Escherichia coli K88 Interaction with IgA Oligosaccharides

Abstract

Diarrhea from enterotoxigenic Escherichia coli (E. coli) expressing the K88 fimbrial adhesin causes high morbidity and mortality among newborn and weaned piglets. K88 fimbrial adhesins are surface filaments with lectin activity that recognize specific glycoconjugates (glycoproteins or glycolipids) on the surface of intestinal cells. Carbohydrates that compete for adhesion attachment could serve as an alternative for disease prevention. In this study, IgA, IgG and IgM oligosaccharides were tested to inhibit the adhesion of E. coli K88 to piglet mucins. Immunoglobulins were isolated from porcine serum by hydrophobic interaction chromatography (HIC) and purified by affinity chromatography. In vitro K88 adhesin interacts specifically with IgA oligosaccharides, but not with carbohydrates of IgG or IgM. Also IgA oligosaccharides partially inhibit the adherence of K88 strain to porcine intestinal mucins.