In recent decades, the incidence of Candida infections has increased in immunocompromised patients. This multicenter study aimed to evaluate in vitro antifungal activities of 8 antifungal agents against the Candida species isolated from 10 university hospitals in Iran. During the period from Dec 2019 to Dec 2021, Candida species were collected from clinical samples of patients. The isolates were identified by PCR restriction fragment length polymorphism and sequencing methods. The antifungal susceptibility tests of each isolate to eight antifungal agents were performed according to the microdilution CLSI M27, M59, and M60 standard methods. A total of 598 Candida strains were isolated from clinical samples. The most commonly isolated Candida species was C. albicans, followed by C. glabrata, C. parapsilosis, Debaryomyces hansenii (Candida famata), C. tropicalis, Pichia kudriavzevii (Candida krusei), C. orthopsilosis, Meyerozyma guilliermondii (Candida guilliermondii), Kluyveromyces marxianus (Candida kefyr), and Clavispora lusitaniae (Candida lusitaniae). MIC90 values in all Candida species were as follows: 0.25 μg/mL for caspofungin and voriconazole; 0.5 μg/mL for amphotericin B and isavuconazole; 2 μg/mL for itraconazole, luliconazole, and posaconazole; and 16 μg/mL for fluconazole. Although 30/285 C. albicans, 15/31 C. hansenii, 3/12 M. guilliermondii, 67/125 C. glabrata, 5/15 P. kudriavzevii, 6/60 C. parapsilosis, and 5/23 C. tropicalis isolates were multiazole resistant with resistance to 2 to 4 azoles, pan-azole resistance was not observed. According to our data, Candida albicans and C. glabrata were the most frequent species isolated from clinical samples in Iran. Caspofungin and voriconazole, with lower MIC90 values, are the most effective than other antifungal agents for the treatment of Candida infections in this region. IMPORTANCE Candida species cause severe invasive infections of the heart, brain, eyes, bones, and other parts of the body. Knowledge of regional distributions of causative Candida agents and their antifungal susceptibility patterns can help to monitor resistance to antifungal agents of various species and support local and national surveillance programs. In the present study, C. albicans and C. glabrata were the most frequently isolated species from clinical samples in Iran. Increasing rates of non-albicans Candida isolates from the Iranian population should be looked at as alarming due to various levels of intrinsic MIC values or resistance to various antifungal drugs. Caspofungin and voriconazole are recommended over fluconazole for the treatment of Candida infections in the study region. However, amphotericin B and isavuconazole are also active against the most common Candida species isolated from patients. Pan azole-resistant Candida species were not observed in the present study.
Keywords: Candida species; Iran; amphotericin B; caspofungin; fluconazole; isavuconazole; itraconazole; luliconazole; posaconazole; voriconazole.