W5/L7 Flashcards
What’s the broad target of penicillins?
Cell wall synthesis
What’s the MoA of penicillins?
They bind PBP transpeptidases to inhibit peptidoglycan synthesis
Why do mycoplasma have intrinsic penicillin resistance?
Their cell wall doesn’t have peptidoglycan
Why does pseudomonas have intrinsic penicillin resistance?
Via the chromosomal beta-lactamases they always produce
Why can’t penicillin G be given orally?
It’s acid labile
What’s the acid-stable form of penicillin G?
Penicillin V
What drug do we treat penicillin-resistant staph with?
Flucloxacillin
What’s another name for co-amoxyclav?
Augmentin
What is co-amoxyclav?
Ampicillin/amoxycillin + clavulanic acid
What is clavulanic acid?
A “suicide inhibitor” of beta-lactamases
What is the penicillin used for pseudomonas? Why?
Carbenicillin - it’s more resistant to beta-lactamases
Which generation of cephalosporins are indicated for bacterial meningitis & why?
3rd generation. They penetrate the BBB
What are the two mechanisms of cephalosporin resistance?
Reduced PBP binding affinity
Acquisition of a beta-lactam insensitive PBP
Which bacteria have intrinsic vancomycin resistance? Why?
Gram -‘ve cells, as the molecule is to large and charged to penetrate their wall
What’s the MoA of glycopeptides?
Binds the terminal D-Ala-D-Ala, of peptidoglycan, which prevents their cross linking
