Micro Ch. 10

a large percentage of antibiotics and semisynthetic drugs are produced by members of the genus 
a) Cephalosporium
b) Penicillium
c) Bacillus 
d) Mycobacterium 
e) Streptomyces

an antimicrobial that inhibits cell wall synthesis will result in which of the following? 
A) Cells become more susceptible to osmotic pressure 
B) Ribosomes lose their function 
C) Cells cannot attach to their hosts 
D) The replication of cells, including cancer cells, slows down
E) The sterols in the cell wall become nonfunctional

Beta-lactam antibiotics have an effect on which of the following types of cells? 
A) animal cells 
B) bacterial cells 
C) fungal cells 
D) virus-infected cells 
E) both animal and fungal cells

Which of the following is a primary advantage of semisynthetic drugs? 
A) have a broader spectrum of action 
B) must have a administered intravenously
C) are less stable and consequently have fewer side effects 
D) are not readily absorbed, so they persist longer
E) work faster 

Which of the following drugs specifically targets cell walls that contain arabinogalactan-mycolic acid?
A) penicillin
B) isoniazid 
C) vancomycin
D) bacitracin
E) methicillin

which of the following antibiotics disrupts cytoplasmic membrane function? 
A) erythromycin
B) tetracycline
C) streptomycin
D) penicillin 
E) amphotericin B

Which of the following is not a target of drugs that inhibit protein synthesis? 
A) movement of the ribosome from one codon to the next 
B) interference with alanine-alanine bridges
C) the enzymatic site of the 50S ribosomal subunit 
D) the tRNA docking site
E) the shape of the 30S ribosomal subunits 

Which scientist coined the term antibiotic?
A) Ehrlich
B) Fleming 
C) Domagk
D) Kirby
E) Waksman

The most limited group of antimicrobial agents is the ____ drugs 
A) antiprotozoan
B) anthelmintic 
C) antibacterial
D) antifungal 
E) antiviral

Another term for the Kirby-Bauer test is the 
A) diffusion susceptibility test 
B) E test 
C) minimum bactericidal concentration test 
D) minimum inhibitory concentration test 
E) broth dilution test

Which of the following statements about the zone of inhibition is FALSE? 
A) It is a clearing zone with no growth 
B) the larger the zone, the more resistant the organism 
C) It is measured after incubation
D) It is measured as a diameter 
E) It is a result of diffusion of the drug out of the paper disk 

Which of the following groups of drugs can become incorporated into the bones and teeth of a fetus? 
A) aminoglycosides 
B) tetracyclines 
C) quinolones 
D) sulfonamides
E) beta-lactams 

Which of the following can result when antibiotic therapy disrupts the normal microbiota? 
A) anaphylactic shock 
B) black hairy tongue 
C) pseudomembranous colitis and thrush
D) thrush 
E) both pseudomembranous colitis and thrush

Which of the following statements concerning development of antibiotic resistance is FALSE? 
A) It is often medicated by R-plasmids 
B) New resistance genes can be gained thru transformation, transduction, or conjugation
C) Resistant cells grow more efficiently and quickly than susceptible cells 
D) Resistant cells are normally in the minority in a bacterial population 
E) Resistance can occur thru mutation of existing bacterial genes

B-lactamase production is an example of which of the following types of resistance?
A) inactivation of the drug 
B) change in the permeability of the drug 
C) alteration of the target of the drug 
D) overproduction of an enzyme in a key metabolic pathway
E) removal of the drug via a pump

Probiotics 
A) are an alternative to the use of chemotherapy involving microbial antagonism
B) involve microbial antagonism 
C) is a term for resistance to antibiotics 
D) involved the use of extracts from microorganisms 
E) are an alternative to the use of chemotherapy

most drugs that inhibit the synthesis of the cell wall act by
A) blocking the secretion of cell wall molecules from the cytoplasm
B) preventing the formation of B-lactamase
C) preventing cross-linkage of NAM subunits 
D) disrupting the formation of the mycolic acid layer of the cell wall 
E) preventing the formation of alanine-alanine bridges 

