Screening for complex carbohydrates inhibiting hemagglutinations by CFA/I- and CFA/II-expressing enterotoxigenicEscherichia colistrains

Numerous structural families of naturally occurring glycopeptides and oligosaccharides have been evaluated as potential inhibitors of hemagglutinations mediated by CFA/I-and CFA/IIpositive enterotoxigenic Escherichia coli strains. Among the preparations tested were glycopeptides with short O-linked (mucin-type) chains, various mixtures containing N-linked glycans (either oligomannoside-, hybrid-or complex-type), three fractions of human milk oligosaccharides, and glycopeptides derived from either pooled new-born meconiums or pooled human red blood cell membranes. In almost all cases, the same inhibitory preparations were active toward all E. coli strains. This emphasizes the close analogy between the carbohydrate specificities of the colonization factors concerned. Such inhibitors always contained lactosamine units in their oligosaccharide backbones, but this structural requirement alone was not sufficient for activity. The glycopeptide mix