In vitro activity of five antifungal drugs against Candida albicans isolates, Sari, Iran

Background and Candida albicans is the most common agent of candidiasis. Management of candidiasis depends on the immune status of the host, severity of disease, and the choice of antifungal drug. Antifungal drugs, specifically triazoles, widely are utilizing for the treatment of invasive fungal infections. The aim of this study was to evaluate the in vitro susceptibility of C. albicans isolates to fluconazole, itraconazole, voriconazole, amphotericin B, caspofungin.
A total of 44 clinical strains of C. albicans isolated from 36 patients, were collected from hospitalized patients at four hospitals at Mazandaran province, and the in vitro antifungal susceptibility testing was performed using based on CLSI methods.
Generally, 34 isolates were susceptible to all of five antifungal drugs, while four isolates showed susceptible or susceptible dose dependent (SDD) and six isolates were SDD or resistance to these antifungal drugs. The lowest MIC with 0.016 µg/ml was for amphotericin B and the highest MICs for fluconazole (16 µg/ml). The lowest MIC50 (0.063 µg/ml) was related to itraconazole and the lowest MIC90 (0.25 µg/ml) to Caspofungin, so the highest MIC50 (1 µg/ml) and MIC90 (4 µg/ml) to fluconazole. The four isolates were resistance to both fluconazole and voriconazole, separately, and five isolates were resistance to itraconazole. Caspofungin showed potent activity against more than 95% C. albicans isolates.
Overall, we reported 9.1% resistance to FLZ and VRZ, 11.3% to ITZ and AMB and 4.6% to CAS. Our finding is in agreement with previous observations that C. albicans isolates that develop resistance, because some antifungal drugs such as fluconazole widely used as prophylaxis.