title: Risk factors and molecular epidemiology of community-onset extended-spectrum β-lactamase-producing Escherichia coli bacteremia.
abstract: OBJECTIVE
  Inadequate empirical therapy for severe infections caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBLEC) is associated with poor outcomes. This study was designed to investigate risk factors for community-onset ESBLEC bacteremia at admission to a tertiary care hospital.
  
  
  METHODS
  A case-control study was performed that included all episodes of ESBLEC bacteremia in the outpatient department or within 48 hours of admission from January 2005 to March 2009. Data on predisposing factors were collected. The molecular epidemiology of ESBLEC clinical isolates was also determined.
  
  
  RESULTS
  Among 25281 blood cultures, 60 episodes of ESBLEC bacteremia were studied, which accounted for 7% of all E. coli bacteremia at admission. Healthcare-associated infection [odds ratio (OR), 8.3; 95% confidence interval (CI), 2.4-28.7; p=0.001], malignancy (OR, 4.6; 95% CI, 1.3-16.3; p=0.018), urinary tract infection (OR, 139.1; 95% CI, 24.6-788.2; p<0.001), hepatobiliary infection (OR, 79.1; 95% CI, 13.5-463.8; p<0.001), third generation cephalosporin usage during preceding 3 months (OR, 16.4; 95% CI, 2.0-131.8; p=0.008), and severe sepsis/septic shock (OR, 73.7; 95% CI, 12.4-438.5; p<0.001) were determined as independent risk factors for community-onset ESBLEC bacteremia. The most common extended-spectrum β-lactamase (ESBL) gene identified was blaCTX-M-15 (n=31) followed by blaCTX-M-14 (n=23).
  
  
  CONCLUSIONS
  The most common types of ESBLs in E. coli causing community-onset bacteremia were CTX-M-15 and CTX-M-14 in Korea. By result of decision tree analysis, the empirical use of carbapenems is suggested only for patients with severe sepsis/septic shock, hepatobiliary infection, or healthcare-associated urinary tract infection.
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, 211 Eonju-ro, Gangnam-gu, Seoul 135-720, Korea. kscpjsh@yuhs.ac.
authors.forename: Yoon Soo
authors.initials: YS
authors.lastname: Park
authors.forename: Il Kwon
authors.initials: IK
authors.lastname: Bae
authors.forename: Juwon
authors.initials: J
authors.lastname: Kim
authors.forename: Seok Hoon
authors.initials: SH
authors.lastname: Jeong
authors.forename: Seung-sik
authors.initials: SS
authors.lastname: Hwang
authors.forename: Yiel-Hea
authors.initials: YH
authors.lastname: Seo
authors.forename: Yong Kyun
authors.initials: YK
authors.lastname: Cho
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
authors.forename: June Myung
authors.initials: JM
authors.lastname: Kim
mesh_terms: D000367:Age Factors; D000368:Aged; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology*; D016022:Case-Control Studies; D002511:Cephalosporins / Q000627:therapeutic use; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D003658:Decision Making, Computer-Assisted; D004926:Escherichia coli / Q000378:metabolism* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D008875:Middle Aged; D017720:Molecular Epidemiology; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D062606:Tertiary Care Centers; D014552:Urinary Tract Infections / Q000453:epidemiology / Q000382:microbiology; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D002511:Cephalosporins; D001618:beta-Lactamases
keywords: CTX-M; Escherichia coli; Risk factors; beta-lactamase