Epidemiological and microbiological characterization of Candidozyma auris (Candida auris) isolates from a tertiary hospital in Cairo, Egypt: an 18-month study

Candidozyma auris (formerly Candida auris) has emerged as a significant multidrug-resistant pathogen. Among 140 antifungal-resistant Candida spp. isolates, 120 were identified as C. auris using chromogenic agar, VITEK 2, and MALDI-TOF. Most cases (60%) were males, and 59% were aged ≥ 60 years. Bloodstream infections were predominant (60.8%), followed by respiratory (20.8%), urinary tract (15%), and other sites. Liver transplantation (35.8%) was the most common underlying risk factor, followed by post-COVID-19 (30.8%) and cancer (25%). All isolates exhibited thermotolerance, halotolerance, anaerobic blood hemolysis, and biofilm formation. Significant association was observed between virulence enzymes activity and both specimen source and clinical conditions (P < 0.001), with strong activity linked to blood isolates, liver transplant, post-COVID-19, and lung cancer. Among antifungal agents, voriconazole (MIC₅₀/₉₀: 0.125/0.5 µg/mL), posaconazole (0.03/0.125 µg/mL), and amphotericin B (0.5/1 µg/mL) showed consistently low MICs. Caspofungin (0.25/1 µg/mL) and micafungin (0.125/0.5 µg/mL) demonstrated favorable activity, with resistance rates of 3.3% and 4.2%, respectively. Fluconazole resistance was observed among all isolates (MIC₅₀/₉₀: 32/32 µg/mL). Itraconazole and ketoconazole showed elevated MICs (MIC₅₀/₉₀: 1/4 and 16/64 µg/mL, respectively) and was inactive against all isolates. Flucytosine (MIC₅₀/₉₀: 64/128 µg/mL) was inactive against 96.7%. Agreement between VITEK 2 and CLSI BMD was strong for fluconazole, voriconazole, amphotericin B, caspofungin, and micafungin (Cohen's kappa ≥ 0.8), but poor for flucytosine (0.35), indicating limited reliability. This report provides crucial local data on antifungal susceptibility and virulence traits of C. auris, supporting infection control and treatment strategies in Egypt.