Liu Shuang, Lioe Trillion Surya, Sun Li, Adriaenssens Evelien M, McCarthy Alan J, Sekar Raju
Department of Biosciences and Bioinformatics, School of Science, Xi'an Jiaotong-Liverpool University, Suzhou, 215123, China; Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, L69 7ZX, UK.
Leiden Institute of Chemistry, Faculty of Science, Leiden University, 2333, CC Leiden, the Netherlands.
Environ Pollut. 2025 Feb 1;366:125403. doi: 10.1016/j.envpol.2024.125403. Epub 2024 Nov 26.
Human-specific faecal contamination has been affecting surface water and is a threat to both the environment and public health due to its potential co-occurrence with pathogens. Extended studies were conducted to detect and quantify faecal contamination using microbial source tracking (MST) markers targeting bacteria and viruses. The prototypical crAssphage, a presumed Bacteroides-infecting phage discovered in 2014, showed superior specificity to human faeces and high abundance in untreated sewage water. This study evaluated the applicability of crAssphage markers, CPQ_056 and CPQ_064, as MST tools for detecting domestic sewage contamination in surface water in China. Validation tests based on domestic sewage and animal faecal samples demonstrated high sensitivity/specificity of 100%/96.7% for CPQ_056 and 100%/100% for CPQ_064 within the scope of this study, surpassing the performance of traditional Bacteroidales markers such as HF183 (100%/80.4% against sewage). MST markers targeting different hosts and validated in the Taihu watershed (CPQ_056, CPQ_064, BacUni, HF183 TaqMan, Pig-2-Bac, and GFD) were quantified in water samples collected from the inflow rivers of Taihu Lake in summer and winter 2020. The results showed the dominance of sewage/wastewater as the source of contamination in all faecal pollution. Spatial analysis revealed higher contamination levels in northwest rivers, which were those most impacted by human activities. There was also a diluting pattern downstream of some rivers. Correlations with water quality parameters indicated the co-occurrence of nutrient-related pollution and faecal contamination, particularly in areas with industrial, low-density residential, green space, and municipal service land uses. The findings established the efficacy of crAssphage markers in enhancing precision and accuracy in monitoring faecal contamination, offering valuable tools for policymakers and environmental managers.
特定于人类的粪便污染一直在影响地表水，由于其可能与病原体同时出现，对环境和公众健康都构成威胁。开展了深入研究，以使用针对细菌和病毒的微生物源追踪（MST）标记物来检测和量化粪便污染。典型的crAssphage是2014年发现的一种推测感染拟杆菌的噬菌体，对人类粪便显示出卓越的特异性，且在未经处理的污水中丰度很高。本研究评估了crAssphage标记物CPQ_056和CPQ_064作为检测中国地表水生活污水污染的MST工具的适用性。基于生活污水和动物粪便样本的验证测试表明，在本研究范围内，CPQ_056的灵敏度/特异性分别为100%/96.7%，CPQ_064为100%/100%，超过了传统拟杆菌标记物如HF183（针对污水的灵敏度/特异性为100%/80.4%）的性能。在2020年夏季和冬季从太湖入流河流采集的水样中，对在太湖流域验证的针对不同宿主的MST标记物（CPQ_056、CPQ_064、BacUni、HF183 TaqMan、Pig - 2 - Bac和GFD）进行了定量分析。结果表明，在所有粪便污染中，污水/废水是主要污染源。空间分析显示，受人类活动影响最大的西北河流污染水平较高。一些河流下游也存在稀释模式。与水质参数的相关性表明，营养相关污染和粪便污染同时存在，特别是在有工业、低密度住宅、绿地和市政服务用地的区域。研究结果证实了crAssphage标记物在提高粪便污染监测的精度和准确性方面的有效性，为政策制定者和环境管理者提供了有价值的工具。
