Stapleton Carl M, Kay David, Wyer Mark D, Davies Cheryl, Watkins John, Kay Chris, McDonald Adrian T, Porter Jonathan, Gawler Andrew
CREH, Catchment and Coastal Research Centre, River Basin Dynamics and Hydrology Research Group, IGES, University of Aberystwyth, Ceredigion, SY23 3DB, UK.
Water Res. 2009 Nov;43(19):4888-99. doi: 10.1016/j.watres.2009.09.015. Epub 2009 Sep 10.
Microbial source tracking techniques are used in the UK to provide an evidence-base to guide major expenditure decisions and/or regulatory action relating to sewage disposal. Consequently, it is imperative that the techniques used robustly index faecal indicator organisms (FIOs) that are the regulatory parameters for bathing and shellfish harvesting areas. This study reports a 'field-scale' test of microbial source tracking (MST) based on the quantitative PCR analyses of Bacteroidales 16S rRNA genetic marker sequences. The project acquired data to test the operational utility of quantitative Bacteroidales MST data, comparing it with FIO concentrations in streams, effluents and bathing waters. Overall, the data did not exhibit a consistent pattern of significant correlations between Bacteroidales MST parameters and FIOs within the different sample matrices (i.e. rivers, bathing waters and/or effluents). Consequently, there was little evidence from this study that reported concentrations and/or percentages of human and/or ruminant faecal loadings (that are based on Bacteroidales MST gene copy numbers) offer a credible evidence-base describing FIO contributions to receiving water 'non-compliance'. The study also showed (i) there was no significant attenuation of the Bacteroidales gene copy number 'signal' through the UV disinfection process; and (ii) single non-compliant samples submitted for Bacteroidales MST analysis, do not reliably characterise the balance of faecal loadings due to the high variability in the MST signal observed. At this stage in the development of the MST tool deployed, it would be imprudent to use the percentage human and/or ruminant contributions (i.e. as indicated by MST data acquired at a bathing water) as the sole or principal element in the evidence-base used to guide major expenditure decisions and/or regulatory action.
在英国，微生物源追踪技术用于提供证据基础，以指导与污水处理相关的重大支出决策和/或监管行动。因此，至关重要的是，所使用的技术要稳健地对粪便指示生物（FIOs）进行索引，而FIOs是沐浴和贝类捕捞区域的监管参数。本研究报告了一项基于拟杆菌目16S rRNA基因标记序列定量PCR分析的微生物源追踪（MST）“实地规模”测试。该项目获取数据以测试定量拟杆菌目MST数据的操作实用性，并将其与溪流、污水和沐浴水中的FIO浓度进行比较。总体而言，在不同样本基质（即河流、沐浴水和/或污水）中，数据并未显示出拟杆菌目MST参数与FIOs之间存在一致的显著相关模式。因此，本研究几乎没有证据表明，基于拟杆菌目MST基因拷贝数报告的人类和/或反刍动物粪便负荷浓度和/或百分比，能提供一个可靠的证据基础来描述FIOs对受纳水体“不符合标准”的贡献。该研究还表明：（i）在紫外线消毒过程中，拟杆菌目基因拷贝数“信号”没有显著衰减；（ii）提交进行拟杆菌目MST分析的单个不符合标准的样本，由于观察到的MST信号存在高变异性，不能可靠地表征粪便负荷的平衡情况。在目前所部署的MST工具的发展阶段，将人类和/或反刍动物贡献的百分比（即如在沐浴水中获取的MST数据所示）用作指导重大支出决策和/或监管行动的证据基础中的唯一或主要要素是不明智的。
