In vitro activity of aminosterols against dermatophytes

We recently reported that aminosterols are fungicidal due to their disrupting the outer membranes of yeasts and that they have a significant in vitro activity against various mould species. Yet, their activity against dermatophytes had never been tested. This study's objective was to evaluate the in vitro activity of squalamine and a synthetic aminosterol derivative (ASD) against various dermatophytes. Susceptibility testing of squalamine, ASD, terbinafine, and griseofulvin was performed, in triplicate, in accord with the Clinical Laboratory and Standards Institute's M38-A2 procedure, using an 80% growth inhibition endpoint. The studies included the following dermatophytes: Trichophyton rubrum, T. mentagrophytes, T. soudanense, Microsporum canis, M. audouinii, M. persicolor; M. cookie and M. gypseum. Squalamine and ASD showed significant in vitro activity against these dermatophytes. The minimum inhibitory concentrations (MICs) ranged from 4-16 mg/l and from 2-8 mg/l for squalamine and ASD, respectively. These findings support further clinical studies of aminosterols activity against superficial dermatophyte infections.