Sub-inhibitory concentrations of heavy metals facilitate the horizontal transfer of plasmid-mediated antibiotic resistance genes in water environment.
Sub-inhibitory concentrations of heavy metals facilitate the horizontal transfer of plasmid-mediated antibiotic resistance genes in water environment.
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DOI：
10.1016/j.envpol.2018.01.032
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发表时间：
2018-06
影响因子：
8.9
通讯作者：
Ye Zhang;A. Gu;Tianyu Cen;Xiangyang Li;M. He;Dan Li;Jianmin Chen
中科院分区：
文献类型：
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作者：
Ye Zhang;A. Gu;Tianyu Cen;Xiangyang Li;M. He;Dan Li;Jianmin Chen
虽然广泛的抗生素耐药性主要归因于过度使用和滥用抗生素产生的选择压力，但最近越来越多的证据表明，抗生素以外的化学物质，如某些金属，也可以通过共同耐药和交叉耐药机制选择和刺激抗生素耐药性。例如，tel、merE和oprdgenes对抗生素和金属都有耐药性。然而，在与环境相关的低浓度（远低于最低抑制浓度[mic]，也称为亚抑制浓度）下，重金属诱导的潜在新抗性几乎没有被探索过。本研究揭示了Cu（II）、Ag(I)、Cr（VI）和Zn（II）等重金属在环境相关浓度和亚抑制浓度下促进ene之间抗生素耐药基因（ARGs）的共轭转移。colistrains。进一步探讨了这一现象的机制，包括细胞内活性氧（ROS）的形成、SOS反应、细胞膜通透性增加以及偶联相关基因的表达改变。这些发现表明，广泛存在于各种环境中的亚抑制水平重金属通过促进ARGs的水平转移而促成了抗性现象。本研究从多个方面提供了低水平重金属对抗生素耐药性传播的生态效应的证据，并强调了加强有效的政策和技术控制环境中金属污染物的紧迫性。
Although widespread antibiotic resistance has been mostly attributed to the selective pressure generated by overuse and misuse of antibiotics, recent growing evidence suggests that chemicals other than antibiotics, such as certain metals, can also select and stimulate antibiotic resistance via both co-resistance and cross-resistance mechanisms. For instance,tetL,merE, andoprDgenes are resistant to both antibiotics and metals. However, the potentialde novoresistance induced by heavy metals at environmentally-relevant low concentrations (much below theminimum inhibitory concentrations [MICs], also referred as sub-inhibitory) has hardly been explored. This study investigated and revealed that heavy metals, namely Cu(II), Ag(I), Cr(VI), and Zn(II), at environmentally-relevant and sub-inhibitory concentrations, promoted conjugative transfer of antibiotic resistance genes (ARGs) betweenE. colistrains. The mechanisms of this phenomenon were further explored, which involved intracellular reactive oxygen species (ROS) formation, SOS response, increased cell membrane permeability, and altered expression of conjugation-relevant genes. These findings suggest that sub-inhibitory levels of heavy metals that widely present in various environments contribute to the resistance phenomena via facilitating horizontal transfer of ARGs. This study provides evidence from multiple aspects implicating the ecological effect of low levels of heavy metals on antibiotic resistance dissemination and highlights the urgency of strengthening efficacious policy and technology to control metal pollutants in the environments.