Detection of the human specific Bacteroides genetic marker provides evidence of widespread sewage contamination of stormwater in the urban environment
Detection of the human specific Bacteroides genetic marker provides evidence of widespread sewage contamination of stormwater in the urban environment
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DOI：
10.1016/j.watres.2011.04.049
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发表时间：
2011-08-01
期刊：
影响因子：
12.8
通讯作者：
McLellan, Sandra L.
中科院分区：
文献类型：
--
作者：
Sauer, Elizabeth P.;VandeWalle, Jessica L.;McLellan, Sandra L.
人类污水对地表水的污染是人类健康的一个主要问题。我们发现，收集和输送来自不透水表面的径流的城市雨水系统，充当了生活污水基础设施中产生的污水的管道。四年来，我们在 45 个雨水排放口收集了总共 828 个样本，并通过基于培养的方法、PCR 和定量 PCR (qPCR) 进行了评估，以测试粪便污染的传统和替代指标。所有排污口至少在一个样本中检测到 HF183（人类）拟杆菌基因标记，表明污水污染在城市环境中几乎无处不在。然而，大多数排放口呈间歇性阳性，检测范围为 11%-100% 的样本。积极的结果与季节性、降雨量或上次降雨以来的天数无关。大约三分之二的排放口具有高水平（> 5000 个拷贝数，即 CN，每 100 毫升）或中等水平（1000-5000 CN 每 100 毫升）人类拟杆菌遗传标记。大肠杆菌 (E. coli) 和肠球菌水平与人类拟杆菌不相关。所有排污口样本中总共 66% 的标准粪便指标水平高于每 100 毫升 10,000 CFU。使用此基准来确定高优先级地点的分层评估将无法标记 35% 的有污水污染证据的样本。此外，高粪便指标会将 33% 的样本标记为优先，而这些样本中污水的证据很少或没有。一个人类拟杆菌遗传标记水平较高的排污口中的肠道病毒水平与未经处理的废水相似，这说明雨水可以作为病原体污染的途径。根据人类拟杆菌属与总拟杆菌属的比率，接受雨水排放的五个河流地点中有四个的粪便污染的主要来源似乎来自污水源，而不是非人类来源。这项研究展示了采用分子方法测试粪便污染替代指标的可行性和好处，以识别污水源和潜在的健康风险，并确定修复工作的优先顺序。 (C) 2011 Elsevier Ltd. 保留所有权利。
Human sewage contamination of surface waters is a major human health concern. We found urban stormwater systems that collect and convey runoff from impervious surfaces act as a conduit for sewage originating from breeches in sanitary sewer infrastructure. A total of 828 samples at 45 stormwater outfalls were collected over a four-year period and assessed by culture based methods, PCR, and quantitative PCR (qPCR) to test for traditional and alternative indicators of fecal pollution. All outfalls had the HF183 (human) Bacteroides genetic marker detected in at least one sample, suggesting sewage contamination is nearly ubiquitous in the urban environment. However, most outfalls were intermittently positive, ranging from detection in 11%-100% of the samples. Positive results did not correlate with seasonality, rainfall amounts, or days since previous rainfall. Approximately two-thirds of the outfalls had high (>5000 copy number, i.e. CN, per 100 ml) or moderate levels (1000-5000 CN per 100 ml) of the human Bacteroides genetic marker. Escherichia coli (E. coli) and enterococci levels did not correlate to human Bacteroides. A total of 66% of all outfall samples had standard fecal indicator levels above 10,000 CFU per 100 ml. A tiered assessment using this benchmark to identify high priority sites would have failed to flag 35% of the samples that had evidence of sewage contamination. In addition, high fecal indicators would have flagged 33% of samples as priority that had low or no evidence of sewage. Enteric virus levels in one outfall with high levels of the human Bacteroides genetic marker were similar to untreated wastewater, which illustrates stormwater can serve as a pathway for pathogen contamination. The major source of fecal pollution at four of five river sites that receive stormwater discharge appeared to be from sewage sources rather than non-human sources based on the ratios of human Bacteroides to total Bacteroides spp. This study shows the feasibility and benefits of employing molecular methods to test for alternative indicators of fecal pollution to identify sewage sources and potential health risks and for prioritization of remediation efforts. (C) 2011 Elsevier Ltd. All rights reserved.