Soybean product inhibits K88 enterotoxigenic Escherichia coli binding to enterocytes

Abstract

Strains of enterotoxigenic Escherichia coli expressing the K88 fimbrial adhesin (K88 ETEC) induce colibacillosis by binding to enterocytes in the small intestine of newborn and weaned piglets and causing secretory diarrhea. Current vaccination protocols are ineffective at preventing K88 ETEC infections during the postweaning period. Consequently, new procedures for preventing and treating postweaning colibacillosis caused by K88 ETEC are needed. Previous studies have shown that extracts of fermented soy products have the potential to prevent ETEC disease by blocking the binding of ETEC to enterocytes. In this study, we evaluated extracts of the fermented soy product, Dochi, for its ability to block K88 ETEC binding to enterocytes. We found that Dochi extracts were able significantly inhibit binding of K88 ETEC to brush borders isolated from porcine enterocytes (50% inhibition, P < 0.05) and cultured porcine intestinal epithelial (IPEC‐J2) cells (60% inhibition, P < 0.05). The inhibitory compound in the Dochi extract was found to elute during fractionation on a Superose 12 FPLC size exclusion column at an approximate molecular weight of 1300 Da. Future studies will be focused on determining the chemical nature of the inhibitory compound and on determining if the inhibitory compound can be used to prevent or treat K88 ETEC‐induced colibacillosis in weaned piglets.Supported by South Dakota State University Research/Scholarship Support Fund, the South Dakota Agricultural Experiment Station, and the South Dakota Center for Infectious Disease Research and Vaccinology.