title: Evaluation of diarrheagenic E. coli in riversheds by quantitative PCR in combination with enrichment.
abstract: Diarrheagenic Escherichia coli (DEC) is a group of the most common agents of diarrhea. Highly virulent DEC strains could cause illness with dozens of organisms. Waterborne DEC may be detected using polymerase chain reaction (PCR); however, environmental contaminants can interfere with PCR reaction, thus causing the prevalence of DEC to be underestimated. In this study, we propose an approach to efficiently quantify trace amounts of DEC. An enrichment procedure was performed to amplify total E. coli including DEC in the water samples. By normalizing the number of pathotype-specific genes to the amplification rate of a housekeeping gene in all E. coli, the quantity of DEC in original samples could be assessed. This method allows detection of trace amounts of DEC in receiving waters. The results showed that the presence of DEC in water samples was partially associated with riverside settlement. The DEC concentration was substantially higher at a few sampling sites, suggesting that evaluation of DEC along the river may help identify previously unknown pollution sources. Although the sustainability of DEC in the receiving waters may be low, the risk of DEC infection from the watershed warrants further examination.
authors.affiliation: Department of Emergency Medicine, Cheng Hsin General Hospital, Taipei, Taiwan, ROC.
authors.forename: Shih-Yung
authors.initials: SY
authors.lastname: Hsu
authors.affiliation: Department of Earth and Environmental Sciences, National Chung Cheng University, 168, University Road, Min-Hsiung, Chiayi, Taiwan, ROC E-mail: bmhsu@ccu.edu.tw.
authors.forename: Bing-Mu
authors.initials: BM
authors.lastname: Hsu
authors.affiliation: Department of Earth and Environmental Sciences, National Chung Cheng University, 168, University Road, Min-Hsiung, Chiayi, Taiwan, ROC E-mail: bmhsu@ccu.edu.tw; †Equal contribution to first author.
authors.forename: Wen-Tsai
authors.initials: WT
authors.lastname: Ji
authors.affiliation: Department of Ophthalmology, Cheng Hsin General Hospital, Taipei, Taiwan, ROC and Department of Life Science, Institute of Molecular Biology and Institute of Biomedical Science, National Chung Cheng University, Min-Hsiung, Chiayi, Taiwan, ROC; †Equal contribution to first author.
authors.forename: Tsui-Kang
authors.initials: TK
authors.lastname: Hsu
authors.affiliation: Department of Earth and Environmental Sciences, National Chung Cheng University, 168, University Road, Min-Hsiung, Chiayi, Taiwan, ROC E-mail: bmhsu@ccu.edu.tw.
authors.forename: Po-Min
authors.initials: PM
authors.lastname: Kao
authors.affiliation: Department of Earth and Environmental Sciences, National Chung Cheng University, 168, University Road, Min-Hsiung, Chiayi, Taiwan, ROC E-mail: bmhsu@ccu.edu.tw.
authors.forename: Tzung-Yu
authors.initials: TY
authors.lastname: Shen
authors.affiliation: Department of Earth and Environmental Sciences, National Chung Cheng University, 168, University Road, Min-Hsiung, Chiayi, Taiwan, ROC E-mail: bmhsu@ccu.edu.tw.
authors.forename: Cheng-Wei
authors.initials: CW
authors.lastname: Fan
authors.affiliation: Department of Safety Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung, Taiwan, ROC.
authors.forename: Yu-Li
authors.initials: YL
authors.lastname: Huang
mesh_terms: D003967:Diarrhea; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections; D016133:Polymerase Chain Reaction; D045483:Rivers / Q000382:microbiology*; D014871:Water Microbiology