Waterborne pathogens are heterogeneously distributed across various spatiotemporal scales in water resources, and representative sampling is therefore crucial for accurate risk assessment. Since regulatory monitoring of microbiological water quality is usually conducted at fixed time intervals, it can miss short-term fecal contamination episodes and underestimate underlying microbial risks. In the present paper, we developed a new automated sampling methodology based on near real-time measurement of a biochemical indicator of fecal pollution. Online monitoring of β-D-glucuronidase (GLUC) activity was used to trigger an automated sampler during fecal contamination events in a drinking water supply and at an urban beach. Significant increases in protozoan parasites, microbial source tracking markers and E. coli were measured during short-term (<24 h) fecal pollution episodes, emphasizing the intermittent nature of their occurrence in water. Synchronous triggering of the automated sampler with online GLUC activity measurements further revealed a tight association between the biochemical indicator and culturable E. coli. The proposed event sampling methodology is versatile and in addition to the two triggering modes validated here, others can be designed based on specific needs and local settings. In support to regulatory monitoring schemes, it should ultimately help gathering crucial data on waterborne pathogens more efficiently during episodic fecal pollution events.

中文翻译：

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使用近实时微生物水质监测对水生病原体和微生物源跟踪标记进行自动靶向采样

水源性病原体在水资源的各种时空尺度上分布不均，因此具有代表性的采样对于准确的风险评估至关重要。由于微生物水质的监管监测通常 以固定的时间间隔进行，因此可能会错过短期的粪便污染事件并低估潜在的微生物风险。在本文中，我们开发了一种新的自动采样方法，该方法基于对粪便污染生化指标的近实时测量。在饮用水供应和城市海滩的粪便污染事件期间，β-D-葡萄糖醛酸酶 (GLUC) 活性的在线监测用于触发自动采样器。原生动物寄生虫、微生物源追踪标记和大肠杆菌显着增加是在短期（<24 小时）粪便污染事件中测量的，强调它们在水中发生的间歇性。同步与在线GLUC活性测量自动取样器的触发进一步揭示的生化指标与可培养之间的紧密关联E.大肠杆菌。提议的事件采样方法是通用的，除了这里验证的两种触发模式外，其他的可以根据特定需求和本地设置进行设计。为了支持监管监测计划，它最终应该有助于在偶发性粪便污染事件期间更有效地收集有关水传播病原体的关键数据。