Isolation And Identification Of Canine Distemper Virus And Study On Antigen Protein Of Canine Distemper Virus

Canine distemper virus were isolated from liver samples of triad colour dogs and poodles. The cDNAs of F gene about 574bp of the CDV strains were amplified by RT-PCR, the results were all positive and were concord with the theory value. The results were examined by electrophoresis. The RT-PCR assay of CDV detection was proved to be specific and sensitive. It can be uesd to rapid diagnosis of CDV.The liver suspension were inoculated on Vero cell and two CDV strains were isolated, which named Ssq and Szg respectively. The two strains also can be cultured and replicated on DK cells(Canine renal cells). The newborn bovine serum would delay the time to adsorb the viruses to the sensitive cells and the stability of pH during the inoculation also contribute to successful isolation and cultivation. The Szg and Ssq strains had clear cytopathic effect(CPE) on Vero cell, and the 50% tissue culture infective dose were TCID₅₀=10^-3.925/0.5ml, TCID₅₀=10^-3.223/0.5ml, respectively. Spherical and capsular virus particles were observed in electron microscope in Vero-cultured virus.Ssq, Szg and Y-1 vaccine strains virus proteins were analyzed by SDS-PAGE and western-blot, the results showed that Ssq and Szg strains had the similar protein bands, and they had the similar 5 protein bands with Y-l strain, their molecular weight were 70.6KD, 57.5KD, 51.3KD, 40.6KD å’Œ 34.1KD, respectively. And they had specific anti-CDV serum reaction with 57.5KD protein in western-blot. The result of reaction appeared one brown band. The three strains virus had a common antigen that is the 57.5KD protein.