Grantee Research Project Results

Quantifying Wastewater Sources of Antibiotic Resistance to Aquatic and Soil Environments and Associated Human Health Risks

EPA Grant Number: R840828
Title: Quantifying Wastewater Sources of Antibiotic Resistance to Aquatic and Soil Environments and Associated Human Health Risks
Investigators: Olabode, Lola , Pruden, Amy , Hamilton, Kerry , Garner, Emily , Harwood, Valerie J.
Institution: Water Research Foundation , Virginia Polytechnic Institute and State University , University of Arizona , West Virginia University , University of South Florida
EPA Project Officer: Packard, Benjamin H
Project Period: August 1, 2024 through April 24, 2025
Project Amount: $2,374,575
RFA: National Priorities: Evaluation of Antimicrobial Resistance in Wastewater and Sewage Sludge Treatment and Its Impact on the Environment Request for Applications (RFA) (2023) RFA Text |  Recipients Lists
Research Category: Human Health , Water , Water Treatment

Objective:

Sewage contains antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), some of which may persist, be amplified, or attenuated through wastewater treatment. To support comprehensive strategies to mitigate the spread of antimicrobial resistance (AMR), there is a need to better quantify outputs of ARB/ARGs from wastewater treatment plants (WWTPs) to the environment and to characterize potential impacts. Here we propose a comprehensive study of ARB/ARGs in WWTP effluent and biosolids, wherein we will quantify and model their fate in aquatic and soil environments. Our goal is to characterize exposure potentials and create a comprehensive risk assessment modeling framework tailored to the unique aspects of AMR and enabling the evaluation of potential mitigation options.

We will pursue five objectives: OBJ. 1. Determine ARB/ARG mass loading ranges in WWTP effluents and biosolids as a function of WWTP characteristics; OBJ. 2. Estimate the degree to which WWTP effluent and biosolid-borne ARB/ARGs attenuate or amplify in the environment and identify controlling factors; OBJ. 3. Evaluate evidence of WWTPs as a source of AMR infections in humans, relative to other sources, across a range of US communities that reflect a spectrum of wastewater management scenarios; OBJ. 4. Develop a human health risk assessment for WWTP effluent and biosolid sources of ARB/ARGs based on the knowledge gaps addressed through OBJ 1-3; OBJ. 5. Engage with stakeholders and translate the research into actionable solutions.

Approach:

We will build upon and apply our extensive database of ARB/ARG occurrence in over 100 WWTPs around the world. We will fill critical knowledge gaps to inform risk assessment through comprehensive field studies at key sites that encompass decentralized systems (Tribal lands in AZ / SD, Puerto Rico, WV), small wastewater systems with aging wastewater infrastructure (rural VA, TN), and very large cities employing advanced treatments for water reuse or discharge to sensitive fresh and salt-water ecosystems (FL, GA, CA, NV, urban VA). We will culture resistant Escherichia coli, Enterococcus spp., and Pseudomonas aeruginosa and apply whole genome sequencing to compare clinical and environmental genotypes. Metagenomic sequencing will generate comprehensive ARB/ARG profiles and identify putative dissemination and exposure hot spots.

Expected Results:

The study design will identify scenarios where AMR spread is most likely and will inform estimates of rates of amplification/attenuation of ARB/ARGs in affected soil and aquatic environments to improve exposure estimates. The AMR-tailored human health risk assessment framework will inform and prioritize management options for mitigating wastewater sources of AMR. Engagement with a diverse range of communities and the utilities that serve them will support a forum for translating the research to mitigation approaches that can help stem the spread of AMR

Supplemental Keywords:

qPCR/dPCR, microbial dose-response, spatial modeling, decision making