Feasibility Study Of Displaying Heterologous Antigens On Bacillus Cereus Cell Surface

S-layer protein CTC surface display system of Bacillus thuringiensis was used to test the possibility of displaying avain influenza virus nucleoprotein (NP), hemagglutinin (HA1) or protein of Mycoplasma gallisepticum agglutinin (pMGA) on the cell surface of Bacillus thuringiensis. Although the experiment demonstrated Bacillus thuringiensis was safe and non-toxic for mice and chickens, but the role of probiotics, not related to reporting; Bacillus cereus, often used as probiotics, This study was used bacterial cell surface display technology to test the possibility of displaying heterologous antigens on the cell surface of bacillus cereus for the development of heat-stable, probiotic oral vaccine using B.cereus as a carrier.1. Construction recombinant strains of Bacillus cereusBacillus thuringiensis recombinant strains CH and BCCH as the original beginning bacterial strains for plasmids extraction and endonuclease, being used for electroporation to Bacillus cereus. The resulting strains include plasmid PCSHAIP named BcA, include two plasmids: CTC- HA1P and pMIL-CSA named BcC. The plasmid pMIL-CSA harboring csaAB operon was co-transferred into B.cereus with the recombinant plasmids which did not harboring csaAB operon.2. Assaying the display of heterologous antigens on the recombinant strainsHaemagglutination assay showed recombinant HAI proteins were displayed on the cell surface of respective recombinant strains. Hemagglutination inhibition assay showed recombinant HA1 proteins displayed on the cell surfaee of recombinants respectively were specific to standard positive serum of avian influenza virus, respectively.3. Immunogenicity of recombinant strains to chiekensThe spores of recombinant strains BcA and BcC were prepared. The AV commercial broiler chickens were immunized by oral route with spores. The serum antibody titers of chiekens immunized with spores of BcA and BcC were assayed by haemagglutination inhibition test. The results showed that the recombinant strains did not elicite humoral response of chickens to respective heterologous antigens displayed on the cell surfaces and didn't exhibite immunogenieity. the mechanism need to be further studied.