Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Weigang Road 1, Nanjing 210095, P.R. China.
Environ Sci Technol. 2022 Nov 1;56(21):14948-14959. doi: 10.1021/acs.est.2c00745. Epub 2022 May 3.
Plastic particles impact the propagation of antibiotic resistance genes (ARGs) in environmental media, and their perturbation on the horizontal gene transfer (HGT) of ARGs is recognized as a critical influencing mechanism. However, studies concerning the influence and influencing mechanisms of plastic particles on the HGT of ARGs were limited, particularly for the effect of particle sizes and ARG vector-associated mechanisms. This study explored the impact of polystyrene (PS) particles with sizes of 75, 90, 100, 1000, and 10000 nm on the HGT (via transformation) of ARGs mediated by pUC19, pSTV29, and pBR322 plasmids into cells. PS particles with sizes ≤100 nm impacted the transformation of ARGs, but large particles (1000 and 10000 nm) showed no obvious effects. Effects of PS particles on the transfer of three plasmids were vastly distinct. For pUC19 with high replication capacities, the transfer was monotonously promoted. However, for pSTV29 and pBR322 with low replication capacities, suppressing effects were observed. This was attributed to two competing mechanisms. The enhancing mechanism was that the direct interaction of PS particles with membrane lipids and the indirect effect associated with bacterial oxidative stress response induced pore formation on the cell membrane and increased membrane permeability, thus enhancing plasmid entrance. The inhibiting mechanism was that PS particles interfered with plasmid replication inside , thus decreasing the bacterial tranformation. This study deepened our understanding of the environmental dissemination of ARGs in plastic contamination.
塑料颗粒会影响环境介质中抗生素抗性基因（ARGs）的传播，其对 ARGs 水平基因转移（HGT）的干扰被认为是一个关键的影响机制。然而，关于塑料颗粒对 ARGs 水平基因转移的影响及其影响机制的研究还很有限，特别是关于颗粒大小和 ARG 载体相关机制的影响。本研究探讨了不同尺寸（75、90、100、1000 和 10000nm）的聚苯乙烯（PS）颗粒对 pUC19、pSTV29 和 pBR322 质粒介导的 ARGs （通过转化）进入 细胞内的 HGT 的影响。尺寸≤100nm 的 PS 颗粒会影响 ARGs 的转化，但大颗粒（1000 和 10000nm）则没有明显的影响。PS 颗粒对三种质粒的转移影响有很大的差异。对于复制能力较高的 pUC19，转移是单调促进的。然而，对于复制能力较低的 pSTV29 和 pBR322，观察到抑制作用。这归因于两种竞争机制。增强机制是 PS 颗粒与膜脂质的直接相互作用以及与细菌氧化应激反应相关的间接作用诱导细胞膜上形成孔，增加了膜的通透性，从而增强了质粒的进入。抑制机制是 PS 颗粒干扰了 细胞内的质粒复制，从而降低了细菌的转化。本研究加深了我们对塑料污染中 ARGs 在环境中传播的理解。
