title: Cefuroxime resistance in Klebsiella pneumoniae. Susceptibility to cefotaxime and ceftazidime despite production of ESBLs.
abstract: The production of beta-lactamases, the outer membrane protein (OMP) patterns, some clinical impacts and the prevalence of resistance among cefuroxime-resistant Danish clinical isolates of Klebsiella pneumoniae were investigated. Fifteen resistant and five susceptible strains were collected from 14 patients during 1991-1994. Isolates from five patients produced extended-spectrum beta-lactamases (ESBLs). Cefuroxime resistance was accompanied by a 10-fold elevation of ciprofloxacin minimal inhibitory concentration (MIC), and for some isolates by an alteration of the OMP pattern. The relationship between alterations of the OMP patterns and cross-resistance to ciprofloxacin and the other antibiotics tested was not universal. Ten of the cefuroxime-resistant strains had elevated MICs of cefotaxime or ceftazidime, but the MICs were still below the breakpoint for susceptibility. The MICs of imipenem were not affected. Nosocomial infection or long-term colonization with resistant strains may be of importance since five patients were not treated with cefuroxime prior to isolation of the resistant strain, and all patients had either serious diseases or stayed at the hospital for a long period of time. The prevalence of cefuroxime and ciprofloxacin resistance among clinical isolates from Copenhagen county during 1990-1995 was 8.3% and 7.5%, respectively, but higher for urinary tract specimens. A greater consumption of cefuroxime as compared to cefotaxime and ceftazidime in this study, as seen generally in Denmark, indicated that ESBLs produced by the investigated strains of K. pneumoniae may be selected with cefuroxime.
authors.affiliation: Department of Clinical Microbiology, University Hospital, Herlev, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Schumacher
authors.forename: U
authors.initials: U
authors.lastname: Skibsted
authors.forename: D S
authors.initials: DS
authors.lastname: Hansen
authors.forename: J
authors.initials: J
authors.lastname: Scheibel
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D002439:Cefotaxime; D002442:Ceftazidime; D002444:Cefuroxime; D003718:Denmark; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D002442:Ceftazidime; D001618:beta-Lactamases; D002439:Cefotaxime; D002444:Cefuroxime