Microplastics (MPs) provide a stable and protective habitat for diverse wastewater bacteria, including pathogenic and antibiotic-resistant species. Therefore, MPs may potentially transport these bacteria through wastewater treatment steps to the environment and far distances. This study investigated bacterial communities of MP-associated bacteria from different stages of municipal wastewater treatment processes to evaluate the potential negative effect of these biofilms on the environment. The results showed a high diversity of bacteria that were strongly attached to MPs. After all treatment steps, the core bacterial groups remained attached to MPs and escaped from the wastewater treatment plant with effluent water. Several pathogenic bacteria were identified in MP samples from all treatment steps, and most of them were found in effluent water. These data provide new insights into the possible impacts of wastewater-derived MPs on the environment. MP-associated biofilms were proved to be important sources of pathogens and antibiotic-resistant genes in natural waters.

微塑料 (MPs) 为各种废水细菌提供了稳定和保护性的栖息地，包括致病性和抗生素抗性物种。因此，MP 可能通过废水处理步骤将这些细菌运输到环境和远距离。本研究调查了来自市政废水处理过程不同阶段的 MP 相关细菌的细菌群落，以评估这些生物膜对环境的潜在负面影响。结果表明，与 MPs 紧密相连的细菌种类繁多。在所有处理步骤之后，核心细菌群仍然附着在 MPs 上，并随废水从废水处理厂逸出。在所有处理步骤的 MP 样品中鉴定出几种病原菌，其中大部分存在于出水中。这些数据为废水衍生的 MPs 对环境可能产生的影响提供了新的见解。MP 相关的生物膜被证明是天然水域中病原体和抗生素抗性基因的重要来源。