A. involve microbial antagonism.
B. are an alternative to the use of chemotherapy.
C. involve the use of extracts from microorganisms.
D. is a term for resistance to antibiotics.
E. are an alternative to the use of chemotherapy involving microbial antagonism.
Alterations in the structure of which of the following are an important aspect of Gram-negative bacterial resistance to antimicrobial drugs?
D. cytoplasmic membrane
Most drugs that inhibit the synthesis of the cell wall act by
A. preventing the cross-linkage of NAM subunits.
B. blocking the secretion of cell wall molecules from the cytoplasm.
C. preventing the formation of alanine-alanine bridges.
D. disrupting the formation of the mycolic acid layer of the cell wall.
E. preventing the formation of ?-lactamases.
Which of the following drugs inhibits nucleic acid synthesis specifically in prokaryotes?
Which of the following is NOT a criterion by which all antimicrobial agents can be evaluated?
A. their spectrum of action
B. their efficacy
C. their activity against cell walls
D. their route of administration
E. their safety
Which of the following works by inhibiting ergosterol synthesis?
C. amphotericin B
E. both fluconazole and turbinafine
Which of the following statements concerning development of antibiotic resistance is FALSE?
A. It is often mediated by R-plasmids.
B. Resistant cells are normally in the minority in a bacterial population.
C. Resistant cells grow more efficiently and quickly than susceptible cells.
D. New resistance genes can be gained through transformation, transduction, or conjugation.
E. Resistance can occur through mutation of existing bacterial genes.
Which of the following groups of drugs can become incorporated into the bones and teeth of a fetus?
?-lactamase production is an example of which of the following types of resistance?
A. alteration of the target of the drug
B. inactivation of the drug
C. change in the permeability of the drug
D. overproduction of an enzyme in a key metabolic pathway
E. removal of the drug via a pump
Which of the following is a measurement associated with the broth dilution test?
A. the zone of inhibition
B. lack of turbidity
C. cell lysis
D. lack of turbidity and zone of inhibition
E. presence of turbidity and cell lysis
Most broad-spectrum antibiotics act by
A. inhibiting the synthesis of the cell wall.
B. inhibiting protein synthesis.
C. inhibiting nucleic acid synthesis.
D. inhibiting metabolic pathways.
E. disrupting the cytoplasmic membrane.
A large percentage of antibiotics and semisynthetic drugs are produced by members of the genus
The Etest determines which of the following?
D. both susceptibility and MIC
E. both MBC and MIC
Which of the following statements is true of selective toxicity?
A. Selective toxicity takes advantage of structural differences between host and pathogen.
B. To be effective, an antimicrobial agent must be more toxic to the patient than the pathogen.
C. Selective toxicity takes advantage of metabolic differences between host and pathogen.
D. Antimicrobial agents must target structural differences between host and pathogen and be more toxic to the patient than the pathogen.
E. Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogen.
Which of the following is NOT a target of drugs that inhibit protein synthesis?
A. the shape of the 30S ribosomal subunit
B. interference with alanine-alanine bridges
C. the enzymatic site of the 50S ribosomal subunit
D. movement of the ribosome from one codon to the next
E. the tRNA docking site
Antimicrobial sugar analogs are effective for
A. preventing bacterial protein synthesis.
B. preventing cell membrane synthesis.
C. preventing virus attachment.
D. preventing nucleic acid synthesis.
E. blocking a metabolic pathway.
Antimicrobials that block protein synthesis by binding to the mRNA are
B. antisense nucleic acids.
E. nucleic acid analogs.
Who discovered the first widely available antibiotic?
E. Ehrlich and Waksman
A. are antimetabolic drugs.
B. were the first widely used antimicrobial drugs.
C. indirectly inhibit the synthesis of nucleic acids.
D. are no longer widely used.
E. were the first widely used antimetabolic antimicrobial and indirectly inhibit nucleic acid synthesis.
An antimicrobial that inhibits cell wall synthesis will result in which of the following?
A. Cells become more susceptible to osmotic pressure.
B. Cells cannot attach to their hosts.
C. Ribosomes lose their function.
D. The sterols in the cell wall become nonfunctional.
E. The replication of cells, including cancer cells, slows down.
Which of the following statements about the zone of inhibition is FALSE?
A. It is measured as a diameter.
B. The larger the zone, the more resistant the organism is.
C. It is a clearing zone with no growth.
D. It is a result of diffusion of the drug out of the paper disk.
E. It is measured after incubation.
Which of the following antibiotics disrupts cytoplasmic membrane function?
E. amphotericin B
Which of the following interferes with cell wall synthesis by blocking alanine bridge formation?
E. both cycloserine and vancomycin
Which of the following pathways is specifically inhibited by sulfonamides?
A. the conversion of tetrahydrofolic acid to PABA
B. the conversion of PABA to dihydrofolic acid
C. the conversion of dihydrofolic acid to tetrahydrofolic acid
D. the conversion of PABA to tetrahydrofolic acid
E. the conversion of dihydrofolic acid to PABA
Infection of the ________ would be the hardest to treat with antimicrobial drugs.
It is inappropriate to prescribe antibacterial agents to treat colds or flu because
A. the microbes involved can develop resistance rapidly.
B. these diseases are transmitted by endospores, which are hard to kill.
C. these diseases exhibit cross resistance.
D. these diseases are caused by viruses.
E. these diseases can act synergistically with each other.
Which of the following is a primary advantage of semisynthetic drugs?
A. They are less stable and consequently have fewer side effects.
B. They work faster.
C. They have a broader spectrum of action.
D. They must be administered intravenously.
E. They are not readily absorbed, so they persist longer.
The most limited group of antimicrobial agents is the ________ drugs.
The cooperative activity of drugs such as beta-lactam antibiotics and clavulanic acid,
A. cross resistance.
D. selective toxicity.
Disruption of the normal microbiota can result in infections caused by which of the following microbes?
B. Candida albicans
C. Clostridium difficile
D. both Mycobacterium and Clostridium difficile
E. Candida albicans, Mycobacterium, and Clostridium difficile
Which of the following drugs specifically targets cell walls that contain arabinogalactan-mycolic acid?
Which of the following can result when antibiotic therapy disrupts the normal microbiota?
A. anaphylactic shock
B. black hairy tongue
C. pseudomembranous colitis
E. both pseudomembranous colitis and thrush