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A large percentage of antibiotics and semisynthetic drugs are produced by members of the genus
Penicillium.
Mycobacterium.
Bacillus.
Cephalosporium.
Streptomyces.
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Streptomyces
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An antimicrobial that inhibits cell wall synthesis will result in which of the following?
Ribosomes lose their function.
The sterols in the cell wall become nonfunctional.
Cells cannot attach to their hosts.
The replication of cells, including cancer cells, slows down.
Cells become more susceptible to osmotic pressure
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Cells become more susceptible to osmotic pressure
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Beta-lactam antibiotics have an effect on which of the following types of cells?
virus-infected cells
animal cells
fungal cells
bacterial cells
both animal and fungal cells
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bacterial cells
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Which of the following is a primary advantage of semisynthetic drugs?
They must be administered intravenously.
They have a broader spectrum of action.
They work faster.
They are less stable and consequently have fewer side effects.
They are not readily absorbed, so they persist longer.
|
They have a broader spectrum of action.
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Which of the following drugs specifically targets cell walls that contain arabinogalactan-mycolic acid?
penicillin
bacitracin
isoniazid
vancomycin
methicillin
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isoniazid
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Which of the following antibiotics disrupts cytoplasmic membrane function?
amphotericin B
streptomycin
erythromycin
penicillin
tetracycline
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amphotericin B
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Which of the following is NOT a target of drugs that inhibit protein synthesis?
movement of the ribosome from one codon to the next
interference with alanine-alanine bridges
the tRNA docking site
the shape of the 30S ribosomal subunit
the enzymatic site of the 50S ribosomal subunit
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interference with alanine-alanine bridges
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Which scientist coined the term antibiotic?
Domagk
Waksman
Kirby
Ehrlich
Fleming
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Waksman
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The most limited group of antimicrobial agents is the __________ drugs.
antifungal
anthelmintic
antibacterial
antiprotozoan
antiviral
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antiviral
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Another term for the Kirby-Bauer test is the
E test.
broth dilution test.
diffusion susceptibility test.
minimum inhibitory concentration test.
minimum bactericidal concentration test
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diffusion susceptibility test.
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Which of the following statements about the zone of inhibition is FALSE?
It is measured as a diameter.
The larger the zone, the more resistant the organism is.
It is measured after incubation.
It is a result of diffusion of the drug out of the paper disk.
It is a clearing zone with no growth.
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The larger the zone, the more resistant the organism is.
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Which of the following groups of drugs can become incorporated into the bones and teeth of a fetus?
quinolones
tetracyclines
aminoglycosides
sulfonamides
beta-lactam
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tetracyclines
|
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Which of the following can result when antibiotic therapy disrupts the normal microbiota?
black hairy tongue
anaphylactic shock
pseudomembranous colitis
thrush
both pseudomembranous colitis and thrush
|
both pseudomembranous colitis and thrush
|
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Which of the following statements concerning development of antibiotic resistance is FALSE?
Resistant cells are normally in the minority in a bacterial population.
It is often mediated by R-plasmids.
.Resistant cells grow more efficiently and quickly than susceptible cells
Resistance can occur through mutation of existing bacterial genes.
New resistance genes can be gained through transformation, transduction, or conjugation.
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Resistant cells grow more efficiently and quickly than susceptible cells
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B Lactamase production is an example of which of the following types of resistance?
inactivation of the drug
alteration of the target of the drug
change in the permeability of the drug
removal of the drug via a pump
overproduction of an enzyme in a key metabolic pathway
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inactivation of the drug
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Probiotics
involve the use of extracts from microorganisms.
involve microbial antagonism.
are an alternative to the use of chemotherapy involving microbial antagonism.
are an alternative to the use of chemotherapy.
is a term for resistance to antibiotics.
|
are an alternative to the use of chemotherapy involving microbial antagonism.
