Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, P.R. China.
Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, P.R. China.
Water Res. 2023 Oct 1;244:120520. doi: 10.1016/j.watres.2023.120520. Epub 2023 Aug 24.
Constructed wetlands (CWs) have been identified as significant sources of micro(nano)plastics (MPs/NPs) and antibiotic resistance genes (ARGs) in aquatic environments. However, little is known about the impact of MPs/NPs exposure on horizontal gene transfer (HGT) of ARGs and shaping the corresponding ARG hosts' community. Herein, the contribution of polystyrene (PS) particles (control, 4 mm, 100 μm, and 100 nm) to ARG transfer was investigated by adding an engineered fluorescent Escherichia coli harboring RP4 plasmid-encoded ARGs into CWs. It was found MPs/NPs significantly promoted ARG transfer in a size-dependent manner in each CW medium (p < 0.05). The 100 μm-sized PS exhibited the most significant promotion of ARG transfer (p < 0.05), whereas 100 nm-sized PS induced limited promotion due to its inhibitory activity on microbes. The altered RP4-carrying bacterial communities suggested that MPs/NPs, especially 100 µm-PS, could recruit pathogenic and nitrifying bacteria to acquire ARGs. The increased sharing of RP4-carrying core bacteria in CW medium further suggested that ARGs can spread into CW microbiome using MPs/NPs as carriers. Overall, our results highlight the high risks of ARG dissemination induced by MPs/NPs exposure and emphasize the need for better control of plastic disposal to prevent the potential health threats.
人工湿地（CWs）已被确定为水生环境中微（纳）塑料（MPs/NPs）和抗生素抗性基因（ARGs）的重要来源。然而，对于 MPs/NPs 暴露对 ARGs 水平基因转移（HGT）的影响以及对相应 ARG 宿主群落的塑造知之甚少。在此，通过将携带 RP4 质粒编码的 ARGs 的工程化荧光大肠杆菌添加到 CWs 中，研究了聚苯乙烯（PS）颗粒（对照、4 mm、100 μm 和 100 nm）对 ARG 转移的贡献。结果发现 MPs/NPs 以尺寸依赖的方式显著促进了每个 CW 介质中的 ARG 转移（p < 0.05）。100 μm 尺寸的 PS 表现出最显著的促进 ARG 转移（p < 0.05），而 100 nm 尺寸的 PS 由于对微生物的抑制活性而诱导的促进作用有限。携带 RP4 的细菌群落的改变表明 MPs/NPs，特别是 100 µm-PS，可以招募致病菌和硝化细菌来获得 ARGs。CW 介质中携带 RP4 的核心细菌的共享增加进一步表明，ARG 可以使用 MPs/NPs 作为载体传播到 CW 微生物组中。总体而言，我们的研究结果强调了 MPs/NPs 暴露引起的 ARG 传播的高风险，并强调需要更好地控制塑料处理，以防止潜在的健康威胁。
