Fingerprint Stimulated Raman Scattering Imaging Unveils Ergosteryl Ester as a Metabolic Signature of Azole-Resistant .

(), a major fungal pathogen, causes life-threatening infections in immunocompromised individuals. Fluconazole (FLC) is recommended as first-line therapy for treatment of invasive fungal infections. However, the widespread use of FLC has resulted in increased antifungal resistance among different strains of , especially , which is a leading source of hospital-acquired infections. Here, by hyperspectral stimulated Raman scattering imaging of single fungal cells in the fingerprint window and pixel-wise spectral unmixing, we report aberrant ergosteryl ester accumulation in azole-resistant compared to azole-susceptible species. This accumulation was a consequence of lipogenesis. Lipid profiling by mass spectroscopy identified ergosterol oleate to be the major species stored in azole-resistant . Blocking ergosterol esterification by oleate and suppressing sterol synthesis by FLC synergistically suppressed the viability of and limited the growth of biofilm on mouse skin . Our findings highlight a metabolic marker and a new therapeutic strategy for targeting azole-resistant by interrupting the esterified ergosterol biosynthetic pathway.