一株鸭源新城疫病毒毒力基因分析及其对鸭的致病性研究

Analysis of the Virulent Genes of One Newcastle Disease Viruses Isolated from Duck and its Pathogenicity Experiment in Duck

为了解中国鸭源新城疫病毒（Newcastle disease virus,NDV）的毒力特点,从2009年广东地区发病鸭群中分离和鉴定出1株新城疫病毒（简称NDV-104）,对其生物学特性、致病性和融合蛋白（fusion,F）、血凝素神经氨酸酶（hemagglutinin-neuraminidase,HN）基因进行了研究。结果显示,分离株的MDT、ICPI和IVPI分别为56.4 h、1.95和1.64,结合F蛋白裂解位点（112~117位）的氨基酸序列分析,确定了分离株为新城疫强毒。致病性结果表明,分离病毒对雏鸭具有感染性和致病性。F基因遗传进化结果显示,分离株属于基因Ⅶd亚型。F、HN蛋白的氨基酸同源性结果表明,分离株与2000年以来国内外分离到的基因Ⅶ型NDV同源性较高,分别为96.6%~99.3%和97.0%~99.7%,而其与常用疫苗株B1、V4、Clone30、Mukteswar和LaSota的F、HN蛋白氨基酸序列的同源性较低,且与LaSota株和V4株的同源性最低,分别仅为88.1%和87.6%,说明分离株与经典新城疫病毒毒株存在一定的差异。

To explore the epidemiological understanding of Newcastle disease virus （NDV） in ducks, a Newcastle disease virus （NDV-104） was isolated from duck in Guangdong province in 2009. The biologically characteristic, pathogenicity and F and HN gene were explored. The results showed that MDT, ICPI and IVPI of the isolated strain were 56.4 h, 1.95 and 1.64, respectively. Combined with the analysis of the amino acid sequence of the F protein cleavage site （112 to 117）, indicating it belonged to velogenic NDVs. The pathogenicity results showed that the isolated strain was infectious and pathogenic in ducks. Genetic analysis revealed that the isolate strain belonged to the gene Ⅶd subtype. The homology analysis of F and HN protein＇s amino acid showed that the isolated strain shared 96.6% to 99.3% and 97.0% to 99.7%, respectively, with genotype Ⅶ NDVs since 2000. However, the F and HN protein＇s amino acid of the isolate strains were low similarity with the common vaccine strains, such as B1, V4, Clone30, Mukteswar and LaSota, and were 88.1% and 87.6% similarity with LaSota and V4, which were different from the classical strains of NDV.