In vitro performance of eugenol and cinnamaldehyde on biofilms produced by Candidozyma auris

Candidozyma auris has high rates of resistance to antifungals and hospital disinfectants. This yeast remains on surfaces for long periods, favoring the colonization of patients. Similarly Candida species, it produces persistent biofilms, which contribute to invasive infections, resulting in high mortality rates. In the search for new therapeutic alternatives of antifungal action, natural products have been widely studied due to their pharmacological potential and diverse biological activities. Eugenol and cinnamaldehyde are derived from the essential oils of cinnamon and clove, respectively, and have shown action against several microorganisms, including Candida species. The aims of the present study were to evaluate the antibiofilm activity of the natural products eugenol and cinnamaldehyde on clinical isolates of C. auris. Both products showed inhibitory action on planktonic form. Biofilm biomass was considerably reduced for most of the evaluated isolates. On the other hand, during the treatment period, the metabolic activity of most isolates increased, compared to control, possibly due to the heteroresistance phenomenon; however, further studies are still needed to support this hypothesis.