Phylogenetic analysis of Viral Hemorrhagic Septicemia Virus (VHSV) isolated from olive flounders (Paralichthys olivaceus)

Abstract

Viral Hemorrhagic Septicemia Virus (VHSV) is the most important viral pathogens that infects the olive flounders reared in Korean aquaculture. Thirty VHSV isolates were identified in farmed olive flounders from 2007 to 2011 by using the Epithelioma Papulosum Cyprini (EPC) cell line. The genetic diversity of the VHSV was evaluated by analyzing the nucleotide sequences of the partial Glycoprotein (G) and Nucleocapsid protein (N) genes of the 30 isolates. Researchers found that all the isolates were closely related to the Japanese and North American genotype IVa which is clearly distinct from the 3 European genotypes. The isolates formed a unique subgroup which was genetically separated from the Japanese and North American isolates. The nucleotide sequences of the 30 isolates exhibited very close identity with each other (>98.6% identity). This study shows that the VHSV genotype IVa strains are widely distributed throughout olive flounder farms in Korea.