新城疫病毒强毒株的分离与鉴定

Isolation and Identification of High Virulent Newcastle Disease Virus

从发病率为１００％、病死率为９７％的鸡群中分离到１株病毒。该病毒凝集鸡红细胞的作用可被新城疫标准阳性血清所抑制，证明所分离的毒株为新城疫病毒。鸡胚半数致死量、最小致死量致死鸡胚的平均时间、１日龄雏鸡脑内致死指数、６周龄雏鸡静脉致死指数、血凝解脱及血凝素热稳定性等试验表明，分离毒为新城疫病毒强毒株，其毒力比标准强毒Ｆ４８Ｅ８株还强。血凝抑制试验和中和试验表明，分离毒的血凝性与Ｆ４８Ｅ８相同。

One virus isolate was got from one chicken flock with the morbidity of 100% and mortality of 97%. The isolate revealed to be able to agglutinate chicken haemocytes with the agglutination reaction to be inhibited by Newcastle disease virus standard antiserum. The isolate was confirmed to be Newcastle disease virus based on 50% embryo lethal dose(ELD 50 ), mean death time (MDT) of chicken embryos, intracerebral pathogenicity index (ICPI) in 1 day old chicken, intravenous pathogenicity index (IVPI) in 6 week old chicken, dehaemagglutination and haemagglutinin heat stability. The isolate was proved more virulent than F 48 E 8 strain. The results of hemagglutination and neutralization tests indicated that the isolate was identical to in haemagglutination and quite different from the F 48 E 8 strain in neutralization property.