The antimicrobial peptide ToAP2 is synergic with caspofungin and amphotericin B against Candida auris

Candida auris is a multidrug-resistant fungus associated with invasive infections, high mortality rates, therapeutic failure, and nosocomial outbreaks in different regions of the world. This situation highlights the need for new antifungal drugs. Antimicrobial peptides (AMPs) are evolutionarily conserved molecules present in different organisms that are considered promising alternatives for the development of new therapies. In this work, we evaluated the in vitro antifungal activity of two scorpion venom antimicrobial peptides, ToAP1 and ToAP2, against 11 different strains of C. auris . ToAP2 demonstrated activity against most isolates with minimal inhibitory concentrations ranging from 50 to 100 µM (150–300 µg/mL). In contrast, all isolates were resistant to ToAP1. Furthermore, ToAP2 showed synergistic effect with amphotericin B and caspofungin against C. auris , with fractional inhibitory concentration indices of 0.25 to 0.37 and 0.03 to 0.12, respectively. These results suggest that this AMP can be further explored as a potential molecule alone or in combination with other available treatments for C. auris infections.