Survival of Vibrio cholerae in industrially polluted water, with particular reference to iron concentrations

Abstract

High levels of iron are often found in surface waters due to the discharge of iron-containing industrial effluents. The effect of iron as well as pH on the survival of Vibrio cholerae (non-O1, E1 Tor and classical strains) in water samples from 12 points, where selected industrial effluents were discharged into rivers, was studied. All three V. cholerae strains survived longest during spring. V. cholerae non -O1 survived significantly longer than E1 Tor and classical strains. At pH 8.0, the survivalof V. cholerae increased with increase in iron concentration (1 to 10 mg/l) of polluted water. At lower than pH 8.0, the effect of iron was not significant. In polluted water, at pH 8.0, the presence of iron resulted in prolonged V. cholerae survival at lower concentrations than those required for survival in distilled water. We suggest that chemical contamination of water may be one of the important factors instrumental in the subsequent ability of V. cholerae to persist, multiply and survive in the aquatic environment.