Analysis of the polymorphism of 16S-23S rDNA intergenic spacer regions from 34 Vibrio parahaemolyticus strains by denaturing gradient gel electrophoresis

Using PCR-denaturing gradient gel electrophoresis (PCR-DGGE), the polymorphism of 16S-23S rDNA intergenic spacer regions (ISR) from 34 Vibrio parahaemolyticus strains, including type strains and those isolated from environment and aquatic animals, were analyzed. The phylogenic relationships of these strains were also analyzed. The results showed that the ISRs could be separated into 4−10 different bands through PCR-DGGE. Thirty-four V. parahaemolyticus strains shared 15 polymorphic sites. Using MVSP, 34 strains were clustered into four groups, H, I, J, and K. Strains A18 and A25 had farthest genetic distance, with a value of 0.4. The present study suggested that ISR PCR-DGGE provided a new method for genotyping of V. parahaemolyticus.