French lecture 1

Question 1

What are the 4 mechanism of selective activity exploited in fighting bacteria? (BONUS: can you give some examples of each?)

Answer 1

1.) Inhibit pathway found in bacteria but not humans (ex folate synthesis) 2.) Inhibit pathway that exists in both humans and bacteria in ways specific to bacteria (ex target difference in ribosomes, target DNA gyrase which is similar to topoisomerase) 3.) Target macromolecular structure that does not exist in humans (ex target cell wall) 4.) Target macromolecular structure that is different in bacteria (ex target cell membrane component ergosterol in fungi which is similar to cholesterol)

Question 2

Define bactericidal.

Answer 2

Kill bacteria.

Question 3

Define bacteriostatic.

Answer 3

Stop bacteria growth and allow immune system to mop it up.

Question 4

Which antibiotics are bactericidal? (general classes bold/underlined from this unit)

Answer 4

Penicillins, cephalosporins, vancomycin, aminoglycosides, quinolones&fluoroquinolones, metronidazole

Question 5

Which antibiotics are bacteriostatic? (general classes bold/underlined from this unit)

Answer 5

Tetracylines, macrolides, chloramphenicol

Question 6

Which methods of killing bacterial are bactericidal?

Answer 6

Inhibit cell wall synthesis, disrupt cell membrane function, interfere with DNA function or synthesis

Question 7

Which methods of killing bacterial are bacteriostatic?

Answer 7

Inhibit protein synthesis (except amino glycosides which are -cidal), inhibit intermediary metabolic pathways

Question 8

T or F: Bacteriostatic agents are best for immunocompromised individuals.

Answer 8

False. Require bactericidal agents.

Question 9

Define antibacterial spectrum.

Answer 9

The number and type of different bugs killed by a certain antibiotic.

Question 10

What are the 3 mechanisms of antibacterial resistance.

Answer 10

Natural, escape, acquired

Question 11

What happens in the escape method of resistance?

Answer 11

The antibiotic reaches bacteria, but the environmental conditions promote the bacteria survival despite the antibiotic.

Question 12

What plasmid gene encodes for drug resistance?

Answer 12

MDR gene

Question 13

What happens in the natural method of resistance?

Answer 13

The antibiotic chosen is simply not capable of killing the bacteria because the bacteria natually lack the target for that antibiotic.

Question 14

What happens in the acquired method of resistance?

Answer 14

Bacteria mutate or receive a plasmad that confers antibiotic resistance.

Question 15

What mechanisms can a bacteria use to become antibiotic resistant? (5 things)

Answer 15

1.) Alter the antibiotic target 2.) Destroy the antibiotic with enzymes 3.) Up-regulate alternative resistant metabolic pathways 5.) Decrease influx 5.) Increase efflux

Question 16

How can you minimize resistance?

Answer 16

Only use antibiotics when necessary, select the antibiotic that kills the most bacteria, use adequate concentrations and durations to prevent escape of bacteria

Question 17

T or F: Bacteriostatic agents are preferred in severe infections.

Answer 17

False. Bactericidal

Question 18

T or F: Bactericidal agents and bacteriostatic agents take approximately the same amount of time to act.

Answer 18

False. Bactericidal agents act more quickly, action is irreversible, and may have sustained effect after drug is eliminated from blood.

Question 19

What are the two most common routes of administration for antibiotics?

Answer 19

IV and oral

Question 20

What are the advantages of the oral route of antibiotic administration?

Answer 20

Ease, patient acceptance, lower cost

Question 21

What are the disadvantages of the oral route of antibiotic administration?

Answer 21

GI upset, alteration of intestinal flora, lack of absorption, unsuitable for patients who are npo

Question 22

What are the advantages of the IV route of antibiotic administration?

Answer 22

Rapid and predictable plasma levels

Question 23

What are the disadvantages of the IV route of antibiotic administration?

Answer 23

Need greater training to administer, more expensive, require strict antiseptic conditions