title: Prevalence and quantification of pathogenic Vibrio parahaemolyticus during shrimp culture in Thailand.
abstract: Vibrio parahaemolyticus is a major cause of seafood-borne gastroenteritis. The human pathogenic strains possess tdh or trh or both genes. In Thai shrimp farming, the level of pathogenic V. parahaemolyticus contamination has not been completely characterized, although it has been identified as a risk for people who consume undercooked shrimp. In this study, the prevalence and concentration of V. parahaemolyticus (total Vp) and pathogenic V. parahaemolyticus (tdh+ Vp and trh+ Vp) were investigated during shrimp culture cycles using the most probable number (MPN) method and were confirmed by PCR and the loop-mediated isothermal amplification (LAMP) techniques. The prevalence and concentration of total Vp were high in broodstock and egg samples at the start of the hatchery cycle, but the organism decreased in the subsequent larval and postlarval stages. In contrast, total Vp was low at the beginning of the pond cycle and dramatically increased during the later stages of culture. Broodstock and fresh feed were important sources of V. parahaemolyticus. Numbers of tdh+ Vp and trh+ Vp detected by the LAMP technique were much greater than those detected by the PCR technique, especially in the late stages of the pond cycle. A direct correlation between total Vp and pathogenic Vp was demonstrated only during the harvest stage. This study will be useful as a guideline to establish levels of V. parahaemolyticus presence which can be considered as safe during shrimp culture. In addition, it could be used to identify the source of V. parahaemolyticus, which has recently been reported to be one of the etiologic agents of acute hepatopancreatic necrosis disease.
authors.affiliation: Food Safety and Health Research Unit, Department of Microbiology, Faculty of Science, Department of Biomedical Science, Faculty of Medicine, and Department of Mathematics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand.
authors.forename: Mingkwan
authors.initials: M
authors.lastname: Yingkajorn
authors.forename: Pimonsri
authors.initials: P
authors.lastname: Mitraparp-Arthorn
authors.forename: Suphachai
authors.initials: S
authors.lastname: Nuanualsuwan
authors.forename: Ratanaruji
authors.initials: R
authors.lastname: Poomwised
authors.forename: Noochanat
authors.initials: N
authors.lastname: Kongchuay
authors.forename: Natchaya
authors.initials: N
authors.lastname: Khamhaeng
authors.forename: Varaporn
authors.initials: V
authors.lastname: Vuddhakul
mesh_terms: D000818:Animals; D054884:Host-Pathogen Interactions; D033561:Penaeidae / Q000382:microbiology*; D013785:Thailand; D014736:Vibrio parahaemolyticus / Q000302:isolation & purification*