Antifungal activity of arginine based-surfactants against Yeasts

M. ELISA FAIT; S. MYLEK; PATRICIA GRILLO; JULIANA COTABARREN; EDUARDO PRIETO; GRACIELA GARROTE; ROMINA F. VAZQUEZ; SABINA M. MATÉ; SUSANA R. MORCELLE; LAURA S. BAKÁS

La Plata

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Biofísica (SAB); 2018

Sociedad Argentina de Biofísica (SAB)

The antifungal activity of two novel arginine-based compounds (Bz-Arg-NHC10 and Bz-Arg-NHC12), which were synthesized by an enzymatic strategy, was studied against different Candida species, using two clinical isolates (C. albicans and C. tropicalis) and the strain Candida albicans ATCC 64548 from the American Type Culture Collection (ATCC, Manassas, USA) as indicator microorganisms. Cetrimide (alkyl trimethyl ammonium bromide mixture), a commercial cationic disinfectant was used for comparison. Minimum Inhibitory Concentrations (MIC) were calculated from DO measurements after 24 h of exposure to the compounds. Results were corroborated using the resazurin assay. Minimum Fungicidal Concentrations were also obtained. The three surfactants proved antifungal activity against all isolates, revealing their potential use as effective disinfectants. The effect of surfactants on pathogens survival was analyzed in Sabouraud Dextrose Broth added with Bz-Arg- NHC10 or Bz-Arg-NHC 12 at different concentrations. Viability curves showed a decrease of the number of viable microorganism after 24 h of incubation when compared to that of the control in absence of the surfactant. Experiments in lipid monolayers composed by dioleoylphosphatidylcholine (PC), phosphatidylethanolamine (PE) and ergosterol (ERG) confirmed that both surfactants can insert in the fungal membranes, suggesting it as a possible target for the antifungal activity. Morphological changes in yeasts exposed to the surfactants were analyzed by AFM. Finally, antiadhesive activity was studied pretreating polyestyrene microplates with different surfactant concentrations. Overall, the evidence from this preliminary study supports the use of these arginine-based surfactants as an alternative to commercial cationic surfactants, especially for their use as additives in topical formulations and for superficial disinfection.