Simulated vaginal fluid: Candida resistant strains' biofilm characterization and vapor phase of essential oil effect

Introduction: Vulvovaginal candidiasis is a disease that affects millions of women worldwide. Oral formula-tions, topical creams or ointments are the conventional dosage forms, with an increase in drug administra-tion through vaginal via. The use of simulated biological fluids (e.g. vaginal fluid) in the evaluation of antifungal therapies may better mimic the real biological environments and therefore provide a better understanding of the behavior of the antifungal.Methods: The main objective of this work was to compare planktonic growth and biofilm formation of Can-dida species, on common growth medium, Sabouraud Dextrose Broth (SDB) and on vaginal simulation condi-tions, Simulated Vaginal Fluid (SVF), through the optical density determination, colony-forming units and scanning electron microscopy. In addition, under the same conditions this study also evaluated the ability of vapor phase of oregano and white thyme essential oils (VP-EOs), potential alternative treatment, to inhibit biofilm formation and to destroy mature biofilms of vaginal isolates, through the colony-forming units determination.Results: Candida isolates maintained the same biofilm formation capacity and morphology in both media (SVF and SDB). Furthermore, the results obtained in this work related with VP-EOs effect agree with results acquired, previously, with SDB. This means that the effect of VP-EOs is not affected by the SVF medium, and that this fluid allows the dissolution of the volatile and bioactive compounds.Conclusions: These results can predict the in vivo behavior, suggesting a potential effective application of VP-EOs as prophylactic or therapeutic treatment for biofilm-related vulvovaginal candidiasis.(c) 2022 The Author(s). Published by Elsevier Masson SAS on behalf of SFMM. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)