Flashcards in Mechanisms of antibiotic resistance Deck (11):
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
Sensitivity testing - what does a greater zone of inhibition mean?
greater sensitivity to antibiotic (susceptible)
Mechanisms of drug resistance (5)
- no target = no effect
- Reduced permeability (drug can't get in!)
- Enzymatic degredation
- Altered target (mutations)
- Drug efflux
Absent target example
Treating infection that is non-bacterial
Reduced permeability examples
- Vancomycin has no effect on gram- bacteria
- Gentamicin - no effect on anaerobic organisms (uptake = O2 dependent)
Target alteration example
MRSA - altered penecillin binding protein does not bind Blactams
Enzymatic degredation example
penecillin and cephalosporins; B lactamases - breaks them down
Where are resistance genes encoded?
Name the mechanism by which resistance is transferred
What is meant by horizontal transfer of resistance?
Transferred between organisms - transporins and interns