Immunization evaluation of type III secretion system recombinant antigens and shiga like toxin binding subunit of E. coli O157:H7

Background and 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 recombinant proteins can create immunity against bacterial infections. The purpose of this study was to investigate the immunity of recombinant proteins Intimin, EspA and Stx2b against infection of E. coli O157 H7.
Material and In this descriptive-laboratory study, recombinant Intimin, EspA and Stx2b proteins were expressed in E.coli BL21 DE3 under the influence of IPTG. The expression of recombinant proteins was examined by SDS-PAGE and Western Blot. The recombinant proteins were purified using the affinity Ni-NTA chromatography. Immunization was performed in mice with pure protein and the antibody titer was determined by ELISA. After immunization, the mice were infected with bacteria and the bacterial loss and mortality of the mice were examined. Statistical analysis was done with SPSS software.
The recombinant proteins were expressed in host E.coli BL21 (DE3), and SDS-PAGE analysis revealed expression of recombinant proteins. The recombinant proteins were confirmed by Western Blot. ELISA results showed that Immunization induced a humoral response to EspA, Intimin and Stx2b. The loss of bacteria in mice was 102 cfu / ml and Mortality rate were reduced to 60 Percent.
The results showed that recombinant proteins produced an intense humoral response and also protects animals against live challenges using E.coli O157: H7.