Isolation and identification of Brucella organisms in Iran

Background: Brucellosis is a zoonotic, chronic and infectious disease, which is caused by bacteria of genus Brucella. The present study investigated exactly what species and biovars of Brucella are responsible for brucellosis in Iran. Materials and methods: The various species of Brucella were mostly being isolated from suspected specimens of animal fetus, placenta, vaginal swab, lymph nodes, milk, and human blood and bone marrow cultures. A total of 618 strains of B. abortus and 2413 strains of B. melitensis have been subjected to the identification procedures. Results: Of 3031 isolates, 618 and 2413 were B. abortus and B. melitensis, respectively. Strains of B. abortus were isolated from cattle (612 cases) and sheep (6 cases). These isolates were biovars 1 (70 cases), 2 (1 case), 3 (511 cases),4 (1 case), 5 (30 cases) and 9 (5 cases). Biovar 3 is considered as the endemic one and biovars 1 and 5 are the most prevalent. B. melitensis strains were isolated from sheep and goats (1717 cases), cattle (109 cases), camel (5 cases), dogs (4 cases) and human beings (497 cases). These isolates were biovars 1 (2102 cases), 2 (205 cases) and 3 (106 cases). B. suis, B. neotomae, B. ovis and B. canis were not isolated. Conclusion: In many regions of Iran B. abortus biovar 3 still remains the dominant one, however, for B. melitensis biovar 1 is the most prevalent one.