Extended-spectrum beta-lactamases from Klebsiella pneumoniae strains isolated at an Italian hospital.
Eighteen strains of Klebsiella pneumoniae recently isolated from hospitalized patients were resistant or moderately resistant to oxyimino-cephalosporins (ceftazidime and/or cefotaxime), aztreonam, cefoxitin and all but one were susceptible to imipenem. Analysis of enzymes produced by these clinical isolates revealed a wide pattern of extended-spectrum beta-lactamases. All isolates produced one or more beta-lactamases that were characterized preliminarily by their isoelectric point. Strains isolated early were from patients in the Intensive Care Unit and produced an ES beta-lactamase with an apparent pI of 7.6, whereas the later isolates were from surgical and medical wards of the same hospital and produced ES beta-lactamases with apparent pI of 8.2 and 8.4, respectively. This suggests the emergence of SHV-5 and MIR-1 beta-lactamases in our hospital. Agarose gel electrophoresis of plasmid DNA revealed the presence of a similar plasmid of approximate size 60 Kb in all isolates.
Istituto di Microbiologia, Università di Pavia, Italy.
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L
Pagani
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Ronza
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Giacobone
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Romero
D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000235:genetics; D006801:Humans; D007525:Isoelectric Focusing; D007558:Italy; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests / Q000379:methods; D010641:Phenotype; D010957:Plasmids / Q000032:analysis; D001618:beta-Lactamases / Q000032:analysis*
D004269:DNA, Bacterial; D001618:beta-Lactamases