Prokaryotic Expression And Immunogenicity Analysis Of Flagellar FljB Of Salmonella Abortus Equi

Equine abortus salmonellosis was also known as equine paratyphoid, which caused by Salmonella abortus equi. Equine abortus salmonellosis can cause equine abortion, joint prominent stallions and foals diarrhea. Equine will become carrier of the disease after it infected with equine abortus salmonellosis, and may become a source of infection. Phase II flagellin fljB of Salmonella abortus equi constitutes flagellar antigen(H antigen), which plays a key role in invasion and diffusion of this bacteria, and leads to a strong immune response after it invades the host.In this study, according to the published sequences of fljB gene of Salmonella abortus equi on Genbank, a pair of primers were designed, fljB gene was amplified using Salmonella abortus equi isolated from Xinjiang with these primers, and fljB gene sequence was analyzed using molecular biology softwares. The results showed that Salmonella abortus equi isolated from Xinjiang was highly homologous to the published on Genbank. The target fragments fljB were cloned to the pET-28 a vector, and prokaryotic recombinant plasmid pET-28a-fljB was constructed. The recombinant plasmid was transformed into host BL21(DE3) cells, and recombinant protein fljB was expressed by induced with IPTG. The SDS-PAGE analysis revealed that the expressed recombinant protein fljB was 42 kD. Western blotting indicated that recombinant protein could be reacted with Salmonella abortus equi serum. Then the purified fljB protein was immunized mice and antibody dilution of immunized mice serum was 1:64000.In this study, Salmonella abortus equi flagellin fljB was successfully cloned, and pET-28a-fljB prokaryotic recombinant plasmid was constructed, then purified recombinant protein was obtained. The results indicated that prokaryotic recombinant fljB had a good immunogenicity. This result laid the foundation for the use of the protein.