Characterization and antifungal susceptibilities of candida species isolated from clinical samples

Identification of yeast isolates from clinical specimens and determination of antifungal susceptibilities are essential for rapid and accurate treatment. The aim of this study was, to identify Candida species isolated from vaginal swabs and urine samples by conventional methods, chromogenic media, automated systems and determine the role of molecular methods for diagnosis and to investigate antifungal susceptibilities of isolates against various agents by determining minimal inhibition concentration (MIC) levels. A total of 100 isolates were isolated and identified by germ tube formation, corn meal - tween 80 agar morphology; CHROMagar Candida, Candida ID, Brillance Candida Agar, BIGGY Agar as chromogenic media, VITEK 2-YST commercial kits werw used for identification and the results were compared. Fatty Acid Methyl Esters (FAME) of isolates were analyzed to determine relationship of isolates in regard to fatty acids by cluster analysis. In addition, different profiles which were obtained from cutting of ITS and 26S D1/D2 regions of isolates by PCR- Restriction Enyzme Analysis were determined and the distance among species was examined by DNA sequence analysis. According to the results, isolates were identified as; Candida albicans, C. glabrata, C. kefyr, C. krusei, C. lusitaniae and C. dubliniensis. In-vitro antifungal susceptibility profiles of isolates were studied by using Microdilution Method and VITEK 2 AST-Y06 card methods and the results were compared. 100 % sensitivity was detected for all antifungals except fluconazole; but 5.1 % of isolates were resistant to fluconazole. In addition, MIC values showed differences due to the method used, for some antifungals. Our results demonstrated, molecular techniques to be an alternative for identification of Candida species, but more studies are needed. The majority of the isolates were found to be susceptible to the tested antifungal agents, but the presence of fluconazole resistance in some isolates showed the importance of identification of the yeasts to species level and determine antifungal susceptibility testing results, in daily practice.