Overview
Trichosporon asahii is a basidiomycetous yeast found in soil, water, and on human skin. It is the primary cause of invasive trichosporonosis in immunocompromised patients, particularly those with neutropenia or hematologic malignancies. It is inherently resistant to echinocandins and shows variable susceptibility to amphotericin B.
Metal Dependencies
T. asahii requires iron for growth and produces siderophore-like molecules for iron acquisition. Its zinc-dependent proteases and manganese-dependent superoxide dismutase contribute to tissue invasion and oxidative stress resistance. Metal availability in the host — particularly during neutropenia when nutritional immunity is compromised — facilitates its expansion.
Ecological Role
T. asahii forms robust biofilm on medical devices and mucosal surfaces. These biofilms confer up to 1000-fold increased resistance to antifungal agents compared to planktonic cells. Within the gut mycobiome, T. asahii can engage in interkingdom interactions with bacteria, potentially participating in mixed-species biofilm communities that enhance mutual persistence.
Conditions Associated
Invasive trichosporonosis carries mortality rates exceeding 50% in immunocompromised hosts. T. asahii has also been detected at elevated abundance in the gut mycobiome of inflammatory bowel disease patients. Its intrinsic echinocandin resistance limits treatment options to azoles and amphotericin B formulations.
Cross-References
- iron — siderophore-mediated acquisition
- biofilm — antifungal resistance mechanism
- candida albicans — differential antifungal susceptibility comparison
- nutritional immunity — host defense evasion