Near-Complete Avipoxvirus Genome Assembled from Skin Lesions of Dead Eurasian Crane (Grus grus)

Avian pox is a globally spread viral disease affecting a wide spectrum of wild and domesticated bird species. The disease is caused by a diverse group of large DNA viruses, namely, avipoxviruses (genus <i>Avipoxvirus</i>, family <i>Poxviridae</i>). In this study, gross pathological examination and histopathological examination of skin lesions and several organs suggested acute poxvirus infection of a Eurasian crane (<i>Grus grus</i>, Linnaeus, 1758). Avipoxvirus infection was confirmed by testing wart-like lesions via gene-specific PCR assay and sequencing the obtained amplicon. Phylogenetic analysis of the gene encoding the DNA polymerase revealed that the crane poxvirus clustered in clade A, subclade A3. A large fragment of the poxvirus genome (306,477 bp in length) was assembled from the DNA of a skin specimen. Our study reaffirms previous findings that even complex virus genomes can be determined from a metagenomic assemblage generated directly from avian tissue samples without prior virus isolation, a promising approach for the epidemiologic surveillance of avipoxvirus infections in wild birds and domestic poultry.