Fusarium keratoplasticum infection in diabetic foot ulcers following antimicrobial therapy

Fusarium species are important opportunistic fungal pathogens. Diabetic foot infection (DFI) involves diverse causative pathogens; however, the potential for fungal etiologies is often overlooked. We describe a case of DFI following foot trauma. Despite prior broad-spectrum antimicrobial therapy, the wound failed to heal and presented persistent swelling and pain. Microbiological re-evaluation and molecular identification confirmed the causative agent as Fusarium keratoplasticum (F. keratoplasticum), a pathogenic species within Fusarium solani species complex (FSSC). The isolate exhibited high MICs against most antifungals, thus systemic antifungal therapy was withheld. Successful management was achieved through systematic surgical debridement combined with silver-ion dressings, resulting in pathogen eradication and complete wound healing. Currently, F. keratoplasticum infections remain extremely limited, particularly those definitively confirmed to species level. This case broadens the pathogen spectrum of DFI and highlights the need for comprehensive etiologic evaluation in therapy-refractory wounds, offering a non-pharmacological strategy for resistant fungal infections.