Characterization of Vibrio parahaemolyticus and its specific phage from shrimp pond in Palk Strait, South East coast of India.

Phage therapy is an alternative and eco-friendly biocontrol agent to prevent and control multidrug resistant bacteria in the aquatic system. The aim of this study is to isolate and characterize the Vibrio parahaemolyticus and its potential lytic phage from Penaeus monodon growing-out by rearing in shrimp ponds in Palk Strait, South East coast of India. The conventional phenotypic characteristics and molecular identification was confirmed using 16S rRNA sequence and to determine the antibiotic resistant profiles. The V. parahaemolyticus phage was effective against V. parahaemolyticus through one-step growth experiments, phage survival was determined by long-term storage at various temperatures and pH. Further, transmission electron microscope (TEM) revealed that the lytic phage belongs to the Myoviridae family. The isolated lytic phage (VVP1) was more specific against N1A V. parahaemolyticus and was able to infect N7A V. parahaemolyticus, N3B and N13B Vibrio alginolyticus strains. Evaluation of microcosm studies with P. monodon larvae infected with V. parahaemolyticus showed the survival of larvae in the presence of phage treatment at 2.3 × 10 PFU/mL was enhanced when compared with the control. This study provides the application of phage as a useful strategy to prevent and eliminate or reduce shrimp pathogenic V. parahaemolyticus in the aquaculture system.