Contribution of polymerase chain reaction (PCR) to improve assessment of drinking water quality: a comparison study

在饮用水质量监测和监测领域提供服务的公司不断努力提高其服务的质量和速度。在微生物水质监测领域，分子技术具有广阔的应用前景。这可能是通过基于培养的技术从水中分离的假定大肠杆菌菌落的快速鉴定的情况。在魁北克，微生物水质监测的新技术必须得到省当局(CEAEQ)的批准。Exova是一家总部位于魁北克市的专门从事水质检测的公司，该公司使用MFC介质通过MFC琼脂方法检测饮用水中是否存在耐热大肠菌群。然而，该方法不是完全特异的，而且可以检测出非粪源微生物，因为假阳性结果，必须进行耗时的补充试验才能确认结果。因此，魁北克当局最近提议修改他们的指南，要求测量存在的大肠杆菌而不是耐热大肠杆菌。为了确保符合CEAEQ的建议，Exova必须验证一种能够检测饮用水中存在的大肠杆菌而不是耐热大肠菌的新程序。该项目的目标是比较各种检测水中大肠杆菌存在的方法，并确定哪种方法提供最好的成本/效益优势。与Exova合作，我们将使用三种不同的方法同时分析1000个井水样本：1)Colilert方法；2)基于MI琼脂培养的方法；3)基于MFC琼脂培养的方法，与Maheux等人提出的快速大肠杆菌特异性实时PCR检测相结合。(2011a)。我们希望，在该项目结束时，与Exova的合作将通过改善饮用水监测和为评估微生物质量提供的服务质量而证明是成功的和有利可图的合作。

Companies that offer services in the domain of drinking water quality surveillance and monitoring continuously attempt to improve the quality and the rapidity of their services. In the field of microbiological water quality monitoring, molecular technologies are very promising. This could be the case for the rapid identification of presumptive E. coli colonies isolated from water by culture-based techniques. In Quebec, new technologies for microbiological water quality monitoring must be approved by the provincial authorities (CEAEQ). Exova is a company based in Québec City specializing in water quality testing that uses the mFC medium to detect the presence of thermotolerant coliforms in drinking water with the mFC agar method. However, this method is not totally specific and non-fecal origin microorganisms can be detected with this method as false-positive results and supplementary time-consuming test must be performed to confirm the result. Consequently, the Quebec authorities recently proposed modifying their guidelines to require the measurement of the presence of E. coli instead of thermotolerant coliforms.To ensure compliance with the CEAEQ proposition, Exova have to validate a new procedure able to detect the presence of E. coli rather than thermotolerant coliforms in drinking water. The objective of this project is to compare various methods to detect the presence of E. coli in water and, to identify the one that offers the best cost/benefit advantages. In collaboration with Exova, we will simultaneously analyze 1000 water samples of well water using three different methods: 1) the Colilert method 2) the MI agar culture-based method and, 3) the mFC agar culture-based method coupled with a rapid E. coli-specific real-time PCR assay proposed by Maheux et al. (2011a). It is our hope that at the conclusion of this project, the collaboration with Exova will have proven successful and profitable collaboration by improving drinking water monitoring and the quality of services offered to assess the microbiological quality.