Immune reactivity of Brucella melitensis-vaccinated rabbit serum with recombinant Omp31 and DnaK proteins

ABSTRACT

Brucella melitensis infection is still a major health problem for human and cattle in developing countries and the Middle East. In this study, in order to screen immunogenic candidate antigens for the development of a Brucella subunit vaccine, a cytoplasmic protein [DnaK] and an outer membrane protein [Omp31] of B. melitensis were cloned, expressed in E.coli BL21 and then purified using Ni-NTA agarose. Immunized serum was prepared from a rabbit inoculated with attenuated B. melitensis. It was proved that immunized serum contains antibodies against recombinant Omp31 [rOmp31] and DnaK [rDnaK] by Western blot and ELISA assays. The results may suggest the importance of these proteins as subunit vaccines against B. melitensis as well as targets for immunotherapy