Intellectual Ventures Laboratory, 14360 SE Eastgate Way, Bellevue, WA, 98007, USA.
Global Health Labs, 14360 Eastgate Way, Bellevue, WA, 98007, USA.
Sci Rep. 2022 May 11;12(1):7741. doi: 10.1038/s41598-022-11468-2.
Inadequate drinking water quality is among the major causes of preventable mortality, predominantly in young children. Identifying contaminated water sources remains a significant challenge, especially where resources are limited. The current methods for measuring Escherichia coli (E. coli), the WHO preferred indicator for measuring fecal contamination of water, involve overnight incubation and require specialized training. In 2016, UNICEF released a Target Product Profile (TPP) to incentivize product innovations to detect low levels of viable E. coli in water samples in the field in less than 6 h. Driven by this challenge, we developed a phage-based assay to detect and semi-quantify E. coli. We formulated a phage cocktail containing a total of 8 phages selected against an extensive bacterial strain library and recombined with the sensitive NanoLuc luciferase reporter. The assay was optimized to be processed in a microfluidic chip designed in-house and was tested against locally sourced sewage samples and on drinking water sources in Nairobi, Kenya. With this assay, combined with the microfluidic chip platform, we propose a complete automated solution to detect and semi-quantify E. coli at less than 10 MPN/100 mL in 5.5 h by minimally trained personnel.
饮用水水质不足是可预防死亡的主要原因之一，主要发生在幼儿身上。识别受污染的水源仍然是一个重大挑战，特别是在资源有限的情况下。目前测量大肠杆菌（E. coli）的方法，即世界卫生组织（WHO）首选的衡量水中粪便污染的指标，需要过夜孵育，并且需要专门的培训。2016 年，联合国儿童基金会（UNICEF）发布了一个目标产品概况（TPP），以鼓励产品创新，在 6 小时内检测到野外水样中低水平的活大肠杆菌。受这一挑战的驱动，我们开发了一种基于噬菌体的检测方法来检测和半定量水中的大肠杆菌。我们配制了一种噬菌体混合物，其中包含总共 8 种噬菌体，这些噬菌体是针对广泛的细菌株库选择的，并与敏感的 NanoLuc 荧光素酶报告基因重组。该检测方法经过优化，可在内部设计的微流控芯片中进行处理，并在肯尼亚内罗毕的当地污水样本和饮用水源中进行了测试。通过该检测方法，结合微流控芯片平台，我们提出了一个完整的自动化解决方案，由经过最少培训的人员在 5.5 小时内以低于 10 MPN/100 毫升的检测限检测和半定量水中的大肠杆菌。
