Antibiotics | Plastic Waste Promotes Enrichment of Antibiotic Resistance Genes in Aquatic Environments

This study reveals how plastic waste promotes the enrichment of antibiotic resistance genes (ARGs) in aquatic environments and discusses its potential impact on aquatic organisms and seafood safety. The research also evaluates the effects of different plastic types on ARG levels, providing new insights into the environmental risks of plastic pollution and ARG dissemination.

 

Literature Overview
This article, titled 'Enrichment of Antibiotic Resistance Genes on Plastic Waste in Aquatic Ecosystems, Aquatic Animals, and Fishery Products', published in the journal Antibiotics, reviews and summarizes the association between plastic waste and antibiotic resistance genes (ARGs) in aquatic environments. The article highlights that the biofilms formed on plastic debris surfaces, known as plastispheres, provide an ideal environment for the proliferation of antibiotic-resistant bacteria (ARB) and horizontal gene transfer (HGT) of ARGs. Furthermore, after aquatic animals ingest microplastics, ARGs can become enriched and potentially enter the human body through the food chain, posing public health risks.

Background Knowledge
Antimicrobial resistance (AMR) has become a global health crisis, with its spread closely linked to environmental factors. Aquatic ecosystems serve as significant reservoirs for ARGs, and the widespread presence of plastic waste exacerbates this issue. Microplastics (MPs), nanoplastics (NPs), and macroplastics can influence ARG dynamics by adsorbing antibiotics and promoting bacterial biofilm formation. In particular, biofilms formed on plastic surfaces provide a high-density microbial environment for gene transfer, facilitating the spread of resistance genes through natural transformation, conjugation, and transduction. Additionally, the type, aging, and surface characteristics of plastics affect their capacity for ARG enrichment. The study emphasizes the importance of reducing plastic pollution in water bodies to mitigate ARG dissemination and calls for further research into the interaction mechanisms between plastic pollution and AMR to develop effective prevention and control strategies.

 

 

Research Methods and Experiments
The study systematically reviewed the literature to analyze the impact of plastic waste on ARG enrichment in freshwater, marine, and aquaculture systems. Researchers employed various experimental approaches, including co-culturing microplastics (MPs) with bacteria, quantifying ARG abundance via qPCR, analyzing microbial community structures using high-throughput sequencing, and conducting molecular dynamics simulations to study antibiotic-plastic interactions. Additionally, the effects of plastic particle types (e.g., PE, PP, PS, PVC) and aging treatments (e.g., UV exposure, oxidation) on ARG levels were assessed, with machine learning methods applied to predict antibiotic adsorption characteristics.

Key Conclusions and Perspectives

• The biofilm (plastisphere) formed on microplastic surfaces exhibits higher ARG abundance compared to surrounding water and natural solid substrates (e.g., sand, rocks).
• Microplastics (especially PE and PP) facilitate horizontal gene transfer of antibiotic resistance genes in freshwater and marine environments, particularly linked to surface aging and increased roughness.
• Co-exposure to microplastics and antibiotics significantly increases ARG expression in aquatic animals such as fish and shellfish.
• During biofilm formation, the ecocorona on plastic surfaces promotes microbial colonization and enhances the spread of antibiotic resistance genes.
• The ability of microplastics to adsorb antibiotics is closely related to plastic type, environmental pH, electrolyte levels, and dissolved organic matter content.
• In laboratory simulations, polypropylene (PP) and polystyrene (PS) microplastics promoted plasmid-mediated ARG transfer, particularly evident on aged plastic particles.
• The aging process of microplastics in aquatic environments (e.g., UV radiation, mechanical shear) enhances their capacity for antibiotic resistance gene adsorption and transfer efficiency.
• Both microplastics and nanoplastics (NPs) significantly influence ARG expression in aquatic systems, with polylactic acid (PLA) microplastics showing the strongest enrichment effect on ARGs.
• Microplastics more readily promote ARG dissemination in freshwater compared to marine environments, potentially related to plastic surface charge and environmental ionic strength.
• The size, shape, and surface chemical properties of microplastics affect their capacity for ARG enrichment, with smaller particles showing a higher surface-to-volume ratio, thereby enhancing ARG adsorption.

Research Significance and Prospects
The study highlights the complex relationship between plastic pollution and the spread of antibiotic resistance genes, emphasizing the influence of plastic types, environmental conditions, and microbial communities on ARG enrichment. Future research should focus on quantitatively evaluating the impact of microplastics on ARG dissemination in diverse aquatic ecosystems and integrate ecotoxicological and epidemiological approaches to explore specific health risks associated with plastic pollution. Moreover, investigating the interactions between plastic aging, microbial community succession, and ARG transfer mechanisms will aid in formulating more effective pollution control strategies.

 

 

Conclusion
Plastic waste in aquatic ecosystems promotes the enrichment and horizontal transfer of antibiotic resistance genes (ARGs) through the formation of biofilms (plastispheres), affecting the safety of aquatic organisms and seafood products. This study systematically analyzed the effects of microplastics (MPs), nanoplastics (NPs), and macroplastics on ARG dynamics in freshwater, marine, and aquaculture environments, revealing significant differences among plastic types in terms of antibiotic adsorption and gene transfer capabilities. Notably, polypropylene (PP) and polylactic acid (PLA) microplastics exhibited the strongest ARG enrichment, while polyvinyl chloride (PVC) microplastics enhanced ARG persistence. The findings indicate that plastic pollution not only impacts ecosystem health but may also amplify the global public health crisis of antimicrobial resistance via the food chain. Therefore, reducing plastic pollution in water bodies, monitoring plastic-associated ARG dissemination pathways, and developing plastic degradation technologies are crucial measures to curb the spread of antibiotic resistance.

 

Franca Rossi, Serena Santonicola, and Giampaolo Colavita. Enrichment of Antibiotic Resistance Genes on Plastic Waste in Aquatic Ecosystems, Aquatic Animals, and Fishery Products. Antibiotics.