Advanced Analytical Platform for SARS-CoV-2 Wastewater Surveillance

截至2022年5月初，新冠肺炎疫情已导致加拿大370多万例阳性病例和3.92万人死亡。不幸的是，目前在全人群范围内进行鼻咽拭子检测是不切实际的，特别是对于传染性更强的关注变体（VOCs）。废水监测已被确定为在社区一级追踪COVID-19的一种具有成本效益的方法。事实上，由彭慧博士和伊丽莎白·爱德华兹博士共同领导的UofT团队目前正在监测9个污水处理厂的SARS-CoV-2趋势，这些污水处理厂为300多万安大略省居民提供服务。然而，目前的废水SARS-CoV-2监测方法受到分析方法和基本机制方面的一些局限性的挑战。面对不断增加的最新变种“欧米克隆”病例，对更精确监控的需求更加迫切。在拟议的项目中，UofT团队将与环境、保护和公园部（MECP）、多伦多公共卫生部（TPH）、多伦多水务和商业测试实验室（SiREM）合作，开发一个先进的SARS-CoV-2废水监测分析平台。本项目将追求三个研究目标。首先，通过整合三种双正交试验，建立一种新的样品富集方法。新的样品富集方法有望将当前SARS-CoV-2废水监测的灵敏度提高10倍。我们还旨在建立一种新的LC-MS方法来快速检测废水中新的挥发性有机化合物。这种方法可能比qPCR和下一代测序具有宝贵的优势，包括周转时间短，准确性高。最后，我们将重点阐明尽管存在RNA酶，但SARS-CoV-2病毒RNA在废水中稳定性的基本机制。散弹枪蛋白质组学将用于鉴定废水中哪些蛋白质与病毒RNA复合物。通过拟议的联盟项目建立的分析平台预计将推进SARS-CoV-2废水监测，并将在安大略省废水监测倡议的下一阶段被MECP采用。

As of early May, 2022, the outbreak of COVID-19 had led to over 3.7 million positive cases and 39,200 deaths in Canada. Unfortunately, and especially with more contagious variants of concern (VOCs), performing current nasopharyngeal swabs testing at a population-wide level is impractical. Wastewater surveillance has been benchmarked as a cost-effective way to trace COVID-19 at the community level. Indeed, the UofT team, co-led by Dr. Hui Peng and Dr. Elizabeth Edwards, is currently monitoring SARS-CoV-2 trends in nine wastewater treatment plants that serve more than three million Ontario residents. However, the current wastewater SARS-CoV-2 surveillance approach is challenged by several limitations related to analytical methods and fundamental mechanisms. In the face of rising cases of the latest variant, Omicron, the need for more accurate surveillance is even more pressing. In the proposed project, the UofT team will develop an advanced analytical platform for SARS-CoV-2 wastewater surveillance by partnering with the Ministry of the Environment, Conservation and Parks (MECP), Toronto Public Health (TPH), Toronto Water and a commercial testing lab (SiREM). Three research objectives will be pursued in this project. First, a new sample enrichment method will be established by integrating three biorthogonal assays. The new sample enrichment method is expected to improve the sensitivity of the current SARS-CoV-2 wastewater surveillance by a factor of 10. We also aim to establish a novel LC-MS method for the rapid detection of new VOCs in wastewaters. This method may provide valuable advantages over qPCR and next-generation sequencing including short turnaround time, and high accuracy. Lastly, we will focus on elucidating the fundamental mechanism for the stability of SARS-CoV-2 viral RNA in wastewaters despite presence of RNases. Shotgun proteomics will be employed to identify which proteins complex with viral RNA in wastewaters. The analytical platform established through this proposed Alliance project is expected to advance SARS-CoV-2 wastewater surveillance, and will be adopted by MECP in a next phase of the Ontario wastewater surveillance initiative.