| 四环素抗生素对污泥中四环素抗性基因丰度和表达水平的作用影响 |
| 摘要点击 2304 全文点击 824 投稿时间：2019-07-24 修订日期：2019-09-29 |
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| 中文关键词 四环素抗生素 四环素抗性基因 基因丰度 转录表达水平 活性污泥 |
| 英文关键词 tetracycline antibiotic tetracycline resistance gene gene abundance transcriptional expression level activated sludge |
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| 中文摘要 |
| 为研究四环素（TC）抗生素对其抗性基因（TC-ARGs）转录表达的作用影响，以从活性污泥中筛选获得的四环素抗性细菌（TRB）作为研究对象，采用荧光定量PCR和逆转录PCR方法检测了7种TC-ARGs，包括tetA、tetC、tetG、tetM、tetO、tetW和tetX基因的丰度和表达水平，并探讨了TC与TC-ARGs丰度及其表达水平之间的相关关系.结果表明，在整个培养周期内，tetA、tetG和tetW基因丰度随TC暴露浓度的增大总体呈现上升趋势，但其余TC-ARGs基因丰度整体波动较大.TC胁迫对不同TC-ARGs的转录表达水平作用影响差别较大，其中，tetA基因表达水平相对稳定，且随TC浓度的升高而上调，在TC浓度为100 mg·L-1时，其上调倍数高达5.3倍.在短期（1 d）TC胁迫下，TC-ARGs转录表达水平随TC浓度的升高整体呈现上调趋势.由相关性分析可知，tetA和tetW基因丰度与其转录表达水平之间存在显著的线性相关性，表明其基因丰度可在一定程度上衡量和评价其抗性表达水平，进而反映其功能活性和环境风险. |
| 英文摘要 |
| Tetracycline resistant bacteria (TRB) screened from activated sludge were used to study the effect of tetracycline (TC) antibiotic on the transcriptional expression of tetracycline resistance genes (TC-ARGs). The gene abundances of seven TC-ARGs including tetA, tetC, tetG, tetM, tetO, tetW, and tetX, as well as their expression levels, were quantified by quantitative PCR (qPCR) and reverse transcriptional PCR (RT-PCR). The correlations between TC concentrations and gene abundance of TC-ARGs and their expression levels were discussed. The results showed that the gene abundances of tetA, tetG, and tetW generally increased with increasing TC exposure concentrations during the entire culture cycle, whereas other TC-ARGs fluctuated greatly. The impact of TC stress on the transcriptional expression level of different TC-ARGs varied to a great extent. The gene expression of tetA was relatively stable and exhibited an upregulated trend with increasing TC concentrations. When the TC concentration was 100 mg·L-1, the upregulation of tetA expression was as high as 5.3-fold compared with the control. Under short-term TC stress (one day), the transcriptional expression level was upregulated with increasing TC concentration. The correlation results showed that gene abundances of tetA and tetW correlated significantly with their respective expression levels, indicating that they can evaluate expression levels to a certain extent, which can further mirror functional activities and environmental risks. |
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