Genome Sequencing And Analysis Of Canine Distemper Virus PS Strain And Detection Of PS Strain Distributions By Real-time RT-PCR

Canine distemper is a disease caused by canine distemper virus which can lead to many animalsinfected. It has high morality and infected fur animals and other wildlife and dogs.The CDV PS strain (Panshi strain) was isolated from the raccon dogs tissue infected with it,through passaging in live animals and cell inoculation, it can be reproduced stably in Vero cells.This study designed10pairs of primers referring to wild strain A75/17, amplified10fragments ofthe full genome of the CDV and sequenced the genome. Homology analysis showed that the genome ofPS strain has a97.9%homology with MKY-KM08isolated strain, and has the homology with otherstrains between93.0%and97.0%. The homology with CDV3vaccine strain and Onderstepoort vaccinestrain is93.2%and93.0%respectively. Phylogenetic tree analysis showed that all the CDV strains weredivided into two branches: vaccine strains and wild strains, PS strain and MKY-KM08strain belong tothe same branch, which is named Asia1type.Infecting dogs with PS strain, we study the virus distribution in dogs and the changes of the virusloads in blood and swab by real-time PCR. The result showed that, the virus distributed in liver, spleen,lungs, brain and mesenteric lymph nodes, especially in the spleen and brain (5.2×1010copies/mL and1.0×109copies/mL). It showed that PS strain mainly infected the immune system and nervous system.The virus in swabs from22clinical sample were detected. The test demonstrate that the real-time PCRassay can be used to quantification the virus load in dogs, and provided a new method to the study ofpathogenic mechanism and transmission route.The purpose of this study was to research the genetic variation of the CDV-PS strain, analysis thesusceptible tissue in vivo by sequencing the full genome, biological characteristics and virus distribution.It provides reference for the prevention and early diagnosis of CDV.