resistance mech Flashcards
sulfonamides
altered enzyme, decreased uptake, increased PABA synthesis
vancomycin
bacteria amino acid modification (D-ala D-ala TO D-ala D-lac)
aminoglycosites (gentamicin, neomycin, amikacin, tobramycin, streptomycin)
bacterial transferase enzymes inactive the drug (either by acetylation, phosphorylation, or adenylation)
piperacillin, ticarcillin
beta-lactamases; use with a beta-lactamase inhibitor
fluoroquinolones (cipro, levofloxacin)
chromosome-encoded mutation in DNA gyrase (topoisomerase II), plasmid mediated resistance, efflux pumps
tetracyclines (tetracycline, doxycycline, minocycline)
decreased uptake or increased efflux out of bacterial cells by plasmid-encoded transport pumps
macrolides (azithro, clarithro, erythro)
methylation of 23S rRNA-binding site
dicloxacillin, nafcillin, oxacillin
MRSA resistance: altered penicillin-binding protein target site
penicillin G,V
penicillinase (beta-lactamase) cleaves beta-lactam ring
amoxicillin, ampicillin
penicillinase (beta-lactamase) cleaves beta-lactam ring
chloramphenicol
plasmid-encoded acetyltransferase inactivates
1st gen cephalosporin (cefazolin, cephalexin)
structural change in penicillin-binding-proteins/transpeptidases
2nd gen cephalosporin (cefoxitin, cefaclor, cefuroxime)
structural change in penicillin-binding-proteins/transpeptidases
3rd gen cephalosporin (ceftriaxone, cefotaxime, ceftazidime)
structural change in penicillin-binding-proteins/transpeptidases
4th gen cephalosporin (cefepime)
structural change in penicillin-binding-proteins/transpeptidases
