The plastisphere paradox: microplastics as engines of antimicrobial resistance and hosts for polymer degraders

Microplastics (MPs) have emerged as serious ecological pollutants that harbor diverse microbial communities in their biofilm ecosystem termed as plastisphere. This community serves as a reservoir for antibiotic resistance genes (ARGs), antimicrobial resistant bacteria (ARB) as well as other microorganisms involved in pollutant degradation. However, the dynamic interactions between antimicrobial resistance (AMR) and bioremediation in the plastisphere community are not well deciphered. This review examines the dual role of MPs as ARG vectors as well as emerging platforms for microplastic and other pollutant bioremediation. Plastisphere biofilms act as a hub for horizontal gene transfer (HGT), driven by active microbial interfaces, extracellular polymeric matrices, and co-selection pressures exerted due to antibiotics, heavy metals, and biocides. Metagenomics and metatranscriptomics approaches reveal the cohabitation of functional genes associated with both AMR and microplastic degradation, mediated by enzymes and multifunctional molecules such as biosurfactants. However, bioaugmentation using plastisphere derived microbial population risks HGT of ARGs or virulence factors to non-native and indigenous microorganisms. Hence, such applications call for stringent biosafety assessments to prevent inadvertent and unwanted ARG dissemination. By integrating ecological perils with advanced biotechnological opportunities, this review underlines the plastisphere paradox and highlights the demand for multiomics-driven One Health approaches to bring forth the interconnected challenges of MPs pollution, AMR, and bioremediation. This exploration yields promising avenues for developing integrated strategies that can address both persistent microplastic pollution and AMR spread concomitantly.