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Most drugs that inhibit the synthesis of the cell wall act by
blocking the secretion of cell wall molecules from the cytoplasm.
preventing the formation of alanine-alanine bridges.
preventing the formation of β-lactamases.
preventing the cross-linkage of NAM subunits.
disrupting the formation of the mycolic acid layer of the cell wall.
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preventing the cross-linkage of NAM subunits.
|
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Most broad-spectrum antibiotics act by
inhibiting protein synthesis.
inhibiting nucleic acid synthesis.
inhibiting metabolic pathways.
inhibiting the synthesis of the cell wall.
disrupting the cytoplasmic membrane.
|
inhibiting protein synthesis
|
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Which of the following antifungals works by inhibiting ergosterol synthesis?
amphotericin B
nystatin
turbinafine
fluconazole
both fluconazole and turbinafine
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both fluconazole and turbinafine
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Sulfonamides
were the first widely used antimicrobial drugs.
indirectly inhibit the synthesis of nucleic acids.
were the first widely used antimetabolic antimicrobial and indirectly inhibit nucleic acid synthesis.
are no longer widely used.
are antimetabolic drugs.
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were the first widely used antimetabolic antimicrobial and indirectly inhibit nucleic acid synthesis.
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Which of the following pathways is specifically inhibited by sulfonamides?
the conversion of dihydrofolic acid to PABA
the conversion of tetrahydrofolic acid to PABA
the conversion of dihydrofolic acid to tetrahydrofolic acid
the conversion of PABA to tetrahydrofolic acid
the conversion of PABA to dihydrofolic acid
|
the conversion of PABA to dihydrofolic acid
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Which of the following drugs inhibits nucleic acid synthesis specifically in prokaryotes?
5-fluorocytosine
rifampin
tetracycline
actinomycin
quinolones
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quinolones
|
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The cooperative activity of drugs such as beta-lactam antibiotics and clavulanic acid, a β-lactamase inhibitor, is known as
cross resistance.
selective toxicity.
antimetabolism.
chemotherapy.
synergism.
|
synergism
|
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Alterations in the structure of which of the following are an important aspect of Gram-negative bacterial resistance to antimicrobial drugs?
ribosomes
plasmids
porins
mitochondria
cytoplasmic membrane
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porins
|
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It is inappropriate to prescribe antibacterial agents to treat colds or flu because
these diseases are caused by viruses.
these diseases exhibit cross resistance.
these diseases are transmitted by endospores, which are hard to kill.
these diseases can act synergistically with each other.
the microbes involved can develop resistance rapidly.
|
these diseases are caused by viruses.
|
|
Who discovered the first widely available antibiotic?
Fleming
Ehrlich
Ehrlich and Waksman
Waksman
Domagk
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Domagk
|
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Which of the following statements is true of selective toxicity?
Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogen.
To be effective, an antimicrobial agent must be more toxic to the patient than the pathogen.
Antimicrobial agents must target structural differences between host and pathogen and be more toxic to the patient than the pathogen.
Selective toxicity takes advantage of structural differences between host and pathogen.
Selective toxicity takes advantage of metabolic differences between host and pathogen.
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Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogen.
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Antimicrobials that block protein synthesis by binding to the mRNA are
antisense nucleic acids.
macrolides.
beta-lactams.
aminoglycosides.
nucleic acid analogs.
|
antisense nucleic acids.
|
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The Etest determines which of the following?
susceptibility
MIC
MBC
both susceptibility and MIC
both MBC and MIC
|
both susceptibility and MIC
|
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Which of the following is NOT a criterion by which all antimicrobial agents can be evaluated?
their safety
their activity against cell walls
their efficacy
their route of administration
their spectrum of action
|
their activity against cell walls
|
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Which of the following interferes with cell wall synthesis by blocking alanine bridge formation?
beta-lactams
bacitracin
vancomycin
cycloserine
both cycloserine and vancomycin
|
both cycloserine and vancomycin
|
|
Antimicrobial sugar analogs are effective for
preventing bacterial protein synthesis.
preventing cell membrane synthesis.
preventing virus attachment.
blocking a metabolic pathway.
preventing nucleic acid synthesis.
|
preventing virus attachment.
|
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Which of the following is a measurement associated with the broth dilution test?
lack of turbidity
cell lysis
lack of turbidity and zone of inhibition
presence of turbidity and cell lysis
the zone of inhibition
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lack of turbidity
|
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Infection of the __________ would be the hardest to treat with antimicrobial drugs.
brain
colon
kidneys
liver
heart
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brain
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Disruption of the normal microbiota can result in infections caused by which of the following microbes?
