Porcine milk fat globule membrane proteins that bind to F4ac fimbria of Escherichia coli

Abstract

Post‐weaning colibacillosis in pigs is caused by enterotoxigenic Escherichia coli (ETEC) which is often controlled by antibiotic feed supplements with potential risk of generation of antibiotic resistant bacteria. Prevention of attachment of F4ac+ ETEC to intestinal mucosa may potentially be used as one of antibiotic‐free strategies for the control of this disease. F4ac+ ETEC has been reported to bind to fat globule membrane in porcine milk. In this study, we used two different methods to identify individual milk fat globule membrane (MFGM) proteins that interact with F4ac fimbria. First, two‐dimensional SDS‐PAGE overlay Western Blot was used to demonstrate the interaction between F4ac and several MFGM proteins: namely, lactadherin, butyrophilin, adipophilin, acyl‐CoA synthetase 3, and fatty acid binding protein 3. Subsequently, affinity chromatography was designed to isolate the following F4ac‐binding proteins from the porcine MFGM: lactadherin, butyrophilin, adipophilin, acyl‐CoA synthetase 3, fatty acid binding protein 3, and xanthine dehydrogenase. Selected individual proteins and their subunits (e.g. carbohydrates) are being tested for their inhibitory effects against attachment of ETEC to porcine enterocytes. This project was supported by the Saskatchewan Agriculture Development Fund, WCVM Canadian Vitamins Class Action Settlement Fund.