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Can Human Associated Bacteroides (HF183MGB) be used as a Pathogen Predictor in Urban Watersheds?
Citation:
Snyder, B., M. Molina, O. Georgacopoulous, AND S. Dye. Can Human Associated Bacteroides (HF183MGB) be used as a Pathogen Predictor in Urban Watersheds? ISME 16, Montreal, CANADA, August 21 - 26, 2016.
Impact/Purpose:
To be presented at the 16th International Symposium on Microbial Ecology
Description:
The fate and transport dynamics of fecal indicators and pathogenic microorganisms are poorly characterized in urban watersheds. Moreover, very little is understood about the actual relationship between fecal indicator bacteria (FIB) and the risk to public health. In this study we focused on understanding the behavior of a human-associated Bacteroides marker (HF183MGB) in relation to the presence of E. coli and selected waterborne pathogens and toxins (Salmonella sp. and Shiga-toxin (Stx2)) in a highly urbanized watershed. The Proctor Creek watershed, in downtown Atlanta, Georgia, U.S.A. is listed on the Environmental Protection Agency’s (EPA) 303(d) impaired waters list due to failing fecal coliforms standards. Water grab samples were collected every two weeks at 12 locations throughout the watershed. Average culturable E. coli was high throughout the watershed; ranging from 369 – 30,124 MPN/100 mL. HF183MGB was present at 11 out of 12 sites, ranging from 15,325 – 8,257,914 gene copies (GC)/100 mL and exhibited a significant correlation with culturable (r2=0.89) and molecular (r2=0.90) signals of E. coli. In contrast to the widespread distribution of HF183MGB, Salmonella and Stx2 were present in 50 and 42% of the sites, respectively. These pathogens were largely found in locations impacted by a high density of storm water inlets and outfalls, regardless of the presence of HF183MGB. Results indicate that human fecal contamination is present and widespread throughout the watershed but the lack of correlation between Salmonella/Stx2 and HF183MGB suggests that other sources are contributing to the presence of these pathogens in the watershed.
