Isolation, Identification And Genome Sequencing Of The Canine Distemper Virus SY-12Strain

Canine distemper is a disease caused by canine distemper virus which can lead to manyanimals infected. It has high morality and mortality and infected fur animals and other wild-lifeand dogs. The vaccine is used to prevent canine distemper, but failure to the emergence of alarge number of canine distemper virus variants. Therefore, to carry out isolation andidentifieation of new emerging viruses and genome sequencing of them have a very importantsignificance. The study includes two parts: isolation and identifieation of canine distemper virusfrom affected raccoon dog, and genome sequencing and analysis of the CDV SY-12isolate.A virus strain was isolated from the lung of a raccoon dog suspected as canine distemper inSongyuan city, Jilin province. Supernatants from cell extracts of lung, liver were inoculate toVero cells and significant cytopathic effect (CPE) was produced. The isolate was confirmed bymorphology, serological tests and experimental infection of animals. Viral RNA from animaltissue and infection cells were detected by reverse transcription polymerase chain reaction(RT-PCR). The virus isolate was designated as CDV SY-12. The successful isolation of CDVSY-12provided a basis for futher search on canine distemper epidemiology in raccoon dog.To clarify the genetic variation and genetic characteristics of CDV SY-12isolate, completegenome sequence analysis was done. The full genome of the CDV was amplified by9fragments,cloned into the vecter pMD18-T, and sequenced the full length of the genome.Homology analysis showed that the genome of CDV isolate has a98.8%homology withCDV PS isolated strain, and has a homology with other strains between92.3%and98.8%. Thehomology with Onderstepoort vaccine strain is92.3%. Phylogenetic trees analysis showed thatall the CDV strains are divided into two clusters: vaccine strain and wild strain, CDV SY-12isolate, CDV PS isoate and MKY-KM08belong to the same cluster, which is named Asia1type.