Most broad-spectrum antibtiotics act by 
A) disrupting the cytoplasmic membrance
B) inhibiting metabolic pathways 
C) inhibiting the protein synthesis
D) inhibiting the synthesis of the cell wall 
E) inhibiting nucleic acid synthesis 

Which of the following antifungals works by inhibiting ergosterol synthesis? 
A) fluconzaole
B) turbinafine
C) amphotericin B 
D) nystatin 
E) both fluconazole and turbinafine

Sulfonamides 
A) were the first widely used antimicrobial drugs 
B) are antimetabolic 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

Which of the following pathways is a 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 PAB

22) Which of the following drugs inhibits nucleic acid synthesis specifically in prokaryotes?
A) quinolones
B) actinomycin
C) rifampin
D) tetracycline
E) 5-fluorocytosine

23) The cooperative activity of drugs such as beta-lactam antibiotics and clavulanic acid, a β-lactamase inhibitor, is known as
A) antimetabolism.
B) selective toxicity.
C) cross resistance.
D) synergism.
E) chemotherapy

24) Alterations in the structure of which of the following are an important aspect of Gram-negative bacterial resistance to antimicrobial drugs?
A) plasmids
B) porins
C) mitochondria
D) cytoplasmic membrane
E) ribosomes

25) It is inappropriate to prescribe antibacterial agents to treat colds or flu because
A) the microbes involved can develop resistance rapidly.
B) these diseases exhibit cross resistance.
C) these diseases can act synergistically with each other.
D) these diseases are transmitted by endospores, which are hard to kill.
E) these diseases are caused by viruses.

26) Who discovered the first widely available antibiotic?
A) Domagk
B) Ehrlich
C) Fleming
D) Waksman
E) Ehrlich and Waksman

27) Which of the following statements is true of selective toxicity?
A) To be effective, an antimicrobial agent must be more toxic to the patient than the pathogen.
B) Selective toxicity takes advantage of metabolic differences between host and pathogen.
C) Selective toxicity takes advantage of structural 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

28) Antimicrobials that block protein synthesis by binding to the mRNA are
A) macrolides.
B) antisense nucleic acids.
C) beta-lactams.
D) nucleic acid analogs
E) aminoglycosides.

29) The Etest determines which of the following?
A) susceptibility
B) MBC
C) MIC
D) both susceptibility and MIC
E) both MBC and MIC

30) Which of the following is NOT a criterion by which all antimicrobial agents can be evaluated?
A) their route of administration
B) their spectrum of action
C) their activity against cell walls
D) their efficacy
E) their safety

31) Which of the following interferes with cell wall synthesis by blocking alanine bridge formation?
A) beta-lactams
B) cycloserine
C) bacitracin
D) vancomycin
E) both cycloserine and vancomycin

32) Antimicrobial sugar analogs are effective for
A) preventing cell membrane synthesis.
B) blocking a metabolic pathway.
C) preventing virus attachment.
D) preventing nucleic acid synthesis.
E) preventing bacterial protein synthesis.

33) 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

34) Infection of the __________ would be the hardest to treat with antimicrobial drugs.
A) heart
B) kidneys
C) liver
D) brain
E) colon

35) Disruption of the normal microbiota can result in infections caused by which of the following microbes?
A) Mycobacterium
B) Candida albicans
C) Clostridium difficile
D) both Mycobacterium and Clostridium difficile
E) Candida albicans, Mycobacterium, and Clostridium difficile

36) The antimicrobials called quinolones act by
A) inhibiting cell wall synthesis.
B) disrupting cytoplasmic membranes.
C) inhibiting nucleic acid synthesis.
D) inhibiting a metabolic pathway.
E) inhibiting protein synthesis

37) Amphotericin B is an antifungal drug that
A) inhibits nucleic acid synthesis.
B) inhibits protein synthesis.
C) inhibits cell wall synthesis
D) disrupts cytoplasmic membranes.
E) blocks a metabolic pathway.

38) The mechanism of action of the antibiotic vancomycin is
A) inhibition of protein synthesis.
B) inhibition of a metabolic pathway.
C) inhibition of nucleic acid synthesis.
D) inhibition of cell wall synthesis.
E) disruption of cytoplasmic membranes