Diagnosis of Brucellosis via BACTEC Blood Culture System

Brucellosis is a zoonosis infectious disease and endemic in Iran. The certain diagnosis of disease is established on isolation of brucella from blood and other clinical samples. So, because of fastidious nature of this organism and problems in its isolation by conventional methods, and attending to the high prevalence of brucellosis in Kashan, Iran, the BACTEC9050 blood culture system was used in this survey for diagnosis of brucella bacteremia; advantages of this method has been discussed, too.

In this descriptive research, the blood samples of 206 patients suspected to brucellosis were studied in Brain-Heart Infusion (BHI) broth and BACTEC9050 blood culture system simultaneously.

In a period of 5 days, from 206 samples, totally 50 cases were positive; 32 cases were positive in both methods and 18 cases were positive only in BACTEC method. Continuing the incubation, 14 cases became positive but 4 cases were negative, even after 30 days of incubation. The average incubation period for specimens to become positive was 4 days.

The BACTEC automatic system reduced the examination process, and economized the time and the material. In cases that this system is not available for diagnosis of brucella, it is recommended to keep the final subcultures in 37°C for 1 month to get better diagnostic results.