Sabouri Fereshteh, Vasfi Marandi Mehdi, Bashashati Mohsen
a Department of Poultry Diseases, Faculty of Veterinary Medicine , University of Tehran , Tehran , Iran.
b Department of Avian Disease Research and Diagnostic , Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization (AREEO) , Karaj , Iran.
Avian Pathol. 2018 Feb;47(1):90-99. doi: 10.1080/03079457.2017.1376735. Epub 2017 Nov 10.
Newcastle disease is an economically important and highly contagious disease affecting wild and domestic avian species. Despite extensive vaccination efforts within the poultry industry, Newcastle disease virus (NDV) outbreaks causing significant economic losses still occur. Rural chickens may act as a potential reservoir of NDVs for commercial poultry due to poor biosecurity and inadequate vaccination. The aim of this study was to investigate the phylogenetic relationship and molecular characterization of eight NDVs isolated from backyard poultry in Iran during 2011-2013. The complete coding sequence of fusion (F) and haemagglutinin-neuraminidase (HN) genes of eight NDVs were determined and compared with other published NDVs. Based on inter-population distances and phylogenetic topology between available NDV categories, Iranian isolates formed a novel VIIl sub-genotype distinct from previous groups designated in genotype VII. Furthermore, both F and HN genes of the Iranian isolates shared high nucleotide sequence similarity with viruses isolated in China. All viruses analysed contained a polybasic cleavage site motif (G/RRRQKR↓F), indicating that all isolates could be categorized as a virulent pathotype. No mutation was observed in the neutralizing epitopes of the F protein. Analysis of amino acids associated with neutralizing antigenic sites within the HN protein revealed that all isolates exhibited a unique amino acid (Q) at position 347. These results emphasize the need for strengthening the biosecurity measures implemented on village flocks and practicing a mandatory vaccination programme for local poultry. Moreover, continuous monitoring of NDVs in different species of birds can help to gain more knowledge about the evolution of this virus and prevent future panzootics.
新城疫是一种对经济有重要影响且具有高度传染性的疾病，可感染野生和家养禽类。尽管家禽行业进行了广泛的疫苗接种工作，但仍会发生导致重大经济损失的新城疫病毒（NDV）疫情。由于生物安全措施差和疫苗接种不足，农村鸡群可能成为商业家禽新城疫病毒的潜在储存宿主。本研究的目的是调查2011 - 2013年期间从伊朗后院家禽中分离出的8株新城疫病毒的系统发育关系和分子特征。测定了8株新城疫病毒融合（F）基因和血凝素 - 神经氨酸酶（HN）基因的完整编码序列，并与其他已发表的新城疫病毒进行了比较。根据现有新城疫病毒类别之间的群体间距离和系统发育拓扑结构，伊朗分离株形成了一个新的VIII亚基因型，与之前在基因型VII中指定的组不同。此外，伊朗分离株的F基因和HN基因与在中国分离的病毒具有高度的核苷酸序列相似性。所有分析的病毒都含有一个多碱性裂解位点基序（G/RRRQKR↓F），表明所有分离株都可归类为强毒株型。在F蛋白中和表位中未观察到突变。对HN蛋白中与中和抗原位点相关的氨基酸分析表明，所有分离株在347位均表现出独特的氨基酸（Q）。这些结果强调了加强对乡村鸡群实施生物安全措施以及对当地家禽实施强制疫苗接种计划的必要性。此外，持续监测不同鸟类物种中的新城疫病毒有助于更多地了解该病毒的进化并预防未来的大流行。
