Chang-Ho Kanga, YuJin Shina, SeokCheol Janga, HongSik Yub, SuKyung Kimb, Sera Anb, Kunbawui Parkc, Jae-Seong Soa,*
a Department of Biological Engineering, Inha University, Incheon, Republic of Korea
b West sea Fisheries Institute, National Institute of Fisheries Sciencet (NIFS), Incheon, Republic of Korea
c Food Safety and Processing Research Division, National Institute of Fisheries Science (NIFS), Busan, Republic of Korea
Vibrio parahaemolyticus, found frequently in oysters, is the most prevalent gastroenteritis-causing pathogen in Korea and in several other Asian countries. This study monitored changes in the environmental parameters and occurrence of V. parahaemolyticus in oyster aquaculture sites. Of the 44 presumed V. parahaemolyticus isolates obtained, when tested against 16 antibiotics, 90.9, 86.4, and 75.0% of the 44 isolates exhibited resistance to vancomycin, ampicillin, and streptomycin, respectively. PCR analysis for the presence of the toxR gene confirmed 31 of the 44 isolates as being positive V. parahaemolyticus strains. The toxR positive isolates were tested for the presence of thermostable direct hemolysin (tdh) and tdh-related hemolysin (trh) virulence genes. Only 9.1% toxR positive isolate exhibit the trh gene and none of the isolates were tested positive for tdh. The occurrence of multi drug resistance strains in the environment could be an indication of excessive usage of antibiotics in agriculture and aquaculture fields.
Key word : Vibrio parahaemolyticus; Oyster; Occurrence; toxR; trh