Mechanisms of antibiotic resistance Flashcards Preview

Clinical Pathology > Mechanisms of antibiotic resistance > Flashcards

Flashcards in Mechanisms of antibiotic resistance Deck (11):
1

How do antibiotic resistance strains affect treatment?

- Risk of over treatment if resistance taken into account i.e. broad spectrum -> resistance
- Risk of under treatment i.e. if traditional antibiotics used
- Use of alternative treatments which are expensive, last line or toxic

2

Sensitivity testing - what does a greater zone of inhibition mean?

greater sensitivity to antibiotic (susceptible)

3

Mechanisms of drug resistance (5)

- no target = no effect
- Reduced permeability (drug can't get in!)
- Enzymatic degredation
- Altered target (mutations)
- Drug efflux

4

Absent target example

Treating infection that is non-bacterial

5

Reduced permeability examples

- Vancomycin has no effect on gram- bacteria
- Gentamicin - no effect on anaerobic organisms (uptake = O2 dependent)

6

Target alteration example

MRSA - altered penecillin binding protein does not bind Blactams

7

Enzymatic degredation example

penecillin and cephalosporins; B lactamases - breaks them down

8

Where are resistance genes encoded?

PLASMIDS

9

Name the mechanism by which resistance is transferred

Conjugation

10

What is meant by horizontal transfer of resistance?

Transferred between organisms - transporins and interns

11

What is meant by vertical transfer of resistance?

Resistance transferred to daughter cells of bacterial cell division

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