Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada.
School of Public Health, University of Alberta, 11405-87 Avenue, Edmonton, Alberta T6G 1C9, Canada.
Environ Sci Technol. 2020 Aug 18;54(16):10201-10206. doi: 10.1021/acs.est.0c02896. Epub 2020 Jul 27.
Free-living amoebae (FLA) are ubiquitous protozoa in aquatic/soil habitats and known to resist various disinfection methods commonly used in drinking and wastewater treatment plants. Reoviruses are emerging as useful infectious enteric virus indicators of wastewater treatment efficacy. The possible enhanced protection FLA may provide reoviruses, however, has not been previously described. Using an infectious clinical reovirus isolate in coculture with three FLA, namely, , , and , we followed reovirus persistence (by quantitative reverse transcription polymerase chain reaction (RT-qPCR)) and infectivity (TCID). Virions present in samples persisted over the experimental time period, with most virions remaining infectious. Surprisingly, electron microscopy revealed virions accumulated within the nucleus of amoebae. The current work appears to be the first report of reovirus being internalized within FLA and remaining infectious, providing a previously unreported environmental reservoir and potential mode of dissemination. FLA also appeared to be providing some logs in protection to internalized viruses during UV irradiation, which if not accounted for when determining UV dosage needed for sufficient disinfection may result in unintentional release of pathogens into surrounding water systems.
自由生活阿米巴虫（FLA）是水生/土壤栖息地中普遍存在的原生动物，已知能够抵抗饮用水和废水处理厂中常用的各种消毒方法。呼肠孤病毒作为废水处理效果的有用传染性肠道病毒指标正在出现。然而，FLA 可能提供的增强保护作用尚未得到先前描述。我们使用传染性临床呼肠孤病毒分离株与三种 FLA（即 、 、 和 ）进行共培养，通过定量逆转录聚合酶链反应（RT-qPCR）和 TCID 法来跟踪呼肠孤病毒的持续存在和感染性。样品中存在的病毒粒子在实验期间持续存在，大多数病毒粒子仍然具有感染性。令人惊讶的是，电子显微镜显示病毒粒子在阿米巴虫的核内积累。目前的工作似乎是首次报道呼肠孤病毒在 FLA 内被内化并保持感染性，为以前未报道的环境储存库和潜在的传播方式提供了依据。FLA 似乎还在紫外线照射下为内化病毒提供了一些保护作用，如果在确定足够消毒所需的紫外线剂量时没有考虑到这一点，可能会导致病原体意外释放到周围的水系统中。
