MICROM 442 Study Guide - Final Guide: Multiple Drug Resistance, Cell Membrane, Empiric Therapy
Document Summary
B-lactamases: b-lactamases hydrolyze b-lactam rings, gram -: b-lactamases localized in the periplasmic space (higher level resistance, gram +: b-lactamases secreted (often lower-level resistance, plasmid-based, constitutive expression, chromosome-based, inducible (common in g-) During normal conditions (repressed): wall fragments are recycled by ampd, ampr is in a repressor configuration precursors, ampc is not expressed. Don"t treat spicem organism with 1st, 2nd, 3rd generation. Cephalosporins because it can lead to quick generation of. B-lactam resistance: target site alteration leads to methicillin resistance (primarily. Detecting methicillin resistance: lab testing, susceptibility to ethicillin, cefoxitin, or oxaclllin via disk diffusions, mics, detection of the meca gene via pcr, detection of pbp2a protein (latex agglutination) Cell wall agents: vancomycin bloakc peptidoglycan crosslinks of gram. Empiric therapy for enterococcus: faecalis, rarely resistant to vancomycin (<1%, best therapy is ampicillin. Faecium: frequently resistant to vancomycin, daptomycin is common alternative (still 15% res, consult your antibiogram, hospital populations may vary.
