Susceptibility studies of farmed pacific white shrimp, Penaeus vannamei to non-AHPND strain of Vibrio parahaemolyticus

Abstract
Isolation and identification of bacteria from haemolymph, stomach and hepatopancreas (HP) were carried out from 37 farms in Tamil Nadu, India to find out the prevalence of Vibrio parahaemolyticus (Vp) infections with special reference to acute hepatopancreatic necrosis disease (AHPND). Bacterial identifications were done based on the morphological, physiological and biochemical characteristics. Vp isolates were identified by polymerase chain reaction (PCR) targeting Vp specific toxR and tlh genes, human pathogenic tdh and trh genes, and AHPND causing AP1, AP2, AP3 (pirAvp) and AP4 (pirAvp and pirBvp) genes. Histopathological and immunohistochemical (IHC) techniques were employed to identify the pathology due to Vp in HP tissues. Based on the morphological, physiological, biochemical and molecular characterization, 74 isolates were identified as Vp (35.14%), V. harveyi (21.62%), V. anguillarum (16.22%), V. campbellii (10.81%), V. mimicus (8.11%), V. alginolyticus (5.41%), and V. aeruginosa (2.7%). All isolates were negative for tdh, trh, AP1, AP2, AP3 and AP4 genes. Histopathology and IHC revealed that the HP was the prime organ affected in Vp infection. It further proved that the IHC could be used as an important tool to identify the establishment of infection in hepatopancreatic tissues.
Description
TNV_IJVASR_Nov.2021_50(6)_53-68
Keywords
Veterinary Science, Veterinary Pathology
Citation