Microplastics and antimicrobial resistance: A growing threat to aquatic health, food safety, and the one health framework.

Microplastics (MPs), defined as plastic particles <5 mm, are emerging contaminants in aquatic ecosystems with serious implications for aquaculture. Originating from degraded plastics, MPs enter aquaculture systems via feed, equipment, water, and runoff. Once present, they cause physiological harm to aquatic organisms, triggering oxidative stress, inflammation, and intestinal damage. MPs also serve as substrates for biofilm formation, enabling the persistence of pathogens and facilitating horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs). This accelerates antimicrobial resistance (AMR), threatening fish health, food safety, and the One Health framework. This review synthesizes current knowledge on MPs in freshwater and marine systems, their role in bio-corona (BC) formation and quorum sensing (QS), and their function as ARG vectors. It highlights the link between aquaculture-associated MPs and antibiotic-resistant bacteria (ARBs), stressing the need for sustainable feed, biodegradable materials, and improved waste management. Existing regulatory frameworks are insufficient, but emerging solutions such as enzyme-mediated bioremediation and biofilm disruption offer promise. An integrated, interdisciplinary approach is urgently needed to mitigate MP pollution, protect aquatic biodiversity, and ensure the long-term sustainability of aquaculture.