title: Diversity of beta-lactam resistance levels among related Klebsiella pneumoniae strains isolated in an intensive care unit.
abstract: Seven multiresistant Klebsiella pneumoniae strains isolated in an intensive care unit were studied. Susceptibility to beta-lactams was determined with the E test. Molecular-typing of the isolates was performed by a PCR-based technique (ERIC2-PCR). Sonic cell-extracts were used as beta-lactamase preparations. Beta-lactamase quantities were evaluated measuring nitrocefin hydrolysis. The similarity of the ERIC2-PCR patterns indicated that the seven isolates constituted a single clone. The levels of resistance to oximino-beta-lactams, however, were different. There were indications that the differences in susceptibilities were due, at least partly, to differences in the levels of expression of an extended-spectrum beta-lactamase (most likely SHV-5). Related K. pneumoniae isolates may exhibit different levels of resistance to beta-lactams. Therefore, comparison of resistance phenotypes is of limited usefulness in epidemiological investigations of nosocomial infections caused by resistant K. pneumoniae.
authors.affiliation: Department of Microbiology, Evangelismos General Hospital, Athens, Greece. opaniara@netor.gr
authors.lastname: Paniara
authors.forename: E
authors.initials: E
authors.lastname: Platsouka
authors.forename: H
authors.initials: H
authors.lastname: Dimopoulou
authors.forename: E
authors.initials: E
authors.lastname: Tzelepi
authors.forename: V
authors.initials: V
authors.lastname: Miriagou
authors.forename: L S
authors.initials: LS
authors.lastname: Tzouvelekis
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D019818:Clavulanic Acid / Q000494:pharmacology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D004196:Disease Outbreaks; D004359:Drug Therapy, Combination / Q000494:pharmacology; D006115:Greece / Q000453:epidemiology; D006801:Humans; D007362:Intensive Care Units; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D019818:Clavulanic Acid; D002442:Ceftazidime; C117193:beta-lactamase SHV-5; D001618:beta-Lactamases