Investigation on prevalence of Vibrio parahaemolyticus in oyster in Tra Vinh province

Abstract

Vibrio parahaemolyticus carrying tdh and/or trh gene is one of important foodborne pathogens in humans. Most of the infected cases are due to eating raw or undercook seafood. In this study, a total of 30 oyster samples including 15 samples collected from the retail seafood shops in Tra Vinh city and 15 oyster samples collected from the oyster farms located in Lang Chim river, Duyen Hai town, Tra Vinh
province was tested to detect V. parahaemolyticus carrying virulent genes caused intestinal diseases by PCR method. Antibiotic resistance of V. parahaemolyticus strains isolated from 30 oyster samples was also examined using disk diffusion method. There were 6 types of antibiotics examined in this study, including streptomycin (10µg), ampicillin (10µg), chloramphenicol (30µg), gentamycin (10µg),
nalidixic acid (30µg) and ofloxacin (10µg). The studied results indicated that 30/30 (100%) oyster samples contained V. parahaemolyticus. However, the V. parahaemolyticus strains carrying tdh or trh genes was not found in this study. The
result of antimicrobial resistance test indicated that bacteria showed high resistance to streptomycin (80%) and ampicillin (60%). This study results can be used for understanding microbiological risk of seafood in Tra Vinh province.