Effects of microplastic concentration, composition, and size on Escherichia coli biofilm-associated antimicrobial resistance

ABSTRACT Microplastics (MPs) have emerged as a significant environmental pollutant with profound implications for public health, particularly as substrates to facilitate bacterial antimicrobial resistance (AMR). Recently, studies have shown that MPs may accommodate biofilm communities, chemical contaminants, and genetic material containing AMR genes. This study investigated the effects of MP concentration, composition, and size on the development of multidrug resistance in Escherichia coli . Specifically, we exposed E. coli to varying concentrations of different MP types, including polyethylene, polystyrene, and polypropylene, across a range of sizes (3–10, 10–50, and 500 µm). Results indicated that the…