Screening and evaluation of heavy metals facilitating antibiotic resistance gene transfer in a sludge bacterial community
Screening and evaluation of heavy metals facilitating antibiotic resistance gene transfer in a sludge bacterial community
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污泥细菌群落中促进抗生素抗性基因转移的重金属筛选与评价
DOI：
10.1016/j.scitotenv.2019.133862
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发表时间：
2019-12-10
影响因子：
9.8
通讯作者：
Qiu, Yong
中科院分区：
文献类型：
--
作者：
Lin, Hai;Jiang, Lintian;Qiu, Yong
最近越来越多的证据表明，重金属可以刺激细菌之间抗生素抗性基因（ARG）的转移。然而，以往的研究大多集中在纯菌株，重金属对细菌群落，特别是活性污泥中ARG转移的影响尚未得到明确的探讨。本研究采用高通量流式细胞仪和生物培养箱相结合的方法，研究了不同浓度的重金属对污泥细菌ARG转移的影响。以大肠杆菌MG 1655为供体，构建了广宿主范围IncP-1质粒pKJK 5，发现0.5 mmol/L Pb、0.1 mmol/L As和0.005 mmol/L Hg对污泥细菌群落中ARG的转移有明显的促进作用。此外，在微流控芯片上的交配实验也证明了在上述重金属胁迫下附着群落的更高的转移频率。分离了Pb、As和Hg胁迫下的接合子，并对其遗传学进行了描述。As和Hg的优势菌属为假单胞菌属，分别占88%和96%。铅胁迫下，接合转移菌主要为气单胞菌属和肠杆菌属，分别占56%和32%。与重金属转运和细胞代谢相关的ABC转运蛋白和氨基酸代谢在预测接合子微生物代谢功能中占主导地位。本研究可为污水处理厂中ARG扩散的风险评估和控制提供参考。(c)2019 Elsevier B. V.版权所有。
Recent growing evidence suggests that heavy metals can stimulate the transfer of antibiotic resistance genes (ARGs) between bacteria. However, most previous studies focused on pure strains, the effect of heavy metals on ARG transfer in bacterial communities, especially in activated sludge, has not been clearly explored. In this study, a high-throughput method, combining computerized incubator (Bioscreen C) and flowcytometry, was developed to evaluate different concentrations of heavy metals influencing ARG transfer in sludge bacteria communities. By using Escherichia coli MG1655 as the donor of broad-host range IncP-1 plasmid pKJK5, it was found that 0.5 mmol/L Pb, 0.1 mmol/L As and 0.005 mmol/L Hg could obviously promote ARG transfer in sludge bacteria communities. Furthermore, mating assays on microfluidic chips also proved higher transfer frequencies in attached communities under the above heavy metal stresses. Transconjugants under Pb, As and Hg stresses were isolated and phylogenetically described. For As and Hg, the dominant genus was Pseudomonas, accounting for 88% and 96%, respectively. While under Pb stress, the genera Aeromonas and Enterobacter were the main transconjugants, accounting for 56% and 32% respectively. Moreover, ABC transporters and Amino acid metabolism, which were related to heavy metal transport and cellular metabolism, were dominant in the prediction of microbial metabolic function of transconjugants. This study can be helpful for risk assessment and control of ARG spreading in WWTPs. (c) 2019 Elsevier B.V. All rights reserved.