Some biological and molecular biology characteristics of a virulent strain of Duck plague virus VG-04 isolated in Hung Yen province in 2004

Abstract

In this study, a virulent virus strain of VG-04 isolated in Hung Yen in 2004 was determined for some biological and molecular biology characteristics. The studied result showed that the VG-04 virus strain was capable to replicate and kill duck embryo, the indexes of ELD50 and EID50 were 105.27/0.2 ml and 107.46/0,2ml, respectively. The experimental infection result on duck showed that the VG-04 virus strain could replicate and kill the experimental ducks with the typical symptoms and lesions, the index (LD50) of the VG-04 virus strain for duck was 109.13/0.5 ml. The nucleotide (nt) sequence analysis of the US7 gene showed that the VG-04 virus strain was closely related to the live attenuated vaccine strain of duck enteritis virus DP-EG-2000, sharing 100% similarity level for nt. When comparing the VG-04 virus strain with other worldwide representative virus strains of duck viral enteritis, the rate of nucleotide similarity level ranged from 96.5 to 99.6%.