Detection of the New O3:K6 Strain of Vibrio parahaemolyticus by Group-Specific Polymerase Chain Reaction / 대한임상병리학회지

ABSTRACT

BACKGROUND: Recently, a new serotype O3K6 has caused a pandemic of Vibrio parahaemolyti-cus infection. The new O3K6 serovar differs from the old O3K6 strains at least in 7 base positions within a 1,346 bp region of the toxRS gene involved in the regulation of the virulence. We per-formed a group-specific polymerase chain reaction (GS-PCR) test for detection of the new O3K6 strains using species-specific primers. METHODS: A total of 48 V. parahaemolyticus were isolated from clinical specimens of patients with diarrhea in different geographic areas of Seoul (Hanyang University Hospital, 20 cases), Inchon (Gachon Medical Center, 26 cases) and Gwangju (Chonnam University Hospital, 2 cases) from 1998 to 2001 in Korea. All isolates were examined for the presence of tdh/trh genes and ure-ase activity. The serovars of isolates were determined by slide agglutination tests with specific anti-sera (O3K6/O4K68). A GS-PCR method, detecting the new O3K6 clone, was used in this study. RESULTS: All these isolates carried the tdh gene but not the trh gene and did not produce urease. The thirty three of the 48 samples (69%) were positive using the GS-PCR method. Thirty of thirty three cases (91%) were O3K6 using the slide agglutination test. The three cases (9%) were O4K68. CONCLUSIONS: We confirmed the epidemicity of the new V. parahaemolyticus O3K6 using the GS-PCR method in Korea.