University of Utah, Civil and Environmental Engineering, Salt Lake City, Utah, USA
West Virginia University, Civil and Environmental Engineering, Morgantown, West Virginia, USA.
Appl Environ Microbiol. 2018 Mar 1;84(6). doi: 10.1128/AEM.02510-17. Print 2018 Mar 15.
Fecal indicator bacteria (FIB) are the basis for water quality regulations and are considered proxies for waterborne pathogens when conducting human health risk assessments. The direct detection of pathogens in water and simultaneous identification of the source of fecal contamination are possible with microarrays, circumventing the drawbacks to FIB approaches. A multigene target microarray was used to assess the prevalence of waterborne pathogens in a fecally impaired mixed-use watershed. The results indicate that fecal coliforms have improved substantially in the watershed since its listing as a 303(d) impaired stream in 2002 and are now near United States recreational water criterion standards. However, waterborne pathogens are still prevalent in the watershed, as viruses (bocavirus, hepatitis E and A viruses, norovirus, and enterovirus G), bacteria ( spp., spp., enterohemorrhagic and enterotoxigenic , uropathogenic , , spp., spp., and spp.), and eukaryotes ( spp., , and ) were detected. A comparison of the stream microbial ecology with that of sewage, cattle, and swine fecal samples revealed that human sources of fecal contamination dominate in the watershed. The methodology presented is applicable to a wide range of impaired streams for the identification of human health risk due to waterborne pathogens and for the identification of areas for remediation efforts. The direct detection of waterborne pathogens in water overcomes many of the limitations of the fecal indicator paradigm. Furthermore, the identification of the source of fecal impairment aids in identifying areas for remediation efforts. Multitarget gene microarrays are shown to simultaneously identify waterborne pathogens and aid in determining the sources of impairment, enabling further focused investigations. This study shows the use of this methodology in a historically impaired watershed in which total maximum daily load reductions have been successfully implemented to reduce risk. The results suggest that while the fecal indicators have been reduced more than 96% and are nearing recreational water criterion levels, pathogens are still detectable in the watershed. Microbial source tracking results show that additional remediation efforts are needed to reduce the impact of human sewage in the watershed.
粪便指示菌（FIB）是水质法规的基础，并且在进行人类健康风险评估时被认为是水传播病原体的替代品。通过微阵列可以直接检测水中的病原体，并同时识别粪便污染的来源，从而避免了 FIB 方法的缺点。使用多基因靶标微阵列评估了一个粪便受损的多用途流域中水生病原体的流行情况。结果表明，自 2002 年被列为 303(d)受损溪流以来，流域中的粪便大肠菌群有了显著改善，现在接近美国休闲水标准。然而，该流域仍然存在水生病原体，因为检测到病毒（细小病毒、戊型肝炎和甲型肝炎病毒、诺如病毒和肠道病毒 G）、细菌（ spp.、 spp.、肠出血性和肠毒性 、尿路致病性 、 spp.、 spp.和 spp.）和真核生物（ spp.、 和 ）。将溪流微生物生态学与污水、牛和猪粪便样本进行比较，结果表明人类粪便污染是该流域的主要来源。所提出的方法适用于广泛的受损溪流，可用于确定水传播病原体对人类健康的风险，并确定需要修复的区域。水中水传播病原体的直接检测克服了粪便指示物范式的许多局限性。此外，粪便损害来源的识别有助于确定需要修复的区域。多靶基因微阵列可同时识别水传播病原体，并有助于确定损害来源，从而进行进一步的重点调查。本研究展示了该方法在一个历史上受损的流域中的应用，该流域已经成功实施了最大日负荷总量削减，以降低风险。结果表明，虽然粪便指示物的减少超过了 96%，并且接近休闲水标准，但在流域中仍能检测到病原体。微生物源追踪结果表明，需要进一步的修复工作来减少流域中人类污水的影响。
