RESUMO
BACKGROUND: Vibrio parahaemolyticus is one of the most important food-borne pathogens in Korea. Although the mechanism of its pathologic effect is still not clearly understood, epidemiological studies have suggested a very strong association of thermostable direct hemolysin (TDH) and thermostable direct hemolysin-related hemolysin (TRH) with the disease. We detected the tdh gene and the trh gene of V. parahaemolyticus isolates by polymerase chain reaction (PCR). METHODS: V. parahaemolyticus strains were isolated from clinical specimens of patients with diarrhea in different geographic areas of Seoul (16 cases), Inchon (27 cases) and Kwang Joo (2 cases) in Korea between 1998 and 2000. The colonies selected were identified by using the API 20E identification strip (API system, Analytab Products, Montalieu-Vercieu, France). PCR protocols were established for specific detection of the tdh and trh genes. Oligonucleotide primers were designed based on the reported nucleotide sequence of the tdh2 gene and the trh1 gene, respectively. RESULTS: The protocols established for the tdh and trh genes could detect 400 fg (100 colony-forming units) of cellular DNA carrying the respective gene. All strains of V. parahaemolyticus isolates in this study contained the tdh gene but not the trh gene. CONCLUSIONS: The detection of the tdh gene and trh gene of V. parahaemolyticus using the PCR is an easy and rapid method.