Natural interspecies recombinant bovine/porcine enterovirus in sheep

Members of the genus Enterovirus (family Picornaviridae) are believed to be common and widespread among humans and different animal species, although only a few enteroviruses have been identified from animal sources. Intraspecies recombination among human enteroviruses is a well-known phenomenon, but only a few interspecies examples have been reported and, to our current knowledge, none of these have involved non-primate enteroviruses. In this study, we report the detection and complete genome characterization (using RT-PCR and long-range PCR) of a natural interspecies recombinant bovine/porcine enterovirus (ovine enterovirus type 1; OEV-1) in seven (44 %) of 16 faecal samples from 3-week-old domestic sheep (Ovis aries) collected in two consecutive years. Phylogenetic analysis of the complete coding region revealed that OEV-1 (ovine/TB4-OEV/2009/HUN; GenBank accession no. JQ277724) was a novel member of the species Porcine enterovirus B (PEV-B), implying the endemic presence of PEV-B viruses among sheep. However, the 5' UTR of OEV-1 showed a high degree of sequence and structural identity to bovine enteroviruses. The presumed recombination breakpoint was mapped to the end of the 5' UTR at nucleotide position 814 using sequence and SimPlot analyses. The interspecies-recombinant nature of OEV-1 suggests a closer relationship among bovine and porcine enteroviruses, enabling the exchange of at least some modular genetic elements that may evolve independently.