摘要

       为了全面了解氯化（一种广泛使用的消毒技术）对饮用水中细菌群落和抗生素耐药组的影响，本研究应用高通量测序和宏基因组方法来研究抗生素抗性基因 (ARG) 和细菌群落的变化模式在饮用水处理和分配系统中。在属水平上，氯化可以有效去除嗜甲基菌、甲基单胞菌、Limnobacter 和多核杆菌，同时增加饮用水中假单胞菌、嗜酸菌、鞘氨醇单胞菌、Pleomonas 和 Undibacterium 的相对丰度。在饮用水中共检测到 15 种类型的 151 种 ARG，氯化明显增加了它们的总相对丰度，同时降低了它们在机会细菌中的多样性（p < 0.05）。残留氯被确定为驱动细菌群落转移和抵抗组改变的关键因素。多药耐药基因（主要编码耐药-结瘤-细胞分裂运输系统）和杆菌肽耐药基因bacA作为处理和分配系统中占优势的持久性ARGs，主要由耐氯细菌Pseudomonas和Acidovorax携带，主要贡献于ARGs丰度增加。在本研究中观察到的细菌群落转移与抗生素耐药性改变之间的强相关性可能为氯化作用对抗生素耐药性的影响背后的机制提供新的线索。

       For comprehensive insights into the effects of chlorination, a widely used disinfection technology, on bacterial community and antibiotic resistome in drinking water, this study applied high-throughput sequencing and metagenomic approaches to investigate the changing patterns of antibiotic resistance genes (ARGs) and bacterial community in a drinking water treatment and distribution system. At genus level, chlorination could effectively remove Methylophilus, Methylotenera, Limnobacter, and Polynucleobacter, while increase the relative abundance of Pseudomonas, Acidovorax, Sphingomonas, Pleomonas, and Undibacterium in the drinking water. A total of 151 ARGs within 15 types were detectable in the drinking water, and chlorination evidently increased their total relative abundance while reduced their diversity in the opportunistic bacteria (p < 0.05). Residual chlorine was identified as the key contributing factor driving the bacterial community shift and resistome alteration. As the dominant persistent ARGs in the treatment and distribution system, multidrug resistance genes (mainly encoding resistance-nodulation-cell division transportation system) and bacitracin resistance gene bacA were mainly carried by chlorine-resistant bacteria Pseudomonas and Acidovorax, which mainly contributed to the ARGs abundance increase. The strong correlation between bacterial community shift and antibiotic resistome alteration observed in this study may shed new light on the mechanism behind the chlorination effects on antibiotic resistance.

https://pubs.acs.org/doi/abs/10.1021/acs.est.5b03521