Abstract: Candida is the most common etiological factor among fungal infections. They are responsible, inter alia, for vulvovaginal candidiasis and candidemia. One of the key elements of mycological diagnostics of the above-mentioned infections is the determination of drug susceptibility of fungi to various antimicrobial drugs, including fluconazole. In routine diagnostics, sensitivity to fluconazole is most often determined with the use of concentration gradient strips (E-tests). Two slightly different schemes for determining the MIC of fluconazole – developed by EUCAST and CLSI are considered as reference methods. The aim of the study was to compare the MIC obtained using both reference methods and those obtained using E-tests. 32 clinical strains and 4 reference strains were tested. On the basis of the obtained results, the strains were appropriately classified as sensitive to fluconazole, resistant or sensitive dose-depending. The obtained MIC values differed depending on the method used. Despite this, the vast majority of strains were classified into the same drug susceptibility categories, regardless of the treatment scheme chosen. Single incompatibilities concerned mainly NCAC strains. The observed discrepancies in the obtained results, both the MIC values and the clinical classification of strains into appropriate categories, require further verification and determination of the reasons for their occurrence. These inconsistencies may raise doubts as to the reliability of the obtained test results and hinder the selection of a specific method during mycological diagnostics.

Key words: Candida, CLSI, EUCAST, E-test, fluconazole