从自然发病鸡中分离出一株新城疫病毒

应用电镜技术、血清学检查、生物学试验等方法，从未注射过疫苗的某自然发病鸡群分离出一株新城疫病毒。该分离株对１０日龄鸡胚的平均致死时间为１１６小时，静脉接种致病指数为０．０６，其毒力介于新城疫病毒的ＬａＳｏｔａ株与Ｖ４株之间。免疫原性试验结果表明，该分离株具有免疫后无不良反应、免疫后６天开始产生抗体、产生的抗体效价高、对新城疫强毒的攻击能１００％保护等特点，是一株良好的新城疫候选疫苗株

Isolation and Identification of a Newcastle Disease Virus from naturely infected Chickens

One strain of Newcastle disease virus (NDV) was isolated from chickens with clinical symptom by eletron microscopy and serological and biological test Those chickens were not inoculated with any ND vaccine Pathogenicity test indicated that the virulence of the isolate was between LaSota and V4 vaccine strain of ND Immunogenicity test showed that the antibody to NDV was induced in the chickens inoculated with the isolate,and all chickens were protected against the challenge of a virulent NDV,F48E9