SIP-SRS imaging of cell wall synthesis identifies a synergy between micafungin and amphotericin B

Candida species, one of the most important opportunistic fungal pathogens, causes life-threatening infections in immunocompromised individuals and presents a formidable challenge in clinical practice. This challenge is exacerbated by the growing prevalence of drug resistance, particularly against last resort antifungal treatments such as Amphotericin B (AmB). AmB exhibits its antifungal activity by binding to ergosterol in fungal cell membranes, but it can also interact with cholesterol in mammalian cells, leading to host toxicity. In this study, we harness SIP-assisted hyperspectral SRS microscopy (SIP-SRS) to directly visualize and interrogate the dynamics of fungal cell wall synthesis under antifungal treatment. By leveraging the enhanced sensitivity and spatial resolution of SIP-SRS, we undercover previously inaccessible details of fungal metabolism and drug interactions. Our findings demonstrate a synergistic inhibition of fungal growth by AmB and micafungin, an antifungal from a different class, highlighting the therapeutic promise of combined antifungal strategies and opening promising avenues for combating drug-resistant fungal infections.