Evaluation of the B-D urine culture kit

Split samples of urine transported to the laboratory at 5 degrees C and in a boric acid-glycerol-sodium formate preservative (B-D Urine Culture Kit; Becton, Dickinson & Co.) were cultured immediately and, in the case of preserved urine, after 24 and 48 h of storage at 25 degrees C. Agreement between the results for cultures of specimens originally yielding greater than 10(5) colony-forming units (CFU) per ml and the results for urine preserved for 24 and 48 h was 85 and 71%, respectively. One-third of the specimens originally yielding 10(4) to 10(5) CFU per ml yielded less than 10(4) CFU per ml after 24 h of storage in preservative. Provided greater than 10(4) CFU per ml in specimens preserved for up to 24 h is regarded as equivalent to greater than 10(5) CFU per ml in original urine specimens, agreement of results was greater than 90%.