Phylogenetic analysis of two Chinese orf virus isolates based on sequences of B2L and VIR genes

Orf virus (ORFV) is an enveloped virus with a double-stranded DNA genome, causing a contagious pustular dermatitis, mainly in goats and sheep. In this study, two strains of ORFV were isolated from sheep and goat samples in Xinjiang and Shaanxi, China. The B2L and virus interferon resistance (VIR) genes of these two isolates were sequenced and analyzed after PCR amplification. Phylogenetic analysis showed that the two isolates clustered with other ORFV strains but were separated into different subgroups. The Xinjiang strain shared the highest homology with the Gansu strain, whereas the Shaanxi strain shared higher homology with the Taiwan and Hubei strains. This is the first report of the molecular characterization of ORFV in Northwest China, and it provides new information on the genotyping of the causative agents responsible for contagious ecthyma dermatitis outbreaks in China.