Risk factors and outcomes of carbapenem-nonsusceptible Escherichia coli bacteremia: a matched case-control study

J Microbiol Immunol Infect. 2011 Apr;44(2):125-30. doi: 10.1016/j.jmii.2010.06.001. Epub 2011 Jan 14.


Background: Infections due to carbapenem-resistant Enterobacteriaceae have been the emerging problem worldwide. This primary object of this study was to understand the risk factors and clinical outcomes of carbapenem-nonsusceptible Escherichia coli (CNSEc) bacteremia.

Methods: We conducted a matched case-control study in a 3,715-bed tertiary care medical center in northern Taiwan. The controls were selected among patients with carbapenem-susceptible E coli and were matched with CNSEc for bacteremia.

Results: Fifty-one patients were included in this study (17 cases and 34 controls). Bivariate analysis showed that prior exposure to carbapenems (p<0.001), stay in intensive care units (p=0.016), placement of central venous catheters (p=0.001), chronic liver diseases (p<0.001), uremia with regular dialysis (p=0.004), and mechanical ventilation (p=0.004) were associated with CNSEc bacteremia. Multivariate analysis revealed that prior exposure to carbapenems [odds ratio (OR), 29.17; 95% confidence interval (CI), 1.76-484.70; p=0.019], uremia with regular dialysis (OR, 98.58; 95% CI, 4.02-999; p=0.005) and chronic liver diseases (OR, 27.86; 95% CI, 2.31-335.83; p=0.009) were independent risk factors for CNSEc bacteremia. Compared with carbapenem-susceptible E coli group, CNSEc group had a longer hospital stay (68.4 days vs. 35.8 days; p=0.04) and a higher disease severity, as indicated by a Pittsburgh bacteremia score greater than or equal to 4 (5.6% vs. 2.5%; p=0.015). Patients with CNSEc bacteremia had a higher overall in-hospital mortality rate (94.12% vs. 50.00%; p=0.002), but there was no difference in the 28-day mortality between these two groups.

Conclusions: CNSEc bacteremia would lead to a poor outcome among patients with prior exposure to carbapenems, chronic liver disease, and uremia with regular dialysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / therapeutic use*
  • Bacteremia / complications
  • Bacteremia / drug therapy*
  • Carbapenems / therapeutic use*
  • Case-Control Studies
  • Escherichia coli / drug effects*
  • Escherichia coli / growth & development
  • Escherichia coli Infections / drug therapy*
  • Escherichia coli Infections / mortality
  • Female
  • Hospital Mortality
  • Humans
  • Intensive Care Units
  • Length of Stay
  • Liver Diseases / complications
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Odds Ratio
  • Regression Analysis
  • Risk Factors
  • Survival Analysis
  • Taiwan
  • Treatment Outcome
  • Uremia / complications


  • Anti-Bacterial Agents
  • Carbapenems