RAPD PCR discloses high genetic heterogeneity among Vibrio parahaemolyticus from various environments along the southwest coast of India

Abstract

Vibrio parahaemolyticus is a leading cause of food-borne gastroenteritis in Asia as well as in other countries. In this study, RAPD fingerprinting was applied to generate a picture of the genotypic distribution and the genetic diversity of V. parahaemolyticus along the southwest coast of India. A total of 80 strains from three different sources (tropical estuary, shrimp farm, and sea foods) were analysed. Two random primers were applied, and they produced fragments ranging from 200 to 3000 bp. Primer one revealed a monomorphic 400 bp dark band in all the strains whereas primer two revealed two monomorphic dark bands of 800 and 1800 bp in the majority of the strains. The dendrogram exhibited clustering of the strains into many RAPD profiles. Tremendous genomic variation was observed among the co-occurring V. parahaemolyticus populations that disclosed high intraspecific genomic diversity. Grouping of strains from different environments into the same clusters indicates there is no biogeographical effect on the distribution of RAPD profiles in V. parahaemolyticus populations at the scale of metres and kilometres.