Interaction Between Amorolfine and Voriconazole Against Fusarium species

Fusarium species represent a range of fungal pathogens capable of causing diverse mycotic diseases. Relative to antibacterial drugs, few effective antifungal agents have been developed to date, and all are subject to significant limitations. As such, there is an urgent need to design novel antifungal treatments for infections caused by Fusarium spp. Herein, 15 clinical isolates, including 5 Fusarium oxysporum and 10 Fusarium solani strains, were analyzed to explore the relative inhibitory effects of different combinations of amorolfine (AMO) and voriconazole (VOR) on the growth of these fungal pathogens. These analyses were conducted by measuring minimal inhibitory concentration (MIC) values for these antifungal agents in a broth microdilution assay and by using an in vivo model of Fusarium-infected Galleria mellonella. These experiments revealed that in isolation, AMO and VOR exhibited MIC values ranging from 4 to 16 μg/mL and 2 to 8 μg/mL, respectively. However, these effective MIC values fell to 1-2 μg/mL and 0.5-2 μg/mL, respectively, when AMO and VOR were administered in combination with one another, exhibiting synergistic activity against 73.3% of analyzed Fusarium strains. Subsequent in vivo analyses conducted using the G. mellonella model further confirmed that combination VOR + AMO treatment was associated with significantly improved larval survival following Fusarium spp. infection. Together, these results serve as the first published evidence demonstrating that VOR and AMO exhibit synergistic activity against infections caused by Fusarium spp., indicating that they may represent an effective approach to antifungal disease treatment.