School of Environment and Energy, Guangzhou Higher Education Mega Centre, South China University of Technology, Guangzhou, 510006, People's Republic of China.
The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, People's Republic of China.
Appl Microbiol Biotechnol. 2022 Sep;106(17):5771-5783. doi: 10.1007/s00253-022-12075-x. Epub 2022 Jul 22.
The emergence and spread of antibiotic resistance genes (ARGs) induced by the overuse of antibiotics has become a serious threat to public health. Heavy metals will bring longer-term selection pressure to ARGs when the concentration of their residues is higher than that of antibiotics in environmental media. To explore the potential roles of montmorillonite (Mt) in the emergence of ARGs under divalent cadmium ion (Cd) stress, Escherichia coli (E. coli) was induced continuously for 15 days under Cd gradient concentrations (16, 32, 64, 96, and 128 μg∙mL) with and without Mt. Subsequently, antibiotic resistance testing, transcriptomics, transmission electron microscope, scanning electron microscopy, and Fourier transform infrared were conducted for analysis. The results of characterization analysis showed that Cdcould enhance the expression of resistance genes such as penicillin, tetracycline, macrolactone, and chloramphenicol in E. coli. Moreover, compared with Cd, Mt-Cd could inhibit the promotion of these resistances by alleviating the expressions of genes involved in cell wall/membrane, protein synthesis, transport systems, signal transduction, and energy supply processes. Therefore, the study promoted the understanding of Cd in triggering bacterial antibiotic resistance and highlighted a novel theme of clay's ability to mitigate ecological risk of antibiotic resistance caused by heavy metals. KEY POINTS: • Montmorillonite (Mt) could inhibit the promotion of antibiotic resistances. • E. coli formed a unique resistance mechanism by interacting with Mt and Cd. • Mt stimulated cellular signal transduction, cellular component, and energy supply.
抗生素的过度使用导致抗生素耐药基因（ARGs）的出现和传播，对公共卫生构成了严重威胁。当重金属残留浓度高于环境介质中的抗生素浓度时，会对 ARGs 带来更长时间的选择压力。为了探索在二价镉离子（Cd）胁迫下蒙脱石（Mt）在 ARGs 出现中的潜在作用，用和不用 Mt 连续 15 天在 Cd 浓度梯度（16、32、64、96 和 128μg·mL）下诱导大肠杆菌（E. coli）。随后，进行抗生素耐药性测试、转录组学、透射电子显微镜、扫描电子显微镜和傅里叶变换红外分析。表征分析结果表明，Cdcould 增强青霉素、四环素、大环内酯和氯霉素等耐药基因在 E. coli 中的表达。此外，与 Cd 相比，Mt-Cd 通过减轻参与细胞壁/膜、蛋白质合成、运输系统、信号转导和能量供应过程的基因表达，抑制了这些耐药性的促进作用。因此，该研究促进了对抗生素耐药性的触发的理解，并强调了粘土减轻重金属引起的抗生素耐药性生态风险的能力的新主题。关键点：
• 蒙脱石（Mt）可以抑制抗生素耐药性的增强。
• E. coli 通过与 Mt 和 Cd 相互作用形成独特的耐药机制。
• Mt 刺激细胞信号转导、细胞成分和能量供应。
