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，但它们在形成抗药性方面的作用却鲜为人知。本研究揭示了饮用水消毒过程中抗生素抗性基因（ARGs）谱的变化、与移动基因元件（mge）的共现以及潜在的宿主。我们发现臭氧/氯（O3/Cl2）耦合消毒通过在主要由假单胞菌携带的耐药结瘤细胞分裂和ATP结合盒抗生素外流家族中富集ARGs，显著增加了ARGs和MGE携带抗生素耐药contigs的相对丰度，不动杆菌、分枝杆菌和甲基胞菌，而抗菌树脂/氯耦合消毒对ARG和MGE的丰度没有显著变化。此外，抗生素外排与β-内酰胺ARGs和MGEs的共现模式得到了广泛的鉴定，并在所有样本中检测到携带recR和mexH基因的arc，其中O3/Cl2消毒后每个细胞的最高丰度为2.25×10-2拷贝。序列无关的binning分析成功地获得了Acidovorax sp.MR-S7和Hydrogenophaga sp.IBVHS2两个携带ARG的基因组草图，进一步揭示了O3/Cl2消毒过程中宿主与ARG的关系。总的来说，这项研究为饮用水消毒过程中抗药性的变化提供了新的见解。

       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/10.1021/acs.est.8b05907