Abx Resistance Clinical Perspective

Question 1

What are the 5 principles of Abx resistance?

Answer 1

1. resistance is likely to emerge given sufficient time and drug use
2. abx resistance is progressive (low–> intermediate –> high levels of resistance)
3. orgs that are resistant to one abx are likely to become resistance to other abx (for expl, thru plasmid conjugation)
4. once resistance appears, it rarely goes away
5. use of abx by one person affects people around them

Question 2

T or F: resistance against abx can persist for 12 mos after administration of abx therapy

Answer 2

true = WHEN TREATING TH EPT AVOID THE USE OF THE SAME CLASS OF ABX FOR AT LEAST 12 MOS (concerned about reinfection by the same organsim)

Question 3

WHat is the similarity btwn cancer and infection?

Answer 3

cancer and infections both can mutate as a result of applied therapy (but the mutated cancer is not contagious)

Question 4

What are the 3 uses in clinical medicine?

Answer 4

1. prophylactic use
2. empiric use
3. targeted use

Question 5

What are the 3 goals of abx use?

Answer 5

1. prevention or cure of infection with minimal toxicity
2. minimal impact on pt’s flora
3. minimal impact on flora of other pt/enviro

Question 6

What are the 3 “players” that need to be considered when treating an infection?

Answer 6

1. pt
2. abx agent
3. microbe

Question 7

What class of abx have the highest rate of adverse rxns?

Answer 7

sulfa- and clinda-

Question 8

What % of S. aurea are MRSA?

Answer 8

62%

Question 9

What % of S. epidermis is MRSE?

Answer 9

67%

Question 10

___% of E. coli is cipro resistant?

Answer 10

42%

Question 11

___% of S. pneumoniae is cipro resistant?

Answer 11

36%

Question 12

___% of E. clocae is ceftriaxone resistant?

Answer 12

41%

Question 13

The initial coverage of a seriously ill infected patient must include …

Answer 13

coverage of abx rest. gram + and gram - (and yeast if pt is at risk)

Question 14

Once the etiology of an infection is determined the treatment must be …

Answer 14

de-escalated to limit toxicity and the emergence of new resistance (and cos too)

Question 15

Initial therapy of serious infections is critical and determines…

Answer 15

mortality
LOS (length of stay)
cost of therapy

Question 16

What are the 4 possible reasons of higher mortality of MRSA bacteremia?

Answer 16

1. delay in effective therapy
2. diff pt population
3. higher virulence of isolates
4. lower efficacy of vancomycin for MRSA then B-lactams for MSSA

Question 17

What are drugs acinetobacter anitratus bacteremia and pneumonia resistant to?

Answer 17

aztreonam
cefoperazone
cefotaxime
ceftazidime
ciprofloxacin
gentamicin
tobramycin
ticarcillin
TMP/SMX

Question 18

What are drugs acinetobacter anitratus bacteremia and pneumonia susceptible to?

Answer 18

imipenem
amphicillin/sulbactam
amikacin
tigercycline

Question 19

What are drugs acinetobacter anitratus bacteremia and pneumonia treated with?

Answer 19

imipenem

Question 20

Describe the gene that conferes acinetobacter resistance.

Answer 20

resistance island of 45 resistance genes (AbaR1 resistance island)

Question 21

What is collateral damage?

Answer 21

ecological adverse effects of abc therapy (–> selection of drug resistant orgs)

Question 22

What are the 2 abx classes commonly liked to collateral damage?

Answer 22

cepalosporins and quinolones

Question 23

What are the common risk factors for nosocomial infection?

Answer 23

• advanced age
• severity of illness
• transfer from nursing homes
• prolonged hospitalization
• GI surgery or transplantation
• invasive devices (esp CVL)
• exposure to abx (esp cephalosporins)