Genetic Analysis of Orf Virus (ORFV) Strains Isolated from Goats in China: Insights into Epidemiological Characteristics and Evolutionary Patterns

• Published in: Virus research Vol. 334; p. 199160
• Main Authors: Li, Shaofei, Jing, Tian, Zhu, Fang, Chen, Yiming, Yao, Xiaoting, Tang, Xidian, Zuo, Chenxiang, Liu, Mingjie, Xie, Yanfei, Jiang, Yuecai, Wang, Yunpeng, Li, Dengliang, Li, Lulu, Gao, Shikong, Chen, Dekun, Zhao, Huiying, Ma, Wentao
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-09-2023; Elsevier
• Subjects: Contagious ecthyma; Evolution; Orf virus; Phylogenetic analysis; Phylogenetic analysis; Evolution; Orf virus; Contagious ecthyma
• ISSN: 0168-1702; 1872-7492
• DOI: 10.1016/j.virusres.2023.199160

•ORFV genes concentrated in SA00-like and IA82-like clusters.•East and south asia are the major transmission site of ORFV.•Specific motifs suggested multiple survival strategies in ORFV.•The potential epitopes can be used for vaccine design.
Contagious ecthyma (CE) is an acute infectious zoonosis caused by orf virus (ORFV) that mainly infects sheep and goats and causes obvious lesions and low market value of livestock, resulting in huge economic losses for farmers. In this study, two strains of ORFV were isolated from Shaanxi Province and Yunnan Province in China, named FX and LX. The two ORFVs were located in the major clades of domestic strains respectively, and exhibited distinct sequence homology. We analyzed the genetic data of core genes (B2L, F1L, VIR, ORF109) and variable genes (GIF, ORF125 and vIL-10) of ORFV to investigate its epidemiological and evolutionary characteristics. The sequences from 2007 to 2018 constituted the majority of the viral population, predominantly concentrated in India and China. Most genes were clustered into SA00-like type and IA82-like type, and the hotspots in East and South Asia were identified in the ORFV transmission trajectories. For these genes, VIR had the highest substitution rate of 4.85 × 10−4, both VIR and vIL-10 suffered the positive selection pressure during ORFV evolution. Many motifs associated with viral survival were distributed among ORFVs. In addition, some possible viral epitopes have been predicted, which still require validation in vivo and in vitro. This work gives more insight into the prevalence and phylogenetic relationships of existing orf viruses and facilitate better vaccine design.