Transferable enzymatic resistance to third-generation cephalosporins during nosocomial outbreak of multiresistant Klebsiella pneumoniae.
Klebsiella pneumoniae strains that were resistant to third-generation cephalosporins and amikacin were recovered from 62 of 395 patients (15.7%) during 1986. 25 isolates (40%) caused urinary tract infections. The outbreak involved three intensive care units (54 isolates), and spread from one unit to another and then to four wards (8 isolates). K pneumoniae of various serotypes and strains of different Enterobacteriaceae demonstrating the same antibiotic resistance pattern were isolated, which suggests dissemination of an R-factor. The isolates had low-level resistance to third-generation cephalosporins (mode minimum inhibitory concentration of cefotaxime, 2 mg/l) but remained sensitive to cephamycins. Cefotaxime was effective in cases of uncomplicated urinary tract infection, but failed in major infections at other sites. 1-5 mg/l of the beta-lactamase inhibitors clavulanic acid or sulbactam restored normal activity to cefotaxime against the multiresistant strains. Resistance to third-generation cephalosporins was mediated by a new broad-spectrum enzyme of isoelectric point 6.3. Resistance to beta-lactams and aminoglycosides was transferable to Escherichia coli. The emergence of transferable enzymatic resistance to newer beta-lactams in K pneumoniae strains indicates a major risk of spread of such resistance to otherwise sensitive strains.
D000583:Amikacin / Q000627:therapeutic use; D002439:Cefotaxime / Q000627:therapeutic use; D002511:Cephalosporins / Q000494:pharmacology* / Q000627:therapeutic use; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D004196:Disease Outbreaks; D004352:Drug Resistance, Microbial; D004755:Enterobacteriaceae / Q000302:isolation & purification; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D010297:Paris; D012008:Recurrence; D014552:Urinary Tract Infections / Q000188:drug therapy; D001618:beta-Lactamases / Q000032:analysis
D002511:Cephalosporins; D000583:Amikacin; D001618:beta-Lactamases; D002439:Cefotaxime