First Detection and Genetic Characterization of Equus Caballus Papillomavirus 1, 2 and 7 in China

Abstract

Background: Nine species of Equus caballus papillomavirus (EcPV) have been reported to infect horses, however, there are so far no reports of such infections in China. Results: In our pioneer study with Chinese horses, we found EcPV-1 in intranasal papilloma and nasal swabs, EcPV-2 in nasal swabs and semen, and EcPV-7 primarily in semen. This indicates that EcPVs are indeed hosted by horses in China, and that EcPV-2 and 7 may be getting transmitted though breeding. Sequence analyses for complete genomic sequences of EcPV-1 (G2), EcPV-2 (XJ-KS1391) and EcPV-7 (XJ-zs1) were performed which indicated that EcPV-1, 2 and 7, that infect horses in China, share 99.3% nt identity with the already published sequences for EcPV-1, 2 and 7. These observations indicate that three types of EcPVs identified in the current study are highly similar variants of previously known types of EcPV-1, 2 and 7. Phylogenetic analysis based on L1 genes in GenBank showed that EcPV-1, 2 and 7, found in Chinese horses, are closely related to and clustered together with already known EcPV-1, 2 and 7, respectively. Conclusion: Our study provides a novel evidence for EcPVs infection and circulation in Chinese horses and thus lays the foundation for a systematic and detailed epidemiological study of these infections in Chinese horses.