Resistance To Antimicrobial Agents

Question 1

How do you kill microbes?

Answer 1

Disinfectants:
- widespread damage
- denature proteins
- disrupt cell membranes
- oxidizing agents
Antiobiotics:
- selected target
- cell wall, DNA
- ribosomes
- synthetic pathways
- discrimiate

Question 2

What are the main mechanism of antibiotic resistance?

Answer 2

Altered receptor sites do not allow antibiotics to fit
Decreased permeabiliy of plasma membrane does not allow antiobiotic to enter
Antibiotics removed from cell via pumps
Antibiotics broken down by enzymes

Question 3

What are the B- lactam group of antibiotics?

Answer 3

Penicillins
Cephalosporins
Monobactams
Carbapenems
They inhibit the cell wall synthesis by binding to penicillin binding proteins(no peptidoglycan)

Question 4

Resistance in Staphylococcus aureus

Answer 4

Gram postive coccus
Coloniser of skin and nasal cavity
Important pathogen- causes pneumonia, wound infections, meningitis, toxic-shock syndrome
Treatment is usually penicillin, ampicillin resistant
80-90% strains now resistant
Production of penicillinase - breaks down certain B-lactam abx
SO treatment - Flucloxacillin designed to kill S. aureus that makes penicillinase

Question 5

Antibiotic resistance

Answer 5

Associated with:

• increased risk of hospitalisation
• increased length of stay
• increased hospital costs
• increased risk of death