title: Urinary tract infections due to extended-spectrum beta-lactamase-producing Gram-negative bacteria: identification of risk factors and outcome predictors in an Australian tertiary referral hospital.
abstract: OBJECTIVE
  Extended-spectrum beta-lactamase-expressing Gram-negative bacilli (ESBL-GNB) now commonly cause community-acquired infections, including urinary tract infections (UTI), and represent a challenge for practitioners in choosing empirical antibiotics. The aim of this study was to describe the epidemiology and clinical characteristics of UTIs/bacteriuria due to ESBL-GNB in Australia.
  
  
  METHODS
  At a single-site tertiary referral hospital, 100 cases with UTIs/bacteriuria due to ESBL-GNB were matched to 100 cases where UTIs/bacteriuria were caused by organisms matching the ESBL bacterial species that had routine susceptibility to antibiotics. Potential risk factors for ESBL-GNB UTI/bacteriuria and differences in clinical outcomes were identified.
  
  
  RESULTS
  Length of admission prior to positive sample (odds ratio (OR) 1.3, p = 0.03, per week), exposure to antibiotics (OR 5.7, p < 0.001), return from overseas travel (OR 6.5, p = 0.002), and nursing home residency (OR 4.2, p = 0.03) were identified as risk factors associated with ESBL-GNB UTI/bacteriuria in the multivariate analysis. In addition, ESBL-GNB-infected cases subsequently had a longer inpatient stay (median 6 vs. 2 days, p = 0.002) and were admitted to the intensive care unit more frequently (28/100 vs. 8/100, p < 0.001).
  
  
  CONCLUSIONS
  Our results emphasize the need for culture of a mid-stream urine specimen prior to commencing antibacterials, especially in patients with the risk factors identified herein associated with ESBL-GNB UTI/bacteriuria.
authors.affiliation: Victorian Infectious Diseases Service at the Peter Doherty Institute for Infection and Immunology, Royal Melbourne Hospital, Victoria, Australia; Department of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Osthoff
authors.affiliation: Victorian Infectious Diseases Service at the Peter Doherty Institute for Infection and Immunology, Royal Melbourne Hospital, Victoria, Australia.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: McGuinness
authors.affiliation: Victorian Infectious Diseases Service at the Peter Doherty Institute for Infection and Immunology, Royal Melbourne Hospital, Victoria, Australia.
authors.forename: Aaron Z
authors.initials: AZ
authors.lastname: Wagen
authors.affiliation: Victorian Infectious Diseases Service at the Peter Doherty Institute for Infection and Immunology, Royal Melbourne Hospital, Victoria, Australia; Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Victoria, Australia. Electronic address: damon.eisen@mh.org.au.
authors.forename: Damon P
authors.initials: DP
authors.lastname: Eisen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001315:Australia / Q000453:epidemiology; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D005260:Female; D006090:Gram-Negative Bacteria / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D062606:Tertiary Care Centers; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D001618:beta-Lactamases / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases
keywords: Antibiotic resistance; ESBL; Gram-negative bacteria; Urinary tract infection