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Sources of Antibiotic Resistance Genes in a Rural River System
Author(s) -
McConnell Mandy M.,
Hansen Lisbeth Truelstrup,
Neudorf Kara D.,
Hayward Jenny L.,
Jamieson Rob C.,
Yost Chris K.,
Tong Anthony
Publication year - 2018
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2017.12.0477
Subject(s) - watershed , wastewater , fecal coliform , antibiotic resistance , sewage treatment , antibiotics , resistance (ecology) , feces , environmental science , biology , veterinary medicine , ecology , microbiology and biotechnology , environmental engineering , water quality , medicine , machine learning , computer science
The increasing prevalence of antibiotic resistance genes (ARGs) in the environment is problematic due to the risk of horizontal gene transfer and development of antibiotic resistant pathogenic bacteria. Using a suite of monitoring tools, this study aimed to investigate the sources of ARGs in a rural river system in Nova Scotia, Canada. The monitoring program specifically focused on the relative contribution of ARGs from a single tertiary‐level wastewater treatment plant (WWTP) in comparison to contributions from the upgradient rural, sparsely developed, watershed. The overall gene concentration significantly ( p < 0.05) increased downstream from the WWTP, suggesting that tertiary‐level treatment still contributes ARGs to the environment. As a general trend, ARG concentrations upstream were found to decrease as proximity to human‐impacted areas decreased; however, many ARGs remained above detection limits in headwater river samples, which suggested their ubiquitous presence in this watershed in the absence of obvious pollution sources. Significant correlations with ARGs were found for HF183 human fecal marker, Escherichia coli, and some antibiotics, suggesting that these markers may be useful for prediction and understanding of ARG levels and sources in rural rivers. Core Ideas Tertiary wastewater treatment contributed antibiotic resistance genes (ARGs) to the river. ARG levels decreased as proximity to anthropogenic influence decreased. ARGs were observed at detectable levels even in undeveloped headwaters. High flow conditions correlated to high ARG loading in the river. Positive correlations were found between ARGs and fecal indicators.