Molecular characterization and antifungal susceptibility of candida species isolated from vulvovaginitis in Jahrom city, south of Iran

Abstract

Background: Vulvovaginal candidiasis (VVC) is a significant health issue due to Candida spp. Although Candida albicans is considered a major causative agent of vaginal candidiasis, non-albicans species have increased during previous decades. Objectives: This research aimed at molecular identification and assessing antifungal susceptibility of VVC isolated Candida spp. Methods: A professional physician examined two hundred and ninety-five suspected females with vaginitis. The specimens were collected by sterile cotton swabs. Swabs were inoculated on Sabouraud dextrose agar plates and then incubated for 48-72 hours at 35°C. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect all Candida species. Broth microdilution, according to the M27-A3 and M27-S4 CLSI documents, were employed for determining the antifungal susceptibility tests of caspofungin (CAS), voriconazole (VRC), itraconazole (ITC), fluconazole (FLU), clotrimazole (CLO), ketoconazole (KTO), amphotericin B (AMB), and nystatin (NYS). Results: A total of 295 females suspected of vulvovaginal candidiasis were examined. The culture results were positive in 50.5% (149 of 295) of specimens. According to molecular identification techniques, C. albicans 133/149 (89.2%), C. glabrata 8/149 (5.4%), and C. kefyr 2/149 (1.4%) were the main species. A mixed infection of C. albicans and C. glabrata 6/149 (4 %) was detected. The geometric mean values to all Candida strains were in increasing order as the following: CAS, 0.075 µg/mL; VRC, 0.091 µg/mL; ITC, 0.15 µg/mL; AMB, 0.22 µg/mL; CLO, 0.23 µg/mL; KTO, 0.28 µg/mL; NYS, 0.88 µg/mL; FLU, 1.48 µg/mL. Further, the MIC ranges of all Candida isolates to the tested antifungal agents were in increasing order as follows: CAS: 0.031-0.25 µg/mL, KTO and ITC: 0.031-2 µg/mL, VRC: 0.031-4 µg/mL, CLO and AMB: 0.031-8 µg/mL, NYS: 0.06-4 µg/mL, and FLU: 0.12-128 µg/mL. Conclusions: We reported 1 (7.2 %) C. glabrata isolate resistance to FLU and 2 (14.3%) C. glabrata isolates susceptible-dose-dependent (SDD) to CAS. We also reported 6 (4.5%), 5 (3.8%), and 2 (1.5%) C. albicans resistance to ITC, FLU, and AMB, respectively, but 100% C. albicans susceptible to CAS and VRC.