immune reactivity of sera obtained from brucellosis patients and vaccinated-rabbits to a fusion protein from brucella melitensis

objective(s): brucella spp. are facultative intracellular pathogens which can stay alive and multiply in professional and nonprofessional phagocytes. immunity against brucella melitensis involves antigen-specific cd4+ and cd8+ t-cells activation and humoral immune responses. due to negative aspects of live attenuated vaccines, much attention has been focused on finding brucella-protective antigens to introduce them as potential subunit vaccine candidates. materials and methods: a chimeric gene encoding trigger factor (tf), omp3148-74 and bp2687-111 fragments (tob) from b. melitensis was successfully cloned, expressed in escherichia colibl21-de3 and purified by ni-nta agarose column. antibodies to recombinant tob (rtob) have been investigated in brucella-infected human sera and a pool serum prepared from b. melitensis-vaccinated rabbits. results: our results showed that the immunized rabbit pool serum strongly reacted with rtob. in addition, antibodies against rtob were detectable in 76.5% of sera obtained from infected patients. conclusion: these findings suggest that rtob may provide a potential immunogenic candidate which could be considered in future vaccine studies.