摘要

废水处理厂被公认为进入环境的抗生素抗性基因和抗生素抗性细菌的热点。但是，这些基因和细菌在接收生态系统中的持久性仍然知之甚少。该研究的目的是评估最终废水释放对最终废水接收湖中微生物多样性和抗生素抗性基因库的影响。在处理过程中，总可培养异养菌和不可培养细菌的数量（表示为16S rRNA基因拷贝数）显着减少。沉积物中耐氨苄青霉素的细菌数量高于水样，表明耐氨苄西林的细菌在淡水沉积物中积累。使用外源方法，我们捕获了56个抗性质粒，并对其进行了进一步表征。下一代测序表明，在研究的基因组中代表的微生物菌群是相应环境的典型特征。在最终流出物中观察到最高的抗生素抗性基因相对丰度，这表明从废水处理厂中释放出相当多的基因。但是，与其他研究的基因组相比，湖水中基因的最低相对丰度和最低多样性表明，污水处理后释放对湖水微生物群落中抗生素抗性的影响可忽略不计。此外，过去不加控制的污水倾倒入该水库，以及湖上游的水质较低，表明污水处理厂保护了所研究的生态系统。

Wastewater treatment plants have been recognised as hotspots for antibiotic resistance genes and antibiotic-resistant bacteria which enter the environment. However, the persistence of these genes and bacteria in receiving ecosystems remains poorly understood. The aim of the study was to evaluate the effect of final effluent release on microbial diversity and the antibiotic resistance gene pool in a final effluent-receiving lake. The numbers of total culturable heterotrophs and unculturable bacteria (represented as the 16S rRNA gene copy number) were significantly reduced during the treatment process. The number of ampicillin-resistant bacteria was higher in the sediment than in water samples, suggesting accumulation of ampicillin-resistant bacteria in freshwater sediments. Using an exogenous method, we captured 56 resistance plasmids which were further characterised. Next-generation sequencing revealed that the microbial phyla represented in the studied metagenomes were typical of corresponding environments. The highest relative abundance of antibiotic resistance genes was observed in the final effluent, suggesting that a considerable number of genes were released from the wastewater treatment plant. However, the lowest relative abundance and lowest diversity of the genes in the lake water, compared to the other studied metagenomes, suggest a negligible effect of treated sewage release on antibiotic resistance within water microbial communities of the lake. Furthermore, uncontrolled sewage dumping into this reservoir in the past as well as lower quality of the water upstream of the lake indicated that the wastewater treatment plant protected the studied ecosystem.

https://www.sciencedirect.com/science/article/pii/S0048969718339238