title: Risk factors for bloodstream infections caused by extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae.
abstract: The objective of this study was to identify risk factors for bacteremia by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae. Retrospective case-control study performed in a 450-bed acute care academic tertiary hospital in Barcelona, Spain. Cases included 53 patients with ESBL-producing E. coli or K. pneumoniae bacteremia, and 159 controls with non-ESBL-producing E. coli or K. pneumoniae bacteremia. Controls were matched in a 3:1 ratio to case patients according to species of infecting organism, age, and severity of illness in the 24-48 h before blood sample collection for culture calculated by the Simplified Acute Physiology Score (SAPS II) system. Previous antimicrobials were more frequently administered to cases than to controls (56.5% vs 17%, p < 0.001). Binary logistic regression showed that the number (> 2) of different families of antimicrobials received within 90 days before bloodstream infection was the only predictor of ESBL-producing E. coli or K. pneumoniae in blood culture (OR = 2.29, 95% CI 1.35-3.88, p = 0.002).
  
  
  CONCLUSIONS
  Previous use of different families of antimicrobials (more than two) in patients with bloodstream infection caused by E. coli or K. pneumoniae increased the risk for ESBL-producing strains.
authors.affiliation: Hospital del Mar, Barcelona, Spain.
authors.forename: Olivia Ferrández
authors.initials: OF
authors.lastname: Quirante
authors.forename: Santiago Grau
authors.initials: SG
authors.lastname: Cerrato
authors.forename: Sonia Luque
authors.initials: SL
authors.lastname: Pardos
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology*; D016022:Case-Control Studies; D004926:Escherichia coli / Q000201:enzymology*; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology*; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases