Antibiotics - Morris Flashcards
How does MRSA acquire resistance?
Acquires SCCmecA
Produces altered PBPs
Beta lactamase inhibitor wont make a difference
Piperacillin - and Pip tazo spectrum of activity
Piperacillin = broad gram negative
PipTazo - Broad gram neg and anaerobes
Gut anaerobes are known for making
Beta lactamase
3rd gen Cephalosporins considered
Extended spectrum Beta lactams
Which carbapenem is very resistant to Pseudomonas?
Ertapenem!
Greatest value of the cephalosporins?
Effective against ESblactamases
Staph aureus resistant first due to
a beta lactamase
Mechanism of action of Vanco - (hint) how is it different from the beta lactams
- Binds directly D-ala D-ala
- Skips the PBPs -
- prevents crosslinking
Because of the size and shape of vanco what can’t it bind to?
Gram negative cell walls
what are some of the toxicities of Vanco?
Renal failure, nephrotoxic
VISA - vancomycin intermediately susceptible Staph - mechanism
Thickened cell wall
reduced access of vanco
VRSA-
Alteration of the D-ala to D-Lac
preventing binding prevent crosslinking
DNA gyrase is a …(type 2 Top)
Topoisomerase 2
- A tetramer
GryA GyrB 2 subunits each
works ahead of the replication fork
Topoisomerase 4 made up of (Type 2 top)
ParC and ParE
Works AFTER the replication fork
In Gram negatives the FQs target mainly…
DNA gyrase - GyrA especially