Pili of Vibrio cholerae O1 biotype E1 Tor: a comparative study on adhesive and non-adhesive strains.

Pili were found on the cell surface of non-adhesive Vibrio cholerae O1 Biotype E1 Tor as well as the adhesive strain. Purified pili of the adhesive and non-adhesive strains were morphologically, electrophoretically, and immunologically, indistinguishable from each other. The molecular weights of both pilin (subunit protein of the pilus) were about 16,000 daltons as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These 16 kDa pili are different from the pilus colonization factor, which is a 20.5 kDa protein, reported by Taylor et al. The 16 kDa pili of Vibrio cholerae O1 Biotype E1 Tor have hemagglutinating activity, but may have no role in colonization, because non-adhesive strains also have such pili.