UH: Drug-resistant pathogen spread studied in waterways

New groundbreaking research aims to evaluate potential human health risks from bacteria in surface water systems across four US states. The project involving the University of Hawaiʻi at Mānoa will assess the environmental spread of antimicrobial-resistant pathogens—disease-causing microorganisms that have evolved to withstand the effects of antibiotics and other medicines designed to kill them—through wastewater discharge and agricultural runoff.

The three-year study recently received a $2.4 million grant from the Environmental Protection Agency.

“Hawaiʻi’s unique combination of cesspools and agricultural runoff flowing into our watersheds presents distinct challenges for antimicrobial resistance spread that we need to understand better,” said Tao Yan, director of the UH Mānoa Water Resources Research Center and professor in the UH Mānoa Department of Civil and Environmental Engineering. “This study will help us develop targeted strategies to protect our communities and the pristine water resources that are so vital to our island ecosystems.”

UH Mānoa researchers will focus on Kauaʻi’s Hanalei River, where they will examine how cesspools and animal agriculture contribute to the spread of antimicrobial resistance. The river system in Hawaiʻi, along with waterways in Nebraska, New Jersey and California, were selected to represent diverse environmental conditions and pollution sources.

The study addresses growing concerns about antimicrobial resistance spreading beyond clinical settings. While wastewater treatment plants effectively remove many pollutants, they may inadvertently introduce to the environment antimicrobial-resistant bacteria and genes through effluent discharge into rivers and streams.

The research team will employ advanced shotgun metagenomic sequencing—breaking down all DNA from a sample and analyzing the pieces to identify every organism—to identify and track antimicrobial resistance genes from various sources. Environmental engineers will develop predictive models to understand how these resistant bacteria and genes proliferate in different environments.

A key outcome of the study will be the development of a risk assessment tool enabling stakeholders to better understand the health threats posed by antimicrobial-resistant bacteria in their water systems. This information could help water managers and policymakers implement measures to reduce human exposure to these contaminants.

The study is led by the University of Nebraska-Lincoln, and includes expertise from Rutgers University, the University of California Riverside and Iowa State University.