Micro Chapter 9 Flashcards
Which of the following scientists started the modern era of chemotherapy with the discovery that trypan red dye destroyed trypanosomes, the causative agent of African sleeping sickness? A) Paul Ehrlich B) Sahachiro Hata C) Gerhard Domagk D) Selman Waksman
A
Which of the following scientists was instrumental in the discovery and production of penicillin? A) Alexander Fleming B) Howard Florey C) Ernst Chain D) All of the above
D
Which of the following scientists discovered streptomycin, an antimicrobial treatment for tuberculosis? A) Paul Ehrlich B) Sahachiro Hata C) Gerhard Domagk D) Selman Waksman
D
An antimicrobial’s therapeutic index is
A) The drug level required for clinical treatment of an infection
B) The drug level at which the agent becomes too toxic for the host
C) The ratio of the toxic dose to the therapeutic dose
D) The level of effectiveness in a population
C
A drug that inhibits growth of microbial cells, damages host tissues, and results in undesirable side effects has a \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ therapeutic index. A) Low B) Moderate C) High D) None of the above
A
Which of the following groups functions as a narrow-spectrum antibiotic? A) Cephalosporins B) Vancomycin C) Trimethoprim D) Chloramphenicol
B
Which of the following groups functions as a broad-spectrum antibiotic? A) Tetracyclines B) Dapsone C) Polymyxin B D) Quinolones
A
The minimal inhibitory concentration (MIC) is
A) The lowest concentration of a drug that inhibits infection
B) The lowest concentration of a drug that kills the host
C) The lowest concentration of a drug that prevents growth of a particular pathogen
D) The lowest concentration of a drug that kills the pathogen
C
The level of antimicrobial activity of a drug can be estimated from A) Dilution susceptibility tests B) Disk diffusion tests C) The Etest D) All of the above
D
In the Kirby-Bauer method, a large zone of inhibition means that the pathogen is
A) More likely to kill the host
B) More susceptible to the antibiotic
C) Less susceptible to the antibiotic
D) Less likely to cause disease in any host
B
A plot of minimal inhibitory concentration (MIC) versus diameter of the zone of inhibition is used to estimate the degree of microbial resistance to a drug in the A) Dilution susceptibility test B) Kirby-Bauer method C) Etest D) None of the above
B
The most selective antibiotics are those that A) Inhibit cell wall synthesis B) Inhibit protein synthesis C) Act as metabolic antagonists D) Inhibit nucleic acid synthesis
A
The most important feature of the penicillin molecule is the A) Amino sugars B) Lactone groups C) Beta-lactam ring D) Multi-ring structures
C
Penicillins work by
A) Activating autolytic enzymes
B) Blocking the transpeptidation reaction that forms peptidoglycan cross-links
C) Stimulating holins to form holes in the plasma membrane
D) All of the above
D
Which of the following is a naturally produced antibiotic? A) Ampicillin B) Carbenicillin C) Ticarcillin D) Penicillin G
D
Which of the following antibiotics inhibits cell wall synthesis? A) Macrolides B) Vancomycin C) Sulfonamides D) Quinolones
B
In addition to penicillins, which group of antibiotics also exhibits a beta-lactam ring structure? A) Trimethoprim B) Sulfonamides C) Cephalosporins D) Chloramphenicol
C
Which of the following antibiotics is the "drug of last resort" in cases of antibiotic-resistance Staphylococcus aureus infections? A) Aminoglycosides B) Vancomycin C) Chloramphenicol D) Sulfonamides
B
Aminoglycosides work by
A) Inhibiting the binding of aminoacyl-tRNA molecules to the A site of ribosomes
B) Binding to the small ribosomal subunit to interfere with protein synthesis
C) Inhibiting peptide chain elongation during protein synthesis
D) Inhibiting the peptidyl transferase reaction
B
