Greaves Justin, Stone Daniel, Wu Zhenyu, Bibby Kyle
Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, IN, 46556, USA.
Water Res X. 2020 Sep 2;9:100067. doi: 10.1016/j.wroa.2020.100067. eCollection 2020 Dec 1.
Fecal indicator bacteria (FIB) are typically used to monitor microbial water quality but are poor representatives of viruses due to different environmental fate. Viral fecal indicators have been proposed as alternatives to FIB; however, data evaluating the persistence of emerging viral fecal indicators under realistic environmental conditions is necessary to evaluate their potential application. In this study, we examined the persistence of five viral fecal indicators, including crAssphage and pepper mild mottle virus (PMMoV), and three bacterial fecal indicators (, enterococci and HF183/BacR287) in large-scale experimental ponds and freshwater mesocosms. Observed inactivation rate constants were highly variable and ranged from a minimum of -0.09 d for PMMoV to a maximum of -3.5 d for HF183/BacR287 in uncovered mesocosms. Overall, viral fecal indicators had slower inactivation than bacterial fecal indicators and PMMoV was inactivated more slowly than all other targets. These results demonstrate that bacterial fecal indicators inadequately represent viral fate following aging of sewage contaminated water due to differential persistence, and that currently used fecal indicator monitoring targets demonstrate highly variable persistence that should be considered during water quality monitoring and risk assessment.
粪便指示菌（FIB）通常用于监测微生物水质，但由于不同的环境归宿，它们并不是病毒的良好代表。病毒粪便指示物已被提议作为FIB的替代品；然而，评估新兴病毒粪便指示物在实际环境条件下的持久性数据对于评估其潜在应用是必要的。在本研究中，我们研究了包括crAssphage和辣椒轻斑驳病毒（PMMoV）在内的五种病毒粪便指示物以及三种细菌粪便指示物（肠球菌和HF183/BacR287）在大型实验池塘和淡水微宇宙中的持久性。在未覆盖的微宇宙中，观察到的失活速率常数变化很大，范围从PMMoV的最小值-0.09 d到HF183/BacR287的最大值-3.5 d。总体而言，病毒粪便指示物的失活比细菌粪便指示物慢，并且PMMoV的失活比所有其他目标都更慢。这些结果表明，由于持久性不同，细菌粪便指示物不能充分代表受污水污染的水老化后的病毒归宿，并且目前使用的粪便指示物监测目标显示出高度可变的持久性，在水质监测和风险评估过程中应予以考虑。
