Microplastics, Nanoplastics and Nanoparticles: Emerging Dynamic Carriers of Extracellular DNA Antibiotic Resistance Genes in the Environment

Antibiotics and heavy metals contribute to antimicrobial resistance (AMR) selection and propagation, but it has not been well examined how microplastics (MPs), nanoplastics (NPs), and engineered nanoparticles (ENPs) contribute to antibiotic resistance genes (ARGs) spread via extracellular DNA (eDNA) in the environment. An increasing body of research, however, suggests that MPs, NPs, and ENPs could play a more significant role in propagating extracellular antibiotic resistance genes (eARGs) via eDNA. The fate of eDNA may be affected by MPs/NPs and ENPs detected in aquatic environments. As a result, MPs/NPs and ENPs can serve as carriers of ARGs, allowing them to be transported between bacteria, and they can act as vehicles for eDNA transfer. With the coexistence of intracellular DNA (iDNA) and intracellular ARGs (iARGs) and eDNA/eARGs with MPs/NPs and ENPs, it is more critical now than ever to understand how these pollutants influence ARG environmental fate. In this review, we discuss how MPs/NPs, their biofilms, and ENPs spread ARGs via eDNA in the environment and their potential impacts over time. Additionally, the main mechanisms by which eDNA interacts with MPs/NPs and ENPs in ARG evolution were discussed. The gap in knowledge in this particular area was proposed as a prospective research topic for understanding AMR spread through emerging pollutants. Furthermore, the review emphasizes that by aligning with one health perspective, MPs/NPs and ENPs may potentially contribute to the spread of environmental antibiotic resistance. Therefore, developing mitigation strategies to reduce the release of MPs, NPs, and ENPs into the environment is crucial. This can help minimize the dissemination of ARGs via eDNA. Some examples of such strategies include improving wastewater treatment systems, controlling sewage release, and regulating the use of agricultural chemicals.