Deck 13: Antimicrobial Therapy

Question 1

Mutation of DNA that produces an altered ribosome is an example of what type of bacterial resistance mechanism?

A) alteration of a metabolic pathway
B) alteration of an enzyme
C) development of enzymes
D) alteration of target

Answer 1

D

Question 2

Side effects due to antimicrobial agents may involve all of the following except

A) allergic reactions
B) anaphylactic shock
C) disruption of microbial flora
D) increased antibiotic susceptibility of replacement microflora

Answer 2

D

Question 3

A microorganism that can use ready-made folic acid from its environment and no longer needs to synthesize it from the PABA precursor demonstrates an example of what type of antimicrobial resistance mechanism?

A) alteration of an enzyme
B) alteration of targets
C) development of enzymes
D) alteration of a metabolic pathway

Answer 3

D

Question 4

Which of following is not a way to limit the ability of microorganisms to acquire drug resistance?

A) high levels of antimicrobial agent in the patient
B) inhibiting growth of invading microbes so immune defenses can kill them
C) taking antibiotics until the patient feels better
D) taking two antibiotics synergistically

Question 5

Which of the following is not considered a mode of action by antimicrobial agents?

A) Inhibition of protein synthesis.
B) Inhibition of cell wall synthesis.
C) Inhibition of membrane permeability.
D) Disruption of selective toxicity.

Question 6

Purine or pyrimidine analogs:

A) act as antimetabolites
B) inhibit ribosome function
C) disrupt cell membrane function
D) inhibit cell wall function

Question 7

Which of the following directly pertain to inhibition of cellular protein synthesis by antimicrobial agents?

A) cellular cytoplasm is lost
B) binding and inhibition of RNA polymerase
C) imitation or molecular mimicry of normal molecules
D) interferes with accurate translation of mRNA message

Question 8

Selective toxicity

A) harms the microbes without significantly harming the host.
B) causes host damage without causing significant damage to the microbe.
C) is the maximum tolerable dose of a drug per kilogram of body weight.
D) is the same as the spectrum of activity for any given drug.

Question 9

Mechanisms of bacterial resistance to antimicrobial agents include all of the following except

A) alteration of ribosomes
B) alteration of an enzyme
C) development of enzymes
D) alteration of normal microflora

Question 10

A special group of chemical substances that are used to treat diseases caused by microbes:

A) antibiotics
B) synthetic drugs
C) semi-synthetic drugs
D) antimicrobial agents

Question 11

Rifamicin

A) inhibits RNA synthesis
B) inhibits nucleic acid synthesis
C) disrupts cell membrane function
D) acts as an antimetabolite

Question 12

Polypeptide antibiotics that act as detergents and distort bacterial cellular membranes do so by:

A) acting as antimetabolites
B) inhibiting cell wall synthesis
C) disrupting cell membrane function
D) inhibiting nucleic acid synthesis

Question 13

Paul Ehrlich

A) coined the term chemotherapy
B) discovered salvarsan in 1910
C) discovered the antibiotic streptomycin
D) accomplished two of the above.

Question 14

Destruction or inactivation of antimicrobial agents is an example of what kind of bacterial resistance mechanism?

A) target alteration
B) membrane permeability alteration
C) enzyme development
D) enzyme alteration

Question 15

The mode of action of an antimicrobial agent refers to

A) killing of all microorganisms.
B) inhibition of growth of bacteria.
C) how it exerts its effects upon microorganisms.
D) the broad spectrum of activity of the antimicrobial agent.

Question 16

Penicillin was discovered by ____________ and was isolated by ________ .

A) Gerhard Domagk; Alexander Fleming
B) Selman Walksman; Ernest Fourneau and Paul Erhlich
C) Ernst Chain and Howard Florey; Paul Erhlich
D) Alexander Fleming; Ernst Chain and Howard Florey

Question 17

Antibiotics inhibit protein synthesis

A) by disrupting cell membrane fraction
B) by binding to 80S ribosomal subunits
C) by interfering with the accurate reading of the mRNA message
D) by binding to a 60S ribosomal subunit

Question 18

Because the tetracyclines are effective against a large variety of different organisms,they are considered to

A) be narrow-spectrum drugs
B) have a therapeutic dosage level
C) be bacteriocidal
D) be broad-spectrum drugs

Question 19

Any chemical substance used in medical practice is known as a/an

A) antibiotic
B) antimicrobial agent
C) semi-synthetic drug
D) chemotherapeutic agent

Question 20

Antibiotics bind to RNA polymerase and

A) act as base analogs
B) inhibit cell wall synthesis
C) disrupt cell membrane function
D) inhibit transcription

Question 21

Determining microbial sensitivity to an antimicrobial agent by using a filter paper soaked with the drug on a bacterial lawn on an agar plate is called:

A) dilution method
B) disk diffusion method
C) automated testing
D) phage typing

Question 22

Which one of the following antimicrobial agents is an inhibitor of cell wall synthesis?

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

Question 23

The characteristic that applies to an ideal antimicrobial agent:

A) allergenic
B) instability
C) short shelf life
D) selective toxicity

Question 24

Antibiotics that contain a beta-lactam ring

A) bind to and cross-link peptidoglycans
B) act as an antimetabolite
C) bind to a bacterial RNA polymerase
D) are erroneously incorporated as nucleic acids

Question 25

Resistance of a microorganism to an antibiotic

A) means that the microorganism is susceptible to the antibiotic
B) can be acquired by genetic changes as well as by non-genetic mechanisms
C) leads to a disruption of cell membrane function
D) leads to a disruption of normal microflora

Question 26

Which of the antibiotics inhibit protein synthesis in susceptible bacteria?

