title: Prevalence and impact of extended-spectrum β-lactamase production on clinical outcomes in cancer patients with Enterobacter species bacteremia.
abstract: OBJECTIVE
  We examined the prevalence of extended-spectrum β-lactamase (ESBL) production and the impact of ESBL on clinical outcomes in cancer patients with Enterobacter spp. bacteremia.
  
  
  METHODS
  Using prospective cohort data on Enterobacter bacteremia obtained between January 2005 and November 2008 from a tertiary care center, the prevalence and clinical impact of ESBL production were evaluated.
  
  
  RESULTS
  Two-hundred and three episodes of Enterobacter spp. bacteremia were identified. Thirty-one blood isolates (15.3%, 31/203) scored positive by the double-disk synergy test. Among 17 isolates in which ESBL genes were detected by polymerase chain reaction and sequencing, CTX-M (n = 12), SHV-12 (n = 11), and TEM (n = 4) were the most prevalent ESBL types. Prior usage of antimicrobial agents (77.4% vs. 54.0%, p = 0.02) and inappropriate empirical antimicrobial therapy (22.6% vs. 3.0%, p < 0.001) were more commonly encountered in the ESBL-positive group than in the extended-spectrum cephalosporin-susceptible ESBL-negative group, respectively. Clinical outcomes did not differ significantly between the two groups (30-day mortality rate, 19.4% vs. 17.0%, p = 0.76; median length of hospital stay, 24.0 days vs. 30.5 days, p = 0.97). Initial presentation of severe sepsis/septic shock, pneumonia, and intra-abdominal infection were independently associated with 30-day mortality.
  
  
  CONCLUSIONS
  The prevalence of ESBL-producing isolates was 15.3% in cancer patients with Enterobacter bacteremia. Although inappropriate empirical therapy was more common in the ESBL-positive group, ESBL production was not associated with poorer outcomes.
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Sun Jong
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Medical Center, Seoul, Korea.
authors.forename: Ki-Ho
authors.initials: KH
authors.lastname: Park
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Chung-Ang University Hospital, Seoul, Korea.
authors.forename: Jin-Won
authors.initials: JW
authors.lastname: Chung
authors.affiliation: Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Heungsup
authors.initials: H
authors.lastname: Sung
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Chung-Ang University Hospital, Seoul, Korea.
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000150:complications* / Q000188:drug therapy / Q000382:microbiology; D002648:Child; D015331:Cohort Studies; D004754:Enterobacter / Q000201:enzymology* / Q000235:genetics; D004756:Enterobacteriaceae Infections / Q000150:complications* / Q000188:drug therapy / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D011446:Prospective Studies; D016896:Treatment Outcome; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases
keywords: Enterobacter; Neoplasms; beta-Lactamases