Heavy metal copper accelerates the conjugative transfer of antibiotic resistance genes in freshwater microcosms
Heavy metal copper accelerates the conjugative transfer of antibiotic resistance genes in freshwater microcosms
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重金属铜加速淡水微观世界中抗生素抗性基因的接合转移
DOI：
10.1016/j.scitotenv.2020.137055
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发表时间：
2020-05-15
影响因子：
9.8
通讯作者：
Luo, Yi
中科院分区：
文献类型：
--
作者：
Wang, Qing;Liu, Lei;Luo, Yi
最近的研究一直表明，在不使用抗生素的情况下，抗生素耐药基因(ARGs)的丰度不断增加。有大量的定量数据表明，在具有人为影响的环境中，ARGs水平的升高与重金属的浓度有关。然而，重金属促进ARGs在环境细菌中的增殖和水平基因转移的机制仍不清楚。本研究在淡水微宇宙中验证了四种典型重金属(铜、镉、铅、锌)对Rp4介导的Args接合转移的影响。结果表明，铜、铅、锌等典型重金属对Rp4的接合转移有促进作用，其中以铜(5.0mUg/L)促进接合转移的能力最强，是对照组的16倍。在接合转移微宇宙中，分离每个可培养接合子的种类，并通过药敏试验评估它们的最低抑菌浓度(MIC)。铜的结合转运增加的机制是铜引起细胞损伤，镉的结合转运减少的机制是镉增加了胞外聚合物的含量。本研究证实，金属铜通过细胞损伤作用促进环境介导型Rp4的接合转移，从而加速ARGs的传递和增殖。(C)2020爱思唯尔B.V.保留所有权利。
Recent studies have consistently demonstrated increasing abundances of antibiotic resistance genes (ARGs) in the absence of antibiotic use. There is a large amount of quantitative data that has correlated the elevated ARGs levels with the concentrations of heavy metals in environments with anthropogenic impact. However, the mechanisms by which heavy metals facilitate the proliferation and horizontal gene transfer of ARGs among environmental bacteria were still unknown. This study validated effects of four typical heavy metals (Cu, Cd, Pb, Zn) on the plasmid RP4 mediated conjugative transfer of ARGs in freshwater microcosms. The results suggested that the typical heavy metals including Cu, Pb and Zn would promote conjugative transfer of the plasmid RP4, and Cu (5.0 mu g/L) had the greatest ability to increase conjugative transfer by 16-fold higher than the control groups. In conjugative transfer microcosms, the species of each cultivable transconjugant were isolated, and their minimum inhibitory concentrations (MICs) were assessed via antibiotic susceptibility testing. The mechanism of the increased conjugative transfer of Cu was that Cu induced cell damage and the reduced conjugative transfer of Cd was that Cd increased the content of extracellular polymers substances (EPS). This study confirms metal Cu facilitates the conjugative transfer of environmental-mediated plasmid RP4 by cell damage effect, there- fore accelerating the transmission and proliferation of ARGs. (C) 2020 Elsevier B.V. All rights reserved.