Istituto Zooprofilattico Sperimentale della Sardegna, 07100 Sassari, Italy.
Dipartimento di Scienze Biomediche, Università di Sassari, 07100 Sassari, Italy.
Viruses. 2022 Jul 4;14(7):1473. doi: 10.3390/v14071473.
Orf virus (ORFV) is distributed worldwide and is the causative agent of contagious ecthyma that mainly occurs in sheep and goats. This disease was reported for the first time at the end of 18th century in Europe but very little is currently known about the temporal and geographic origins of this virus. In the present study, the use of new Italian whole genomes allowed for better inference on the evolutionary history of ORFV. In accordance with previous studies, two genome types (S and G) were described for infection of sheep and goats, respectively. These two well-differentiated groups of genomes originated for evolutive convergence in the late 1800s in two different areas of the world (Europe for S type and Asia for G type), but it was only in the early 1900s that the effective size of ORFV increased among hosts and the virus spread across the whole European continent. The Italian strains which were sequenced in the present study were isolated on the Mediterranean island of Sardinian and showed to be exclusive to this geographic area. One of them is likely representative of the early European forms of ORFV which infected sheep and became extinct about one century ago. Such an ancient Sardinian strain may have reached the island simple by chance, where it quickly adapted to the new habitat.
口疮病毒（ORFV）分布于全球，是引起传染性羊口疮的病原体，主要感染绵羊和山羊。该疾病于 18 世纪末首次在欧洲报道，但目前对于该病毒的时间和地理起源知之甚少。在本研究中，使用新的意大利全基因组数据，有助于更好地推断 ORFV 的进化历史。与之前的研究一致，发现了两种基因组类型（S 和 G），分别感染绵羊和山羊。这两组截然不同的基因组起源于 19 世纪末在世界上两个不同地区（欧洲为 S 型，亚洲为 G 型）的进化趋同，但直到 20 世纪初，ORFV 在宿主中的有效种群数量才增加，病毒才传播到整个欧洲大陆。本研究中测序的意大利毒株是在地中海撒丁岛分离的，仅在该地理区域发现。其中一种可能代表了一个世纪前感染绵羊并已灭绝的早期欧洲 ORFV 形式。这种古老的撒丁岛毒株可能只是偶然到达该岛屿，在那里它很快适应了新的栖息地。
