Research On The Variances Of Hepatopancreatic Parvovirus Causing Liver And Pancreas Disease In Shrimp

Abstract

Hepatopancreatic parvovirus (HPV) causes hepatopancreas disease in shrimp and retards growth. Inconsistent results between the currently used polymerase chain reaction (PCR) method and histopathology were observed at the aquatic pathology laboratory of the Research Institute for Aquaculture No. 2. PCR methods from five different publications were then used to investigate this phenomenon on two samples of whiteleg shrimp (Penaeus vannamei) that had already shown histopathological signs of HPV. One set of PCR primers (H441F/H441R) successfully amplified a DNA fragment of HPV from the two samples. The nucleotide sequence of HPV obtained using Sanger sequencing was used to construct a phylogenetic tree to examine the relationship to other known types of HPV. The sequencing and phylogenetic results confirmed the presence of an HPV nucleotide sequence amplified using the H441F/H441R primers and revealed a close relationship between the HPV sequence obtained in this study and other HPV isolates from Taiwan and South Korea. Another 20 shrimp samples suspected of HPV infection were tested using the H441F/H441R primers to validate the effectiveness of the PCR procedure. The study highlighted the need for detecting HPV with a wide range of primers to achieve reliable results, given the genetic diversity of HPV based on geographic and host species variation. The HPV-positive results in cultured shrimps emphasized the need to develop a new PCR procedure for rapid and convenient detection of HPV at shrimp farms.