title: Epidemiology of urinary tract infections caused by extended-spectrum beta-lactamase-producing Escherichia coli.
abstract: OBJECTIVE
  To describe the epidemiology of urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli.
  
  
  METHODS
  We performed three studies: a trend study (1999 to 2004) to assess the evolution and origin of ESBL-producing E. coli isolates from urine samples; a comparison of the susceptibility patterns of ESBL-producing E. coli and a random sample of non-ESBL-producing E. coli isolated in the same interval, and a retrospective chart review to determine the risk factors for acquisition of, and outcomes from, urinary tract infections caused by ESBL-producing E. coli (n = 61) compared with a random sample of non-ESBL-producing E. coli urinary tract infections (n = 61) from patients attending our institution and matched by temporal occurrence.
  
  
  RESULTS
  ESBL-producing E. coli significantly increased from 2 (0.20%) to 89 (5.52%) isolates per year (P value for trend = 0.000). Of the 161 patients with urinary tract infections caused by ESBL-producing E. coli, 100 (62%) were attending ambulatory health centers, and 61 (38%) were attending the hospital. ESBL-producing E. coli showed a significant reduction in the susceptibility to most antimicrobials, although carbapenems and fosfomycin retained significant activity. The chart review study showed that previous treatment with fluoroquinolones (odds ratio 12.98, 95% confidence interval 1.81 to 106.51, P = 0.017) and the presence of a urinary catheter (odds ratio 2.64, 95% confidence interval 1.01 to 6.88, P = 0.047) were independent risk factors associated with infections caused by ESBL-producing E. coli.
  
  
  CONCLUSIONS
  ESBL-producing E. coli is a problem of increasing importance. Our study results may help physicians select appropriate antimicrobial therapy in patients suspected of having urinary tract infections caused by ESBL-producing E. coli.
authors.affiliation: Department of Internal Medicine, Hospital Marina Baixa, Villajoyosa, Alicante, Spain. ena_jav@gva.es
authors.forename: Javier
authors.initials: J
authors.lastname: Ena
authors.forename: Francisco
authors.initials: F
authors.lastname: Arjona
authors.forename: Carmen
authors.initials: C
authors.lastname: Martínez-Peinado
authors.forename: Maria Del Mar
authors.initials: Mdel M
authors.lastname: López-Perezagua
authors.forename: Concepción
authors.initials: C
authors.lastname: Amador
mesh_terms: D000368:Aged; D004926:Escherichia coli / Q000201:enzymology / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000652:urine; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D014552:Urinary Tract Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000652:urine; D014556:Urine / Q000382:microbiology; D001618:beta-Lactamases / Q000378:metabolism* / Q000652:urine
chemical_list: D001618:beta-Lactamases