Background: Brucellosis is a major cause of zoonosis disease and is endemic in hamadan Province in Iran. The purpose of this study was to isolate Brucella species from brucellosis patients and identify different species of this bacterium in order to determine the prevalence of the species.

Materials and Methods: This study was descriptive- cross sectional and fifty blood samples were obtained from brucellosis patients with clinical symptoms. The samples were cultured in BACTEC system and incubated for 14 days. Then, the samples were cultured on Brucella agar and biochemical tests were done for identification of bacteria. Finally, Polymerase Chain Reaction (PCR) applied for confirmation and isolated identification with specific primers.

Results: Seven Brucella strains were isolated from 50 blood samples of the patients with brucellosis by blood culture and PCR. The PCR results on blood specimens showed 4 positive in spite of the negative results of blood culture. PCR and biochemical methods revealed that all the 11 isolated bacteria were Brucella Melitensis.

Conclusion: This study was designed to evaluate PCR technique as a diagnostic tool for brucella spp in comparison to conventional techniques. This study showed a high prevalence of brucellosis due to Brucella Melitensis in Hamadan Province and efforts in this region should be aimed at the eradication of this bacterium.