A Multivalent Vaccine for Preventing Piglet Diarrhea A New Multivalent Vaccine Candidate Targeting Fimbriae and Enterotoxin of Enterotoxigenic Escherichia coli for Preventing Newborn Piglet Diarrhea

In order to develop the K88ac-3ST a -LT 2 trivalent genetically engineered inactivated vaccine, the recombinant strain BL21(DE3)(pXK88ac3ST a LT 2 ) was constructed. ELISA test showed that the K88ac-3ST a -LT 2 fusion protein could be recognized by ST a monoclonal antibody, LT 2 and K88ac antibody. The test of intragastric administration in the suckling mouse confirmed that the expressed fusion protein had lost the toxicity of the natural ST a enterotoxin. The results of immune experiments showed that K88ac-3ST a -LT 2 fusion protein could induce rabbits to produce serum antibodies, which had the effect of neutralizing the toxicity of natural ST a enterotoxin. Efficacy test of the K88ac-3ST a -LT 2 genetically engineered inactivated vaccine showed that the immune protection rate of the newborn piglets could reach 85% on the 1st day after suckling. At the same time, it was determined that the minimum immunization doses for mice and pregnant sows were 0.2 mL and 2.5mL respectively. This study provided scientific parameters for the industrialized production of the vaccine and showed that the K88ac-3ST a -LT 2 trivalent genetically engineered inactivated vaccine had a broad immune spectrum for E. coli diarrhea in newborn piglets. Through this research, a new genetic engineering vaccine candidate strain was provided for more effective prevention of E. coli diarrhea in piglets.