Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
Anal Chem. 2020 Dec 1;92(23):15472-15479. doi: 10.1021/acs.analchem.0c03218. Epub 2020 Nov 10.
The rapid spread of antibiotic resistance threatens our fight against bacterial infections. Environments are an abundant reservoir of potentially transferable resistance to pathogens. However, the trajectory of antibiotic resistance genes (ARGs) spreading from environment to clinic and the associated risk remain poorly understood. Here, single-cell Raman spectroscopy combined with reverse DO labeling (Raman-rDO) was developed as a sensitive and rapid phenotypic tool to track the spread of plasmid-borne ARGs from soil to clinical bacteria via transformation. Based on the activity of bacteria in assimilating H to substitute prelabeled D under antibiotic treatment, Raman-rDO sensitively discerned a small minority of phenotypically resistant transformants from a large pool of recipient cells. Its single-cell level detection greatly facilitated the direct calculation of spread efficiency. Raman-rDO was further employed to study the transfer of complex soil resistant plasmids to pathogenic bacteria. Soil plasmid ARG-dependent transformability against five clinically relevant antibiotics was revealed and used to assess the spreading risk of different soil ARGs, i.e., ampicillin > cefradine and ciprofloxacin > meropenem and vancomycin. The developed single-cell phenotypic method can track the fate and risk of environmental ARGs to pathogenic bacteria and may guide developing new strategies to prevent the spread of high-risk ARGs.
抗生素耐药性的迅速传播威胁着我们对抗细菌感染的斗争。环境是病原体潜在可转移耐药性的丰富储库。然而，抗生素耐药基因 (ARGs) 从环境传播到临床并相关风险仍然知之甚少。在这里，单细胞拉曼光谱结合反向 DO 标记 (Raman-rDO) 被开发为一种敏感和快速的表型工具，通过转化跟踪质粒携带的 ARGs 从土壤传播到临床细菌。基于细菌在抗生素处理下同化 H 以替代预标记的 D 的活性，Raman-rDO 灵敏地区分了大量受主细胞中少数表型耐药的转化体。其单细胞水平检测极大地方便了传播效率的直接计算。Raman-rDO 进一步用于研究复杂土壤抗性质粒向致病菌的转移。揭示了土壤质粒 ARG 对抗五种临床相关抗生素的转化能力，并用于评估不同土壤 ARG 的传播风险，即氨苄西林>头孢菌素和环丙沙星>美罗培南和万古霉素。所开发的单细胞表型方法可以跟踪环境 ARG 对致病菌的命运和风险，并可能指导制定新策略来防止高风险 ARG 的传播。
