Design and construction of expression vector containing the chimeric antigen of B. melitensis Omp25-Omp31 to production of a vaccine against brucellosis

Brucella is gram-negative intracellular bacterial pathogens of both humans and animals. Among the six recognized Brucella species, Brucella melitensis is the main etiologic agent involved in ovine and caprine brucellosis and is also the most pathogenic species of humans. We amplified by specific primers, two of the best outer membrane antigens Omp31 and Omp25 for this disease, and the construction of recombinant chimeric Omp31-Omp25 combination of them, with using the (EAAAK)2 linker. The sequence analysis results showed that strain Rev1 of melitensis for Omp25 antigen has most homology with the strains melitensis M16 and also Omp31 antigen showed the most homology with of B. Ovis melitensis species. Then recombinant chimera Omp31-Omp25 was cloned into Pet32a vector and transform into BL21 (DE3) host cell for expression