A) amikacin
B) tyrothricin
C) vancomycin
D) cephalexin

Question 27

Characteristics of an ideal antimicrobial agent include all of the following except

A) resistance by microorganisms
B) reasonable cost
C) long shelf life
D) toxicity not easily altered

Question 28

A test to determine the effectiveness of an antimicrobial agent that uses growth of a test microorganism in patients' blood serum:

A) disk dilution method
B) dilution method
C) disk diffusion method
D) serum killing power method

Question 29

The mode of action of penicillin is

A) inhibition of cell wall synthesis
B) disruption of cell membranes
C) inhibition of protein synthesis
D) inhibition of nucleic acid synthesis

Question 30

Clear area on agar that surrounds a filter paper disk on the disk diffusion tests and represents inhibited growth of a test microorganism is called:

A) minimum inhibitory concentration
B) minimum bactericidal concentration
C) zone of inhibition
D) serum killing power

Question 31

Chloramphenicol,a bacteriostatic antimicrobial agent,is an inhibitor of:

A) nucleic acid synthesis
B) cell wall synthesis
C) cell membrane function
D) protein synthesis

Question 32

What antibiotic kills bacteria by disrupting their cell membranes?

A) erythromycin
B) rifampin
C) tetracycline
D) polymyxin B

Question 33

Which of the following antibiotics is an inhibitor of DNA gyrase?

A) ethambutol
B) ciprofloxacin
C) tobramycin
D) neomycin

Question 34

The lowest concentration of drug that yields no growth during a dilution method is called

A) minimum bactericidal concentration
B) minimum inhibitory concentration
C) mutant prevention concentration
D) serum killing power

Question 35

Antimetabolites include all of the following except

A) trimethoprin
B) isoniazid
C) nitrofurantoin
D) sulfanilamide

Question 36

The ideal antimicrobial agent

A) should be soluble in body fluids
B) have an unpredictable toxicity
C) should have interactions with other drugs or foods
D) all of these criteria are met by most antimicrobial agents

Question 37

Which does not involve testing microbial sensitivity to antimicrobials?

A) disk diffusion method
B) dilution method
C) minimum inhibitory concentration
D) toxic dosage level

Question 38

Imidazoles and triazoles are antimicrobial agents that are effective:

A) bacteriostatic agents
B) bactericidal agents
C) antifungal agents
D) antiviral agents

Question 39

A decreased efficacy of an antimicrobial agent during combination therapy is called

A) antagonism
B) cross-resistance
C) synergism
D) second-line

Question 40

The development of second-line and third-line antimicrobial agents demonstrates

A) cross-resistance
B) the effectiveness of first-line drugs
C) an effective method to limit drug resistance
D) the increasing difficulty of treating drug resistant bacteria

Question 41

A patient comes to you from a nursing home with a high fever. Is it better to start the patient on a broad spectrum drug or a narrow spectrum drug? Is it better to start the patient on one antibiotic or multiple antibiotics? Defend your decision.

Question 42

The sulfonamide antibiotics kill bacteria by

A) interfering with cell wall synthesis
B) disrupting folic acid metabolism
C) reacting with bacterial cell membranes
D) inhibiting bacterial motility

Question 43

Describe three mechanisms for antibiotic resistance. If exposure to antibiotics does not induce drug-resistant mutations to occur,why do we see so many more drug-resistant strains today?

Question 44

Which one of the following pairs is incorrectly matched with antibiotic and its target?

A) penicillin; gram positive bacteria
B) nystatin; fungi
C) tetracycline; viruses
D) griseofulvin; fungi

Question 45

Why are resistant organisms found often in hospitalized patients?

A) stringent efforts maintain sanitary conditions
B) many infections in patients are being treated with different antibiotics
C) doctors are treating outpatients with multiple antibiotics
D) two of the above

Question 46

Interferons and immunoenhancers

A) are widely used to treat viruses
B) cause no side effects
C) include levamisole and inosiplex
D) have been thoroughly researched

Question 47

Tetracyclines interfere with

A) the effectiveness of birth control pills
B) transcription
C) patients with heart defects
D) metabolic reactions

Question 48

Rimantadine is an effective antimicrobial agent against:

A) viruses
B) protozoa
C) bacteria
D) fungi

Question 49

A Candida albicans infection of the intestine,vagina or oral cavity is commonly treated with

A) cefotaxime
B) rifampin
C) streptomycin
D) nystatin

Question 50

Cephalosporins are not

A) wide spectrum antibiotics
B) antibiotics with few side effects
C) disruptors of cell membrane function
D) used prophylactically in patients undergoing surgery

Question 51

Metronidazole

A) is effective against viruses
B) has no side effects
C) prevents overgrowth of Candida yeast infections
D) is useful in the treatment of amoebas and Giardia

Question 52

Describe the targets or action for 3 of the following: antifungal agents,antiviral agents,antiprotozoan agents and antihelminthic agents.

Question 53

Examples of antiviral agents include all of the following agents except

A) acyclovir
B) ribavirin
C) quinine
D) zidovudine (AZT)