title: Development of a urinary-specific antibiogram for gram-negative isolates: impact of patient risk factors on susceptibility.
abstract: BACKGROUND
  Traditional antibiograms guide clinicians in selecting appropriate empiric antimicrobials, but they lack data on syndrome/disease-specific susceptibility, isolate location, polymicrobial infections, and patient risk factors. The aim of this study was to develop a urinary-specific antibiogram and to evaluate the impact of risk factors on antimicrobial susceptibility.
  
  
  METHODS
  This retrospective descriptive study used culture and susceptibility data from January 1 to December 31, 2012. A urinary antibiogram specific for Escherichia coli (EC), Proteus mirabilis (PM), Klebsiella pneumoniae (KP), and Pseudomonas aeruginosa (PA) was developed. Urinary and standard antibiogram susceptibilities were compared. Urinary isolates were then stratified by risk factors-residence before admission, age, systemic antimicrobial use for ≤30 days, hospitalization for ≤30 days, and hospital unit-to determine the impact on antimicrobial susceptibility.
  
  
  RESULTS
  There were 2,284 urinary isolate encounters. Overall antimicrobial susceptibility was increased, and the prevalence of extended-spectrum β-lactamase-producing isolates was significantly greater (KP, 14% vs 7% [P = .001]; EC, 13% vs 9% [P < .001]; PM, 18% vs 10% [P = .004]) in the urinary antibiogram vs the standard antibiogram. Health care facility residence had the greatest impact on susceptibility for all urinary isolates, especially on fluoroquinolone susceptibility for EC and PM.
  
  
  CONCLUSIONS
  Using a syndromic antibiogram and incorporating patient risk factors into susceptibility data may be more useful in guiding clinicians in selecting more appropriate empiric therapy.
authors.affiliation: Department of Pharmacy, Advocate Lutheran General Hospital, Park Ridge, IL.
authors.forename: Nicole
authors.initials: N
authors.lastname: Rabs
authors.affiliation: Department of Pharmacy, Advocate Lutheran General Hospital, Park Ridge, IL. Electronic address: sarah.wieczorkiewicz@advocatehealth.com.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Wieczorkiewicz
authors.affiliation: Department of Microbiology, ACL Laboratories, Rosemont, IL.
authors.forename: Michael
authors.initials: M
authors.lastname: Costello
authors.affiliation: Russell Institute for Research and Innovation, Advocate Lutheran General Hospital, Park Ridge, IL.
authors.forename: Ina
authors.initials: I
authors.lastname: Zamfirova
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D014552:Urinary Tract Infections / Q000382:microbiology*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antimicrobial resistance; Urinary tract infection