一株鸭源基因Ⅸ型新城疫病毒广西分离株的生物学特性及全基因序列分析

摘要

In order to evaluate the biological and genetic characteristics of a Newcastle disease virus strain GX19/2011from duck in Guangxi,the pathogenecity index (MDT, ICPI and IVPI) and complete genome sequence were determined in this study. The results showed that ELD50 was 10-9.48/0.1 mL, MDT was 51.4h, ICPI was 1.80, IVPI was 2.82, indicating that GX19/2011 was of virulent NDV. The virus strain was used to infect respectively the 35-and 50-day-old SPF ducks, resulting in 100%incidence in both duck groups, but the mortality were 100%and 70%respectively. The complete genome of the virus contained 15192 bp,most closely related to the reference strains such as F48E8, GD09-2, JS/1/02/Du and JS/1/97/Ch in genotypeⅨ. The virus exhibited that amino acid sequence of the cleavage site of fusion (F) protein was 112R-R-Q-R-R-F117, which belonged to virulent strain. The results of biologi-cal and molecular epidemiology characterization showed that GX19/2011 isolate was a virulent strain with severe patho-genicity in duck.%为全面了解广西分离株GX19/2011的生物学和遗传特性，对分离株的鸡胚平均致死时间（MDT）、1日龄鸡脑内接种致病指数（ICPI）、6周龄鸡胚静脉接种致病指数（IVPI）和对鸭的致病力进行测定，并对其全基因遗传特性进行研究研究。结果显示：该分离株的ELD50为10-9.48/0.1 mL、MDT为51.4h、ICPI为1.80、IVPI为2.82。使用该毒株分别感染35日龄和50日龄的鸭，发病率均为100%，死亡率分别为100%，70%。该毒株全长为15192bp，与F48E8和GD09-2等参考毒株的亲缘关系较近，均属于基因Ⅸ型。该分离株F蛋白裂解位点的氨基酸序列为112R-R-Q-R-R-F117，具有强毒株的典型特征。生物学特性和遗传进化分析结果都表明该毒株为速发型强毒株，同时对鸭具有较强的致病力。