Chapter 20

Question 1

antimicrobials that kill microbes directly are called

Answer 1

bactericidal

Question 2

antimicrobials that prevent microbes from growing are called

Answer 2

bacteriostatic

Question 3

what is selective toxicity

Answer 3

selectively finding and damaging/destroying pathogens without damaging the host

Question 4

narrow-spectrum antimicrobials affect a narrow range of __

Answer 4

microbial types

Question 5

broad-spectrum antimicrobials affect a broad range of __

Answer 5

gram-positive and gram-negative bacteria

Question 6

what is a superinfection

Answer 6

overgrowth of normal microbiota that is resistant to antimicrobials

Question 7

treatment with ___ spectrum antimicrobials can lead to superinfections

Answer 7

broad

Question 8

What are the modes of action of antimicrobials?

Answer 8

• inhibition of cell wall synthesis
• inhibition of protein synthesis
• inhibition of nucleic acid replication and transcription
• injury to plasma membrane
• inhibition of essential metabolite synthesis

Question 9

how do penicillin and cephalosporins affect the cell wall of a microorganism?

Answer 9

prevent peptidoglycan synthesis

Question 10

ethambutol and isoniazid inhibit cell wall synthesis in mycobacteria by inhibiting the incorporation and synthesis of ____

Answer 10

mycolic acid

Question 11

streptomycin and chloramphenicol inhibit ___ synthesis by targeting bacterial 70S ribosomes

Answer 11

protein

Question 12

how do polymyxins and daptomycin inhibit membrane function?

Answer 12

bind to membrane and change permeability

Question 13

nalidixic acid and rifamycin inhibit ___ synthesis

Answer 13

nucleic acid

Question 14

sulfonamide and trimethoprim inhibit the synthesis of __ by inhibiting folic acid synthesis

Answer 14

metabolites

Question 15

What are the modes of action of antifungal drugs?

Answer 15

• inhibit mitochondria function
• inhibit DNA and RNA synthesis
• disrupt microtubule function
• disrupt membrane
• inhibit ergosterol synthesis
• inhibit synthesis of B(1–>3)
• inhibit chitin synthesis

Question 16

what are the mechanisms of resistance?

Answer 16

• enzymatic destruction of the drug
• prevention of penetration to the target site of the microbe
• alteration of the drug’s target site
• rapid efflux (ejection) of the antibiotic

Question 17

what are modes of action of antiviral drugs?

Answer 17

• block the receptors on the host cell that bind to the virus
• block fusion of the virus and cell
• prevent viral uncoating
• inhibit viral DNA integration into the host genome
• inhibit assembly and exit