The detection of Brucella spp by BACTEC 9050 blood culture system

Recent reports have demonstrated that automated continous monitoring blood culture systems are fast and efficent in the detection of Brucella spp. In this retrospective study, the detection of these slow-growing bacteria by BACTEC 9050 blood culture system was evaluated. For this purpose, 60 patients, whose blood cultures were monitored by using BACTEC 9050 system were included into the study. Brucella spp. were isolated in 26 of 31 patients from whom two blood cultures were obtained and in 17 of 29 patients from whom single blood culture were obtained. The majority of isolates (84.1%) were detected within 7 days of incubation while the earliest detection was on the 3rd day in two samples. However, the bacteria were isolated by subcultures after 30 days of incubation in 8 of the samples. In conclusion, the routine 5 or 7 days-incubation protocols with BACTEC 9050 system were not efficient for the isolation of Brucella spp. Obtaining two blood cultures and prolonged incubation followed by subcultures increased the probability of bacterial isolation.