Study Of Biological Features Of Canine Distemper Virus Isolate In Yangzhou And Analysis Its Fusion Region

Dogs clinically diagnosed as canine distemper in Yangzhou region during the period of March to May in 2001 were investigated on epidemiology and diagnosed in laboratory.The Africa monkey kidney cell line(Vero) was used to isolate virus.The isolate caused cytopathic erfect(CPE) in Vero cells.Following the examination of electron microscope,immuofluresecence assay,it was identified as CDV infection.The physical and chemical characteristics,hemagglutination activity,cell virulence of the isolate were investigated.The isolate were sensitive to chloroform,acid and heat;only reacting on red bood cell of birds.In Vero cells,TCID50 of the isolate were 10-4.6-10-5.0/ml, 10-4.4-10-4.9/ml, 10-4.8-10-5.1/ml respectively,diameter of the plaque of viruses was 0.4 to 0.6mm.To establish a suit of intergrity molecular biology method detecting on canine distemper virus,one pair of primers which amplify 324bp fragment had been designed and synthesized .The virus RNA was extracted from CDV infected Vero cells by classical method.Results showed that this study established a specific and sensitive RT-PCR method to detect CDV.To explore variation of CDV influencing upon failing of immunity,this study investigated and analysised the fusion region gene of CDV isolate and other relative viruses.Results showed that the isolate was partly different from others,however the vaccines showed no difference.This not only provides the bases of occurring CDV,also reminds us to prevent CDV in many ways.