Abstract
Interactions between Yersinia enterocolitica and purified intestinal mucins from rabbit and humans were investigated. Plasmid-bearing virulent organisms (but not plasmid-free nonvirulent bacteria) bound well to both mucins, suggesting that adherence was controlled by the virulence plasmid. Examination of binding to 14 different preparations of purified human intestinal mucin (8 preparations obtained from normal subjects and 6 samples from patients with cystic fibrosis) revealed no differences between normal and cystic fibrotic mucins in ability to serve as a binding substrate for virulent Y. enterocolitica. Analyses of binding curves suggested the presence of a single type of noninteracting receptor for Y. enterocolitica in both rabbit and human mucins with similar (but not necessarily identical) structures. Virulent bacteria bound to polystyrene through hydrophobic interactions that could be disrupted by treating the organisms with tetramethyl urea. In contrast, binding of plasmid-bearing Y. enterocolitica to intestinal mucin was not susceptible to tetramethyl urea and therefore does not appear to involve hydrophobic interactions. Prior incubation of organisms with mucin significantly inhibited binding to polystyrene, suggesting that mucin can mask hydrophobic adhesins on the bacterial surface. Hapten inhibition studies revealed that the monosaccharides galactose and N-acetylgalactosamine and the disaccharide lactose could markedly reduce (but not abolish) bacterial adherence to mucin but other monosaccharides and the RGD peptide had no effect on mucin binding. We conclude that virulent Y. enterocolitica is capable of interacting with the carbohydrate moiety of intestinal mucin. These interactions appear to be plasmid mediated and not hydrophobic.