Extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae: risk factors for infection and impact of resistance on outcomes

Clin Infect Dis. 2001 Apr 15;32(8):1162-71. doi: 10.1086/319757. Epub 2001 Mar 26.


The prevalence of antibiotic resistance among extended-spectrum beta-lactamase (ESBL)--producing Escherichia coli and Klebsiella pneumoniae has increased markedly in recent years. Thirty-three patients with infection due to ESBL-producing E. coli or K. pneumoniae (case patients) were compared with 66 matched controls. Total prior antibiotic use was the only independent risk factor for ESBL-producing E. coli or K. pneumoniae infection (odds ratio, 1.10; 95% confidence interval, 1.03--1.18; P=.006). Case patients were treated with an effective antibiotic a median of 72 hours after infection was suspected, compared with a median of 11.5 hours after infection was suspected for controls (P<.001). ESBL-producing E. coli or K. pneumoniae infection was associated with a significantly longer duration of hospital stay and greater hospital charges (P=.01 and P<.001, respectively). Finally, many ESBL-producing E. coli and K. pneumoniae isolates were closely related. ESBL-producing E. coli and K. pneumoniae infections have a significant impact on several important clinical outcomes, and efforts to control outbreaks of infection with ESBL-producing E. coli and K. pneumoniae should emphasize judicious use of all antibiotics as well as barrier precautions to reduce spread.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Case-Control Studies
  • Drug Resistance, Microbial
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology
  • Escherichia coli / genetics
  • Escherichia coli / isolation & purification
  • Escherichia coli Infections / complications
  • Escherichia coli Infections / drug therapy
  • Escherichia coli Infections / economics
  • Escherichia coli Infections / microbiology*
  • Fees and Charges
  • Female
  • Hospitalization
  • Humans
  • Klebsiella Infections / complications
  • Klebsiella Infections / drug therapy
  • Klebsiella Infections / economics
  • Klebsiella Infections / microbiology*
  • Klebsiella pneumoniae / drug effects*
  • Klebsiella pneumoniae / enzymology
  • Klebsiella pneumoniae / genetics
  • Klebsiella pneumoniae / isolation & purification
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Risk Factors
  • beta-Lactamases* / biosynthesis


  • beta-Lactamases