antibiotic resistance Flashcards
What are the ESCAPPM organisms?
Gram -ve
These are inducible chromosomal mediated b-lactamase production. therefore will inactivate 3rd gen cephalosporins.
E Enterobacter species
S Serratia species
C Citrobacter species
A Acinetobacter species
P Pseudomonas aeruginosa
P Proteus vulgaris (ie. indole-positive Proteus species; not P. mirabilis)
M Morganella morganii
Describe susceptibility of enterococci
resistant to cephalosporin and fluclox
are inhibited (not killed) by penicillin and vancomycin
often not reflected in vivo.
Use GENTAMICIN +/- penicillin
Vancomycin has intrinsic resistance to?
gram negative.
only used for gram +ve
What is the mechanism of resistance of VRE (vancomycin resistant enterococci)?
D-ala D-Ala changed to D-Ala-D-Lac
so vanc can’t bind but can still cross-link
Mx of MRSA
sick –> vancomycin
hospital –> fusidic acid + rifampicin + linezolid
community –> Bactrim, clindamycin, ciprofloxacin
Mx of Vanc resistance staph aureus
IV teicoplanin and linezolid, daptomycin, tigecycline
oral: rifampicin + fusidic acid
Management of VRE
tigecycline, daptomycin
What is ESBL, mechanism, common organism and management
extended spectrum beta lactamases
mechanism: mutation in existing beta lactase genes
common organism: klebsiella, e.coli
management: meropenem, nitrofurantoin, colistin, tigecycline
what is the main mechanism of gram -ve resistance to linezolid?
reduced penetration
due to outer membrane barrier
What is the main mechanism of pseudomonas b-lactam resistance?
porin porin alteration
prevent entry of abx through the outer cell membrane
What is a mechanism b-lactam antibiotic resistance from MRSA?
penicillin-binding protein (PBP) modification
What does ampc- type b lactamase expression cause?
resistance to 1st-3rd gen cephalosporins
