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Of duck paramyxovirus disease (duck Newcastle disease) is the acute septic infectious disease caused by the of duck paramyxovirus (ducks source Newcastle disease virus). Disease to diarrhea and neurological symptoms, bleeding or ulcers, glandular gastric mucosa focal white bleeding of the intestinal mucosa and pancreas or spleen necrosis as the main feature. Incidence of day-old duck at 5-8 weeks of age, the incidence and mortality rates of up to 20% -60% and 10% -15%, the individual ducks both of which up to 90%. The carcass the paramyxovirus through diseased poultry, offal, excrement or secretions and contaminated feed, water, grass, and other appliances is generally believed that horizontal transmission through the digestive tract, respiratory tract or conjunctiva. Our laboratory in 2008 to a virus isolated from the day-old ducklings and death duck embryo performance the suspected paramyxovirus disease symptoms by the biological characteristics of the test, RT-PCR amplified F gene fragment determine isolates paramyxovirus. Therefore, we speculated the Ap paramyxovirus by Peidan vertical transmission. This study of the 2008-2009 performance paramyxovirus-like disease symptoms day-old ducklings and death duck embryo paramyxovirus Isolation and identification of biological characteristics and genetic separated into four duck paramyxovirus Characteristics. The pathogenicity index MDT and ICPI determination to results 50.4-58.0 h and 1.68-1.75, respectively, showed that the isolates were virulent strain. The pathogenicity tests show representative strains of different day-old ducklings had strong pathogenicity, morbidity and mortality rates of 70% -100% 20% -100%. RT-PCR amplification and sequence analysis of the F gene of four isolates, results show that 99.8% -100% homology isolates isolated from the the Feicheng region 1-day-old ducklings before the laboratory to the SDFCH strain the highest homology of 99.5% -99.8%, with other ducks source, from chicken, geese source, pigeon NDV homology were and 88.1% -98.4,88.4% -98.7% 88.6% -97.6% and 90.8% -94.8%; Phylogenetic analysis showed that, The four duck paramyxovirus SDFCH in the same branch, are the type of gene Ⅶ d. Separation the strains with SDFCH strains between highly homologous genetic relationship between highly similar, presumably related to these strains by duck embryo transfer. According to the NDV virus genome sequence published in GenBank, 19 pairs of primers were designed and synthesized by RT-PCR method to amplify and sequence analysis on the to separate strains SDWF02 whole genome. The results showed that the full-length 15192bp, SDWF02 in the NP gene 5 'untranslated region of existence 6bp insert published in GenBank the NDV gene Ⅴ - Ⅶ, Ⅸ in type genome length, containing the 3' leader sequence, 5 'trailing sequence and 6 open reading frame of the gene order is 3'-NP-PMF-HN-L-5 '. SDWF02 gene 3 'end complementary to the 12 nucleotides in the 5' terminal 12 nucleotides of pairing, the start of the respective genes, termination sequences and other NDV corresponding sequence highly homologous, NP-P, PM, MF, F-HN , HN-L of each gene region sequence length of the order of 1bp, 1bp, 1bp, 31bp, and 47 bp. Homology analysis showed that the the SDWF02 at home and abroad in recent years, separation of genotype Ⅶ the chicken source of GM, chicken/China/Guangxi9/2003, chicken/China/Guangxi11/2003 to duck from ducks, Muscovy / China (Fujian) / FP1 / 02, Laying duck/JSD0812/2008, Goose source ZJ1, SF02 homology, with the other genotypes of NDV strains tradition Lasota between 97.0% -97.3%; F48E9 lower Mukteswar equivalent endogenous only 82.8% - 89.1%. Moreover, compared with the other strains, SDWF02 168,441,470 bits in the NP protein, P protein 18,34,47,59,127,146 bit 42,100,140 bits of the M protein, HN protein 36,111,439,443 bits and L protein 421,578,583,659,1866,1930-bit own unique amino acid substitution, it may have led to the emergence of these amino acids of the strains by duck embryo transfer .
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