Abstract
The seasonal variation in the occurrence of V. vulnificus in relation to water temperature and salinity was studied along the Dutch coast. In two consecutive years V. vulnificus strains could be isolated in August when the water temperature was highest. The indole-positive strains isolated from North Sea water samples were identical to most strains isolated from human disease and from the environment. However, strains isolated from four of five patients living in countries around the North Sea were different from the North Sea isolates in that they were indole-negative and have a lower NaCl tolerance.