Background. Atopic dermatitis is an inflammatory skin disease characterized by recurrent lesions and intense pruritus. Nowadays there is a stepwise approach to the treatment of atopic dermatitis, which is defined by disease intensity and complications such as secondary skin infections. However, the current management of atopic dermatitis may not always lead to the expected outcome due to not only immune dysregulation of both adaptive and innate immunity but also imbalance of the skin microbiome. Aims. The aim of the study was to evaluate changes in the composition of the skin microbiome in both lesional and non-lesional skin in patients with atopic dermatitis during standard treatment. Materials and methods. Twenty patients with atopic dermatitis and twenty six healthy controls over 18 years old were included into the study. All microbiome samples were obtained from lesional and non-lesional skin sites of atopic dermatitis patients before and after therapy. Whereas samples from healthy controls were taken once from a flexor surface of the elbow. Species identification of clinical isolates were identified using MALDI Biotyper Sirius (Bruker Daltonics). Results. At baseline, the prevalence of S. aureus colonization among patients with atopic dermatitis was 34.20% in lesional skin and 32.50% in non-lesional skin. After treatment, there was a significant decrease in the prevalence of S. aureus carriage in both lesional and non-lesional skin areas (р 0.05). However, no significant difference was observed in the proportion of all other staphylococci (р 0.1). Interestingly, S. aureus was not found in healthy controls. Conclusions. The results of the study demonstrated the effectiveness of standard therapy for managing patients with atopic dermatitis as it had a positive impact on the skin microbial community and showed a decrease in S. aureus proportion after the treatment.

BACKGROUND: Oral lichen planus is a chronic inflammatory condition of the oral mucosa characterized by white, lacy lesions. The etiology of oral lichen planus is complex and remains unclear, but it is thought to be a T-cell mediated autoimmune disease. Several factors have been implicated in the pathogenesis of oral lichen planus, including genetic predisposition, dental materials, iatrogenic factors, infections, autoimmunity, and bowel disease. The microflora of the oral cavity plays an important role in maintaining oral health and preventing disease. However, its role in the development and progression of oral lichen planus is not yet totally understood. Some studies have shown that there are differences in the microflora of oral lichen planus patients compared to healthy controls. These differences may be related to the inflammatory process in oral lichen planus, or they may be a contributing factor to the disease. AIM: Identify the prevalence of the detection of periodontopathogenic microorganisms in oral lichen planus patients and compare their prevalence in healthy non-oral lichen planus patients. MATERIALS AND METHODS: A cross-sectional, single-center study was conducted. A total of 75 patients were recruited, 45 with oral lichen planus and 30 healthy controls. The groups were formed by simple random sampling. The diagnosis of oral lichen planus was confirmed histologically in the main group. The forms and localization of oral lichen planus were determined in the main group based on clinical examination. In the control group, patients were divided into two subgroups depending on the presence of chronic periodontitis or gingivitis. The prevalence of periodontal pathogens was assessed based on the analysis of culture results. Among the 48 bacteria isolated from the oral mucosa of the affected site in the main and control groups, we focused on the microbiota of only periodontal bacteria to study their role and assess their impact on disease progression. RESULTS: Among the 45 patients with a clinical diagnosis of oral lichen planus, there were 10 (22.22%) men and 35 (77.78%) women, with a mean age of 55.3±13.4 years. The control group included 30 healthy volunteers, 8 (26.67%) men and 22 (73.33%) women, with a mean age of 54.8±12.7 years. In patients with oral lichen planus regardless of their periodontal status the percentage of seropositivity for A. actinomycetemcomitans, V. parvula, P. gingivalis, T. denticola is higher compared to their healthy counterparts with gingivitis and periodontitis. CONCLUSION: The study found an increased frequency of detection of pathogenic microorganisms, such as A. actinomycetemcomitans, V. parvula, P. gingivalis, and T. denticola, in patients with oral lichen planus, regardless of the presence of periodontitis. These periodontopathogens may be associated with oral lichen planus. However, further studies are needed to clarify their role in the pathogenesis of the disease.

