Environmental drivers of antibiotic resistance: Synergistic effects of climate change, co-pollutants, and microplastics
Maryam Zarean, Sejal H. Dave, Satinder Kaur Brar, Raymond W. M. Kwong
Abstract
Antimicrobial resistance (AMR) is an urgent global health concern, increasingly driven by environmental factors such as climate change, chemical co-pollutants, and microplastics (MPs). MPs, synthetic particles smaller than 5 mm, facilitate the spread of antibiotic resistance genes (ARGs) by providing surfaces for biofilm development and concentrating pollutants like antibiotics and heavy metals. The interplay among these environmental stressors intensifies under the influence of climate change, which exacerbates ARG proliferation through elevated temperatures, extreme weather events, and enhanced horizontal gene transfer (HGT). The seasonal and pollutant-induced mechanisms of ARG proliferation underscore the intricate interaction of environmental factors, particularly in hotspots such as wastewater treatment plants. Key drivers of ARG enrichment includes antibiotics, heavy metals, organic pollutants (e.g., pesticides, non-antibiotic pharmaceuticals, etc.), and MPs. They contribute to resistance proliferation through synergistic mechanisms such as co-resistance, cross-resistance, and enhanced HGT. Aging MPs, enriched by biofilm formation, amplify their pollutant adsorption capacities and modulate ARG dynamics in polluted environments. This review examines the complex synergies among environmental drivers of antibiotic resistance, highlighting their collective and individual contributions to ARG proliferation. It integrates knowledge of ARG dynamics in ecosystems and assesses associated public health risks, such as pathogen dissemination, biofilm-mediated resistance transfer, and ecological disturbances. Addressing these challenges requires integrating advanced wastewater treatment technologies with innovative therapeutics, such as next-generation antibiotics and bacteriophage therapy while targeting mobile genetic elements. Prioritizing cost-effective, scalable, and site-specific solutions is essential to mitigate the global AMR crisis.