摘要

       污水处理厂 (WWTP) 的生物处理过程是最常见的污水处理方法，可能会导致污水中细菌种群中表型/基因型比例的选择性消除和/或变化。因此，污水处理中使用的基于活性污泥的污水处理厂构成了肠道细菌的重要库，其中含有潜在的可转移抗性基因。这些微生物与处理过的废水一起，可以渗透到土壤、地表水、农村地下水供应和饮用水中。因此，本研究的目的是确定污水处理（传统的厌氧/缺氧/好氧 (A2/O) 工艺、机械-生物 (MB) 系统、序批式反应器 (SBR)、使用活性污泥法的 13 个处理厂流出的污水中的抗生素抗性细菌 (ARB)（包括大肠杆菌）和抗生素抗性基因 (ARGs) 的数量与营养物质去除率 (MB-ERN) 相关的机械-生物系统技术。无论采样时间和处理废水类型如何，ARB 和 ARG 均无显着差异（p>0.05）。在具有 MB 和 MB-ERN 系统的污水处理厂中观察到 ARB 和 ARGs 的减少百分比最高（高达 99.9%）。在使用 SBR 的污水处理厂中检测到的减少量最低。在采用 A2/O 系统和 SBR 的污水处理厂的污水 (EFF) 中，观察到微生物总数中对新一代抗生素（CTX 和 DOX）具有抗性的细菌百分比显着增加（p<0.05）。在分析的所有 ARG 中，观察到 EFF 样品中 ARG 拷贝的最高流行率是 sul1、tet(A) 和 qepA，最低的是 blaTEM 和 blaSHV。尽管所呈现的研究结果表明，在废水处理过程中，ARB 和 ARGs 的去除效率很高，尤其是具有 MB 和 MB-ERN 系统的污水处理厂，但 EFF 仍然是 ARGs 的重要储存库，可以转移到其他微生物。

       Biological treatment processes at wastewater treatment plants (WWTPs), which are the most common methods of sewage treatment, could cause selective elimination and/or changes in the proportions of phenotypes/genotypes within bacterial populations in effluent. Therefore, WWTPs based on activated sludge used in sewage treatment constitute an important reservoir of enteric bacteria which harbour potentially transferable resistance genes. Together with treated wastewater, these microorganisms can penetrate the soil, surface water, rural groundwater supplies and drinking water. Because of this, the aim of this study was to determine the impact of various modification of sewage treatment (the conventional anaerobic/anoxic/oxic (A2/O) process, mechanical-biological (MB) system, sequencing batch reactors (SBR), mechanical-biological system with elevated removal of nutrients (MB-ERN)) on the amount of antibiotic resistant bacteria (ARB) (including E. coli) and antibiotic resistance genes (ARGs) in sewage flowing out of the 13 treatment plants using activated sludge technology. There were no significant differences in ARB and ARGs regardless of time of sampling and type of treated wastewater (p > 0.05). The highest percentage of reduction (up to 99.9%) in the amount of ARB and ARGs was observed in WWTPs with MB and MB-ERN systems. The lowest reduction was detected in WWTPs with SBR. A significant increase (p < 0.05) in the percentage of bacteria resistant to the new generation antibiotics (CTX and DOX) in total counts of microorganisms was observed in effluents (EFF) from WWTPs with A2/O system and with SBR. Among all ARGs analyzed, the highest prevalence of ARGs copies in EFF samples was observed for sul1, tet(A) and qepA, the lowest for blaTEM and blaSHV. Although, the results of presented study demonstrate high efficiency of ARB and ARGs removal during the wastewater treatment processes, especially by WWTPs with MB and MB-ERN systems, EFF is still an important reservoir of ARGs which can be transferred to other microorganisms.

https://www.sciencedirect.com/science/article/abs/pii/S0048969718318138