School of Biological Science and Medical Engineering, Beihang University; Beijing 100083, China.
Department of Clinical Laboratory, Beijing Bo'ai Hospital, China Rehabilitation Research Center, Capital Medical University, Beijing 100068, China.
Anal Chem. 2023 Oct 24;95(42):15556-15565. doi: 10.1021/acs.analchem.3c02243. Epub 2023 Oct 10.
Rapid antifungal susceptibility testing (AFST) is urgently needed in clinics to treat invasive fungal infections with the appropriate antifungal drugs and to slow the emergence of antifungal resistance. However, current AFST methods are time-consuming (24-48 h) due to the slow growth of fungal cells and the methods not being able to work directly for clinical samples. Here, we demonstrate rapid AFST by measuring the metabolism in single fungal cells using stimulated Raman scattering imaging and deuterium probing. Distinct metabolic responses were observed in to different classes of antifungal drugs: while the metabolism was inhibited by amphotericin B, it was stimulated by azoles (fluconazole and voriconazole) and micafungin. Accordingly, we propose metabolism change as a biomarker for rapid AFST. The results were obtained in 4 h with 100% categorical agreement with the gold standard broth microdilution test. In addition, a protocol was developed for direct AFST from positive blood cultures. This method overcomes the limitation of slow growth in conventional methods and has the potential for the rapid diagnosis of candidemia and other clinical fungal infections.
临床上急需快速抗真菌药敏检测（AFST），以便用适当的抗真菌药物治疗侵袭性真菌感染，并减缓抗真菌耐药性的出现。然而，由于真菌细胞生长缓慢，而且目前的 AFST 方法不能直接用于临床样本，因此这些方法耗时较长（24-48 小时）。在这里，我们通过使用受激拉曼散射成像和氘探测来测量单个真菌细胞的代谢，从而实现了快速的 AFST。我们观察到不同类别的抗真菌药物对代谢有明显的不同反应：两性霉素 B 抑制了代谢，而唑类（氟康唑和伏立康唑）和米卡芬净则刺激了代谢。因此，我们提出代谢变化作为快速 AFST 的生物标志物。该方法在 4 小时内获得结果，与金标准肉汤微量稀释试验的分类一致性达到 100%。此外，还制定了从阳性血培养物中直接进行 AFST 的方案。该方法克服了传统方法中生长缓慢的局限性，有望快速诊断念珠菌血症和其他临床真菌感染。
