Contamination caused by microbial fecal pollution in water bodies is a serious problem in many countries, especially in low- and middle-income countries. Therefore, fecal source tracking is an important method used to understand the source of fecal contamination and to decrease the hazard of waterborne diseases that occurs in the environment. In this study, a human-associated genetic marker for Escherichia coli (H8) was used to investigate the source of fecal contamination in the Mae Klong River, Thailand. Real-time PCR was performed with this marker for 500 E. coli isolates collected from 10 sampling sites along the river, including MK10 (upstream) to MK1 (downstream). The results showed that the proportions of H8-positive isolates were 46, 14, 10, 18, 14, 38, 12, 26, 32, and 14% at MK10–MK1, respectively. All positive proportions were significantly different between the locations (p < 0.001). The higher occurrence of E. coli with H8 marker detection indicated that domestic wastewater was largely discharged without proper treatment, which is attributable to the high population and the absence of proper sewage treatment in those areas.

水体中微生物粪便污染造成的污染在许多国家是一个严重的问题，特别是在低收入和中等收入国家。因此，粪便源头追踪是了解粪便污染源和降低环境中发生的水传播疾病危害的重要方法。在这项研究中，使用与人类相关的大肠杆菌(H8) 遗传标记来调查泰国湄公河的粪便污染源。使用此标记对 500 个大肠杆菌进行实时 PCR从沿河 10 个采样点收集的分离物，包括 MK10（上游）到 MK1（下游）。结果表明，在MK10-MK1，H8阳性分离株的比例分别为46%、14%、10%、18%、14%、38%、12%、26%、32%和14%。不同位置的所有阳性比例均存在显着差异（p < 0.001）。带有H8标记检测的大肠杆菌的较高发生率表明，生活废水大部分未经适当处理就排放，这归因于这些地区人口众多且没有适当的污水处理。