Genetic heterogeneity among Vibrio alginolyticus isolated from shrimp farms by PCR fingerprinting.

AIMS

To study the strain variability among Vibrio alginolyticus isolates from different sources by insertion sequence-targeted PCR fingerprinting and whole cell protein profile analysis.

METHODS AND RESULTS

Eleven strains of V. alginolyticus were isolated from seven different sources including healthy, infected, farm-reared and wild shrimps. Following biochemical characterization, the isolates were analysed by PCR fingerprinting and whole cell protein analysis by SDS-PAGE. The strains were genetically different irrespective of the sources of isolation.

CONCLUSIONS

Strain variation exists in V. alginolyticus isolates obtained even from the same source, and PCR fingerprinting is a simple and efficient method in identifying strain-specific variations among the different isolates.

SIGNIFICANCE AND IMPACT OF THE STUDY

Vibrio alginolyticus is implicated in severe vibriosis of marine aquaculture systems although many strains are avirulent and could be used as probiotic strains. As a wide variation exists among this species, differentiating the harmful and beneficial strains would help in finding ways of controlling the infections by eliminating harmful shrimp pathogenic vibrios.