Candida albicans
Clostridium difficile
Mycobacterium
both Mycobacterium and Clostridium difficile
Candida albicans, Mycobacterium, and Clostridium difficile
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Candida albicans, Mycobacterium, and Clostridium difficile
|
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The antimicrobials called quinolones act by
inhibiting cell wall synthesis.
inhibiting protein synthesis.
disrupting cytoplasmic membranes.
inhibiting a metabolic pathway.
inhibiting nucleic acid synthesis.
|
inhibiting nucleic acid synthesis
|
|
Amphotericin B is an antifungal drug that
inhibits cell wall synthesis.
inhibits protein synthesis.
inhibits nucleic acid synthesis.
blocks a metabolic pathway.
disrupts cytoplasmic membranes
|
disrupts cytoplasmic membranes
|
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The mechanism of action of the antibiotic vancomycin is
inhibition of cell wall synthesis.
inhibition of nucleic acid synthesis.
inhibition of protein synthesis.
disruption of cytoplasmic membranes.
inhibition of a metabolic pathway.
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inhibition of cell wall synthesis
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The tetracyclines interfere with
nucleic acid synthesis.
protein synthesis.
folic acid synthesis.
cell wall synthesis.
cell membrane component synthesis.
|
protein synthesis
|
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Trimethoprim is an example of antimicrobials that
inhibit cell wall synthesis.
inhibit nucleic acid synthesis.
disrupt cytoplasmic membranes.
inhibit metabolic pathways.
inhibit protein synthesis.
|
inhibit metabolic pathways.
|
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The mechanism of action of erythromycin is
disruption of cytoplasmic membranes.
inhibition of cell wall synthesis.
inhibition of protein synthesis.
inhibition of a metabolic pathway.
inhibition of nucleic acid synthesis.
|
inhibition of protein synthesis.
|
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Methicillin is an example of the beta-lactam class of drugs that
inhibit protein synthesis.
inhibit cell wall synthesis.
disrupt cytoplasmic membranes.
inhibit nucleic acid synthesis.
inhibit metabolic pathways.
|
inhibit cell wall synthesis.
|
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Ribavirin is an antiviral that interferes with
nucleic acid synthesis.
cell wall synthesis.
protein synthesis.
cell membrane component synthesis.
viral attachment.
|
nucleic acid synthesis
|
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The antimicrobial polymyxin
disrupts cytoplasmic membranes.
inhibits nucleic acid synthesis.
inhibits protein synthesis.
inhibits cell wall synthesis.
blocks a metabolic pathway.
|
disrupts cytoplasmic membranes
|
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The mechanism of action of sulfonamides is
inhibition of metabolic pathways.
inhibition of cell wall synthesis.
disruption of cytoplasmic membranes.
inhibition of protein synthesis.
inhibition of nucleic acid synthesis.
|
inhibition of metabolic pathways
|
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Organs that are commonly affected by drug toxicity include the kidneys and the liver.
True
False
|
true
|
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Paul Erhlich coined the term antibiotics for the "magic bullet" antimicrobials he pursued.
True
False
|
false
|
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Antisense nucleic acids are designed to have no side effects against humans.
True
False
|
true
|
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Many antimicrobial drugs that affect the cytoplasmic membrane are used only externally because they can be toxic to humans.
True
False
|
true
|
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If a subculture of an MIC test grows in an MBC test, the concentration of the drug was bactericidal.
True
false
|
false
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