动物轮状病毒A(RVA)被认为是新兴的来源,新型RVA菌株,有可能在人类中引起全球传播。一个很好的例子是最近出现的由P[8]VP4基因和DS-1样骨架基因组成的G8牛RVA。然而,在人类循环过程中,动物RVA来源的基因发生了哪些进化变化,目前还没有很好的文献记载.越南的轮状病毒监测发现,DS-1-likeG8P[8]毒株出现在2014年,在两个流行的浪潮中传播,在2021年消失了。这种监测为我们提供了一个独特的机会来调查进化变化的整个过程,发生在动物RVA中,该动物跳过了宿主物种屏障。在2014年至2021年间从越南急性腹泻儿童收集的843个G8P[8]样本中,根据使用聚丙烯酰胺凝胶电泳鉴定的基因组RNA的独特电泳型选择了58个菌株。对这58个菌株的全基因组序列分析表明,在第一波流行(2014-17)中占主导地位的菌株携带动物RVA衍生的VP1,NSP2和NSP4基因。然而,来自第二波流行(2018-21)的菌株失去了这些基因,它们被同源的人类RVA衍生基因取代,从而在完全DS-1样的人RVA基因骨架上创建具有G8P[8]的菌株。G8VP7和P[8]VP4基因经历了一些点突变,但它们所属的系统发育谱系保持不变。我们,因此,提出了关于动物RVA衍生基因在跨越宿主物种屏障后从后代菌株的主链基因中排出的趋势的假设。这项研究强调了对循环野生型菌株进行长期监测的重要性,以便更好地了解新出现的菌株的适应过程和命运,人群中动物来源的RVA。有必要进行进一步的研究,以揭示溢出动物RVA易于在人类之间传播的分子机制,以及驱逐动物来源的基因和在当地人群中形成的群体免疫所起的作用。
Animal rotaviruses A (RVAs) are considered the source of emerging, novel RVA strains that have the potential to cause global spread in humans. A case in point was the emergence of G8 bovine RVA consisting of the P[8] VP4 gene and the DS-1-like backbone genes that appeared to have jumped into humans recently. However, it was not well documented what evolutionary changes occurred on the animal RVA-derived genes during circulation in humans. Rotavirus surveillance in Vietnam found that DS-1-like G8P[8] strains emerged in 2014, circulated in two prevalent waves, and disappeared in 2021. This surveillance provided us with a unique opportunity to investigate the whole process of evolutionary changes, which occurred in an animal RVA that had jumped the host species barrier. Of the 843 G8P[8] samples collected from children with acute diarrhoea in Vietnam between 2014 and 2021, fifty-eight strains were selected based on their distinctive electropherotypes of the genomic RNA identified using polyacrylamide gel electrophoresis. Whole-genome sequence analysis of those fifty-eight strains showed that the strains dominant during the first wave of prevalence (2014-17) carried animal RVA-derived VP1, NSP2, and NSP4 genes. However, the strains from the second wave of prevalence (2018-21) lost these genes, which were replaced with cognate human RVA-derived genes, thus creating strain with G8P[8] on a fully DS-1-like human RVA gene backbone. The G8 VP7 and P[8] VP4 genes underwent some point mutations but the phylogenetic lineages to which they belonged remained unchanged. We, therefore, propose a hypothesis regarding the tendency for the animal RVA-derived genes to be expelled from the backbone genes of the progeny strains after crossing the host species barrier. This study underlines the importance of long-term surveillance of circulating wild-type strains in order to better understand the adaptation process and the fate of newly emerging, animal-derived RVA among the human population. Further studies are warranted to disclose the molecular mechanisms by which spillover animal RVAs become readily transmissible among humans, and the roles played by the expulsion of animal-derived genes and herd immunity formed in the local population.