Virology Department, Arboviruses and Haemorrhagic Fever Viruses Unit, Institut Pasteur de Dakar, Dakar, Senegal.
Epidemiology, Clinical Research and Data Science Department, Institut Pasteur de Dakar, Dakar, Senegal.
J Med Virol. 2022 Nov;94(11):5593-5600. doi: 10.1002/jmv.28027. Epub 2022 Aug 5.
To assess the genetic diversity of circulating dengue virus 2 (DENV-2) in Senegal, we analyzed nine newly generated complete genomes of strains isolated during the 2018 outbreaks and 06 sequences obtained in 2018 and 2019 from Thiès and Rosso, respectively. Phylogenetic analyses revealed that Senegalese strains belonged to the cosmopolitan genotype of DENV-2, but we observed intragenotype variability leading to a divergence in two clades associated with specific geographic distribution. We report two DENV-2 variants belonging to two distinct clades. Isolates from the "Northern clade" (n = 8) harbored three nonsynonymous mutations (V1183M, R1405K, P2266T) located respectively on NS2A, NS2B, and NS4A, while isolates from the "Western clade" (n = 7) had two nonsynonymous mutations (V1185E, V3214E) located respectively in the NS2A and NS5 genes. These findings call for phylogeographic analysis to investigate routes of introductions, dispersal patterns, and in-depth in vitro and functional study to elucidate the impact of observed mutations on viral fitness, spread, epidemiology, and pathology.
为评估塞内加尔登革热病毒 2 型(DENV-2)的遗传多样性,我们分析了在 2018 年暴发期间分离的 9 株新生成的完整基因组序列和分别于 2018 年和 2019 年在蒂埃斯和罗索获得的 06 个序列。系统发育分析显示,塞内加尔毒株属于 DENV-2 的世界性基因型,但我们观察到了导致两个与特定地理分布相关的分支发生分化的同型内变异性。我们报告了两种属于两个不同分支的 DENV-2 变体。来自“北部分支”(n=8)的分离株携带三个非同义突变(V1183M、R1405K、P2266T),分别位于 NS2A、NS2B 和 NS4A 上,而来自“西部分支”(n=7)的分离株携带两个非同义突变(V1185E、V3214E),分别位于 NS2A 和 NS5 基因上。这些发现呼吁进行系统地理学分析,以调查传入途径、扩散模式,并进行深入的体外和功能研究,以阐明观察到的突变对病毒适应性、传播、流行病学和病理学的影响。