Evaluation of incubation times for urine cultures.

Nine hundred eighty-two predominantly outpatient urine cultures were evaluated for detection of uropathogens and identification and susceptibility testing after incubation for 12 to 16 h. These results were compared with results obtained after 36 and 60 h of incubation. There was 98% agreement in the detection of uropathogens and interpretation of culture results. The only consistent problem was in the detection of yeasts. Although uropathogens could be reliably detected as early as 12 h, the percentage of cultures considered too young to work on increased as incubation times decreased.