Comparison of immunization potential from recombinant proteins EIT and Stx2B nanoparticulated based on chitosan in animal model, as nanovaccin candidate against E. coli O157:H7

 E. coli O157:H7 with its ability of quick implantation inside gastrointestinal tract that causes hemolytic uremic and bloody diarrhea in humans is an important subject to investigate. One of the effective ways to prevent these infections is using nanovaccines prepared from immunogenic recombinant protein from bacterial virulence factors. In this research, the chitosan encapsulated by recombinant protein of EIT with and without Stx2B were introduced to BALB/c mice and immunogenicity was evaluated and compared. In this experimental study the recombinant protein of EIT and Stx2B were nanoparticulated with chitosan through ionic gelation method after expression and purification with Ni-NTA column and approval by Western blotting. After Vaccinations antibodies against rStx2B and rEIT in the mice’s serum and feces were detected by ELISA. Challenge test for neutralization and protection against Stx2 toxin was applied with immunized serum by Fisher's exact test. Evaluation of IgA and IgG antibody levels in the mice’s serum and also the IgA level in their feces showed more appropriate immunity oral-injection groups with the both nanoparticulated antigens. The protection challenge study show that, the mice group which received rEIT+ rStx2B could neutralize the toxin activity significant difference (P<0.05) between test and control groups of mice was recorded. The data indicate these multiple vaccine candidates with both nanoparticulated recombinant proteins EIT and Stx2B with chitosan, provide more effective protection against of E. coli O157:H7