Genomic Sequencing and Analysis of Enzootic Nasal Tumor Virus Type 2 Provides Evidence for Recombination within the Prevalent Chinese Strains

Abstract

In recent years, the clinical cases of ENTV-2 infection have increased and become prevalent in several provinces of China. In this study, we reported the occurrence of ENTV-2 in one goat farm in Chongqing, southwest China. The complete genome of an emerged ENTV-2 isolate (designated as CQ2) was sequenced with 7468 bp in length. Phylogenetic analysis revealed that ENTV-2 consisted of two main lineages. Lineage 1 was composed of Chinese strains and could be subdivided into five sublineages. CQ2 and the other six recent isolates from China were clustered in sublineage 1.5; however, CQ2 was significantly different from the other six isolates. Furthermore, recombination analysis suggested that CQ2 might be a recombinant variant derived from sublineage 1.5 and sublineage 1.2 strains, with the recombination region in areas of pro and pol genes. In conclusion, we sequenced and analyzed the complete genome of a potential ENTV-2 recombinant, which may contribute to our understanding of the genetic variation and evolution of ENTV-2 in China.