Protein synthesis inhibitors: bactericidal or bacteriostatic?
Bacteriostatic - only one group is bactericidal... (Aminoglycosides)
Functions of ribosome at:
2. Peptidyl-transferase activity; Exit tunnel
*Both have P, A sites
Mnemonic for 30s versus 50s protein synthesis inhibitors
"Buy AT 30s, CCEL at 50s"
1. 30s inhibitors
2. 50s inhibitors
c. Erythromycin (macrolides)
d. Linezolid (variable)
50s inhibitor with SEVERELY toxic effects
Mechanisms that bacteria use to become resistant to antibiotics by physically changing the antibiotic
1. Cleave critical bonds in antimicrobial
2. Add small groups to antimicrobial
Beta-lactamase is very common in what bug?
Staphylococcus (S. aureus)
Timeline of S. aureus resistance
1. 1940s: penicillin resistance
2. 1960: methicillin resistance (MRSA)
General mechanisms that bacteria use to become resistant to antibiotics
1. Active efflux of antibiotic out of site
2. Loss of entry of antibiotic to site
3. Cleave critical bonds in antimicrobial
4. Add small groups to antimicrobial
Efflux leads to what type of antibiotic resistance? Which bug?
1. Macrolide (Erythromycin) resistance
Mechanisms of S. aureus antibiotic resistance
1. Inactivation of antibiotic - penicillinase
2. Acquisition of new target - alternative PBP (transpeptidase)
3. Efflux of antibiotic - pump for macrolides