Environmental antimicrobial resistance is increasingly turning natural environments such as rivers, soils, and air into pathways for the spread of drug-resistant bacteria, according to a recent review. The study highlights that protecting people from drug-resistant infections now requires attention not only in hospitals but also in wastewater treatment plants and farms.
Antimicrobial resistance (AMR) occurs when bacteria and other microbes develop the ability to survive medicines designed to kill them. This makes common infections more difficult or impossible to treat. The World Health Organization has identified AMR as one of the most serious global health threats of this century, with projections indicating tens of millions of potential deaths and significant economic losses if action is not taken.
The review finds that the environment plays an active role in spreading resistance. Resistance genes and bacteria can move between wildlife, livestock, and humans through rivers, lakes, soils, oceans, and even the air. These environmental "hotspots" enable resistance genes to travel on mobile genetic elements like plasmids, which allow bacteria to exchange resistance traits and form multidrug-resistant strains.
Current surveillance efforts focus mainly on clinical samples. However, many environmental bacteria are difficult to grow in laboratories using traditional culture-based methods, leading to underestimation of existing resistance. New technologies are helping researchers better understand how resistance spreads outside clinical settings.
"The message is clear," said lead author Huilin Zhang. "No single method can capture the full story of environmental resistance. What we need is integrated surveillance that links what bacteria can do to what genes they carry, and where they are spreading."
The study adopts a One Health approach that recognizes the interconnectedness of human, animal, and environmental health. The authors recommend addressing AMR through both source control—reducing antibiotics and resistant organisms entering the environment—and process control—intercepting these agents via improved waste management systems.
Suggested source control measures include stricter antibiotic use policies in healthcare and agriculture sectors, stronger regulations especially in low- and middle-income regions, cleaner pharmaceutical production processes, enhanced biodegradation techniques for antibiotics, development of more biodegradable drugs, and exploration of alternative antimicrobials such as peptides or phages.
For process control at critical points like wastewater treatment facilities, advanced methods including hyperthermophilic composting, advanced oxidation processes, membrane filtration technologies, nanomaterials applications, bacteriophage treatments, engineered DNA-scavenging bacteria solutions, and CRISPR-based tools show promise but need further research regarding safety and cost-effectiveness.
Rather than simply counting resistance genes present in environments worldwide, the authors argue for prioritizing monitoring those traits that pose real risks to human health: mobility among bacterial populations; presence within pathogenic organisms; and evolution within real-world ecosystems.
"Environmental AMR is not just about how many resistance genes we can find," said corresponding author Feng Ju. "What matters most is which genes are mobile, which pathogens carry them, and how they evolve in real world ecosystems. That is where surveillance must focus, and where mitigation will have the biggest impact."
The authors call for international adoption of standardized protocols so that data collected on environmental AMR will be comparable across countries over time. They warn that without these standards it will be challenging to detect new threats early enough or design effective interventions under a One Health framework aimed at protecting both public health and ecosystems.
