为了解广东地区鸽新城疫病毒的生物学特性,对广东分离株SD54进行了鸡胚平均死亡时间(MDT)、6周龄鸡静脉接种的致病指数(IVPI)、1日龄雏鸡脑内接种的致病指数(ICPI)的测定,并对该毒株F基因的重要功能区片段进行RT-PCR扩增、测序,利用MEGA 4软件绘制系统进化树。经测定,分离株SD54的MDT为60 hI、VPI为2.49I、CPI为1.6;其F基因裂解位点的氨基酸序列为112RRQKRF117,符合NDV强毒株F基因裂解位点氨基酸序列的特征;系统进化树表明该毒株属于基因Ⅶ,与广西鸽源株Gxp40处于同一细分支,同源性最近,表明该分离株SD54为基因Ⅶ强毒株。
The characteristics of a pigeon Newcastle disease virus strain isolated from Guangdong were studied.Pathogenicity indexes,such as the mean death time(MDT),intravenous pathogenicity index(IVPI) and intracerebral pathogenicity index(ICPI) were 60 h,2.49 and 1.6,respectively.The important functional fragment fo F gene was amplified by reverse transcription(RT)-polymerase chain reaction(PCR) and sequenced.The motif of its cleavage site was 112RRQKRF117,which was consistent with that of velogenic strains of NDV.Phylogenetic analysis of the isolate revealed that it was clustered into genotype Ⅶ and has a closer relationship to pigeon NDV strain Gxp40 isolated in Guangxi.