title: Preoperative Bladder Urine Culture as a Predictor of Intraoperative Stone Culture Results: Clinical Implications and Relationship to Stone Composition.
abstract: OBJECTIVE
  We examine the relationship between urine and stone cultures in a large cohort of patients undergoing percutaneous stone removal and compare the findings in infectious vs metabolic calculi.
  
  
  METHODS
  A total of 776 patients treated with percutaneous nephrolithotomy who had preoperative urine cultures and intraoperative stone cultures were included in the study. Statistical analysis used chi-square or logistic fit analysis as appropriate.
  
  
  RESULTS
  Preoperative urine culture was positive in 352 patients (45.4%) and stone cultures were positive in 300 patients (38.7%). There were 75 patients (9.7%) with negative preoperative cultures who had positive stone cultures, and in patients with both cultures positive the organisms differed in 103 (13.3%). Gram-positive organisms predominated in preoperative urine and stone cultures.
  
  
  CONCLUSIONS
  Preoperative urine cultures in patients undergoing percutaneous nephrolithotomy are unreliable as there is a discordance with intraoperative stone cultures in almost a quarter of cases. There has been a notable shift toward gram-positive organisms in this cohort of patients.
authors.affiliation: Syracuse University School of Medicine, Syracuse, New York.
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Paonessa
authors.affiliation: Hebrew University of Jerusalem, Hadassa Medical School, Jerusalem, Israel.
authors.forename: Ehud
authors.initials: E
authors.lastname: Gnessin
authors.affiliation: University of Montreal, Montreal, Quebec, Canada.
authors.forename: Naeem
authors.initials: N
authors.lastname: Bhojani
authors.affiliation: Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: James C
authors.initials: JC
authors.lastname: Williams
authors.affiliation: Department of Urology, Indiana University School of Medicine, Indianapolis, Indiana. Electronic address: jlingeman@iuhealth.org.
authors.forename: James E
authors.initials: JE
authors.lastname: Lingeman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000302:isolation & purification*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D007669:Kidney Calculi / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D057234:Preoperative Period; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016482:Urinalysis; D001743:Urinary Bladder / Q000382:microbiology / Q000601:surgery*; D014552:Urinary Tract Infections / Q000150:complications / Q000175:diagnosis* / Q000382:microbiology; D014556:Urine / Q000382:microbiology*; D055815:Young Adult
keywords: kidney calculi; nephrolithiasis; nephrostomy, percutaneous; urinary tract infections