Vibrio cholerae non-O1: production of cell-associated hemagglutinins and in vitro adherence to mucus coat and epithelial surfaces of the villi and lymphoid follicles of human small intestines treated with formalin.

Clinically isolated Vibrio cholerae non-O1 strains produced more cell-associated hemagglutinins (HAs) on colonization factor antigen agar after ca. 3 h than after ca. 20 h of incubation at 37 degrees C. A high cell-associated HA producer variant of strain TVN-318, grown for 3 h at 37 degrees C, was entrapped in a native mucus coat covering the human ileal mucosa and displayed a striking ability to adhere to the surface of a Formalin-treated mucus coat, in contrast to a poor cell-associated HA producer variant of TVN-318, grown for 20 h at 37 degrees C. Adherence to the Formalin-treated human mucus coat was confirmed with all of the strains tested. V. cholerae non-O1 strains also possessed the ability to adhere to the epithelial surfaces of Formalin-treated human and rabbit ileal or jejunal villi, as well as human lymphoid follicles, in proportion to cell-associated HA levels. The epithelial surface of the lymphoid follicles provided most of the adherence sites for V. cholerae non-O1 strains under the test conditions. We conclude that a mucus coat covering the human small intestinal mucosa is a primary adherence target for V. cholerae non-O1 strains in human intestinal infections and that cell-associated HAs have at least a partial role in the adherence of V. cholerae non-O1 strains to the human small intestine, suggesting a potential role for V. cholerae non-O1 strains in an oral live vaccine.