SURVIVAL OF CULTURABLE VIBRIO-CHOLERAE O1 AND NON O1 IN SEAWATER, FRESH-WATER AND WASTE-WATER AND EFFECT OF THE WATER ENVIRONMENT ON ENTEROTOXIN PRODUCTION

A study on the survival of V. cholerae O1 cholerae, V. cholerae O1 E1 Tor and V. cholerae non O1 in microcosms containing freshwater, saltwa ter and wastewater from the State of Sao Paulo, Brazil, was carried ou t. The effect of physicochemical environmental factors on the expressi on of vibrio enterotoxigenicity was also analyzed. The three V. choler ae strains tested lived better in filter-sterilized water, confirming that competition is a constraint for vibrios survival. Survival was gr eater at 10 degrees 0 than at 25 degrees C or 35 degrees C, and it was also influenced by alkalinity, pH, chlorides, and sodium and potassiu m concentrations. Longer survival occurred in non-polluted seawater, c onfirming that these vibrios are autochthonous to marine environments. The toxigenicity of V. cholerae O1 cholerae and E1 Tor was not affect ed during the experimental period.