Abstract
Vibrio parahaemolyticus strain D-3, positive in Kanagawa phenomenon, was found to survive at a considerable level for 21 days after oral inoculation at a level of 104 viable units per gram in an estuarine gastropod mollusc, Clithon retropictus, maintained in artificial seawater with salinities of 15 and 20 grams per liter at 25°C. V. parahaemolyticus strain R-13, negative in Kanagawa phenomenon, survived in the mollusc in lower levels than strain D-3. Escherichia coli strain YS-2 survived in the mollusc in levels of less than 103 viable units per gram. All strains were decreased to non-detectable level within 72 hr after inoculation in a marine gastropod, Nerita albicilla, maintained in water with a salinity of 35 grams per liter at 28°C. Levels of V. parahaemolyticus strains detected from C. retropictus were fluctuated largely while those of E. coli strain were rather stable. Strains D-3 and R-13 survived together in C. retropictus after mixed inoculation, in which conversion of Kanagawa phenomenon was not observed.
