Antifungal effect of eugenol on Candida parapsilosis strains isolated from the oral cavity of healthy individuals

The objective was to isolate and identify clinical species of Candida parapsilosis from the oral cavity of individuals without any oral alterations, such as oral candidiasis. Subsequently, the sensitivity of these strains to eugenol and nystatin was evaluated. To this end, the Minimum Inhibitory Concentration (MIC), Minimum Fungicidal Concentration (MFC), microbial growth death curve, and inhibition of virulence factors through micromorphology were determined. Seven strains were selected, six of them were clinical isolates of C. parapsilosis, and one was the American Type Culture Collection (ATCC®) 22019™ standard strain. The MIC was determined to be 256 μg/mL, which coincided with the MFC in 100% of the tested strains. Micromorphology study demonstrated inhibition of virulence structures such as pseudo-hyphae and blastoconidia at all three analyzed concentrations. The microbial death curve showed a fungicidal effect after 24 hours of experimentation in the studied strains. Therefore, eugenol constitutes a promising molecule for the treatment of oral fungal infections.