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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Environmentally Integrated Dairy Management Research » Research » Publications at this Location » Publication #410010

Research Project: Managing Nutrients and Assessing Pathogen Emission Risks for Sustainable Dairy Production Systems

Location: Environmentally Integrated Dairy Management Research

Title: Fecal source tracking and land use associations for antibiotic resistance genes in private wells

item STOKDYK, JOEL - Us Geological Survey (USGS)
item Burch, Tucker
item FIRNSTAHL, AARON - Us Geological Survey (USGS)
item KIEKE, BURNEY - Marshfield Clinic Research
item Cook, Rachel
item Opelt, Sarah
item Spencer, Susan
item Durso, Lisa
item Borchardt, Mark

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Antimicrobial resistance is a growing public health problem, with 2.8 million drug resistant infections in the U.S. annually. Antibiotic resistance genes (ARGs) are an emerging microbial contaminant of groundwater that originate in human and livestock fecal sources. While animal, human, and environmental components are involved, few studies address these components simultaneously. We examined ARG occurrence in private wells in Kewaunee County, where the vulnerable aquifer is influenced by two ARG sources, septic systems and manure. Samples (n = 138) were collected across 4 seasons, and ARGs were related to human wastewater and bovine manure using microbial source tracking; they were also related to land use, rainfall, geology, and well construction variables. Individual ARGs occurred in 5-40% of samples, and human and bovine fecal markers co-occurred with ARGs at similar rates. ARG detection frequencies were lowest when fecal markers were absent, intermediate when co-occurring with one marker (human or bovine), and highest when co-occurring with both human and bovine markers. ARGs were associated with septic system density more often than agricultural land, potentially because of manure’s variable presence on the landscape. By examining ARGs in a mixed land use setting, we showed that both human and bovine fecal sources contributed to ARG occurrence in wells.