Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt.
Virol J. 2011 May 18;8:237. doi: 10.1186/1743-422X-8-237.
Newcastle disease virus represents APMV-1 and is the most characterized among all APMV types. The F protein cleavage site sequence is a well-characterized determinant of NDV pathogenicity in chickens. In this study, the sequences of fusion protein (F) gene of three Newcastle disease virus (NDV) strains isolated from outbreak in chickens in the Al-Sharkia province of Egypt in 2006 were determined.
The viral genomic RNAs were extracted from the infective allantoic fluid and F gene is amplified using primer sets designed from the available sequences of NDV strains from GenBank. The pathogenicity of NDV strains was determined by three internationally recognized tests mean death time, intracerebral pathogenicity index, and intravenous pathogenicity index. The phylogenetic analysis showed that the Egypt isolates are closely related with the genotype II of class II NDV strains.
The sequences of the F genes of the 2006 Egypt isolates are closely related to that of the 2005 Egypt isolate from the same province suggesting that these strains are probably circulating in the vaccinated bird population in Egypt until development of an outbreak.
新城疫病毒代表 APMV-1，是所有 APMV 类型中研究最充分的一种。F 蛋白裂解位点序列是决定新城疫病毒在鸡中致病性的一个重要特征。本研究对 2006 年埃及 Sharkia 省爆发的鸡新城疫病毒（NDV）分离株的融合蛋白（F）基因序列进行了测定。
从感染性的鸡胚尿囊液中提取病毒基因组 RNA，使用从 GenBank 中已有的 NDV 株设计的引物对扩增 F 基因。通过三种国际公认的试验（平均死亡时间、脑内致病指数和静脉内致病指数）确定 NDV 株的致病性。系统进化分析表明，埃及分离株与 II 基因型 II 类 NDV 株密切相关。
2006 年埃及分离株的 F 基因序列与来自同一省份的 2005 年埃及分离株的序列密切相关，表明这些毒株可能在埃及接种鸡群中传播，直到爆发疫情。
