ATTACHMENT OF VIBRIO-CHOLERAE UNDER VARIOUS ENVIRONMENTAL-CONDITIONS AND TO SELECTED SUBSTRATES

Attachment rates of Vibrio cholerae (three tox(+) strains of serotype 01 and two non-01's) were examined using epifluorescent microscopy and TEM. The effects of temperature, pH, various ions and nutrient starva tion on attachment were determined. Optimum attachment occurred at 35 degrees C, pH 2, concentrations of 1.0-1.5% NaCl, 1.0-1.5% KCl, 0.5-0. 1% MgCl2 (with 1.0% NaCl), and 1.0-0.5% CaCl2 (with 1.0% NaCl). After one day of starvation, attachment declined by 75% with little change d uring further starvation. Adhesion to a variety of non-living substrat es, more than 25 species of algae, and three species of aquatic plants was examined using direct fluorescent staining, fluorescent monoclona l antibody and epifluorescent microscopy. Attachment was expressed num erically as an adhesion index. The highest rate of attachment to natur al substrates occurred with (some forms of) chitin and diatomaceous ea rth. Highest rates on algae were noted on three species of green algae , one species of red and one species of yellow green. Since V. cholera e can readily attach to many substrates common in tropic and semi-trop ical estuarine waters and under conditions typical of estuarine and ma rine waters, this is consistent with the hypothesis that the estuarine environment is an ideal reservoir for cholera-causing strains of V. c holerae.