Bovine immune colostrum against 17 strains of diarrhea bacteria and in vitro and in vivo effects of its specific IgG

Bovine colostral antibodies of cows immunized with a multivalent vaccine consisting of whole cells of 17 strains of pathogenic diarrhea bacteria were generated, and the specific IgG with high activities and titres directed against these pathogens was purified using an ammonium sulfate precipitation and verified by SDS-PAGE. We demonstrate that specific IgG has a strong activity of inhibiting in vitro growth and colonization in pathogens by agglutinating with bacteria and destroying cell walls. Normal IgG purified from non-immunized bovine colostrum is incapable of eliciting the same consequences as specific IgG. Specific IgG prevents enteroinvasive Escherichia coli/ Salmonella typhi-induced diarrhea and may exert an effective protection by enhancing splenic NK cell activity, elevating IL-2 level and inhibiting excessive release of TNF-α in mice. Thus, the specific IgG from colostral antibodies of immunized bovine can provide effective protection or therapy for multibacteria-induced diarrhea.