The amplification of E6 genes of human papillomavirus 115 (HPV-115) has been shown in Yili horse samples. This study aimed to determine the cause of the unexpected presence of HPV-115 in horses, which might be attributed to either incorrect procedure followed by the operators or the actual infection of horses by this virus. The qPCR analysis revealed that 64.7% of aborted fetal tissue samples from Yili horses tested positive for HPV-115. Additionally, one whole genome sequence and eight L1 gene sequences were obtained by sequencing. These findings strongly showed that HPV-115 could infect Yili horses. Comparison and phylogenetic analyses of the L1 genes demonstrated that the HPV-115 detected in horses was closely related to the previously discovered HPV-115 strains in humans. Furthermore, the overall seropositivity rate for HPV-115 in horse serum was 11.6% (32 out of 276) by ELISA using expressed recombinant E6 protein. Moreover, the presence of HPV-115 E6 antibodies in horse serum was verified using WB. These results indicated that Yili horses served as a natural host for the HPV-115. This work presents the initial evidence of HPV-115 trans-species infection in horses, which serves as the basis for a comprehensive epidemiological investigation of HPVs infection in animals.

In this study, a novel kirkovirus (kirV) was detected in anal swabs of piglets with diarrhoea, the positive rate was 100% (149/149), but this virus was detected in one of 261 clinically healthy piglets, this result suggests a strong relationship between the kirV and the diarrhoeal disease. We obtained the whole-genome sequences of three kirVs (named Cj-D5, Cj-D32 and Cj-D43), with the length of 3750 nt, shared 86.6%–89.0% nt-identity with equine kirV Equ1 and kirV Cj-7-7. Furthermore, three viruses share32.1%–93.4%, and 22.2%–27.1% of the Rep protein sequence identity with available reference strains of the proposed family Kirkoviridae, and the family Circoviridae, respectively. Moreover, like kirV Equ1 and Cj-7-7, RCR domain and P-loop NTPase domains of Rep protein, and nonanucleotide motif (CAATATTAC), of three viruses, were similar to Circoviruses and Cycloviruses. Phylogenetic analysis showed that these viruses were grouped together with members in the proposed family Kirkoviridae. This is the first report that kirV circulates in piglets with diarrhoea, and next studies are needed to determine the pathogenesis of this virus.