Application of Molecular-Biological Methods for Identification of Vibrio parahaemolyticus

Gergana Krumova-Valcheva, Eva Gyurova, Yordan Gogov

Abstract: Vibrio parahaemolyticus was isolated from sea foods and it is responsible for the appearance of gastroenteritis in humans. Most of the pathogenic strains produce thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH) which are encoded by trh and tdh genes respectively. In this study were tested 130 suspected Vibrio parahaemolyticus strains, previously isolated from live bivalve mollusks (M. galloprovincialis). Their confirmation was done by culture method and Polymerase- Chain Reaction (PCR). The culture methods included ISO 21872-1:2007 and the biochemical confirmation was carried out with API 20E. The PCR-method was performed by amplification of the V. parahaemolyticus specific ToxR-gene and the genes tdh and trh, responsible for pathogenicity. Out of 130 tested isolates only 34 (33%) gave a positive results for Vibrio parahaemolyticus by biochemical approach. The molecular-biological methods confirmed that 12 (28%) of the 34 biochemical-positive strains were positive for the presence of the ToxR gene. None of them were positive for the presence of pathogenic genes (tdh and trh). Compared to the biochemical methods, PCR approach is more rapid and reliable for routine laboratory diagnosis of V. parahaemolyticus in shellfish.

Keywords: live bivalve mollusks; PCR; Vibrio parahaemolyticus

Date published: 2019-06-26