Determination of some virulence factors of Candida albicans cultured from samples of children with atopic dermatitis

Abstract

Background: In atopic dermatitis, impairment of the skin barrier function leads to increased susceptibility to environmental particles and pollutants, thereby contributing to disease pathogenesis and complications, as well as to an increased risk of fungal skin infections. In children with atopic dermatitis, infections caused by Candida species exacerbate the disease and reduce the effectiveness of treatment. Candida species are common opportunistic pathogens colonizing the skin and mucosal surfaces, and more than 200 species have been described. Among these, Candida albicans, C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei are most frequently isolated from the skin, mucosa, and oral cavity. In Mongolia, studies culturing skin fungi and determining their metabolic activity and virulence factors are limited, which constituted the rationale for the present study. Aim: To determine virulence factors and selected biochemical activities of Candida species. Materials and Methods: In this study, Candida species strains cultured from clinical samples of children with atopic dermatitis were used with research approval. The fungal strains preserved at –80°C were revived by culturing on Sabouraud Chloramphenicol Agar and evaluated microscopically after Gram staining. Biofilm-forming activity was determined using the microtiter plate method, in which cultures were grown in broth, optical density was measured using a microplate reader, and values were calculated using a standard formula. Phospholipase activity was assessed using egg yolk agar according to the method developed by Price et al. Results: Of the total cultured isolates, 54.1% (n=33) demonstrated weak biofilm-forming activity (≤ODc / ODc < ~ ≤2×ODc), while 32.79% (n=20) showed moderate biofilm-forming activity (2×ODc < ~ ≤4×ODc). Isolates exhibiting strong biofilm-forming activity (>4×ODc) accounted for 13.1% (n =8) Regarding phospholipase activity, 50% of the isolates showed strong activity, 30% showed moderate activity, 10% showed low activity, and 10% exhibited very weak activity. Conclusions: 1. Virulent fungal strains capable of attaching to host cells are involved in the pathogenesis of atopic dermatitis. 2. Atopic dermatitis is shown to contain fungal strains that damage host cells and are involved in the process of invasion.