Species identification, antifungal susceptibility patterns, and vitamin D3 level in women with vaginal candidiasis: a case-control study in Iran

Vulvovaginal candidiasis (VVC) is a fungal infection that is a global issue of women's health due to its association with morbidity, infertility, and economic costs. This study aimed to compare the vitamin D3 levels between women with VVC to healthy controls and determine the species distribution and susceptibility pattern of isolates. Species identification was performed using sequencing of the ITS-rDNA regions and amplification of the HWP1 gene. Antifungal susceptibility testing was determined by the disk diffusion method. Moreover, serum vitamin D3 levels were measured using a commercial ELISA (enzyme-linked immunosorbent assay) kit. Our results indicated that vitamin D3 level in women with VVC was lower than those of healthy women (p-value < .001). Candida albicans complex (62.8 percent) was the most common species, and most species were susceptible to fluconazole, itraconazole, ketoconazole, and nystatin. In conclusion, our study revealed a potential link between vitamin D3 deficiency and VVC in women. Although our findings showed significantly lower vitamin D3 levels in women with VVC, further research is needed to establish a definitive causative relationship between vitamin D3 deficiency and VVC. Nonetheless, our study highlights the potential importance of maintaining adequate levels of vitamin D3 and the need for further exploration in this area.

Evaluation of overtime phenotypic variation of yeasts in chronic vulvovaginal candidosis cases

Chronic vulvovaginal candidosis results either from reinfection or from the ability of Candida spp. to persist in the vulva and/or vagina. Persistence is usually associated with increased antifungal (mainly azoles) resistance rates, which can explain treatment failure, and/or increased expression of virulence factors by Candida spp. The aim of this study was to assess the mechanisms leading to Candida spp persistence, by studying sequential isolates from women with chronic vulvovaginal candidosis, focusing on strains genotypes, azole resistance and ability to form biofilms along the period of clinical evaluation.The strains were identified at species level by automated analysis of biochemical profiles and molecular typing evaluated by polymorphic DNA analysis. The capacity to form biofilm was assessed with a microtiter plate assay. Fluconazole susceptibility was determined by the microdilution broth assay at both pH 7 (following the recommended guideline) and pH 4.5 (as representative of vaginal pH).We studied samples from 17 clinically recurrent cases. In 53% of the chronic cases there were two or more isolates that had a phylogenetic relationship while the remaining (47%) were caused by different species. In those cases where related strains were involved in recurrence, we verified an increase in MIC at pH 7 and also an increased capacity to form biofilms over time. Significant correlation between these two parameters was observed only in cases caused by C. glabrata, evidencing the importance of these two factors to enhance persistence in the vaginal mucosa for this particular species.

LAY ABSTRACT

Chronic vulvovaginal candidosis (VVC) affects millions of women worldwide. We found that persistence of the same Candida strain on the vaginal mucosa does not account for the great majority of VVC cases. Moreover, modulation of biofilm formation and azole resistance overtime was investigated.