Vulvovaginal candidiasis in Iranian women: Molecular identification and antifungal susceptibility pattern

AIM

Vulvovaginal candidiasis (VVC), is a common fungal infection that remains a global concern. The objectives of this study were molecular identification and assessment of the antifungal susceptibility profile of Candida species, causing VVC in southeast Iran.

METHODS

A cross-sectional investigation was carried out on 119 nonpregnant females suspected of VVC between February 2019 and May 2021. Yeast samples were characterized to the species level by conventional and molecular methods. All Candida isolates were examined for in vitro susceptibility profile to six conventional antifungal drugs using Clinical and Laboratory Standards Institute guidelines.

RESULTS

Out of 119 subjects, 52 (43.7%) cases were affected by VVC, out of whom 11 (21.15%) cases had recurrent vulvovaginal candidiasis (RVVC). The species distribution was as follows; Candida albicans (n = 21; 40.4%), C. glabrata (n = 11; 21.2%), C. tropicalis (n = 9; 17.3%), C. parapsilosis (n = 5; 9.7%), C. africana (n = 3; 5.7%), C. famata (n = 1; 1.9%), C. lusitaniae (n = 1; 1.9%), and C. dubliniensis (n = 1; 1.9%). The resistance rate of Candida isolates to fluconazole, itraconazole, and voriconazole were 15.38%, 11.5%, and 3.8%, respectively. Resistance to fluconazole was obtained in 46% (5/11) of RVVC cases but only in 7% (3/41) of VVC cases.

CONCLUSION

This study demonstrated that the majority of VVC cases were caused by non-albicans Candida species which also were resistant to some antifungal agents. Hence, our findings revealed the importance of conducting periodical epidemiological studies to determine changes in species distribution. Moreover, for effective management of treatment and infection, it is imperative to evaluate the susceptibility profiles of Candida species isolated from VVC patients.

Genetic Analysis of Candida glabrata from Candiduric Patients Using Microsatellite Length Polymorphism, Antifungal Susceptibility, and Enzymatic Profiles

Background: Candida glabrata is the second agent of candiduria with increased resistance to antifungals. Microsatellite length polymorphism (MLP) is one of the genotyping techniques used in the epidemiological investigation to improve clinical management. Objectives: We aimed to detect different genotypes of C. glabrata isolates using six microsatellite markers and the MLP technique. Moreover, our genotypes' association with other countries' genotypes was illustrated using a minimum spanning tree. We investigated in vitro antifungal susceptibility and enzymatic activity profiles of the isolates. Methods: Six microsatellite markers were amplified using multiplex-PCR for 22 C. glabrata strains isolated from urine in pediatric patients admitted to the Abuzar Children's Hospital in Ahvaz, Iran. The PCR products were presented for fragment analysis, and the size of the alleles was determined. Antifungal susceptibility tests and extracellular enzyme activities were also performed. Results: Nineteen multilocus genotypes were detected so that 22.7% of the strains had identical genotypes. The isolates were wild-type for amphotericin B (0.0625 - 2 µg/mL), itraconazole (0.125 - 2 µg/mL), and voriconazole (0.0078 - 0.00625 µg/mL). All the isolates were sensitive to fluconazole at the minimum inhibitory concentration (MIC) range (0.0312 - 16 μg/mL), and three of them were resistant to caspofungin (MIC ≥ 0.5 μg/mL). Moreover, 72.7 and 68.2% of the isolates had no phospholipase and esterase activities. The highest potency of enzymatic activity was obtained in hemolysin and proteinase enzymes. A high genetic diversity (19 genotypes of the 22 isolates) existed among the urinary C. glabrata isolates. Based on the minimum spanning tree, two clusters of our genotypes were related to C. glabrata genotypes in a previous study in Iran, and the third cluster was entirely connected with Chinese genotypes. Conclusions: Most of the isolates were the non-wild type for posaconazole but were rarely resistant to other antifungals. Hemolysin and proteinase secreted as the main virulence factors among the urinary C. glabrata isolates.