Survival of Kanagawa-positive strains ofVibrio parahaemolyticusin a brackish-water area

Abstract

SUMMARY: Vibrio parahaemolyticuswas observed to overwinter in sediments and to be present in considerable numbers in sediments andClithon retropictus(gastropod mollusc) during summer months at a brackish-water area along Hashizu Creek in Japan. The highest level of the organisms was 97·3 × 10⁶and 2·3 × 10⁷/100 g in sediments andC. retropictusrespectively.Production of Kanagawa haemolysin was detected in approximately 12% and 20% of strains isolated from sediments andC. retropictusrespectively at two stations in Hashizu Creek but were not detected at the other three stations. Two haemolysin-producing strains were isolated from water samples but none were isolated fromCorbicula japonica(bivalve molluse). These findings suggest that haemolysin producers are preserved principally in sediments and some shellfish in the brackish-water areas with restricted salinity conditions.