Esmaelizad Majid, Mayahi Vafa, Pashaei Maryam, Goudarzi Hossein
Central Laboratory Department, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Alborz, Iran.
Arch Virol. 2017 Apr;162(4):971-978. doi: 10.1007/s00705-016-3189-9. Epub 2016 Dec 21.
Newcastle disease virus (NDV) is believed to be the cause of fatal poultry disease worldwide. The fusion (F) protein plays a key role in virus pathogenesis, and it is also used for Newcastle disease virus classification. In this study, we determined the complete coding sequence of the F gene in new velogenic NDV isolates with an intravenous pathogenicity index (IVPI) of 1.8 and a mean death time (MDT) of 72 or 48 h. Complete sequences of the F genes of new Iranian isolates were amplified and sequenced in both directions. These isolates were compared to 195 nucleotide sequences from GenBank (available as of 07/17/2016). A phylogenetic tree was constructed for the F gene, using MEGA6 software with statistical analysis based on 500 bootstrap replicates. Evolutionary distances revealed that the new virulent isolates from Iran belonged to genotype VII in a new distinct sub-genotype named VII-(j). This new sub-genotype showed 3% divergence from genotype VIId. Recombination analysis showed that these new isolates were not recombinant NDVs.
新城疫病毒（NDV）被认为是全球范围内家禽致命疾病的病因。融合（F）蛋白在病毒致病机制中起关键作用，也用于新城疫病毒的分类。在本研究中，我们测定了静脉致病性指数（IVPI）为1.8且平均死亡时间（MDT）为72或48小时的新型速发型NDV分离株中F基因的完整编码序列。对新的伊朗分离株F基因的完整序列进行了双向扩增和测序。将这些分离株与来自GenBank的195个核苷酸序列（截至2016年7月17日可用）进行比较。使用MEGA6软件基于500次重复抽样进行统计分析，构建了F基因的系统发育树。进化距离显示，来自伊朗的新型强毒株属于一个名为VII-（j）的新的独特亚基因型中的基因型VII。这个新的亚基因型与基因型VIId有3%的差异。重组分析表明，这些新分离株不是重组NDV。
