Question 1

Which one of the following antibiotics is NOT bactericidal?

Accepted Answer

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

Question 2

Which of the following drugs does NOT act by competitive inhibition?

Accepted Answer

A) ethambutol 
B) isoniazid 
C) streptomycin 
D) sulfonamide 
E) trimethoprim 
A) ethambutol 
B) isoniazid 
C) streptomycin 
D) sulfonamide 
E) trimethoprim C

Question 3

Table 20.1
The following data were obtained from a broth dilution test.
 $$\begin{array} { | c | c | c | } 
\hline \begin{array} { c } 
\text { Concentration of Antibiotic } \
\mathrm { X }
\end{array} & \text { Growth } & \text { Growth in Subculture } \
\hline 2 μg /\mathrm { ml } & + & + \
\hline 10 μg/ \mathrm { ml }& - & + \
\hline 15 μg/ \mathrm { ml } & - & - \
\hline 25μg/ \mathrm { ml } & - & - \
\hline
\end{array}$$
-In Table 20.1,the minimal inhibitory concentration of antibiotic X is

Accepted Answer

A) 2 μg/ml. 
B) 10 μg/ml. 
C) 15 μg/ml. 
D) 25 μg/ml. 
E) The answer cannot be determined based on the information provided. 
A) 2 μg/ml. 
B) 10 μg/ml. 
C) 15 μg/ml. 
D) 25 μg/ml. 
E) The answer cannot be determined based on the information provided. B

Question 4

Explain the difficulties in developing antiviral drugs against DNA viruses,when compared to RNA viruses.

Accepted Answer

Developing antiviral drugs against DNA v

Question 5

Both trimethoprim and sulfamethoxazole inhibit reactions along the same metabolic pathway.

Accepted Answer

A) True 
 B)False

Question 6

Table 20.1
The following data were obtained from a broth dilution test.
 $$\begin{array} { | c | c | c | } 
\hline \begin{array} { c } 
\text { Concentration of Antibiotic } \
\mathrm { X }
\end{array} & \text { Growth } & \text { Growth in Subculture } \
\hline 2 μg /\mathrm { ml } & + & + \
\hline 10 μg/ \mathrm { ml }& - & + \
\hline 15 μg/ \mathrm { ml } & - & - \
\hline 25μg/ \mathrm { ml } & - & - \
\hline
\end{array}$$
-In Table 20.1,as illustrated by the data shown,the minimal bactericidal concentration of antibiotic X is

Accepted Answer

A) 2 μg/ml. 
B) 10 μg/ml. 
C) 15 μg/ml. 
D) 25 μg/ml. 
E) The answer cannot be determined based on the information provided. 
A) 2 μg/ml. 
B) 10 μg/ml. 
C) 15 μg/ml. 
D) 25 μg/ml. 
E) The answer cannot be determined based on the information provided.

Question 7

Lamisil is an allylamine used to treat dermatomycoses.Lamisil's method of action is similar to that of

Accepted Answer

A) polymyxin B. 
B) azole antibiotics. 
C) echinocandins. 
D) griseofulvin. 
E) bacitracin. 
A) polymyxin B. 
B) azole antibiotics. 
C) echinocandins. 
D) griseofulvin. 
E) bacitracin.

Question 8

An antibiotic that attacks the LPS layer would be expected to have a broad spectrum of activity,effective against Gram negative and Gram positive cells.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following antimicrobial agents has the fewest side effects?

Accepted Answer

A) streptomycin 
B) tetracycline 
C) penicillin 
D) erythromycin 
E) chloramphenicol 
A) streptomycin 
B) tetracycline 
C) penicillin 
D) erythromycin 
E) chloramphenicol

Question 10

Table 20.3 The following data were obtained from a broth dilution test:
$$\begin{array}{|l|}
\begin{array} { c | c } 
\hline \text { Concentration of Antibiotic }\ 
\text { X } & \text { Growth } \
\hline 2.0 \mu \mathrm { g } / \mathrm { ml } & - \
\hline 1.0 \mu \mathrm { m } / \mathrm { ml } & - \
\hline 0.5 \mu \mathrm { g } / \mathrm { ml } & - \
\hline 0.25 \mu \mathrm { gl } / \mathrm { ml } & + \
\hline 0.125 \mu \mathrm { g } / \mathrm { ml } & + \
\hline 0 & + \
\hline
\end{array}
\end{array}$$
Bacteria from the 0.25 μg/ml tube were transferred to new growth media
Containing antibiotic X with the following results:
$$\begin{array}{|l|}
\begin{array} { c | c } 
\hline \text { Concentration of Antibiotic }\ 
\text { X } & \text { Growth } \
\hline 2.0 \mu \mathrm { g } / \mathrm { ml } & - \
\hline 1.0 \mu \mathrm { m } / \mathrm { ml } & + \
\hline 0.5 \mu \mathrm { g } / \mathrm { ml } & + \
\hline 0.25 \mu \mathrm { gl } / \mathrm { ml } & + \
\hline
\end{array}
\end{array}$$
The data in Table 20.3 show that these bacteria

Accepted Answer

A) are pathogenic. 
B) developed resistance to antibiotics. 
C) were killed by 0.125 μg/ml of antibiotic X. 
D) were killed by 0.5 μg/ml of antibiotic X. 
E) were resistant to 1.0 μg/ml at the start of the experiment. 
A) are pathogenic. 
B) developed resistance to antibiotics. 
C) were killed by 0.125 μg/ml of antibiotic X. 
D) were killed by 0.5 μg/ml of antibiotic X. 
E) were resistant to 1.0 μg/ml at the start of the experiment.

