title: Effects of processing delay, temperature, and transport tube type on results of quantitative bacterial culture of canine urine.
abstract: OBJECTIVE
  To determine the impact of processing delay, temperature, and transport tube type on results of quantitative bacterial culture (QBC) of canine urine.
  
  
  METHODS
  Diagnostic test evaluation.
  
  
  METHODS
  60 mL of pooled urine from 4 dogs, divided into six 10-mL aliquots.
  
  
  METHODS
  Urine aliquots were spiked with bacteria from 1 of 6 independent Escherichia coli cultures to achieve a target bacterial concentration of 10(5) CFUs/mL. One milliliter from each aliquot was transferred into 5 silicone-coated clot tubes (SCTs) and 5 urine transport tubes (UTTs). Samples were stored at 4°C (39°F) and 25°C (77°F) for 0, 8, and 24 hours, and then standard QBCs were performed.
  
  
  RESULTS
  Median bacterial concentration for urine samples stored in a UTT for 24 hours at 4°C was lower than that for samples stored in an SCT under the same conditions. Conversely, a substantial decrease in median bacterial concentration was identified for samples stored for 24 hours in an SCT at 25°C, compared with the median concentration for samples stored in a UTT under the same conditions. Median bacterial concentration in samples stored in an SCT at 25°C for 24 hours (275 CFUs/mL) was less than the cutoff typically used to define clinically important bacteriuria by use of urine samples obtained via cystocentesis (ie, > 1,000 CFUs/mL).
  
  
  CONCLUSIONS
  Canine urine samples submitted for immediate QBC should be transported in plain sterile tubes such as SCTs. When prolonged (24-hour) storage at room temperature is anticipated, urine samples should be transported in UTTs.
authors.forename: Carly A
authors.initials: CA
authors.lastname: Patterson
authors.forename: Micah A
authors.initials: MA
authors.lastname: Bishop
authors.forename: Julie D
authors.initials: JD
authors.lastname: Pack
authors.forename: Audrey K
authors.initials: AK
authors.lastname: Cook
authors.forename: Sara D
authors.initials: SD
authors.lastname: Lawhon
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques / Q000662:veterinary*; D004283:Dog Diseases / Q000175:diagnosis*; D004285:Dogs; D005260:Female; D008297:Male; D013696:Temperature; D013997:Time Factors; D016482:Urinalysis / Q000662:veterinary*; D059349:Urine Specimen Collection / Q000379:methods / Q000662:veterinary*