摘要

       水生生态系统拥有大量抗生素抗性基因 (ARG)，这些基因可能会发生突变、重组和选择事件。在这里，我们探讨了饮用水常规处理之前（地表原水，RW）和之后（消毒水，DW）以及自来水（TW）和超滤膜（UM，从血液透析设备中回收）通过宏基因组学。共识别出 852 个不同的 ARG，其中 21.8% 仅在 RW，这可能反映了人类活动对采样点河流的影响。尽管在样本之间观察到类似的耐药性特征，但已确定临床相关抗生素类别（青霉烯和肽）的频率存在显着差异。检测到对最后使用的抗生素的耐药性决定因素，包括与 mcr、optrA 和 poxtA 相关的序列以及临床相关的 β-内酰胺酶基因（即 blaKPC、blaGES、blaIMP、blaVIM、blaSPM 和 blaNDM）。 830 个编码序列（CDS - 与 217 种不同的 ARG 相关）被嵌入与移动遗传元件相关的重叠群中，特别是质粒，其中 68% 在 RW、DW 和 TW，表明水环境在抗性传播中的重要性。观察到细菌病原体属的变化，例如处理和分布后分枝杆菌的显着增加。在 UM 中，潜在致病性盐单胞菌属占主导地位。它的基因组草图与 H. stevensii 密切相关，主要承载多药外排泵。这些结果拓宽了我们对全球 ARG 多样性的理解，并强调了跟踪不断扩大的环境抵抗组的重要性。

       Aquatic ecosystems harbor a vast pool of antibiotic resistance genes (ARGs), which can suffer mutation, recombination and selection events. Here, we explored the diversity of ARGs, virulence factors and the bacterial community composition in water samples before (surface raw water, RW) and after (disinfected water, DW) drinking water conventional treatment, as well as in tap water (TW) and ultrafiltration membranes (UM, recovered from hemodialysis equipment) through metagenomics. A total of 852 different ARGs were identified, 21.8% of them only in RW, which might reflect the impact of human activities on the river at the sampling point. Although a similar resistance profile has been observed between the samples, significant differences in the frequency of clinically relevant antibiotic classes (penam and peptide) were identified. Resistance determinants to last resort antibiotics, including sequences related to mcr, optrA and poxtA and clinically relevant beta-lactamase genes (i.e. blaKPC, blaGES, blaIMP, blaVIM, blaSPM and blaNDM) were detected. 830 coding sequences (CDSs - related to 217 different ARGs) were embedded in contigs associated with mobile genetic elements, specially plasmids, of which 68% in RW, DW and TW, suggesting the importance of water environments in resistance dissemination. Shifts in bacterial pathogens genera were observed, such as a significant increase in Mycobacterium after treatment and distribution. In UM, the potentially pathogenic genus Halomonas predominated. Its draft genome was closely related to H. stevensii, hosting mainly multidrug efflux pumps. These results broaden our understanding of the global ARGs diversity and stress the importance of tracking the ever-expanding environmental resistome.

https://www.sciencedirect.com/science/article/abs/pii/S0043135420301664