title: Risk factors, outcome and impact of empirical antimicrobial treatment in extended-spectrum β-lactamase-producing Escherichia coli bacteraemia.
abstract: BACKGROUND
  To investigate patient characteristics and empirical antimicrobial treatment of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) bacteraemia, to determine risk factors, outcome and impact of empirical antimicrobial treatment.
  
  
  METHODS
  We performed a retrospective case-control study of all patients diagnosed with ESBL-EC from January 2011 to September 2012. The control group consisted of patients with non-ESBL E. coli bacteraemia. The groups were compared with respect to empirical treatment, risk factors and outcome, using univariate and multivariate analysis.
  
  
  RESULTS
  The study consisted of 70 consecutive cases of ESBL-producing and 140 controls of non-ESBL-producing E. coli bacteraemia. ESBL-EC prevalence of bloodstream invasive E. coli isolates was 6.1%. The independent risk factor found for ESBL-EC bacteraemia was a prior culture with ESBL production (p < 0.001). A higher frequency of inappropriate empirical antibiotic treatment (p < 0.001) and a trend towards worse outcome was observed in patients infected with ESBL-EC and empirical guidelines were more often not followed (p = 0.013). If the guidelines were followed this was associated with adequate initial antibiotic treatment (p < 0.001).
  
  
  CONCLUSIONS
  Patients with ESBL-EC frequently received inappropriate empirical treatment and guidelines were more often not followed. A prior culture of ESBL-producing bacteria was an independent predictor and risk factor for ESBL-EC bacteraemia. Since the prevalence of ESBL-producing E. coli is increasing the importance of adequate guidelines must be emphasized.
authors.affiliation: From the Faculty of Medicine, Lund University , Malmö , Sweden.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Van Aken
authors.forename: Nathalie
authors.initials: N
authors.lastname: Lund
authors.forename: Jonas
authors.initials: J
authors.lastname: Ahl
authors.forename: Inga
authors.initials: I
authors.lastname: Odenholt
authors.forename: Johan
authors.initials: J
authors.lastname: Tham
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000382:microbiology*; D016022:Case-Control Studies; D002404:Catheterization; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis
chemical_list: D000890:Anti-Infective Agents; D001618:beta-Lactamases
keywords: ESBL; Escherichia coli; antibiotic resistance; bacteraemia/bloodstream infection; empirical antibiotic treatment