New type of adhesive specificity revealed by oligosaccharide probes in Escherichia coli from patients with urinary tract infection.

A series of oligosaccharides derived from glycoproteins or from human milk were coupled to lipid and used as probes of the binding specificities of Escherichia coli isolated from patients with urinary tract infections. Selective binding to the glycoprotein oligosaccharide probes rich in mannose residues (high-mannose type) was demonstrated with fimbriated E coli that give mannose-inhibitable haemagglutination. This observation is in accordance with predictions from inhibition studies. Binding studies with the human milk oligosaccharide probes, which resemble structures found on host-cell membranes, revealed adhesive specificity unrelated to the presence of fimbriae. This new type of host oligosaccharide receptor is affected by the presence of the blood group genetic markers. It involves the disaccharide sequence linked to the membrane-associated lipid moiety of host-cell glycolipids, and may have a role in initiation of infection on damaged epithelial cell membranes.