V. vulnificus strains isolated from different sources of Cuddalore coastal waters were tested for their virulence activity through their LD50 values in mice. As infections of V. vulnificus have been correlated with pre-existing liver disease and hemochromatosis, the role of iron on virulence was determined using. iron overloaded mice. The LD50 was in the range of 10(4)-10(7) cells in normal mice but 10(1)-10(2) cells in iron-injected mice, thus providing evidence that iron may play a major role in the pathogenesis of V. vulnificus.