Antibiotic Resistance Infections

Question 1

Beta-lactams are effective against Gram +/ Gram Negative?

Answer 1

Gram Positive

Question 2

Beta Lactams bind

Answer 2

penicillin binding proteins blocking cross linking causing cell death

Question 3

MRSA has altered Penicillin Binding protein and decreased affinity for all B-lactams. This was likely acquired from:

Answer 3

Coag-negative Staph

Question 4

Vancomycin binds to

Answer 4

Cell wall precursors

Question 5

T/F: Vancomycin Resistant Enterococci (VRE) use alternative precursors for cell wall, vanA and vanB are most common genes, and acquired from environment and other strep species?

Answer 5

True

Question 6

T/F: VRSA was first seen in 2002 with few reports and all the organisms contained the vanB gene?

Answer 6

False: contained vanA

Question 7

Which of the following does not have activity against MRSA?
A) Bactrim
B)Clindamycin
C) Ertapenem
D) Linezolid
E) Tigecycline

Answer 7

C) Ertapenem- B-lactam drug

Question 8

Treatment for S. Aureus skin and soft tissue infections:
A) For a boil
B) MSSA
C) MRSA

Answer 8

A) Surgical drainage- usually adequate
B) Oxacillin/Nafcillin
C) Vanco, Linezolid, Daptomycin, Tigecycline

Question 9

What antibiotic causes C. difficile?

Answer 9

Clindamycin

Question 10

T/F: Linezolid is superior to vancomycin for treating MRSA pneumonia

Answer 10

False: Equivalent

Question 11

Therapy for MRSA pneumonia

Answer 11

Start with Vancomycin, then linezolid. Do not use Daptomycin (inactivated by surfactant)

Question 12

Therapy for MRSA Bacteremia

Answer 12

Start with Vancomycin, then Daptomycin

Question 13

What are 3 mechanisms that decrease permeability in gram negative organisms?

Answer 13

1) Decreased porin expression
2) Active efflux pumps
3) Multi-drug efflux pumps

Question 14

Definition of multidrug-resistant

Answer 14

Resist at least one agent in 3 or more classes

Question 15

What class of drugs was created to overcome Beta-lactamases?

Answer 15

3rd generation cephalosporins

Question 16

4 risk factors for extended spectrum Beta lactamases (ESBL) are:

Answer 16

Location, Antibiotic use, Severity of illness, Devices

Question 17

Clinical presentations of ESBL infections:

Answer 17

UTI, Wound infections, pneumonia, intra-abdominal infections

Question 18

Which of the following is the drug of choice for severe ESBL producing organism infections?
A) FQ
B) TMP/SMX
C) Cefepime
D) Piperacillin/tazobactam
E) Carbapenems

Answer 18

E) Carbapenems

Question 19

T/F: You can use cephalosporins for ESBL treatment

Answer 19

False. DO NOT USE!

Question 20

Carbapenamases hydrolyze all:

Answer 20

Beta-lactams

Question 21

What can make Klebsiella pneumoniae and E.coli highly resistant to almost every drug?

Answer 21

NDM-1: New Delhi Metallo-beta-lactmase 1

Question 22

Treatment for Carbapenemase Producers

Answer 22

No beta lactams. Colistin (nephrotoxic, neurotoxic)? Tigecycline (increased mortality)?

Question 23

Mutation in DNA gyrase and/or topoisomerase IV are alteration in enzymes leading to what type of resistance?

Answer 23

Quinolone resistance in gram-negative pathogens