Distribution of clinical isolates of Candida spp. and antifungal susceptibility of high biofilm-forming Candida isolates

Abstract INTRODUCTION: The increase in the incidence of fungal infections, especially those caused by Candida albicans and other Candida species, necessitates the understanding and treatment of Candida-associated infections. In this study, we aimed to investigate the identification, distribution, and biofilm formation ability of different clinical Candida isolates and evaluate the distribution and antifungal susceptibilities of high biofilm-forming (HBF) Candida isolates. METHODS: For identification, carbohydrate fermentation, carbohydrate assimilation, and ChromAgar tests were used. Biofilm formation was assessed using crystal violet binding assay, while the susceptibility to antifungal agents was determined using ATBTM Fungus 3 test kits. RESULTS: The majority of Candida species were C. parapsilosis (31.3%; 31/99) and C. tropicalis (30.3%; 30/99). C. tropicalis was found to be the most frequently isolated species among all HBF Candida species. HBF Candida isolates were more frequently isolated from vaginal swab (35.7%; 10/28), tracheal aspirate (17.9%; 5/28), and urine (17.9%; 5/28). The majority of tested isolates were resistant to itraconazole and voriconazole, whereas no isolate was deemed resistant to 5-flucytosine. CONCLUSIONS: C. tropicalis displays the highest biofilm formation ability among all the Candida species evaluated, and HBF Candida isolates were more frequently seen in vaginal swab, tracheal aspirate, and urine samples. Our findings revealed that 5-flucytosine is the most efficient antifungal agent against HBF Candida isolates.

Inhibitory effects of curcumin on hyphal development and biofilm formation of five kinds of non-Candida albicans / 中草药

Objective: To observe the inhibitory effects of curcumin on hyphal development and biofilm formation of five kinds of non-Candida albicans. Methods: Serial 2-fold dilution assay was used to determine the MICs of curcumin to C. tropicalis, C. glabrata, C. parapsilokis, C. krusei, C. guilliermondii; XTT assay was used to determine the SMIC50 of curcumin to the five non-C. albicans. Inverted microscope and scanning electron microscope (SEM) were applied to inspectting the morphological change of non-C. albicans treated by curcumin, The dilution method was applied to inspecting the hyphae around the colonies. Results: The MICs of curcumin to C. tropicalis, C. glabrata, C. parapsilokis, C. Krusei, C. guilliermondii were 64, 128, 256, 256, and 128 μg/mL, and the SMIC50 were 512, 512, >512, >512, and 512 μg/mL, respectively. We found that curcumin could inhibit the hyphal and biofilm formation of the five kinds of non-C. albicans by observation with inverted microscope and SEM, and curcumin could inhibit the hyphal development around the colonies by observation with optical microscope. Conclusion: Curcumin could inhibit the hyphal development and biofilm formation of the five kinds of non-C. albicans.