摘要

       来自不同栖息地的微生物之间的抗生素抗性基因 (ARG) 的交换加剧了抗生素耐药性。质粒是重要的 ARG 移动元件，通过水平基因转移 (HGT) 传播。在这项研究中，我们证明了来自可吸入颗粒物 (PM) 的多重抗性质粒的存在及其对基因水平转移的影响。使用接合交配分析和纳米孔测序从医院的 PM 中鉴定出三个可转移的多重抗性质粒。 pTAir-3 包含 26 个水平传输元件和 10 个 ARG。重要的是 pTAir-5 含有碳青霉烯抗性基因 (blaOXA)，该基因与人类和猪共生细菌的质粒具有同源性，因此表明 PM 是抗生素抗性质粒传播的媒介。此外，125 μg/mL PM2.5 和 PM10 分别显着提高了共轭转移率 110% 和 30%，并增加了活性氧 (ROS) 水平。通过全基因组 RNA 测序鉴定与 ROS、SOS、细胞膜、菌毛生成和转座相关基因的上调表达水平，揭示了潜在机制。该研究强调了多重耐药质粒的空气传播以及可吸入 PM 对抗生素耐药性水平转移的影响。

       Antibiotic resistance is exacerbated by the exchange of antibiotic resistance genes (ARGs) between microbes from diverse habitats. Plasmids are important ARGs mobile elements and are spread by horizontal gene transfer (HGT). In this study, we demonstrated the presence of multi-resistant plasmids from inhalable particulate matter (PM) and its effect on gene horizontal transfer. Three transferable multi-resistant plasmids were identified from PM in a hospital, using conjugative mating assays and nanopore sequencing. pTAir-3 contained 26 horizontal transfer elements and 10 ARGs. Importantly pTAir-5 harbored carbapenem resistance gene (blaOXA) which shows homology to plasmids from human and pig commensal bacteria, thus indicating that PM is a media for antibiotic resistant plasmid spread. In addition, 125 μg/mL PM2.5 and PM10 significantly increased the conjugative transfer rate by 110% and 30%, respectively, and augmented reactive oxygen species (ROS) levels. Underlying mechanisms were revealed by identifying the upregulated expressional levels of genes related to ROS, SOS, cell membranes, pilus generation, and transposition via genome-wide RNA sequencing. The study highlights the airborne spread of multi-resistant plasmids and the impact of inhalable PM on the horizontal transfer of antibiotic resistance.

https://www.sciencedirect.com/science/article/abs/pii/S0269749120369852