Clinical Perspectives: Antibiotic Resistance

Question 1

What are the 3 antibiotic uses in clinical medicine?

Answer 1

1. Prophylaxis
2. Empiric use
3. Targeted use

Question 2

What are the 3 goals of antibiotic use?

Answer 2

1. Prevention or cure of infection with a minimum of toxicity to the patient
2. Minimum impact on the patient’s microbial flora
3. Minimum impact on the microbial flora of other patients/environment

Question 3

What are the 5 principles of antimicrobial resistance?

Answer 3

1. Likely to emerge given sufficient time and drug use
2. Progressive: evolving from low levels through intermediate to high levels
3. Organisms that are resistant to one drug are likely to become resistant to other antibiotics
4. Once resistance appears, it is likely to decline slow, if at all
5. Use of antibiotics by one person affects others in the extended and immediate healthcare environment

Question 4

What must initial therapy of a severe infection cover?

Answer 4

Gram negative and gram positive bacteria. Yeast (if pt is at risk i.e. central line or prolonged hospitalization).

Question 5

T or F. Initial therapy of serious infections is critical and determines mortality, loss of susceptibility, and cost of therapy.

Answer 5

T.

Question 6

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

Answer 6

1. Delay in effective therapy
2. Different patient population
3. Higher virulence of isolates
4. Lower efficacy of vancomycin for MRSA than beta-lactams for MSSA

Question 7

What is AbaR1 and what does it do?

Answer 7

It is an 86kb region resistance island that contains a cluster of 45 resistance genes in the MDR Acinetobacter organism.

Question 8

What is collateral damage?

Answer 8

Used to refer to ecological adverse effects of antibiotic therapy; namely, the selection of drug-resistant organisms and the unwanted development of colonization of infection with MDR organisms.

Question 9

What 2 antibiotic classes are commonly linked to collateral damage?

Answer 9

1. Cephalosporins

2. Quinolones

Question 10

What are the 7 common risk factors for nosocomial colonization/infection for MRSA, VRE, ESBL, GNRs, C difficile, and Candida?

Answer 10

1. Advanced age
2. Underlying diseases and severity of illness
3. Inter-institutional transfer, esp from nursing homes
4. Prolonged hospitalization
5. GI surgery or transplantation
6. Invasive devices of all types, esp CVLs
7. Exposure to antibiotics, esp cephalosporins