Isolation,Identification And Genomes Property Analysis Of Avian Paramyxovirus Type 1 And Avian Paramyxovirus Type 4 From Wild Ducks In Some Areas Of Xinjiang

Avain Paramyxovirus(APMV)belongs to Paramyxoviridae,Avulavirus,and its contain a single-stranded,non-segmented RNA genome.APMVs have been divided into 14 serotypes(APMV-1~14)by haemagglutination inhibition test and neuraminidase inhibition test.Among them,Avain Paramyxovirus type 1(APMV-1),also known as Newcastle disease virus(NDV),can cause acute,fervescence,septic and highly contagious diseases.It's a major threat to the poultry industry worldwide and is endemic in most of the countries.Mild interstitial pneumonia and catarrhal tracheitis were observed in chickens which were artificial infected with APMV-4.In this study,specific pathogen-free chicken embryo were inoculated by cloacal and throat swabs treated by using routine method from wild ducks in Yanqi and Fuhai.APMV-1 and APMV-4 were isolated,identified by hemagglutination(HA)and hemagglutination inhibition(HI)test and sequencing of F gene,followed by testing virulence of the isolates.The results showed that 1 strain of APMV-1 and 4 strains of APMV-4 were isolated and named respectively as NDV/Pintail/CH(XJ)/01/2016,APMV-4/Red-crested Pochard/CH(XJ)/02/2016,APMV-4/Pintail/CH(XJ)/04/2016,APMV-4/Wigeon/CH(XJ)/05/2016 and APMV-4/Gadwall/CH(XJ)/06/2016.The mean death time(MDT)and intracerebral pathogenicity index(ICPI)were 102 h and 0.3,120 h and 0,120 h and 0,120 h and 0,and 120 h and 0,respectively,indicating that all of isolates belong to the lentogenic strains.The specific primers were designed according to the APMV-1 and APMV-4 genome sequences obtained from GenBank,and the whole genome of the isolates was amplified respectively by RT-PCR.After the cloning,sequencing and assembling,the phylogenetic tree of each gene was drawn and its phylogeneticrelationship was analyzed.The results showed that the total length of APMV-1 and APMV-4isolates were 15186 nt and 15054 nt,respectively,and the structures of genome were 3'-N-P-M-F-HN-L-5 ',identifying with "six rules" principle of the virus genome in paramyxoviredae family.There are 55 nt leader sequences at the 3 'end of the gene,and trailer sequences of 114 nt and 17 nt at the 5' end,respectively,with the length of from 1 to 47 nt and from 9 to 42 nt of the intergenic sequencest,respectively.Moreover,the F protein cleavage sites were 112G-R-Q-G-R-L117 and 116D-I-Q-P-R-F121,respectively,consisting with the characteristics of lentogenic virus.Phylogenetic analysis showed that APMV-1 isolate belonged to NDV class II genotype II,and had99% nucleotides similarity with NDV vaccine strain Lasota.The nucleotide sequence of APMV-4 isolates and APMV-4 / mallard / 15129/07 genome similarity was the highest,ranging from 96.7% to 97.7%.Above all,in this study genomic features and genetic characteristics of the APMV-1 and APMV-4were analyzed by using bioinformatics techniques,which can help to clarify the genetic variation and of avian paramyxovirus.