CH 20: Antimicrobial Drugs

Question 1

_____ includes drugs that combat disease in the body

Answer 1

Chemotherapy

Question 2

An _____ drug is a chemical substance that destroys pathogenic microorganisms with _____ damage to host tissues

Answer 2

antimicrobial ; minimal

Question 3

An antibiotic is a substance that can be produced by _____ that, in small amounts, inhibits another _____

Answer 3

microbes; microbe

Question 4

Selective toxicity is killing microbes _____ damaging the host

Answer 4

without

Question 5

Antimicrobials generally act either by directly killing microorganisms called _____ or by inhibiting their growth called _____

Answer 5

bactericidal; bacteriostatic

Question 6

Penicillin inhibits _____ synthesis in bacteria

Answer 6

cell wall

Question 7

Penicillin is more effective against _____ - _____ bacteria

Answer 7

gram - positive

Question 8

Chloramphenicol binds to _____ subunit of a ribosome and inhibits _____ bond formation

Answer 8

50S; peptide

Question 9

Streptomycin alters the shape of the _____ subunit of a ribosome so that proteins that are produced use the wrong amino acids

Answer 9

30S

Question 10

Tetracycline binds to the _____ subunit of the ribosome and blocks _____ attachment

Answer 10

30S; tRNA

Question 11

Macrolides bind to the _____ subunit of the ribosome and prevent _____ (the ribosome stalls and cannot proceed down the strand of mRNA)

Answer 11

50S; translocation

Question 12

The quinolones prevent the unwinding by binding to _____ and DNA _____

Answer 12

topoisomerase; gyrase

Question 13

Drug resistance factors can be acquired via random _____ or through _____ gene transfer between bacteria by conjugation or transduction

Answer 13

mutation; horizontal

Question 14

Antibiotic resistance of a bacterial population is measured by amount of antibiotic needed to control _____

Answer 14

growth

Question 15

Misuse of antibiotics selects for resistance mutants because the antibiotic exists at a level that is too _____ for complete killing or stasis

Answer 15

low

Question 16

The 5 misuses of antibiotics are:

Answer 16

1. using outdated or weakened
2. dose regiments are shorter than needed to eradicate infection
3. unnecessary or inappropriate to treat the problem pathogen
4. not used to treat disease but used in animal feed to promote growth
5. using someone else’s leftover rx

Question 17

The 4 modes of antibiotic resistance are:

Answer 17

1. blocking drug’s entry into cell
2. inactivation of the drug by enzymes
3. alteration (mutation) of drug’s target site
4. efflux pumps (ejection) that remove antibiotic from the bacterial cell

Question 18

Compare/Contrast bactericidal and bacteriostatic (give an example of each)

Answer 18

Comparison:

Both have modes of actions to target bacterial