2, the antibiotic that exhibited bactericidal action was

Accepted Answer

A)  A. 
B)  B. 
C)  C. 
D)  D. 
E)  The answer cannot be determined based on the information provided.

Question 16

Which one of the following does NOT belong with the others?

Accepted Answer

A)  cephalosporin 
B)  monobactam 
C)  penicillin 
D)  bacitracin 
E)  streptomycin

Question 17

Which of the following organisms would MOST likely be sensitive to natural penicillin?

Accepted Answer

A)  penicillinase-producing Neisseria gonorrhoeae 
B)  helminths 
C)  Penicillium 
D)  Mycoplasma 
E)  Streptococcus pyogenes

Question 18

Figure 20.1  The antibiotic tetracycline binds to the 30S subunit of the ribosome, as shown by the dark black bar on the right portion of the diagram in Figure 20.1. The effect is to

Accepted Answer

A)  prevent peptide bond formation. 
B)  stop the ribosome from moving along the mRNA. 
C)  prevent transcription. 
D)  interfere with the attachment of the tRNA to mRNA-ribosome complex. 
E)  prevent attachment of DNA.

Question 19

Only microbes produce antimicrobial peptides.

Accepted Answer