Molecular Identification, Antifungal Resistance and Distribution of Pathogenic Yeasts in Bulgaria

A total of 111 yeast isolates were obtained from clinical samples collected at University Multipurpose Hospital for Active Treatment “Sveti Georgi” in Plovdiv, Bulgaria. Species identification was performed using DNA barcoding of the internal transcribed spacer region (ITS1+2). Antifungal susceptibility testing against six drugs revealed that 25 isolates (26.6%) were multidrug-% resistant, including strains of Candida albicans, C. parapsilosis, and C. tropicalis. Resistance was observed against amphotericin B, itraconazole, and posaconazole. These findings underscore the need for continuous local epidemiological surveillance of antifungal resistance in pathogenic yeasts to establish effective treatment strategies. To evaluate the influence of patient demographics on yeast species distribution, Principal Component Analysis (PCA) was employed to explore correlations between yeast species and patient characteristics such as age and gender. The analysis revealed distinct clustering patterns, suggesting that demographic factors may influence the distribution of pathogenic yeasts.