Heterologous extracellular DNA facilitates the development of Trichosporon asahii and T. inkin biofilms and enhances their tolerance to antifungals

Abstract

Trichosporon asahii and T. inkin are emergent agents of deep-seated and disseminated infections in immunocompromised patients. The present study aimed to investigate the role of extracellular DNA (eDNA) and the enzyme deoxyribonuclease (DNase) on the structure of T. asahii and T. inkin biofilms, as well as to examine their effect on the susceptibility to antifungals. Biofilms reached maturity at 48 h; eDNA concentration in the supernatant increased over time (6 < 24 h < 48h). Exogenous eDNA increased biomass of Trichosporon biofilms at all stages of development, enhanced their tolerance to antifungals and improved their structural complexity. DNase reduced biomass, biovolume and thickness of Trichosporon biofilms, thereby rendering them more susceptibility to voriconazole. The results suggest the relevance of eDNA in the structure and antifungal susceptibility of Trichosporon biofilms and highlight the potential of DNase as adjuvant in biofilm control.