Characterization of F,HN Genes of the Newcastle Disease Virus Isolates from Wild Birds in Qinling Mountains

In order to explore the epidemiological status of Newcastle disease virus(NDV) among wild birds in Qinling Mountains.Two hundred and fifty two throat and cloacal swabs obtained from healthy wild birds used to isolate NDV which characterized by both biological and genetic evolution analysis.Five NDVs were isolated and identified,their MDT,ICPI and IVPI were 60.0-76.8 h,0.900-1.261 and 0.41-0.81,respectively.Deduced amino acid sequences of the cleavage sites of fusion(F) protein revealed that all strains had the same motifs(112 RRQKRF117).Phylogenetic analysis of partial F gene(47-420 bp) showed that 5 NDVs belong to VIb genetype.By comparison of the deduced amino acid sequences of hemagglutinin-neuraminidase(HN) glycoprotein,the homology among the 5 isolates was 99.5%-99.8%,shared 91.4%-98.0%、87.1%-87.4% and 89.0%-89.3% identities with VI pigeon NDV,LaSota and F48E9,respectively.The results suggested that there are genetype VIb NDVs in Qinling area,with velogenic molecular characteristics and moderate pathogenicity index,maybe have the same origins with pigeon NDV.