Impact of empirical treatment in extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella spp. bacteremia. A multicentric cohort study

BMC Infect Dis. 2012 Oct 5;12:245. doi: 10.1186/1471-2334-12-245.


Background: The objective of this study is to analyze the factors that are associated with the adequacy of empirical antibiotic therapy and its impact in mortality in a large cohort of patients with extended-spectrum β-lactamase (ESBL)--producing Escherichia coli and Klebsiella spp. bacteremia.

Methods: Cases of ESBL producing Enterobacteriaceae (ESBL-E) bacteremia collected from 2003 through 2008 in 19 hospitals in Spain. Statistical analysis was performed using multivariate logistic regression.

Results: We analyzed 387 cases ESBL-E bloodstream infections. The main sources of bacteremia were urinary tract (55.3%), biliary tract (12.7%), intra-abdominal (8.8%) and unknown origin (9.6%). Among all the 387 episodes, E. coli was isolated from blood cultures in 343 and in 45.71% the ESBL-E was multidrug resistant. Empirical antibiotic treatment was adequate in 48.8% of the cases and the in hospital mortality was 20.9%. In a multivariate analysis adequacy was a risk factor for death [adjusted OR (95% CI): 0.39 (0.31-0.97); P = 0.04], but not in patients without severe sepsis or shock. The class of antibiotic used empirically was not associated with prognosis in adequately treated patients.

Conclusion: ESBL-E bacteremia has a relatively high mortality that is partly related with a low adequacy of empirical antibiotic treatment. In selected subgroups the relevance of the adequacy of empirical therapy is limited.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / therapeutic use*
  • Bacteremia / drug therapy*
  • Bacteremia / microbiology
  • Bacteremia / mortality
  • Child
  • Child, Preschool
  • Cohort Studies
  • Escherichia coli / enzymology*
  • Escherichia coli / isolation & purification
  • Escherichia coli Infections / drug therapy*
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / mortality
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Klebsiella / enzymology*
  • Klebsiella / isolation & purification
  • Klebsiella Infections / drug therapy*
  • Klebsiella Infections / microbiology
  • Klebsiella Infections / mortality
  • Male
  • Middle Aged
  • Spain
  • Survival Analysis
  • Treatment Outcome
  • Young Adult
  • beta-Lactamases / metabolism*


  • Anti-Bacterial Agents
  • beta-Lactamases