Antifungal and anti-biofilm activity of the first cryptic antimicrobial peptide from an archaeal protein against Candida spp. clinical isolates

Candida species cause cutaneous and systemic infections with a high mortality rate, especially in immunocompromised patients. The emergence of resistance to the most common antifungal drugs, also due to bioflm formation, requires the development of alternative antifungal agents. The antimicrobial peptide VLL-28, isolated from an archaeal transcription factor, shows comparable antifungal activity against 10 clinical isolates of Candida spp. Using a fuoresceinated derivative of this peptide, we found that VLL-28 binds to the surface of planktonic cells. This observation suggested that it could exert its antifungal activity by damaging the cell wall. In addition, analyses performed on bioflms via confocal microscopy revealed that VLL-28 is diferentially active on all the strains tested, with C. albicans and C. parapsilosis being the most sensitive ones. Notably, VLL-28 is the frst example of an archaeal antimicrobial peptide that is active towards Candida spp. Thus, this points to archaeal microorganisms as a possible reservoir of novel antifungal agents