Prevalence, risk factors, and impact on clinical outcome of extended-spectrum beta-lactamase-producing Escherichia coli bacteraemia: a five-year study

Int J Infect Dis. 2015 Oct:39:1-6. doi: 10.1016/j.ijid.2015.07.010. Epub 2015 Jul 17.

Abstract

Background: The impact of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) bacteraemia on outcome remains controversial.

Methods: A retrospective analysis of the prevalence, risk factors, clinical features, and outcomes of all ESBL-EC bacteraemia in one French hospital over a 5-year period was performed. A case-control study was undertaken: cases had at least one ESBL-EC bacteraemia and controls a positive non-ESBL-EC bacteraemia.

Results: The prevalence of ESBL-EC bacteraemia increased from 5.2% of all positive E. coli blood cultures in 2005 to 13.5% in 2009 (p<0.003). CTX-M represented 70% of ESBL-EC bacteraemia strains, and strains were not clonally related. On adjusted analysis, the only significant risk factor for ESBL-EC bacteraemia was a previous ESBL-EC colonization (odds ratio 11.3, 95% confidence interval 1.2-107; p=0.003). Initial antimicrobial therapy was less frequently adequate in the ESBL-EC group (48% vs. 85%; p=0.003). The presence of ESBL-EC bacteraemia was not associated with a longer hospital stay (p=0.088). Day 30 mortality was high, but not significantly different in the two groups (30% vs. 27%; p=0. 82).

Conclusion: The prevalence of ESBL-EC bacteraemia has been increasing dramatically. Previous colonization with ESBL-EC was a strong risk factor for ESBL-EC bacteraemia. More inadequate initial antimicrobial therapy was noted in the ESBL-EC group, but mortality and length of hospital stay were not significantly different from those of patients with non-ESBL-EC bacteraemia.

Keywords: Bacteraemia; ESBL Escherichia coli; Hospital stay; Mortality.

MeSH terms

  • Adult
  • Aged
  • Anti-Bacterial Agents / therapeutic use
  • Bacteremia / diagnosis
  • Bacteremia / drug therapy
  • Bacteremia / epidemiology*
  • Bacteremia / microbiology*
  • Case-Control Studies
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology
  • Escherichia coli / isolation & purification
  • Escherichia coli Infections / diagnosis
  • Escherichia coli Infections / drug therapy
  • Escherichia coli Infections / epidemiology*
  • Escherichia coli Infections / microbiology*
  • Female
  • Humans
  • Length of Stay
  • Male
  • Middle Aged
  • Prevalence
  • Retrospective Studies
  • Risk Factors
  • beta-Lactamases / analysis

Substances

  • Anti-Bacterial Agents
  • beta-Lactamases