Antimicrobial resistance Flashcards Preview

IDMM > Antimicrobial resistance > Flashcards

Flashcards in Antimicrobial resistance Deck (15):
1

General mechanisms of gaining resistance

Loss of genetic material
Gain of genetic material (e.g. plasmids or integrons)
Mutation of genetic material

2

General mechanisms of antibiotic resistance

1. enzymatic degradation of AB
2. Altered target
3. Decreased uptake/ Increased secretion
4. Bypass pathway

3

Examples of enzymatic degration of AB

Beta-lactamases (many kinds, for all types of beta-lactams)
Aminoglycoside inactivating enzyme

4

What does SPACE mean?

S: Serratia
P: Pseudomonas
A: Acinetobacter
C: Citrobacter
E: enterobacter

Are AmpC producers

5

Examples of altered AB targets

altered PCP
Ribosomal binding site alteration
DNA gyrase alteration
Change in aa on peptidoglycan chain
Dihydroopterate synthetase alteration
Dihydrofolate reductase alteration

6

Examples of bypass pathways

Using exogenous thymidine to make DNA instead of folate

7

Examples decreased uptake/ increased secretion of Ab

mefA pumps macrolides out
change in porin that allows B-lactam in

8

Mechanisms of resistance to B-lactams

1) beta-lactamases (ESBL is bad!)
2) Altered PBP
3) Porin mutation to increase efflux

9

Mechanisms of resistance to macrolides

1) change in ribosomal binding site
2) efflux pump (mefA)

10

Mechanisms of resistance to tetracyclines

Change in ribosomal binding site

11

Mechanisms of resistance to lincosamide

change in ribosomal binding site

12

Mechanisms of resistance to aminoglycosides

1) change in ribosomal binding site
2) inactivating enzymes

13

Mechanisms of resistance to fluoroquinolones

Point mutation in DNA gyrase/topoisomerase
Efflux pumps

14

Mechanisms of resistance to anti-folates

change in enzyme target site
bypass pathway using exogenous thymidine

15

Examples of superbugs

-MRSA

-VRSA

-VRE

-ESBL (bugs carrying ESBL..)

-CRE (carbapenem resistant enterobacteriaceae) with NDM (New Delhi metallo beta-lactamase) or KPC (Klebsiella pneumoniae cabapenemase)