Funsho-Sanni Olubukola O, Ella Elijah E, Rogo Lawal D, Sanni Olufunsho S, Inabo Helen I, Luka Sodangi A, Shittu Ismaila
Department of Microbiology, Faculty of Life Sciences, Ahmadu Bello University, P.M.B.06, Zaria, Kaduna, Nigeria.
Department of Medical Laboratory Science, Faculty of Allied Health Sciences, College of Health Sciences Bayero University Kano, P.M.B.3011, Kano, Nigeria.
Int J Microbiol. 2022 Oct 31;2022:9979683. doi: 10.1155/2022/9979683. eCollection 2022.
The roles of fusion gene in the virulence of Newcastle disease virus are well established, but the extent of its variation among the XIV, XVII, and XVIII genotypes reported in Central Africa and West Africa has until recently been understudied. In this study, virulent Newcastle disease virus (vNDV) was isolated from dead chickens among vaccinated flocks between March and April 2020. Fusion (F) gene was sequenced and analysed for characterization and information about genetic changes. Many substitutions were observed along the region and some of their functions are yet to be determined. Results showed that all study isolates have virulent cleavage site sequence 112-RRRKR-116/F117 and clustered within genotype XIVb. Sequence analysis showed K78R mutation in the A2 antigenic epitope in all isolates and more along the F-gene which varied in some instances within the isolates. Mutation in this A2 antigenic epitope has been reported to induce escape mutation to monoclonal antibodies generated using the NDV LaSota strain. The range of percentage nucleotide and amino acid homology between the study isolates and commercially available vaccine strains is 81.14%-84.39% and 0.175-0.211, respectively. This report provides evidence of vNDV among vaccinated chicken flock and molecular information about circulating vNDV strains in Kano State, Nigeria, which is useful for the development of virus matched vaccines. Newcastle disease (ND) surveillance and molecular analysis of circulating strains in this region should be encouraged and reported. Furthermore, ND outbreaks or cases among vaccinated poultry presented to veterinary clinics should be reported to the state epidemiologist. Nucleotide sequences were assigned accession numbers OK491971-OK491977.
融合基因在新城疫病毒毒力中的作用已得到充分证实，但在中非和西非报道的第十四、十七和十八基因型中其变异程度直到最近仍未得到充分研究。在本研究中，从2020年3月至4月期间接种疫苗的鸡群中的死鸡中分离出强毒新城疫病毒（vNDV）。对融合（F）基因进行测序和分析，以进行特征鉴定并获取有关基因变化的信息。在该区域观察到许多替换，其中一些功能尚未确定。结果表明，所有研究分离株都具有强毒裂解位点序列112-RRRKR-116/F117，并聚类在第十四基因型b内。序列分析显示，所有分离株的A2抗原表位均有K78R突变，并且在F基因上更多，在某些分离株中有所不同。据报道，该A2抗原表位的突变会诱导对使用新城疫病毒LaSota株产生的单克隆抗体的逃逸突变。研究分离株与市售疫苗株之间的核苷酸和氨基酸同源百分比范围分别为81.14%-84.39%和0.175-0.211。本报告提供了接种疫苗的鸡群中存在vNDV的证据以及尼日利亚卡诺州流行的vNDV毒株的分子信息，这对开发病毒匹配疫苗很有用。应鼓励并报告该地区新城疫（ND）监测和流行毒株的分子分析。此外，应向州流行病学家报告提交给兽医诊所的接种疫苗家禽中的新城疫疫情或病例。核苷酸序列被赋予登录号OK491971-OK491977。
