Effects of processing delay, temperature, and transport tube type on results of quantitative bacterial culture of XXXX urine.

@entity12497 @entity235 @entity793 @entity1346 @entity526
OBJECTIVE: To determine the impact of processing delay, temperature, and transport tube type on results of quantitative bacterial culture (QBC) of @entity235 urine. DESIGN: Diagnostic test evaluation. SAMPLE: 60 mL of pooled urine from 4 @entity235 , divided into six 10-mL aliquots. PROCEDURES: Urine aliquots were spiked with bacteria from 1 of 6 independent @entity526 cultures to achieve a target bacterial concentration of 10(5) CFUs/mL. One milliliter from each aliquot was transferred into 5 @entity1346 -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 @entity12497 under the same conditions. Conversely, a substantial decrease in median bacterial concentration was identified for samples stored for 24 hours in an @entity12497 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 @entity12497 at 25  C for 24 hours (275 CFUs/mL) was less than the cutoff typically used to define clinically important @entity793 by use of urine samples obtained via cystocentesis (ie, > 1,000 CFUs/mL). CONCLUSIONS AND CLINICAL RELEVANCE: @entity235 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.
