title: Relevance of Bacteroidales and F-specific RNA bacteriophages for efficient fecal contamination tracking at the level of a catchment in France.
abstract: The relevance of three host-associated Bacteroidales markers (HF183, Rum2Bac, and Pig2Bac) and four F-specific RNA bacteriophage genogroups (FRNAPH I to IV) as microbial source tracking markers was assessed at the level of a catchment (Daoulas, France). They were monitored together with fecal indicators (Escherichia coli and enterococci) and chemophysical parameters (rainfall, temperature, salinity, pH, and turbidity) by monthly sampling over 2 years (n = 240 water samples) and one specific sampling following an accidental pig manure spillage (n = 5 samples). During the 2-year regular monitoring, levels of E. coli, enterococci, total F-specific RNA bacteriophages, and the general Bacteroidales marker AllBac were strongly correlated with one another and with Rum2Bac (r = 0.37 to 0.50, P < 0.0001). Their correlations with HF183 and FRNAPH I and II were lower (r = 0.21 to 0.29, P < 0.001 to P < 0.0001), and HF183 and enterococci were associated rather than correlated (Fisher's exact test, P < 0.01). Rum2Bac and HF183 enabled 73% of water samples that had ≥ 2.7 log(10) most probably number (MPN) of E. coli/100 ml to be classified. FRNAPH I and II enabled 33% of samples at this contamination level to be classified. FRNAPH I and II complemented the water sample classification obtained with the two Bacteroidales markers by an additional 8%. Pig2Bac and FRNAPH III and IV were observed in a small number of samples (n = 0 to 4 of 245). The present study validates Rum2Bac and HF183 as relevant tools to trace fecal contamination originating from ruminant or human waste, respectively, at the level of a whole catchment.
authors.affiliation: Ifremer, EMP, Laboratoire de Microbiologie, Plouzané, France.
authors.forename: Aourell
authors.initials: A
authors.lastname: Mauffret
authors.forename: Marie-Paule
authors.initials: MP
authors.lastname: Caprais
authors.forename: Michèle
authors.initials: M
authors.lastname: Gourmelon
mesh_terms: D000818:Animals; D041963:Bacteroidetes / Q000235:genetics*; D005243:Feces / Q000382:microbiology*; D005602:France; D005819:Genetic Markers / Q000235:genetics*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D025341:Principal Component Analysis; D012317:RNA Phages / Q000235:genetics*; D011891:Rain; D045483:Rivers / Q000382:microbiology*; D054712:Salinity; D012680:Sensitivity and Specificity; D013696:Temperature; D014871:Water Microbiology; D014873:Water Pollutants / Q000032:analysis*; D060753:Water Quality / Q000592:standards
chemical_list: D005819:Genetic Markers; D014873:Water Pollutants