DISTRIBUTION OF VIBRIO PARAHAEMOLYTICUS IN THE NATURAL ENVIRONMENT1

Abstract

Vibrio parahaemolyticus has been isolated widely from marine environments but appears to be most abundant in in-shore and estuarine areas where ambient temperatures rise seasonally to levels permitting growth of the organism. Japanese and U. S. studies of coastal areas have shown a direct relationship between temperature and abundance of V. parahaemolyticus and this correlates with the seasonal incidence of V. parahaemolyticus food poisoning in Japan. The organism has been isolated from water, sediment, plankton, fish, and shellfish. In North America it seems to be most abundant in molluscan shellfish and in waters of high organic content. Counts of 10–200/ml of water, 1–7/g of sediment and up to 105/g of oyster tissue have been reported for North American inshore areas. Limited information on market seafood samples indicates very low incidence of V. parahaemolyticus on fin fish in Europe and North America and high incidence in Japan during summer months. Limited data on market samples of frozen and fresh shellfish in U.S.A. suggest sporadically high incidence on shrimp, crabmeat, oysters, and clams.