Resistance and Problems Flashcards
Production of coagulase
S. aureus
Production of glycocalyx
Coagulase negative staph
Antiphagocytic capsule
S. pneumoniae
Dextrans (heart valve damage)
Viridans
RHO GTPase inhibitors
C. difficile
GNR resistant to penicillin, cephalosporin, and erythromycin
Pseudomonas
Gram Negative anaerobe causing abdominal infections but usually part of normal flora
B. fragilis
Production of M protein
Pyogenes
Antigenically distinct pili
Gonorrhea
Lack of cell wall
Mycoplasma
Intracellular
Chlamydia
VanA
Vancomycin resistance
Plasmid
Enterococci is main bacteria (faecium common)
Erm
Macrolide resistance
Dimethylation of rRNA –> can’t bind ribosome
Inducible or constitutive: erythromycin resistant if inducible, clidamycin as well if constitutive
Inducible if (+) D test: still sensitive to clindamycin
GyrA mutation
Fluoroquinolones
Accumulation of point mutations
KPC and NDM-1
Cephalexin and carbapenems
K. pneumoniae (rare) and E. coli (super rare)
Found on plasmids
TEM-1
Amoxicillin
mecA
Alter PBP to PBP2a confers resistance to pencillin and cephalosporin
bla gene
Resistance to penicillin found in all staph
Led to development of ampicillin
How many strep have beta lactamase
0%. Resistance via altered PBP
E. faecium vs E. faecalis beta lactam resistance
E. faecium - mutation/overexpression of PBP5
E. faecalis - beta lactamase on plasmid (rare)
Pseudomonas resistance to FluoroQs
Efflux and altered target site
Pseudomonas resistance to beta lactams
Decreased entry
K. pneumonia resistance
SHV-1 chromosomal genes
Penicillin, amp/amox resistance
ampC
Enterobacter (all) and psuedomonas (all) Chromosomal gene Inducible or constitutive Resistant to penicillin and cefazolin If constitutive, also resistant to cephtriaxone Should use carbepenems
