Dynamics of Antimicrobial Resistant Bacteria in Water Environments: Risks via Surface Waters and Combating Strategies.

Water sustains all living systems, maintaining human, animal, and environmental health. However, as open systems, surface waters are highly exposed to microbial and chemical pollutants, including antimicrobials. These contaminants exert selective pressure on densely packed bacterial genomes and drive mutations leading to adaptation. This review explores the dynamics and key drivers underlying the emergence and persistence of antibiotic-resistant bacteria (ARB) in aquatic environments. It delineates both classical and novel horizontal gene transfer (HGT) mechanisms, ranging from conjugation, transduction, and transformation to outer membrane vesicles, gene transfer agents, and intercellular nanotubes. These mechanisms promote the evolution, distribution, and stable persistence of antibiotic resistance genes (ARGs) in aquatic systems, including freshwater sources. Furthermore, the review outlines surface water contaminants and their biomagnification risks in the environment and through the consumption of food from freshwater food webs, drinking water, and animal products. Finally, the review discusses potential mitigation strategies, highlighting advanced treatment technologies, constructed wetlands, and biocontrol approaches using aquatic macrophytes (e.g., water hyacinth), microalgae, and phage-based remediation, while addressing concerns regarding safety, applicability, and scalability. Stewardship programs aligned with One Health frameworks remain vital to mitigating these global risks.