ABSTRACT
The expression of toll-like and adhesive receptors on epithelial cells of the oral mucosa changes in different pathological conditions, both local and systemic levels, in particular, in chronic periodontitis. The long-term presence of periodontal pathogenic microorganisms in the gingival furrow stimulates and supports the inflammatory process. The interaction of periodontal pathogens with epithelial cells of the oral mucosa is the first stage of the development of periodontitis. The pathological process affects the function of epithelial cells, in particular their ability to interact with representatives of microbiocenosis. Therefore, the natural colonization of normal oral microbiota on buccal epitheliocytes, reflecting the ability of epithelial cells to microbial adhesion, is a sensitive indicator of various destabilizing processes. Determining the level of expression of toll-like TLR2 and TLR4 receptors on epithelial cells also allows us to assess the functional state of cells and the severity of the inflammatory process at the level of the oral mucosa, in particular, in chronic periodontitis. In this paper, we studied the receptor-dependent reactions of buccal epithelial cells in chronic periodontitis using flow cytofluorometry and by determining the level of natural (microbial) colonization. The authors also compared these methods for determining the functional state of mucosal cells in chronic periodontitis. The results showed that in patients with periodontitis, the activity of receptors involved in adhesive reactions with the oral microbiota changed slightly and was little higher than in healthy donors. At the same time, the expression of TLRs on epithelial cells in periodontitis changed significantly. Thus, the percentage of cells expressing TLR2 significantly increased, while TLR4 decreased. Concurrently, the percentage of mucosal cells that do not have TLRs increased significantly in oral pathology. Thus, the study of TLR2 - and TLR4-expression on buccal epithelial cells is a more representative test in assessing the severity of the inflammatory process in chronic periodontitis than determining the level of natural colonization.
Subject(s)
Adhesives , Mouth Mucosa , Epithelial Cells , Humans , Toll-Like Receptor 2/genetics , Toll-Like Receptor 4ABSTRACT
Due to the prevalence of biofilm infections caused by Klebsiella pneumoniae, in laboratory diagnostic practice it has a great importance to obtain a standard model of Klebsiella biofilm for evaluating the bactericidal effect and effectiveness of antimicrobial drugs. Describes the method of Klebsiella biofilms formation in vitro. The intensity of biofilm formation was evaluated by the ability of bacteria to bind the crystal violet. The degree of film formation was measured by optical density. The presence of an intercellular matrix was confirmed by staining of Congo-red solution followed by light microscopy. The effect of exogenous and endogenous factors on biofilm formation by K. pneumoniae strains was investigated. The influence of the nutrient composition, the age of the culture («daily¼, «weekly¼), the presence of oxygen and the temperature conditions were studied. The nutrient composition of the medium significantly influenced on biofilm formation of K. pneumoniae: DMEM stimulated biofilm formation in most strains in vitro compared to TSB. The age of the culture (daily, weekly) did not significantly affect the biofilm formation of Klebsiella. At the same time, the temperature of culturing and the presence of oxygen can both stimulate and inhibit biofilm formation, depending on the strain under study. Most strains of Klebsiella better form a biofilm under aerobic conditions at 37º C.
Subject(s)
Biofilms , Klebsiella Infections , Klebsiella pneumoniae , Anti-Bacterial Agents , HumansABSTRACT
When studying the effect of the metabolic products of clinical isolates of enterococci on the viability of Candida albicans, it was found that metabolites of all tested strains of Enterococcus faecium, E. faecalis had a fungistatic effect. At the same time a reliable fungicidal effect is a strain-specific feature. It is better to use the method of delayed antagonism on double-layer agar to assess the antifungal effect of enterococcal metabolism products.
