b-lactamases Flashcards
ESBL (extended spectrum) (ambler class A)
CTX-M-15 enzyme
Serine Carbapenemases (ambler class A)
KPC1, KPC2, KPC3
Metallo-b-lactamases (ambler class B)
NDM-1
Cephalosporinases (class C)
Amp-C
OXA-type (class D)
OA-48
What is an ESBL
hydrolyze most penicillins, cephalosporins, and monobactams
treatment of choice for bug with CTX-M enzyme?
carbapenems (may use zosyn for urinary infection)
metallo b-lactamases
new dehli MBL (NDM-1), very limited tx options
CRE
carbapenem resistant enterobacterales
main mechanism for AmpC
inducible via chromosomally encoded AmpC genes
what is AmpC found in?
HECK-YES
hafnia alvei, enterobacter, citrobacter, Klebsiella, YerSinia
CRE (carbapenem resistant enterobacterales)
KPC genes
VanA or VanB gene
resistance to vanc. treatment includes daptomycin or linezolid
what 2 genes indicate MRSA?
mecA and altered PBP
aminoglycosides dosing strat
concentration dependent
b-lactams
time dependent
daptomycin
conc dependent
fluoroquinolones
conc dependent
vanc
time dependent
MRSA
mecA + PBP2A
