Dépôt numérique

Assessment of multiple fecal contamination sources in surface waters using environmental mitochondrial DNA metabarcoding

Ragot, Rose; Lessard, Florence; Bélanger, André et Villemur, Richard ORCID logoORCID: https://orcid.org/0000-0001-9768-8937 (2023). Assessment of multiple fecal contamination sources in surface waters using environmental mitochondrial DNA metabarcoding The Science of the total environment , vol. 898 , nº 165237. pp. 1-11. DOI: 10.1016/j.scitotenv.2023.165237.

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Waterborne diseases are transmitted to humans through the fecal contamination of water, where homeothermic species are the main reservoir. Fecal indicator bacteria (FIB) are often used to determine the occurrence of fecal contamination. However, FIB cannot provide the source of fecal contamination. Furthermore, as fecal inputs and contamination could originate from multiple sources (e.g., human, livestock, wildlife), multiple source tracking markers are required to identify fecal sources. From a previous study, we developed a mitochondrial DNA (mtDNA) metabarcoding approach to assess the presence of multiple homeotherms in four surface waters. Here, we have broadened our approach by sampling 86 surface water samples from the L'Assomption River and Ville-Marie watersheds (Province of Quebec, Canada). Fecal coliform levels were higher than the expected sanitary recommendations for recreational water (> 200 CFU/100 mL) in 73 % samples. The occurrence of mtDNA from humans, livestock, domestic animals, wild mammals and wild birds was found in 40-88 % of the samples. Multivariate analyses showed significant covariations between homeothermic taxa and fecal coliforms, enterococci, β-D-glucuronidase, conductivity, the human-specific Bacteroidales Hf183 genetic marker, and the human population, in the watersheds of L'Assomption River (p = 0.001) and Ville-Marie (p = 0.015) (Province of Quebec, Canada). Through the application of Bayes Theorem, it was determined that fecal coliforms co-occurred with the detection of bovine, beaver, robin and chicken mtDNA in 100 % of cases in the L'Assomption River watershed, and human mtDNA co-occurred with fecal coliforms in 93 % and 76 % of cases in L'Assomption River watershed and Ville-Marie sub-catchment, respectively. This study suggests that fecal contamination could be the result of multiple species, reinforcing the necessity of using the mtDNA metabarcoding method to monitor multi-animal species. Our results suggest that some wild animals may also contribute to fecal inputs in surface waters, which could result in a potential risk to human health.

Type de document: Article
Mots-clés libres: Mitochondrial DNA metabarcoding Fecal source tracking qPCR Fecal coliforms Bacteroidales Hf183 genetic marker
Centre: Centre INRS-Institut Armand Frappier
Date de dépôt: 09 déc. 2023 18:21
Dernière modification: 09 déc. 2023 18:21
URI: https://espace.inrs.ca/id/eprint/13665

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