Phylogenetic Analysis and Biological Characteristics Identification of a Canine Distemper Virus Strain Isolated from a vaccinated Domestic Dog in the Northeast China

Abstract Canine distemper virus (CDV) is currently circulating in domestic and wild animals. The host range of CDV comprises all families within the order Carnivora, and it has recently expanded to nonhuman primates, moreover the host range still has the potential for further expansion. In this research, a CDV strain named BT was isolated from a vaccinated domestic dog in Changchun, Northeast of China, and identified by Electron microscope (EM) and Immunofluorescence Assay (IFA). The whole genome sequence of the virus was obtained by RT-PCR and Sanger sequencing. Phylogenetic analysis was performed based on the Coding sequence (CDS) of hemagglutinin (H) protein and the complete genome sequence of the virus respectively, the results showed that the CDV-BT strain still classified into the Asia-1 lineage. This research shows that CDV-BT strain’s antigenicity of the epitope 444GDKYPIHFNDER455 in nucleocapsid (N) protein and the epitope 178ARGDIFPPY186 in H protein were significantly different from vaccine strain by amino acid substitutions, and suggests that the characterization of genetic diversity among the circulating CDVs is essential for future CDV’s research and disease monitoring.