Question 11

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

Accepted Answer

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

Question 12

Which of the following antibiotics are used to treat fungal infections? 1.aminoglycosides
2)cephalosporins
3)griseofulvin
4)polyenes
5)bacitracin

Accepted Answer

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. 
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.

Question 13

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

Accepted Answer

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

Question 14

Which of the following statements about drugs that competitively inhibit DNA polymerase or RNA polymerase is FALSE?

Accepted Answer

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. 
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.

Question 15

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 have ribosomes. 
D) they do not reproduce. 
E) they have more genes than bacteria. 
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.

Question 16

The antimicrobial drugs with the broadest spectrum of activity are

Accepted Answer

A) aminoglycosides. 
B) chloramphenicol. 
C) penicillin G. 
D) macrolides. 
E) tetracyclines. 
A) aminoglycosides. 
B) chloramphenicol. 
C) penicillin G. 
D) macrolides. 
E) tetracyclines.

Question 17

Which of the following does NOT constitute an advantage of using two antibiotics together?

Accepted Answer

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. 
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.

Question 18

Antiviral drugs target viral processes that occur during viral infection.

Accepted Answer

A) True 
 B)False

Question 19

Penicillin and streptomycin are commonly used in synergism because they display the same mode of action.

Accepted Answer

A) True 
 B)False

Question 20

Only microbes produce antimicrobial peptides.

Accepted Answer

A) True 
 B)False

Exam 20: Antimicrobial Drugs

Which one of the following antibiotics is NOT bactericidal?

Which of the following drugs does NOT act by competitive inhibition?

Table 20.1 The following data were obtained from a broth dilution test. Concentration of Antibiotic Growth Growth in Subculture 2μg/ + + 10μg/ - + 15μg/ - - 25μg/ - - -In Table 20.1,the minimal inhibitory concentration of antibiotic X is

Explain the difficulties in developing antiviral drugs against DNA viruses,when compared to RNA viruses.

Both trimethoprim and sulfamethoxazole inhibit reactions along the same metabolic pathway.

Table 20.1 The following data were obtained from a broth dilution test. Concentration of Antibiotic Growth Growth in Subculture 2μg/ + + 10μg/ - + 15μg/ - - 25μg/ - - -In Table 20.1,as illustrated by the data shown,the minimal bactericidal concentration of antibiotic X is

Lamisil is an allylamine used to treat dermatomycoses.Lamisil's method of action is similar to that of

An antibiotic that attacks the LPS layer would be expected to have a broad spectrum of activity,effective against Gram negative and Gram positive cells.

Which of the following antimicrobial agents has the fewest side effects?

Table 20.2 The following results were obtained from a disk-diffusion test for microbial susceptibility to antibiotics.Staphylococcus aureus was the test organism. Antibiotic Zone of Inhibition A 3 B 7 C 0 D 10 -In Table 20.2,which antibiotic would be most useful for treating a Salmonella infection?

Which of the following antibiotics are used to treat fungal infections? 1.aminoglycosides 2)cephalosporins 3)griseofulvin 4)polyenes 5)bacitracin

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

Which of the following statements about drugs that competitively inhibit DNA polymerase or RNA polymerase is FALSE?

Protozoan and helminthic diseases are difficult to treat because

The antimicrobial drugs with the broadest spectrum of activity are

Which of the following does NOT constitute an advantage of using two antibiotics together?

Antiviral drugs target viral processes that occur during viral infection.

Penicillin and streptomycin are commonly used in synergism because they display the same mode of action.

Only microbes produce antimicrobial peptides.

The Microbial World and You

Chemical Principles

Observing Microorganisms Through a Microscope

Functional Anatomy of Prokaryotic and Eukaryotic

Microbial Metabolism

Microbial Growth

The Control of Microbial Growth

Microbial Genetics

Biotechnology and Dna Technology

Classification of Microorganisms

The Prokaryotes: Domains Bacteria and Archaea

The Eukaryotes: Fungi, algae, protozoa, and Helminths

Viruses,viroids,and Prions

Principles of Disease and Epidemiology

Microbial Mechanisms of Pathogenicity

Innate Immunity: Nonspecific Defenses of the Host

Adaptive Immunity: Specific Defenses of the Host

Practical Applications of Immunology

Disorders Associated With the Immune System

Microbial Diseases of the Skin and Eyes

Microbial Diseases of the Nervous System

Microbial Diseases of the Cardiovascular and Lymphatic Systems

Microbial Diseases of the Respiratory System

Microbial Diseases of the Digestive System

Microbial Diseases of the Urinary and Reproductive Systems

Environmental Microbiology

Applied and Industrial Microbiology

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