摘要

       目前，活性污泥中抗生素耐药性的发生和增殖越来越受到关注。然而，胞外聚合物（EPS）对抗生素耐药性的作用尚不清楚。研究了序批式反应器（SBRs）中EPS、四环素（TC）耐药菌（TRB）和TC耐药基因（TRGs）之间的变化及相关性。将不含 TC 的 SBR 的性能与添加不同量 TC 的其他两种 SBR 进行比较。当 TC 浓度从 0 增加到 100 μg L-1 时，发现总平均 EPS 含量从 66 mg g-1 VSS 显着增加到 181 mg g-1 VSS。随着EPS含量的增加，三种SBRs污泥中TRB在暴露于TC后从105到106菌落形成单位mL-1显着增加。此外，通过实时荧光定量聚合酶链反应测定三组TRGs（副本mL-1）的浓度，并遵循顺序：外排泵基因>核糖体保护基因>降解酶基因。闲置阶段的TRGs数量多于曝气污泥中的数量。污泥中EPS和TRB之间的相关系数（R2）为0.823（p < 0.01），而EPS和总TRG之间的相关性很差（R2 = 0.463，p > 0.05）。但随着TC的增加，污泥中EPS和TRGs也呈现增加的趋势。

       Antibiotic resistance occurrences and proliferation in activated sludge have attracted more and more attention nowadays. However, the role which extracellular polymeric substance (EPS) plays on the antibiotic resistance is not clear. The changes and correlation among EPS, tetracycline (TC) resistant bacteria (TRB) and TC resistance genes (TRGs) of sequencing batch reactors (SBRs) were investigated. Performance of SBR without TC was compared with two other SBRs to which different amounts of TC were added. Total average EPS contents were found to increase significantly from 66 mg g−1 VSS to 181 mg g−1 VSS as the TC concentrations increased from 0 to 100 μg L−1. As the EPS content increased, TRB in sludge of the three SBRs increased significantly from 105 to 106 colony forming unit mL−1 after being exposed to TC. In addition, the concentrations of three groups of TRGs (copies mL−1) were determined by real-time fluorescence quantitative polymerase chain reaction and followed the order: efflux pump genes > ribosome protected genes > degradation enzyme genes. The numbers of TRGs in the idle stage were larger than those in the aeration sludge. Correlation coefficients (R2) between EPS and TRB in sludge were 0.823 (p < 0.01) while the correlation between EPS and total TRGs was poor (R2 = 0.463, p > 0.05). But it showed the same tendency that EPS and TRGs in sludge increased with the increasing of TC.

https://www.sciencedirect.com/science/article/abs/pii/S0045653514011552