Electron microscopic study of Vibrio cholerae O1 adherence to the mucus coat and villus surface in the human small intestine.

Vibrio cholerae O1, irrespective of the biotype or serotype, adhered to and was entrapped in the mucus coat covering the mucosal surface of isolated human ileal segments. The evidence for such mucus coat adherence was obtained by treatment of the ileal segments with 10% Formalin. In any case, adherence to the mucus coat was much more prominent than adherence to the epithelial cell surface of the small intestinal villi. Mucus coat adherence was affected by sugars and by the growth phase of the bacterial culture and was diminished by the heating of V. cholerae O1. We conclude that the small intestinal mucus coat is a primary adherence target for V. cholerae O1 in human infection and that the cell-associated hemagglutinin of V. cholerae O1 plays a role, at least in part, in adherence.