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

Abstract

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.