Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, United States.
Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, U.K.
Anal Chem. 2020 Nov 3;92(21):14459-14465. doi: 10.1021/acs.analchem.0c02489. Epub 2020 Oct 22.
We report rapid and sensitive phenotyping of bacterial response to antibiotic treatment at single-cell resolution by a Raman-integrated optical mid-infrared photothermal (MIP) microscope. The MIP microscope successfully detected biochemical changes of bacteria in specific to the acting mechanism of erythromycin with 1 h incubation. Compared to Raman spectroscopy, MIP spectroscopy showed a much larger signal-to-noise ratio at the fingerprint region at an acquisition speed as fast as 1 s per spectrum. The high sensitivity of MIP enabled detection of metabolic changes at antibiotic concentrations below minimum inhibitory concentration (MIC). Meanwhile, the single-cell resolution of the technique allowed observation of heteroresistance within one bacterial population, which is of great clinical relevance. This study showcases characterizing antibiotic response as one of the many possibilities of applying MIP microscopy to single-cell biology.
我们通过拉曼集成光学中红外光热（MIP）显微镜报告了在单细胞分辨率下对细菌对抗生素治疗的快速和敏感表型分析。MIP 显微镜成功地检测到了在特定于红霉素作用机制的 1 小时孵育过程中细菌的生化变化。与拉曼光谱相比，MIP 光谱在指纹区域显示出大得多的信噪比，采集速度快达每秒 1 次光谱。MIP 的高灵敏度能够在低于最小抑菌浓度（MIC）的抗生素浓度下检测到代谢变化。同时，该技术的单细胞分辨率允许观察到一个细菌群体内的异抗性，这具有重要的临床意义。这项研究展示了将 MIP 显微镜应用于单细胞生物学的多种可能性之一，即对抗生素反应进行特征分析。
