State Key Joint Laboratory on Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
State Key Joint Laboratory on Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Environ Int. 2019 Apr;125:90-96. doi: 10.1016/j.envint.2019.01.050. Epub 2019 Jan 31.
The emergence and spread of antibiotic resistance has pose a huge threat to both human health and environmental ecosystem. However, little is known regarding the pool of ARGs in extracellular DNA (eDNA). In this study ten ARGs (sul1, sul2, tetW, tetX, ermA, ermB, bla, ampC, cat and cmr) and class I integron (intI1) in the sludge from hospital, pharmaceutical industry, wastewater treatment plant (WWTP), and swine manure, and sediment in urban lake in the form of both eDNA and intracellular DNA (iDNA) were evaluated by quantitative polymerase chain reaction (qPCR). The results showed that every gram of sludge dry weight contained from 7.31 × 10 to 1.16 × 10 copies of extracellular ARGs (eARGs) and from 1.04 × 10 to 2.74 × 10 copies of intracellular ARGs (iARGs). The sludge from hospital with the highest ratio of eARGs to total ARGs (11.02-89.63%), followed by the sediment from urban lake, implying that most of the ARGs in these regions were contributed by eARGs. The relative abundance of eARGs were higher than iARGs in sludge from WWTP and pharmaceutical industry, moreover, 1/3 and 5/9 detected eARGs were higher than the ARGs in the iDNA extracted from sludge of hospital and sediment from urban lake, respectively. Furthermore, the transforming ability of eARGs suggesting that adsorbed eARG is more preferentially coupled to the competent cells than free eARG. These findings highlight the need to focus attention on the contribution of eARGs to the dissemination of antibiotic resistance into environment, and also future needs in mitigating the spread of eARGs in the environment.
抗生素耐药性的出现和传播对人类健康和环境生态系统构成了巨大威胁。然而，人们对细胞外 DNA（eDNA）中 ARG 库的了解甚少。在这项研究中，通过定量聚合酶链反应（qPCR）评估了医院、制药厂、污水处理厂（WWTP）和猪粪以及城市湖泊沉积物中的污泥中的十个 ARG（sul1、sul2、tetW、tetX、ermA、ermB、bla、ampC、cat 和 cmr）和 I 类整合子（intI1）以 eDNA 和细胞内 DNA（iDNA）的形式存在。结果表明，每克污泥干重含有 7.31×10 到 1.16×10 个细胞外 ARG（eARG）和 1.04×10 到 2.74×10 个细胞内 ARG（iARG）。医院污泥中 eARG 与总 ARG 的比例最高（11.02-89.63%），其次是城市湖泊沉积物，这表明这些地区的大多数 ARG 是由 eARG 贡献的。WWTP 和制药厂污泥中的 eARG 相对丰度高于 iARG，此外，检测到的 1/3 和 5/9 的 eARG 高于从医院污泥和城市湖泊沉积物中提取的 iDNA 中的 ARG。此外，eARG 的转化能力表明，吸附的 eARG 比游离的 eARG 更优先与感受态细胞偶联。这些发现强调了需要关注 eARG 对抗生素耐药性向环境传播的贡献，以及未来在环境中减轻 eARG 传播的需要。
