Fluconazole susceptibility testing

The susceptibility of the isolates to FLC was determined using the DD method according to the performance standards for antimicrobial susceptibility testing of Clinical and Laboratory Standards Institute (CLSI) M44-Ed3 [66]. The FLC disks (25 µg, Himedia, Mumbai, India) were placed onto Müller-Hinton agar (Oxoid, Hampshire, UK) supplemented with 2% dextrose and 0.5 µg/mL methylene blue dye and inoculated with a suspension of yeast cells equivalent to 1 × 10⁶ to 5 × 10⁶ CFU/mL. The plates were incubated at 37 °C for 24–48 h. According to the diameters of the developed inhibition zones, Candida isolates were classified as S, SDD, or R following CLSI guidelines M27M44S-Ed3 [67]. Minimum inhibitory concentrations of FLC and repurposing agents: AK, COL, DEX, SMX, and KT were determined in the tested isolates using the BMD method in accordance with CLSI document M27-Ed4 [68]. A 50% inhibition in growth defined the MICs of FLC and KT [23, 67]. The MICs of DEX and SMX were indicated by 80% inhibition [20, 56], while 100% inhibition defined the MICs of AK and COL [21, 69]. Growth-positive and sterility control wells were included in each experiment, and C. albicans ATCC 231GI and ATCC 10231 were included as quality controls.