摘要

       消毒制度被认为是降低饮用水中微生物风险的最可靠策略，但人们对其在塑造抗生素耐药性方面的作用知之甚少。这项研究揭示了抗生素抗性基因 (ARG) 谱的改变、它们与移动遗传元件 (MGE) 的共存以及基于宏基因组组装的饮用水消毒过程中的潜在宿主。我们发现臭氧/氯 (O3/Cl2) 耦合消毒显着增加了 ARGs 和携带 MGE 的抗生素抗性重叠群 (ARCs) 的相对丰度，通过在抗性 - 结节 - 细胞分裂和 ATP 结合盒式抗生素流出中富集 ARGs主要由假单胞菌、不动杆菌、分枝杆菌和甲基囊藻携带的家族，而抗菌树脂/氯耦合消毒对 ARG 和 MGE 的丰度没有显着变化。此外，广泛鉴定了抗生素外排与β-内酰胺ARGs和MGEs的共存模式，在所有样品中均检测到携带recR和mexH基因的ARCs，最高丰度为每个细胞2.25×10-2个拷贝。 O3/Cl2 消毒。序列独立分箱分析成功检索到酸食菌属的两个携带 ARG 的基因组草图。 MR-S7 和 Hydrogenophaga sp。 IBVHS2，进一步揭示了 O3/Cl2 消毒过程中宿主-ARG 的关系。总的来说，这项研究为饮用水消毒过程中抗生素耐药性的改变提供了新的见解。

       Disinfection regimes are considered the most solid strategy to reduce microbial risks in drinking water, but their roles in shaping the antibiotic resistome are poorly understood. This study revealed the alteration of antibiotic resistance genes (ARGs) profiles, their co-occurrence with mobile genetic elements (MGEs), and potential hosts during drinking water disinfection based on metagenomic assembly. We found the ozone/chlorine (O3/Cl2) coupled disinfection significantly increased the relative abundance of ARGs and MGE-carrying antibiotic resistance contigs (ARCs) through the enrichment of ARGs within the resistance–nodulation–cell division and ATP-binding cassette antibiotic efflux families that are primarily carried by Pseudomonas, Acinetobacter, Mycobacterium, and Methylocystis, whereas the antimicrobial resin/chlorine coupled disinfection posed unremarkable changes to the ARG and MGE abundances. Moreover, the co-occurrence patterns of antibiotic efflux and beta-lactam ARGs and MGEs were widely identified, and ARCs carrying the recR and mexH genes were detected in all the samples, with the highest abundance of 2.25 × 10–2 copies per cell after O3/Cl2 disinfection. Sequence-independent binning analysis successfully retrieved two draft ARG-carrying genomes of Acidovorax sp. MR-S7 and Hydrogenophaga sp. IBVHS2, further revealing the host-ARG relationship during O3/Cl2 disinfection. Overall, this study provides novel insights into the antibiotic resistome alteration during drinking water disinfection.

https://pubs.acs.org/doi/abs/10.1021/acs.est.8b05907