Antifungal and antibiofilm activities of Fluconazole, Ketoconazole and Itraconazole against Candida species clinical isolates
Antifungal and antibiofilm activities of Fluconazole, Ketoconazole and Itraconazole against Candida species clinical isolates
Fahimeh Alizadeh,1Mohsen Vafazadeh,2Alireza Khodavandi,3,*
1. Department of Microbiology, Gachsaran Branch, Islamic Azad University, Gachsaran, Iran 2. Department of Microbiology, Gachsaran Branch, Islamic Azad University, Gachsaran, Iran 3. Department of Microbiology, Gachsaran Branch, Islamic Azad University, Gachsaran, Iran
Introduction: Candidiasis is one of the most common fungal infections by opportunistic Candida species, which is mainly caused by Candida albicans. One of the notable features of Candida is to change the yeast form into the hyphae and then biofilm form. Biofilms show an important role in pathogenesis by invading epithelial cells and damaging tissue. Imidazole and triazole based compounds in vitro has been proven to show antifungal as well as antibiofilm activity. This study mainly aimed to assess the effect of three Azole compounds (fluconazole, ketoconazole and itraconazole) on the growth and biofilm of Candida species isolated from immunocompromised patients.
Methods: A total of 120 vaginal samples were taken from patients hospitalized in intensive care and urology departments of Shahid Rajaei Gachsaran Hospital. All recovered yeasts were differentiated by using CHROM agar and routine tests for identification of Candida species. Subsequently, a set of universal primers were used to allow the amplification of target ITS1 and ITS4 ribosomal DNA. The amplify products were purified and sent to outsourcing sequencing service. The sequence similarity was analyzed via nucleotide Blast software against the nonredundant GenBank database in the NCBI and confirmed. Minimal inhibitory concentrations (MICs) of all isolates towards fluconazole, ketoconazole and itraconazole were determined using the microdilution broth assay based on CLSI guidelines for yeasts (M27M44S). Then Crystal Violet (CV) assay was performed to quantify the biofilm and the effect of three major antifungals.
Results: In total, 75% of vaginal samples were positive for Candida, including C. albicans (74.2%), C. krusei (12.9%) and C. tropicalis (12.9%). All isolates were susceptible to ketoconazole and itraconazole while, 80% were dose-dependent susceptible, and the remaining isolates were found to be resistant to the fluconazole. On the other hand, it was found that biofilm reduction in the presence of ketoconazole and/or itraconazole was significantly more than that of fluconazole in all isolates tested, suggesting the important role of two medicines (ketoconazole and/or itraconazole) to prevent the biofilms in different Candida species.
Conclusion: Findings show that the treatment of candidiasis using ketoconazole or itraconazole could be much more effective than the use of fluconazole in reducing biofilm formation and treating candidal vaginitis. This study demonstrated that resistance to antifungals such as fluconazole was found to significantly increase with time. Continued surveillance of changes in species distribution and susceptibility to antifungals are necessary to guide treatment.