Comparison of the B-D urine culture kit with a standard culture method and with the MS-2

A total of 100 random clinical urine specimens were divided and used to compare Becton, Dickinson & Co. B-D Urine Culture Kit-treated urine (BDU) with refrigerated urine (RU). Each RU-BDU pair was cultured with the standard calibrated loop-plate method and also screened with the Abbott Laboratories MS-2 system at 0, 5, and 24 h. An additional 158 positive urine specimens containing greater than 10(5) CFU/ml were tested by standard culturing and MS-2 at 0 and 24 h. In addition, growth curves were run for Escherichia coli containing RU-BDU pairs at 0 and 24 h, and MS-2 detection time frequencies were analyzed. Culture results showed few changes in colony counts at 0 and 5 h for RU and BDU specimens. At 24 h, there were decreased colony counts for 7.0% of RU and 17.7% of BDU specimens. MS-2 results showed detection rates at 0 h of 100% for RU and 82.9% for BDU specimens and at 24 h of 91.1% for RU and 63.3% for BDU specimens. The organisms most frequently missed at 24 h were E. coli, Pseudomonas aeruginosa, and Staphylococcus epidermidis. Growth curve analysis showed a 1-h delay of logarithmic growth in BDU specimens. MS-2 detection time analysis showed delayed positive reports owing to be extended detection time for BDU specimens. The B-D Urine Culture Kit is a convenient transport system; however, some difficulty in recovering organisms at 24 h with the standard culture method and increased difficulty with the MS-2 system were recognized.