| Abstrakt: |
Meropenem, a new parenteral carbapenem, was tested in vitro by an agar-dilution method against 373 standard strains (aerobes and anaerobes) and against nine expanded-spectrum β-lactamase-producing strains and their transconjugants (5 CTX-1, 2 CAZ-1, 2 CAZ-2). Meropenem was compared with methicillin, imipencm, piperacillin, cefoxitin, cefotaxime, ceftazidime, gentamicin, chloramphenicol, clinda-mycin, ciprofloxacin, vancomycin and metronidazole. Meropenem and imipenem exhibited an extended spectrum of activity, with low MICs. Only methicillin-resistant staphylococci, and Pseudomonas (Xanthomonas) maltophilia were resistant. Of the carbapenems, imipenem was more active against methicillin-susceptible staphylococci, streptococci and Enterococcus faecalis, but meropenem was markedly more active against all the Enterobacteriaceae and some pseudomonads. Both had similar activity against Ps. aeruginosa, Acinetobacter spp. and anaerobes. The carba-penem MICs were very low for Enterol icteriaceae producing the expanded-spec-trum β-lactamases. Against CTX-1-producing strains resistant to cefotaxime and ceftazidime and against CAZ-1 or CAZ-2-producers highly resistant to ceftazidime, meropenem was the most active, with MICs lower (0.03–0.12mg/l) than those of imipenem (0.06–0.5 mg/l), for wild type producers and their transconjugants. [ABSTRACT FROM PUBLISHER] |
