Hunan Province Key Laboratory of Rare Metal Mineral Exploitation and Geological Disposal of Wastes,University of South China
Hunan Province Key Laboratory of Pollution Controland Resources Reuse Technology, University of South China
School of Civil Engineering, University of South China

细菌抗生素抗性基因(ARGs)与微/纳米塑料(MPs/NPs)作为新兴污染物,其复合污染逐渐成为环境领域研究的前沿热点。MPs/NPs被认为是ARGs在环境介质中增殖与传播的关键影响因素之一,但其对ARGs水平转移(尤其是转化)的影响机制研究仍较为有限。本研究通过构建耐药质粒pUC19转化体系,揭示不同浓度和尺寸聚苯乙烯(PS)MPs/NPs胁迫下大肠杆菌(E.coli)中ARGs的水平转移规律。结果表明,5mg/L100μm、50mg/L100μm、5mg/L100nm和50mg/L100nmPS暴露后,大肠杆菌的生长抑制率分别达到15.13%、18.59%、26.97%和35.84%(p<0.01),说明PS对大肠杆菌生长抑制作用与浓度成正比,与尺寸成反比。此外,PSMPs(浓度≤5mg/L)和PSNPs(浓度≤50mg/L)冲击会显著促进ARGs的转化过程,且具有浓度依赖性。在同种浓度下,ARGs转化频率随着PS冲击尺寸的增大而减小。其中,100nmPS(50mg/L)对ARGs转化频率的影响最大(增加79.34%)。然而,经过1mmPS(50mg/L)冲击后,ARGs转化频率降低了21.80%,说明高浓度1mmPS冲击抑制了ARGs的转化过程。此外,通过活/死细胞检测分析发现,大肠杆菌细胞膜通透性随着PS浓度的增加持续显著增加(较对照组增加了56.66%~69.47%)。在同浓度条件下,PS尺寸越小细胞膜通透性越高。与PSMPs相似,PSNPs使细胞膜通透性增加了41.99%~46.62%。这说明高浓度PSNPs冲击会通过增强E.coli细胞膜通透性促进ARGs的转化。研究结果阐明了MPs/NPs对ARGs转化的影响机制,为处理ARGs和MPs/NPs复合污染高效控制策略提供了理论依据和技术指导。

As emerging environmental pollutants, antibiotic resistance genes (ARGs) andmicro/nanoplastics (MPs/NPs) have been detected in various environmental media worldwide. Due totheir small size and large surface area, MPs/NPs possess significant potential to act as carriers of ARGs.As such, the combined pollution of ARGs and MPs/NPs has attracted widespread attention due to theirpotential synergistic effects. Although MPs/NPs are considered key factors in the spread of ARGs inenvironmental media, knowledge of the effects and mechanisms of MPs/NPs on the horizontal transfer(particularly the transformation process) of ARGs in Escherichia coli (E. coli) is still largely limited. Tobridge this knowledge gap, this study investigated the effects of different concentrations and sizes ofpolystyrene (PS) on the horizontal transfer of ARGs. We constructed a plasmid-mediatedtransformation system using the antibiotic-resistant plasmid pUC19 as donor and E. coli as recipientbacteria. Our results showed that after exposure to 5 mg/L 100 μm, 50 mg/L 100 μm, 5 mg/L 100 nm,and 50 mg/L 100 nm PS, the growth inhibition rates of E. coli reached 15.13%, 18.59%, 26.97%, and35.84%, respectively (p < 0.01). In addition, the impact of PS MPs (≤ 5 mg/L) and PS NPs (≤ 50mg/L) could significantly promote the transformation process of ARGs in a concentration-dependentmanner. Under the same PS concentration, the ARGs transformation frequency decreased withincreasing PS particle size. Specifically, 100 nm PS at 50 mg/L increased the transfer frequency by79.34%. However, 1 mm PS particles at 50 mg/L resulted in a 21.80% decrease in the ARGstransformation frequency, suggesting that 1 mm PS particles at this concentration inhibit ARGs transfer.Based on the live/dead cell detection, we revealed that, with increasing PS concentration, cell membranepermeability in E. coli significantly increased by 56.66% to 69.47% compared to the control group.Under the condition of the same PS concentration, the cell membrane permeability rises as the PS sizediminishes, implying a negative correlation between them. Similarly, the cell membrane permeability inNPs exposure was increased by 41.99% to 46.62%. These results demonstrated that high concentrationsof NPs might enhance the cell membrane permeability in E. coli, thus facilitating the horizontal transferof ARGs. Our findings elucidated the influence mechanism of MPs/NPs on the transformation of ARGs,providing a theoretical basis and technical guidance for the efficient assessments and control ofcombined ARGs and MPs/NPs pollution.

湖南省自然科学基金资助项目(2024JJ5329);南华大学研究生科研创新资助项目(233YXC004)

唐振平,龚子璇,刘博阳,等.聚苯乙烯微(纳)塑料对抗生素抗性基因转移的影响及其机制[J].能源环境保护,2025,39(1):165−172.

TANG Zhenping, GONG Zixuan , LIU Boyang , et al. Influence and Mechanisms of Polystyrene Micro/Nanoplastics on the Transfer of Antibiotic Resistance Genes[J]. Energy Environmental Protection, 2025 ,39(1): 165−172.