Archive for February 2018

If pathogen A is more resistant to an erythromycin disc on a Kirby-Bauer plate compared to pathogen B, then pathogen A will have a(n) _____ zone of inhibition compared to pathogen B.

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If pathogen A is more resistant to an erythromycin disc on a Kirby-Bauer plate compared to pathogen B, then pathogen A will have a(n) _____ zone of inhibition compared to pathogen B.




A. smaller
B. equal
C. larger
D. All of the choices are correct.
E. None of the choices is correct.




Answer: A

A ratio of the dose of a drug that is toxic to humans versus the minimum effective dose for that pathogen is assessed to predict the potential for toxic drug reactions. This is called the

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A ratio of the dose of a drug that is toxic to humans versus the minimum effective dose for that pathogen is assessed to predict the potential for toxic drug reactions. This is called the



A. Kirby-Bauer.
B. antibiogram.
C. E-test.
D. MIC.
E. therapeutic index (TI).





Answer: E

A clinical microbiologist makes serial dilutions of several antimicrobials in broth and then incubates each drug dilution series with a standard amount of a patient's isolated pathogen. What is this microbiologist setting up?

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A clinical microbiologist makes serial dilutions of several antimicrobials in broth and then incubates each drug dilution series with a standard amount of a patient's isolated pathogen. What is this microbiologist setting up?



A. Kirby-Bauer
B. antibiogram
C. E-test
D. MIC
E. therapeutic index (TI)




Answer: D

Drug susceptibility testing determines

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Drug susceptibility testing determines




A. the patient's response to various antimicrobials.
B. the pathogen's response to various antimicrobials.
C. if normal flora will be affected by antimicrobials.
D. if the drug is increasing to toxic levels in a patient.
E. None of the choices is correct.


Answer: B

A superinfection results from

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A superinfection results from




A. buildup of a drug to toxic levels in the patient.
B. the wrong drug administered to the patient.
C. an immune system reaction to the drug.
D. decrease in most normal flora with overgrowth of an unaffected species.
E. All of the choices are correct.



Answer: D

Microbial resistance resulting from mutation occurs because

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Microbial resistance resulting from mutation occurs because





A. bacterial genomes undergo mutation rapidly.
B. bacterial genomes undergo mutation often.
C. short generation times accumulate mutations in populations.
D. mutations are passed between organisms.
E. All of the choices are correct.



Answer: E

Acyclovir is used to treat

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Acyclovir is used to treat




A. influenza A virus.
B. HIV.
C. herpes simplex virus.
D. respiratory syncytial virus.
E. hepatitis C virus.


Answer: C

There are fewer antifungal, antiprotozoal, and antihelminth drugs compared to antibacterial drugs because fungi, protozoa, and helminths

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There are fewer antifungal, antiprotozoal, and antihelminth drugs compared to antibacterial drugs because fungi, protozoa, and helminths




A. do not cause many human infections.
B. are not affected by antimicrobials.
C. are so similar to human cells that drug selective toxicity is difficult.
D. are parasites found inside human cells.
E. have cells with fewer target sites compared to bacteria.



Answer: C

Antimicrobials that are macrolides

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Antimicrobials that are macrolides





A. disrupt cell membrane function.
B. include tetracyclines.
C. include azithromycin, clarithromycin and erythromycin.
D. are very-narrow-spectrum drugs.
E. are hepatotoxic.




Answer: C

Clavulanic acid

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Clavulanic acid





A. inhibits B-lactamase activity.
B. inhibits peptidoglycan synthesis.
C. inhibits the formation of peptidoglycan cross-linkages.
D. inhibits cell membrane synthesis.
E. None of the choices is correct.




Answer: A

Sulfa drugs work on

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Sulfa drugs work on




A. nucleic acid biosynthesis.
B. ribosome biosynthesis.
C. peptidoglycan biosynthesis.
D. folic acid biosynthesis.
E. None of the choices is correct.


Answer: D

Sulfonamides

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Sulfonamides



A. interfere with elongation of peptidoglycan.
B. block folic acid synthesis.
C. attach to the 30S ribosomal subunit and disrupt protein synthesis.
D. damage cell membranes.
E. block peptidases that cross-link glycan molecules.




Answer: B

Aminoglycosides

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Aminoglycosides



A. interfere with elongation of peptidoglycan.
B. block folic acid synthesis.
C. attach to the 30S ribosomal subunit and disrupt protein synthesis.
D. damage cell membranes.
E. block peptidases that cross-link glycan molecules.



Answer: C

Selective toxicity refers to

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Selective toxicity refers to




A. damage to pathogenic organisms.
B. damage to prokaryotic cell membranes.
C. damage to the target organisms but not host cells.
D. damage to nucleic acids.
E. None of the choices is correct.




Answer: C

Penicillins and cephalosporins

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Penicillins and cephalosporins




A. block folic acid synthesis.
B. attach to the 30S ribosomal subunit and disrupt protein synthesis.
C. damage cell membranes.
D. block peptidases that cross-link glycan molecules.




