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EPA Research on Antibiotic Resistance and Wastewater: A One Health Approach
Citation:
Azzam, K. EPA Research on Antibiotic Resistance and Wastewater: A One Health Approach. U.S. Environmental Protection Agency, Washington, DC, EPA/600/S-24/191, 2024.
Impact/Purpose:
An update to this graphic has been made; see https://cfpub.epa.gov/si/si_public_record_Report.cfm?dirEntryId=365282&Lab=CEMM. This summary graphic highlights the environmental aspects of antibiotic resistance with a focus on water, and is part of a larger One Health project entitled "EPA Research on Antimicrobial Resistance (AMR) in Wastewater". Antibiotic resistant bacteria and their genes are found in streams, rivers, lakes, and oceans, and are frequently traced back to discharge flowing from farms or sewage systems. Wastewater treatment plants may not fully remove resistant pathogens and their genes, and may serve as a reservoir for gene exchange. This graphic has been presented internally and will continue to be presented both internally and externally; it is also a figure in a planned report, and will likely be used for the generation of a One Health EPA AMR website. It has a more narrowed scope than that of AMR, so that all the published primary EPA Research on "Antibiotic Resistance and Wastewater" could be included. However, the plan is for it to remain dynamic, allowing for later inclusion of more research as it's published - placeholders have been secured for ongoing research on ARGs in harmful algal blooms and drinking water treatment plants. Internal EPA AMR researchers may learn of shared connections depicted on this graphic, fostering collaboration. Federal interagency partners, such as the One Health Federal Interagency Coordination (OH-FICC), CDC, or US One Health Coordination Unit (OHCU) may also be interested in this work as the EPA continues to develop their role as a One Health agency contributing to AMR research.
Description:
This is a visual depiction of most, if not all, of the published primary EPA research involving antibiotic resistant bacteria (ARBs) and their genes (ARGs) as well as antibiotics associated with antimicrobial resistance (AMR) in wastewater. The corresponding list of publication citations -with EPA authors underlined- follows the waterways starting from the bottom left corner of the graphic. EPA studies in drinking water distribution systems suggest that disinfected water concurrently enriches ARGs and metal resistance genes. Analyses of 1.2 million kilometers of US rivers and streams and metagenomic surface water studies both concluded that the human impact on antibiotic resistance genes is quantifiable, with more numbers of ARGs and more medically important ARGs found in areas of higher human activity. Food processing plants contaminate rivers and streams with antibiotics, ARGs and ARBS. Numerous studies in wastewater confirm that wastewater treatment plants (WWTPs) do not completely remove antibiotics, ARGs, or ARBs, including medically important ARBs, and the WWTP may serve as a reservoir for gene exchange and increase the risk of ARBs being distributed into the environment as well as to workers in WWTPs. Wastewater reuse studies evaluated risk associated with human exposure to ARBs within these reclaimed waters, and the fate and transport of antibiotics within soil due to wastewater reuse. Agricultural runoff produces large numbers of ARBs. ARGs associated with human pathogens have been identified in the swine gut, which has raised concerns of water safety. Both ARGs and ARBs associated with cattle were found near pastures or cattle feedlot runoff. The EPA leads research developing methods to extract antibiotics from both soil and water, as well as methods to evaluate both ARBs and ARGs in surface waters. A study of a developing karst groundwater system determined that high levels of ARGs were prevalent throughout the aquifer. The risk of human exposure to antibiotics in water has been evaluated, and a national freshwater pilot for monitoring AMR has recently been published. Model research determined that ARGs from domestic municipal waste “trash” ended up in riverbed sediment and surface water. Zoonotic enteric pathogens and ARGs in the feces of white tailed deer have been identified and the risk to water quality evaluated. In order to combat diseases such as citrus greening, the EPA regulates pesticide permits, and some of these pesticides are antibiotics such as streptomycin. Wastewater discharges to surface waters must receive a permit, so the EPA also requires certain resistance management plans associated with pesticide permits. EPA researchers have found ARBs isolated from a constructed wetland contaminated by a crow roost. They have analyzed sources and drivers of ARGs specifically in urban streams, investigated APIs, and discovered a link to the proximity of urban areas. ARBs in the biofilms of hospital shower hoses have been identified. A review of ARBs in water determined that the water column contained the highest proportion of ARBs, fish tissues and feces had the second highest, followed by sediment and sand. A study traced ARGs from domestic septic tanks to river beds and surface water. Finally, a fecal pollution assessment in an urban watershed revealed that ARGs increased after a storm event. This graphic embraces the One Health approach emphasizing the environmental aspects of AMR with a focus on wastewater.
URLs/Downloads:
EPARESEARCHONANTIBIOTICRESISTANCEANDWASTEWATERAONEHEALTHAPPROACHFINAL.PDF (PDF, 1 pp, 3220 KB, about PDF)Citations for Graphic (PDF, 2 pp, 360 KB, about PDF)