Novel equid papillomavirus from domestic donkey

BackgroundPapillomaviruses can be of great medical importance as they infect humans and animals such as Equus species, other livestock and pets. They are responsible for several papillomas and benign tumours in their host. ObjectivesTo describe a novel equid papillomavirus detected in oral swab samples collected from donkeys (Equus asinus) found on the Northwest plateau of China. Study designCross-sectional. MethodsSwab samples collected from the oral mucosa of 32 donkeys in the Gansu Province of China, were subjected to viral metagenomic analysis to detect the presence of Papillomavirus. After de novo assembly, a novel papillomavirus genome designated as Equus asinus papillomavirus 3 (EaPV3) was identified in the studied samples. Additional bioinformatic analysis of the assembled genome was done using the Geneious prime software (version 2022.0.2). ResultsThe complete circular genome of EaPV3 is 7430 bp in length with a GC content of 50.8%. The genome was predicted to contain five ORFs coding for three early proteins (E7, E1, and E2) and two late proteins (L1 and L2). Phylogenic analysis of the nucleotide sequences of the concatenated amino acid sequences of the E1E2L1L2 genes revealed that EaPV3 is most closely related to Equus asinus papillomavirus 1 (EaPV1). The genome analysis of EaPV3 revealed similar genome organisation with other equine papillomavirus and the presence of E7 papillomavirus oncoprotein. Main limitationsSince there were no warts in the oral cavity of the donkeys in this study, and no biopsy samples taken, we are unable to conclusively link the novel virus to any clinical condition in the donkeys. ConclusionsThe Comparative characterisation of EaPV3 and its closest relatives, as well as phylogenetic analysis demonstrated that it is a novel virus specie that clusters within the Dyochipapilloma PV genus.