Evaluation of nonisotopic DNA hybridization methods for detection of the tdh gene of vibrio parahaemolyticus.

Production of the thermostable direct hemolysin (TDH) by Vibrio parahaemolyticus is associated with pathogenicity of the organism and is encoded by the tdh gene. The timely resolution of seafood-associated outbreaks requires rapid and accurate detection of pathogenic V. parahaemolyticus. The specificity of alkaline phosphatase- and digoxigenin-labeled tdh gene probes was evaluated against 61 strains of V. parahaemolyticus (including isolates from recent outbreaks involving oysters from the Pacific Northwest, Texas, and New York), 85 strains of other vibrios, and 7 strains of non-vibrio species from clinical and environmental sources. The probes were specific for detection of the V. parahaemolyticus tdh gene.