title: Antimicrobial resistance in urinary tract infections at a large urban ED: Factors contributing to empiric treatment failure.
abstract: OBJECTIVE
  To calculate the emergency department (ED)-level Escherichia coli percentage of isolates susceptible to commonly used antibiotics and to determine the risk factors associated with inadequate empiric antibiotic therapy among patients treated for urinary tract infections (UTIs) in our ED.
  
  
  METHODS
  Retrospective cohort study conducted at a large tertiary teaching hospital. Participants included patients older than 18years of age who had a urine culture with growth of >100,000 colonies of E. coli. Demographic and therapeutic choices associated with inadequate empiric antibiotic therapy were explored. Antimicrobial susceptibility pattern of E. coli isolates recovered from ED patients were calculated, and stratified by gender and age.
  
  
  RESULTS
  A total of 300 unique patients had E. coli bacteriuria during the study period. Among patients who received at least one dose of antibiotic in the ED, variables independently associated with an increased risk of inadequate empiric therapy were age (relative risk [RR] 1.016; 95% confidence interval [CI] 1.001-1.031; P=0.032), male gender (RR 2.507; 95% CI 1.470-4.486; P=0.001), and use of fluoroquinolones (RR 2.128; 95% CI 1.249-3.624 P=0.005). Sub-group analysis of patients discharged from the ED showed that definitive therapy with nitrofurantoin decreased the risk of inadequate empiric antibiotic therapy by 80% (RR 0.202; CI 0.065-0.638; P=0.006). ED-level antibiograms showed differences in antimicrobial susceptibility of E. coli by age and gender.
  
  
  CONCLUSIONS
  Development of ED-level antimicrobial susceptibility data and consideration of patients' clinical characteristics can help better guide selection of empiric antibiotic therapy for the treatment of UTIs.
authors.affiliation: Department of Medicine, Jackson Memorial Hospital, 1611 NW 12th Avenue, Miami, FL, USA; Division of Infectious Diseases, University of Miami Miller School of Medicine, 1120 NW 14(th) Street, Miami, FL, USA. Electronic address: rossana.m.rosa@gmail.com.
authors.forename: Rossana
authors.initials: R
authors.lastname: Rosa
authors.affiliation: Division of Infectious Diseases, University of Miami Miller School of Medicine, 1120 NW 14(th) Street, Miami, FL, USA; Department of Infection Control and Antimicrobial Stewardship, Jackson Memorial Hospital, 1611 NW12th Avenue, Miami, FL, USA.
authors.forename: Lilian M
authors.initials: LM
authors.lastname: Abbo
authors.affiliation: University of Miami Miller School of Medicine, 1600 NW 10(th) Avenue, Miami, FL, USA.
authors.forename: Kenley
authors.initials: K
authors.lastname: Raney
authors.affiliation: Department of Medicine, Jackson Memorial Hospital, 1611 NW 12th Avenue, Miami, FL, USA.
authors.forename: Hansel E
authors.initials: HE
authors.lastname: Tookes
authors.affiliation: Department of Emergency Medicine, Jackson Memorial Hospital, 1611 NW12th Avenue, Miami, FL, USA. Electronic address: mark.supino@jhsmiami.org.
authors.forename: Mark
authors.initials: M
authors.lastname: Supino
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D001437:Bacteriuria / Q000188:drug therapy* / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects*; D004927:Escherichia coli Infections / Q000188:drug therapy*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D017678:Sex Distribution; D017211:Treatment Failure; D014552:Urinary Tract Infections / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D000890:Anti-Infective Agents
keywords: Antimicrobial resistance; Susceptibility testing; UTI