Antimicrobial susceptibility of inducible AmpC beta-lactamase-producing Enterobacteriaceae from the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Programme, Europe 1997-2000.
Among 11345 clinical isolates from 31 European centres in the MYSTIC (Meropenem Yearly Susceptibility Test Information Collection) Programme (1997-2000), the potential AmpC-producing pathogens were Enterobacter spp. (904 cases), Citrobacter spp. (144) and Serratia marcescens (288). Resistance to ceftazidime or cefotaxime (11-34%) and piperacillin/tazobactam (12%) was observed, indicating stably derepressed expression of AmpC cephalosporinases. Meropenem (MIC(90), 0.25 mg/l; >99% susceptible) and imipenem (MIC(90), 2 mg/l; 98% susceptible) were active, even against these stably derepressed AmpC-producers: Enterobacter spp. (305 strains), Citrobacter spp. (29) and S. marcescens (35). The overall rank order of spectrum (% susceptible) versus the stably derepressed subset of isolates was: meropenem=imipenem (98%)>cefepime (89%)>gentamicin (73%)>ciprofloxacin (62%)>tobramycin (60%) >piperacillin/tazobactam (21%). We suggest increased attention in Europe to: (1) the recognition of these resistant phenotypes, (2) infection control practices, and (3) limiting the overuse of certain selecting extended-spectrum beta-lactam agents (e.g. ceftazidime).
Pfaller
Michael A
MA
Medical Microbiology Division, C606 GH, Department of Pathology, University of Iowa College of Medicine, 200 Hawikins Drive, Iowa City, IA 52242, USA. michael-pfaller@uiowa.edu
Jones
Ronald N
RN
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D004790:Enzyme Induction; D005060:Europe; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D013845:Thienamycins / Q000494:pharmacology; D001618:beta-Lactamases / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D013845:Thienamycins; C048795:AmpC beta-lactamases; D001618:beta-Lactamases; D000077731:Meropenem