Immunization Evaluation of Type III Secretion System Recombinant Antigens and Shiga Like Toxin Binding Subunit of E. coli O157:H7

J Babol Univ Med Sci; 20(7); July 2018; PP: 47-54 Received: Nov 14 2017, Revised: Mar 14 2018, Accepted: Mar 26 2018. ABSTRACT BACKGROUND AND OBJECTIVE: Escherichia coli enterohemorrhagic (EHEC) causes diarrhea, hemolysis colitis, and uremic hemolytic syndrome. Due to the dangers of antibiotic treatment in the EHEC O157: H7 infection, vaccines offer a promising way to prevent infection. The purpose of this study was to investigate the immunity of recombinant proteins Intimin, EspA and Stx2b against infection of E. coli O157 H7. METHODS: In this research study, expression of recombinant Intimin, EspA and Stx2b proteins E.coli BL21 DE3 was induced with IPTG. Recombinant proteins were examined by Western Blot and purified using the affinity Ni-NTA chromatography. Subcutaneous and intraperitoneally immunization of mice was performed and the antibody titer was determined by ELISA. The mice were orally infected with bacteria and the bacterial loss and mortality of the mice were examined. FINDINGS: SDS-PAGE analysis showed expression of proteins with 11,17 and 34 kDa molecular weight. The recombinant proteins were confirmed by Western Blot. ELISA end point titer for humoral response to EspA, Intimin and Stx2b was 25600. The loss of bacteria in mice was 10 cfu / ml and mortality rate were reduced to 60 Percent. CONCLUSION: The results showed that immune response against EspA, Intimin and Stx2b proteins protects animals against challenges using E. coli O157: H7.