Relevance of Bacteroidales and F-specific RNA bacteriophages for efficient fecal contamination tracking at the level of a catchment in France

Appl Environ Microbiol. 2012 Aug;78(15):5143-52. doi: 10.1128/AEM.00315-12. Epub 2012 May 18.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacteroidetes / genetics*
  • Feces / microbiology*
  • France
  • Genetic Markers / genetics*
  • Humans
  • Hydrogen-Ion Concentration
  • Principal Component Analysis
  • RNA Phages / genetics*
  • Rain
  • Rivers / microbiology*
  • Salinity
  • Sensitivity and Specificity
  • Temperature
  • Water Microbiology*
  • Water Pollutants / analysis*
  • Water Quality / standards

Substances

  • Genetic Markers
  • Water Pollutants