Antifungal activity of clinical isolates of Candida non-albicans to the essential oils of Syzygium aromaticum (cloud) and Eucalyptus globulus (eucalyptus)

Abstract

Introduction: The genus Candida possesses a high incidence of infection in humans, with the Candida albicans species being the most isolated in invasive and superficial infections. However, a considerable increase in non-albicans Candida species has been reported in fungal infections. Essential oils, for being volatile, can act as chemical communication signals and defense mechanisms. Objective: Evaluate the effectiveness, in vitro, of the essential oils of Syzygium aromaticum and Eucalyptus globulus in inhibiting the growth of non-albicans Candida species. Methods: To evaluate the antifungal activity of S. aromaticum and E. globulus and the effect of their essential oils on the micromorphology of the species Candida krusei, Candida parapsilosis and Candida glabrata, in this order, the agar diffusion technique and microculture for yeasts. Results: In the diffusion technique, the essential oil of S. aromaticum presented an inhibition halo for Candida krusei, Candida parapsilosis, and Candida glabrata. E. globulus oil, on the other hand, did not show inhibition halo growth in any of the concentrations tested against the three non-albicans Candida species. However, in the microculture, both essential oils have proven to be effective antimicrobials having shown structures indicative of antifungal activity in the highest concentration and different degrees of cell destruction in the other concentrations. Conclusion: In the conditions of this study, it was concluded that the products evaluated exerted antifungal activity against non-albicans Candida strains, highlighting the essential oil of S. aromaticum that showed antimicrobial activity in both methodologies.