Molecular Epidemiological Characteristics of Vibrio parahaemolyticus Isolated from Diarrheal Patients in Jeonnam, Korea

Abstract

To investigate the occurrence and distribution of serotype, specific virulence genes, and pulse field gel electrophoresis (PFGE) patterns in Vibrio parahaemolyticus isolates from Jeonnam, Korea, we tested 87 strains which were identified with V. parahaemolyticus from diarrheal episode patients in 2005. In this study, 16 different O:K serotype combinations of V. parahaemolyticus were determined. The distributions of O and K serotypes were O4:K68 (51.72%), O1:K70 (18.39%), O3:K6 (5.74%), O1:K68 (4.60%) and O3:K57 (4.60%) respectively. Serotype O4:K68 was the regional dominant specific serotype of V. parahaemolyticus in Sinan of Jeonnam, Korea. For the detection of thermostable direct hemolysin (tdh) and TDH-related hemolysin (trh) gene of V. parahaemolyticus, PCR was performed. The tdh gene was detected in all of the V. parahaemolyticus isolates from diarrheal patients, but trh gene was not detected. Analysis of PFGE patterns of 30 V. parahaemolyticus isolates showed 3 groups and 20 types. Among 14 O4:K68 serotypes which were isolated in Sinan, PFGE patterns of 12 strains were closely related (100%), but 2 strains were related by 58.3% and 45.4%, respectively. Also two strains of O1:K4 serotype in Gurye and two strains of O3:K6 serotype in Yeosu were closely related (100%), respectively. Although serotypes (O1:K4, O1:K70, O3:K6 and O4:K68) were different, PFGE patterns were related for more than 80.9%. Therefore, the epidemiological surveillance of V. parahaemolyticus is required by PFGE typing scheme as a further diagnostic tool.