Wanguyun Aken Puti, Oishi Wakana, Rachmadi Andri Taruna, Katayama Kazuhiko, Sano Daisuke
Department of Frontier Sciences for Advanced Environment, Graduate School of Environmental Studies, Tohoku University, Sendai, Japan.
Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Japan.
Front Microbiol. 2024 Apr 30;15:1372641. doi: 10.3389/fmicb.2024.1372641. eCollection 2024.
High genetic diversity in RNA viruses contributes to their rapid adaptation to environmental stresses, including disinfection. Insufficient disinfection can occur because of the emergence of viruses that are less susceptible to disinfection. However, understanding regarding the mechanisms underlying the alteration of viral susceptibility to disinfectants is limited. Here, we performed an experimental adaptation of murine norovirus (MNV) using chlorine to understand the genetic characteristics of virus populations adapted to chlorine disinfection. Several MNV populations exposed to an initial free chlorine concentration of 50 ppm exhibited reduced susceptibility, particularly after the fifth and tenth passages. A dominant mutation identified using whole-genome sequencing did not explain the reduced susceptibility of the MNV populations to chlorine. Conversely, MNV populations with less susceptibility to chlorine, which appeared under higher chlorine stress, were accompanied by significantly lower synonymous nucleotide diversity (π) in the major capsid protein (VP1). The nonsynonymous nucleotide diversity (π) in VP1 in the less-susceptible populations was higher than that in the susceptible populations, although the difference was not significant. Therefore, the ability of MNV populations to adapt to chlorine was associated with the change in nucleotide diversity in VP1, which may lead to viral aggregate formation and reduction in chlorine exposure. Moreover, the appearance of some nonsynonymous mutations can also contribute to the alteration in chlorine susceptibility by influencing the efficiency of viral replication. This study highlights the importance of understanding the genetic characteristics of virus populations under disinfection, which can contribute to the development of effective disinfection strategies and prevent the development of virus populations less susceptible to disinfectants.
RNA病毒的高遗传多样性有助于它们快速适应包括消毒在内的环境压力。由于出现了对消毒较不敏感的病毒，可能会发生消毒不充分的情况。然而，关于病毒对消毒剂敏感性改变的潜在机制的了解有限。在此，我们使用氯对小鼠诺如病毒（MNV）进行了实验适应性研究，以了解适应氯消毒的病毒群体的遗传特征。暴露于初始游离氯浓度为50 ppm的几个MNV群体表现出敏感性降低，尤其是在第五代和第十代传代之后。使用全基因组测序鉴定出的一个主要突变并不能解释MNV群体对氯敏感性降低的原因。相反，在较高氯压力下出现的对氯敏感性较低的MNV群体，其主要衣壳蛋白（VP1）中的同义核苷酸多样性（π）显著降低。尽管差异不显著，但敏感性较低群体中VP1的非同义核苷酸多样性（π）高于敏感性较高的群体。因此，MNV群体适应氯的能力与VP1中核苷酸多样性的变化有关，这可能导致病毒聚集体形成并减少氯暴露。此外，一些非同义突变的出现也可能通过影响病毒复制效率而导致氯敏感性改变。本研究强调了了解消毒条件下病毒群体遗传特征的重要性，这有助于制定有效的消毒策略，并防止出现对消毒剂敏感性较低的病毒群体。
