摘要
      自从最初发现一种可动员的粘菌素抗性基因（mcr-1）以来，已经报道了其他几种变体，其中一些变体可能已经传播了一段时间。公开可用的宏基因组数据为重新分析样本提供了机会，以了解最近发现的抗微生物耐药性基因（ARGs）的进化史。在这里，我们对214095个样本的442 Tbp测序读数进行了大规模宏基因组研究，以描述九种mcr基因变体（mcr-1至mcr-9）的传播和出现。我们的研究结果表明，每种变体的传播并不均匀。相反，来源和地点在传播中起着一定作用。然而，基因组背景和基因本身基本上保持不变。我们报告了在特定环境中出现新亚变体的证据，例如高度流行的mcr-9新变体。这项工作强调了共享基因组数据对ARGs监测的重要性，这有助于我们理解抗微生物耐药性。
ABSTRACT
Since the initial discovery of a mobilized colistin resistance gene (mcr-1), several other variants have been reported, some of which might have circulated a while beforehand. Publicly available metagenomic data provide an opportunity to reanalyze samples to understand the evolutionary history of recently discovered antimicrobial resistance genes (ARGs). Here, we present a large-scale metagenomic study of 442 Tbp of sequencing reads from 214,095 samples to describe the dissemination and emergence of nine mcr gene variants (mcr-1 to mcr-9). Our results show that the dissemination of each variant is not uniform. Instead, the source and location play a role in the spread. However, the genomic context and the genes themselves remain primarily unchanged. We report evidence of new subvariants occurring in specific environments, such as a highly prevalent and new variant of mcr-9. This work emphasizes the importance of sharing genomic data for the surveillance of ARGs in our understanding of antimicrobial resistance.

https://journals.asm.org/doi/full/10.1128/msystems.00105-22