In vitro Antifungal Susceptibility Testing of candida albicans and candida glabrata Isolated from vulvovaginal Candidiasis

Objectives: Vulvovaginal candidiasis (VVC) is defined as the isolation of Candida species in culture from study participants with symptom and sign of the abnormalities of vagina. Recurrent VVC (RVVC) which is defined as four or more culture‑confirmed episodes in a 12‑month period can approximately affect 5–8% of adult women. The rise of RVVC incidence and drugs resistance lead to an important public health issue and challenges clinician’s treatment strategy. The aim of the present investigation was to define in vitro antifungal susceptibility profile of 69 clinical isolates of C. albicans and C. glabrata against Itraconazole (ITC), Voriconazole (VRC), Fluconazole (FLC), Amphotericin B (AMB), Nystatin (NYS) and Caspofungin (CAS). Materials and Methods: Forty-eight strains of C. albicans and 21 strains of C. glabrata used in this study were isolated from 69 patients with vaginal candidiasis in 2016 at Tehran. The test strains were cultured on potato dextrose agar (PDA, Merck, Germany) with chloramphenicol (Merck, Germany) and incubated at 37 ˚C for 48 h. The species level identification of clinical isolates was achieved by using PCR- restriction fragment length polymorphism (RFLP) method. Minimum inhibitory concentration (MIC) was determined according to the recommendations proposed by the Clinical and Laboratory Standards Institute (CLSI) M27-A3 and M27-S4 documents. The geometric mean (GM) MICs, MIC50, MIC90 and ranges were calculated. Results: The GM MICs and MIC ranges of six antifungal agents against 69 candida strains (C. albicans; n: 48 and C. glabrata; n: 21) were obtained. AMB (GM: 0.078 mg/L), CAS (GM: 0.044 mg/L), ITC (GM: 0.15 mg/L) and VRC (GM: 0.06 mg/L) had low MICs against all tested strains, whereas FLC (GM: 1.64 mg/L) and NYS (GM: 0.38 mg/L) had higher MIC. The MIC ranges across all isolates were as follows: AMB: 0.032-0.25 mg/L, CAS: 0.016-0.25 mg/L, ITC: 0.063-1 mg/L, VRC: 0.016-0.5 mg/L, FLC: 0.25-16 mg/L and NYS: 0.125-1 mg/L. Conclusions: Caspofungin, Voriconazole and Amphotericin B were shown to be the most potent antifungal agents against Candida albicans and Candida glabrata isolates obtained from patients with vulvovaginal candidiasis in Tehran. These findings might help clinicians to choose appropriate drugs for treating of vulvovaginal candidiasis caused by Candida albicans and Candida glabrata.