Isolation and Characterization of Vibrio parahaemolyticus in the hepatopancreas of cultured white pacific shrimp - Litopenaeus vannamei

Abstract

Vibrio parahaemolyticus is the most common species among crustaceans, often causing various diseases and significant losses in aquaculture. Acute hepatopancreatic necrosis disease (AHPND) is a newly emerging shrimp disease that has severely damaged the global shrimp industry. This species of bacteria is associated with gastrointestinal illness in humans and has been implicated in foodborne disease. The present study carried out, isolation and characterization of pathogenic bacterial flora isolated from the infected hepatopancreas of vannamei, obtained from various aquafarms in Andhra Pradesh, India, on 11th June 2018. The collected samples were plated on TCBS- (Thiosulfate-Citrate-Bile salt-Sucrose) agar medium and Hi -Chrome vibrio, as described in Bergey's manual of systematic bacteriology. Isolated colonies were subjected to the following tests- microscopic examination, growth at different temperatures, growth at different NaCl concentrations, and biochemical tests. Further purity, maintenance, and propagation of purified cultures were done. The microbial culture was identified using 16s rRNA molecular technique. Phylogenetic Evolutionary analyses and distance matrix were conducted in MEGA7.In the present study, different samples were screened, a total of three green colonies (V44, V45, V46) were isolated, identified by biochemical tests and genetic identification as Vibrio parahaemolyticus. A systematic methodology has been developed to isolate and characterize Vibrio sp. from diseased shrimp and identify them by genetic analysis.