Isolation And Identification Of A Newcastle Disease Virus(NDV) Strain And Sequencing-Homology Analysis Of Partial Fusion Protein

From dead chickens,one virrus was isolated by using eggs and chicken embryo fibroblast.lt was able to agglutinate chicken's erythrocytes and this heamagglutination could be inhibited by Newcastle Disease antiserum.This strain's biological property was tested by barren spot,cross-enutralization and cross-heamagglution inhibited and it was found that it was homological with the standard Newcastle Disease virus(NDV) virulent strain and avirulent strain but it had some diference with the standard strain. This strain's virulence was judged by mean death time of chick embryos(MDT),intracerebral pathogenicity index in day-old chicks(ICPI) and intravenous pathogenicity index in 6-week-old chickens(IVPI) and it was found to be the virulent strain.At last,it was tested by the recurrent infection and found that it was the Newcastle Disease virus(NDV),and it was named HBG-1 strain.In order to find the difference of the cleavage site of this strain with F48E9 and €30 strain,a part of the cleavage site of Fusion protein gene fragment was amplified by RT-PCR using a primer and sequenced.The sequence analysis showed this strain had low homology with F4gE9 and Cso.A phylogenetic tree based on the published sequences of NDV reference strains was constructed and showed the isolated strain HBG-1 belonged to the genotype W NDV,a novel genotype NDV.