Assessment of biofilmforming activity of Fusarium solani isolated from patients’ skin

Abstract

Objective. To study pathogenic factors (adhesion and biofilm formation) in F. solani isolated from skin of patients Materials and methods. A total of 86 strains of F. solani isolated from the skin of patients with a diagnosis of L30.3 “Infectious dermatitis” were selected. The reference strain F. solani F-819 was used for quality control. Samples were collected using a sterile cotton swab from an area of 5 × 5 cm. The primary incubation was at Saburo media (HiMedia, India). Determination of the adhesion of the strains was carried out in the previously developed model from a nitrocellulose plate. Biofilms were formed using the method by Pierce C. et al. in 96-well flat bottom polystyrene plates. The efficiency of F. solani biofilms was assessed by the optical density of the total biomass (staining with Cristal Violet extract) and exopolysaccharide matrix (staining with Congo Red extract). Results. The studied F. solani strains were divided into two groups: isolates from patients with acute course of the disease (group I, n = 54), and isolates from patients with chronic relapsing disease (group II, n = 32). The adhesion of microconidia of isolates from patients with a chronic form is higher compared to isolates from patients with an acute form (p = 0.013) and the reference strain (p = 0.007). 26 (81.2%) isolates from patients with chronic form of the disease and 19 (35.2%) isolates from patients with acute form had an increased ability to form biofilms. The total biofilm mass was higher in F. solani isolates from the patients with chronic disease than that in isolates from the patients with acute course of the disease, and already matured on the 4th day of incubation. An increase in number of exopolysaccharide matrix was observed in F. solani isolated from patients with chronic disease on the 5th day of incubation, which led to increase in total biofilm mass. Conclusions. This study showed that F. solani can form biofilms. Significant differences in adhesion and biofilm formation between clinical strains of F. solani isolated from patients with various forms of the disease were found.