Maryam Homayoon, Yahya Tahamtan, Mohammad Kargar
Enterohemorrhagic Escherichia coli constitute an important current problem of public health and animal production. Extensive efforts have been made to fight the infections caused by the path types which responsible for diseases such as hemorrhagic colitis and hemolytic uremic syndrome. Different vaccines have been tested against these bacteria. Here, the current study was undertaken to evaluate the Humoral and cellular immune responses and protective immunity conferred by an E. coli O157:H7 vaccine with vero cell as adjuvant in mice.
E. coli O157:H7 was grown in the Tryptic Soy Broth (TSB), inactivated with formalin and adjuvant with vero cell and alum. Mice were immunized with inactivated E. coli O157:H7 vaccine to study the splenocytes suspension and serum cytokines proliferation. The serum antibody titers and cytokines Interleukin-1a (IL-1a) and TNF-y were identified by ELISA. At 28 days post immunization, the studied groups were challenged with the LD50 dose of the live bacteria.
Mice immunized with vero cell adjuvant E. coli O157:H7 (VO group) were observed to produce high levels of serum IgG antibodies, also inducing increases in the production of lymphocyte proliferation and secretion of cytokines. Besides, this immunized group produced complete protection after challenge. Our findings introduce that VO immunized mice is capable of releasing an immunological response with several cytokines and produce complete protection after challenge. These obtained results suggested that VO group has the potential as a candidate for vaccine against E. coli O157:H7.