摘要

      氯化作用有助于饮用水中特异性抗生素耐药基因（ARGs）的富集，但其潜在的分子生态机制尚不清楚，这可能会阻碍对由此产生的健康风险的评估和控制。在这项研究中，我们利用亚基因组组装和Resfams注释，分析了在一个完整的饮用水处理和运输系统中ARGs、移动基因元件（MGE）及其宿主菌的共现模式，以及潜在病原体与抗生素抗性的相关性。饮用水中存在7种不同抗性机制的ARG，氯化处理提高了ARGs的总丰度（p<0.05）。编码耐药结节细胞分裂和ATP结合盒抗生素外排泵的ARGs在所有标本中占优势，是ARG积累的主要原因。氯化处理后，ARGs主要由优势鞘氨醇单胞菌、极谱单胞菌、菌丝体、酸乳杆菌、假单胞菌和氟杆菌携带。此外，细菌宿主和MGE的富集对抗生素抗性的改变有很大的贡献。产碱假单胞菌（Pseudomonas alcaligenes）携带多种ARGs，被认为是氯化饮用水中潜在的致病菌。这些发现为研究饮用水氯化过程中宿主-ARGs的关系和抗性改变的机制提供了新的线索。

      Chlorination can contribute to the enrichment of specific antibiotic resistance genes (ARGs) in drinking water, but the underlying molecular ecological mechanisms remain unknown, which may hinder the assessment and control of the resulting health risks. In this study, metagenomic assembly and Resfams annotation were used to profile the co-occurrence patterns of ARGs, mobile genetic elements (MGEs) and their bacterial hosts, as well as the correlations of potential pathogens with the antibiotic resistome, in a full-scale drinking water treatment and transportation system. Seven ARG types involved in different resistance mechanisms occurred in drinking water and chlorination enhanced the total abundance of the ARGs (p <  0.05). The ARGs encoding resistance-nodulation-cell division and ATP-binding cassette antibiotic efflux pumps predominated in all the samples and were primarily responsible for the ARG accumulation. After chlorination, the ARGs were primarily carried by predominant Sphingomonas, Polaromonas, Hyphomicrobium, Acidovorax, Pseudomonas and Fluviicola. Further, enrichment of the bacterial hosts and MGEs greatly contributed to alteration of the antibiotic resistome. Pseudomonas alcaligenes, carrying multiple ARGs, was identified as a potential pathogen in the chlorinated drinking water. These findings provide novel insights into the host-ARG relationship and the mechanism underlying the resistome alteration during drinking water chlorination.

        https://www.sciencedirect.com/science/article/abs/pii/S0304389419307940?via%3Dihub