Answer: D

Important characteristics of antimicrobial drugs include

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Important characteristics of antimicrobial drugs include




A. low toxicity for human tissues.
B. high toxicity against microbial cells.
C. do not cause serious side effects in humans.
D. stable and soluble in body tissues and fluids.
E. All of the choices are correct.



Answer: E

A microaerophile

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A microaerophile




A. grows best in an anaerobic jar.
B. grows with or without oxygen.
C. needs normal atmospheric levels of oxygen.
D. requires a small amount of oxygen but won't grow at normal atmospheric levels.
E. None of the choices is correct.



Answer: D

Cultures of a bacterial species were incubated out on the incubator shelf, in an anaerobic jar, and in a candle jar. After incubation, there was moderate growth of cultures in the candle and anaerobic jars, but heavy growth of the culture on the incubator shelf. This species is a(n)

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Cultures of a bacterial species were incubated out on the incubator shelf, in an anaerobic jar, and in a candle jar. After incubation, there was moderate growth of cultures in the candle and anaerobic jars, but heavy growth of the culture on the incubator shelf. This species is a(n)



A. aerobe.
B. anaerobe.
C. facultative anaerobe.
D. microaerophile.
E. capnophile.




Answer: C

Cultures of a bacterial species were incubated on the shelf of a refrigerator, out on a lab bench top, on the shelf of a 37C incubator, and on the shelf of a 50C incubator. After incubation, there was no growth at 37C and 50C, very slight growth out on the bench top, and abundant growth at refrigeration. What term could be used for this species?

05:45 Add Comment

Cultures of a bacterial species were incubated on the shelf of a refrigerator, out on a lab bench top, on the shelf of a 37C incubator, and on the shelf of a 50C incubator. After incubation, there was no growth at 37C and 50C, very slight growth out on the bench top, and abundant growth at refrigeration. What term could be used for this species?



A. halophile
B. mesophile
C. anaerobe
D. psychrophile
E. capnophile



Answer: D

Facilitated diffusion is limited by

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Facilitated diffusion is limited by



A. substrate concentration.
B. carrier proteins in the membrane.
C. size of the pores in the membrane.
D. osmotic pressure.
E. the size of the cell.



Answer: B

The movement of substances from higher to lower concentration across a semipermeable membrane that must have a specific protein carrier but no energy expenditure is called

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The movement of substances from higher to lower concentration across a semipermeable membrane that must have a specific protein carrier but no energy expenditure is called



A. facilitated diffusion.
B. diffusion.
C. active transport.
D. osmosis.
E. endocytosis.




Answer: A

The movement of substances from lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and cell expenditure of energy is called

05:42 Add Comment

The movement of substances from lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and cell expenditure of energy is called



A. facilitated diffusion.
B. diffusion.
C. active transport.
D. osmosis.
E. endocytosis.





Answer: C

The term facultative refers to

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The term facultative refers to



A. the ability to exist in a wide range of conditions.
B. existing in a very narrow niche.
C. using chemicals for energy production.
D. using light for energy production.
E. using oxygen for metabolism.



Answer: A

The term obligate refers to

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The term obligate refers to



A. the ability to exist in a wide range of conditions.
B. existing in a very narrow niche.
C. using chemicals for energy production.
D. using light for energy production.
E. using oxygen for metabolism.



Answer: B

Archaea, as a group, are not pathogens. This is because

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Archaea, as a group, are not pathogens. This is because


A. they evolved without mammals.
B. mammals evolved special defenses against them.
C. mammalian hosts do not meet their environmental requirements.
D. they are outcompeted by natural flora.E. None of the choices is correct.




Answer: C

The term chemoheterotroph refers to an organism that

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The term chemoheterotroph refers to an organism that



A. uses CO2 for its carbon source.
B. must obtain inorganic compounds for its energy source.
C. gets energy from sunlight.
D. gets energy by oxidizing chemical compounds.
E. does not need a carbon source.




Answer: D

The term photoautotroph refers to an organism that

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The term photoautotroph refers to an organism that



A. is a decomposer.
B. must obtain organic compounds for its carbon needs.
C. gets energy from sunlight.
D. gets energy by oxidizing chemical compounds.
E. does not need a carbon source.



Answer: C

The term photoheterotroph refers to an organism that

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The term photoheterotroph refers to an organism that




A. uses CO2 for its carbon source.
B. utilizes inorganic compounds for its carbon needs.
C. gets energy from sunlight.
D. gets energy by metabolizing organic matter of dead organisms.
E. does not need a carbon source.



Answer: C

The term autotroph refers to an organism that

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The term autotroph refers to an organism that




A. uses CO2 for its carbon source.
B. must obtain organic compounds for its carbon needs.
C. gets energy from sunlight.
D. gets energy by oxidizing chemical compounds.
E. does not need a carbon source.


Answer: A
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