Department of Biomedical Engineering and Department of Electrical and Chemical Engineering , Boston University , Boston , Massachusetts 02215 , United States.
Anal Chem. 2018 Mar 20;90(6):3737-3743. doi: 10.1021/acs.analchem.7b03382. Epub 2018 Feb 27.
The widespread use of antibiotics has significantly increased the number of resistant bacteria, which has also increased the urgency of rapid bacterial detection and profiling their antibiotic response. Current clinical methods for antibiotic susceptibility testing (AST) rely on culture and require at least 16 to 24 h to conduct. Therefore, there is an urgent need for a rapid method that can test the susceptibility of bacteria in a culture-free manner. Here we demonstrate a rapid AST method by monitoring the glucose metabolic activity of live bacteria at the single-cell level with hyperspectral stimulated Raman scattering (SRS) imaging. Using vancomycin-susceptible and -resistant enterococci E. faecalis as models, we demonstrate that the metabolic uptake of deuterated glucose in a single living bacterium can be quantitatively monitored via hyperspectral SRS imaging. Remarkably, the metabolic activity of susceptible bacteria responds differently to antibiotics from the resistant strain within only 0.5 h from the addition of antibiotics. Therefore, bacterial susceptibility and the minimum inhibitory concentration (MIC) of antibiotics can be determined within one cell cycle. Our metabolic imaging method is applicable to other bacteria species including E. coli, K. Pneumoniae, and S. aureus as well as different antibiotics, regardless of their mechanisms of inhibiting or killing bacteria.
抗生素的广泛使用显著增加了耐药菌的数量，这也增加了快速细菌检测和分析其抗生素反应的紧迫性。目前用于抗生素药敏试验（AST）的临床方法依赖于培养，至少需要 16 到 24 小时才能进行。因此，迫切需要一种能够以无培养方式测试细菌敏感性的快速方法。在这里，我们通过使用超光谱受激拉曼散射（SRS）成像来监测活细菌的单细胞水平的葡萄糖代谢活性，展示了一种快速 AST 方法。我们使用对万古霉素敏感和耐药的肠球菌 E. faecalis 作为模型，证明可以通过超光谱 SRS 成像定量监测单个活细菌中氘代葡萄糖的代谢摄取。值得注意的是，敏感细菌的代谢活性对添加抗生素后仅 0.5 小时内的抗生素的反应与耐药菌株不同。因此，抗生素的药敏性和最小抑菌浓度（MIC）可以在一个细胞周期内确定。我们的代谢成像方法适用于包括大肠杆菌、肺炎克雷伯菌和金黄色葡萄球菌在内的其他细菌种类，以及不同的抗生素，无论其抑制或杀死细菌的机制如何。
