Scalp psoriasis and biofilms: electron microscopy

Abstract

of transmission electron microscopy (TEM) - negative contrasting with phosphoric-tungstic acid (FVA) - was tested to identify microorganisms directly in epidermal scales in order to describe the frequency of their occurrence and their morphology. To carry out transmission electron microscopy (TEM) - negative contrast with the staining of the FVА with a microbiological loop, a part of the epidermal scales collected from the affected and unaffected areas of the patient’s scalp was transferred into sterile plastic tubes for Eppendorf microprobes (1.5ml) containing physiological solution (0.1ml) for 10 minutes. The resulting suspensions were applied with an automatic pipette on electron microscopic copper grids with a diameter of 3mm, covered with a transparent mold-varnished substrate-film. Then, a 1.5% solution of FVA (pH 6.7) was applied to the grids with the material for 10 minutes, which stained the objects negatively in black and allowed TEM to clearly reveal the details of their ultrastructural organization. After staining with FVA, the grids were washed with distilled water, transferred to dry filter paper in a Petri dish, dried for 10 minutes, and examined in TEM Jem 100-SX (Jeol, Japan). Abstract Psoriasis is an immune-mediated inflammatory skin disease. When examining punch biopsies of a patient’s scalp with psoriasis, we for the first time used scanning electron microscopy (SEM) in combination with the express method of transmission electron microscopy (TEM) - negative contrasting with phosphoric tungsten acid (FVA). The study compared biopsies from scalp affected and unaffected by psoriasis. It was shown that psoriatic areas of the scalp are covered with bio films consisting of clusters of coccoid bacteria and yeast cells of fungi, connected by thin chaotically located strands. The number of hairs on the affected skin area with psoriasis was 2 times less than on the unaffected one. and the hair cuticle at the lesions was dystrophic. The use of the TEM method revealed only yeast cells in the scalp scales, which, in terms of size, shape (the presence of a wide scar) and monopolar budding, allowed them to be attributed to the genus Malassezia . Fungi of the genus Malassezia were less common in the scales of the affected skin area, as compared to the unaffected one. This discrepancy in the results can be explained by the fact that the formed bacterial-mycotic biofilms, due to the extracellular matrix, affect the vital activity of fungi and prevent them from freely settling between the scales. Most likely, it is the combination of bacteria and fungi in the form of bacterial-mycotic films on the skin that initiates the appearance of psoriatic eruptions, and in further studies it is advisable to consider bacteria and fungi in combination. It is necessary to find out what factors contribute to the formation of such associations during the formation of biofilms, which will allow finding new methods of therapy.