Background. Pneumolysin (Ply) – bacterial cholesterol-dependent cytolysin produced by almost all strains of Streptococcus pneumoniae. Antibodies induced to pneumolysin for some extend are able to neutralize its pathogenic effect on cells.Aim. Investigation of the effect of monoclonal antibodies obtained to native (nPly) and recombinant (rPly) forms of Ply on the neutralization of the cytolytic activity of bacterial Ply in vitro and their preventive properties on mice challenged with a virulent strain of S. pneumoniae.Materials and methods. mAbs to the nPly and rPly forms of Ply was obtained from the ascitic fluid of mice. Polyclonal antibodies pAbs (rPly) were obtained from the serum of rabbits immunized with rPly. The inhibition of erythrocyte hemolysis was assessed by the minimum concentration of mAbs (nPly), pAbs (rPly) and pAbs (rPly), which prevents lysis of erythrocytes induced by nPly. The neutralizing ability of antibodies was evaluated on the ovarian cells of the Chinese hamster CHO-K1 by the minimum concentration of antibodies necessary to protect cells from 4 cytopathogenic doses of nPly. The protective properties of the antibodies were studied with a single intraperitoneal injection of 200 µg of antibodies to mice, followed by challenge with a lethal dose of S. pneumoniae.Results. It was shown that 24 hours after intraperitoneal administration of nPly to mice, the body weight of the animals decreased and degenerative forms of red blood cells appeared in the blood. In in vitro experiments, nPly caused hemolysis of erythrocytes and destruction of CHO-K1 cells by the mechanism of apoptosis. mAbs (nPly), mAbs (rPly) and pAbs (rPly) inhibited erythrocyte hemolysis and neutralized the destruction of CHO-K1 cells. The highest neutralizing activity was shown by mAbs (rPly) and pAbs (rPly). A single injection of the studied antibodies to mice caused a decrease of their death when infected with the S. pneumoniae strain. There were no differences in the protective activity of antibodies.Conclusion. Methods based on neutralizing the toxic effect of Ply S. pneumoniae with the help of antibodies can be considered as a tool to reduce the pathogenicity of pneumococci.

BACKGROUND: Autoimmune pemphigus is a group of severe, potentially fatal bullous dermatoses affecting both skin and mucous membranes. To date, the pathogenesis and therapeutic approaches to the disease have been well studied; despite this, secondary bacterial complications remain the leading cause of death in these patients. Study of qualitative and quantitative composition of skin microbiome in chronic dermatoses is an actual contemporary problem. These data allow one to investigate the influence of microorganisms on the disease severity, relapse rate and remission duration. Analysis of literature sources shows a high interest of scientific groups in the study of microbiome components of the skin and mucous membranes in patients with bullous dermatoses, however, similar works on autoimmune bullous vesicles are still limited. AIM: to compare the composition of the skin microbiome in patients with autoimmune pemphigus and a healthy control group based on the results of the culture method performed. MATERIALS AND METHODS: Experimental, prospective, comparative study. Seventeen patients with previously or first-time diagnosis of autoimmune vesicular disease, as well as a control group of 10 people were included in the study. Patients were enrolled between November 2021 and November 2022. Rakhmanov clinic. All study participants had their skin swabs taken (for patients with rash elements and with apparently unchanged skin in the back or chest area; for the control group, from healthy skin in the back area), after which the material was taken to the laboratory for culture study. RESULTS: Data from 17 patients (5 men, 29.5%; and 12 women, 70.5%; average age 5113.3 years) were analyzed. Also included were 10 individuals from the control group (7 women, 70%; and 3 men, 30%; mean age 4014.7 years). Bacterial growth was detected in all samples submitted. No other microgranisms were identified. Eleven bacterial species were detected on the skin from the rash elements. The most frequent species encountered were: Staphylococcus aureus (in 70.59% of patients), Staphylococcus epidermidis (35.3%), Staphylococcus hominis (17.63%), Staphylococcus haemolyticus and Corynebacterium aurimucosum (11.8%). Twelve bacterial species were isolated on visibly unchanged skin. The most frequent were S. epidermidis (52.9%), S. aureus and S. hominis (35.3%), Staphylococcus capitis and Staphylococcus warneri (17.65%), Micrococcus luteus (11.76%). Fifteen bacterial species were identified in the control group. The following species were found most frequently: S. hominis (60%), S. capitis (50%), M. luteus (40%), S. epidermidis, S. haemolyticus and S. warneri (20%). The mean value of bacterial colony-forming units per 1 ml on rash elements was 5106.338752.46; on visibly unchanged skin 593.231223.06; in the control group 349.33915.52. CONCLUSIONS: We were able to obtain primary data on the composition of the skin microbiome in 17 patients with various types of autoimmune pemphigus and compare them with the control group. The data obtained demonstrate a great variety of microbial communities on the skin and a significant quantitative difference in the composition on the skin of patients and controls. A limitation of the study is the chosen cultural method, which cannot fully reflect all the diversity of microorganisms. To confirm the hypotheses put forward, we plan to conduct an additional study involving a larger number of patients and using genomic sequencing methods to identify microbial communities.

Intense training loads alter the skin microbiome and defence mechanisms in athletes, yet adaptation profiles remain insufficiently characterised. This study evaluated the relationships between skin bacterial microbiome structure, antimicrobial activity, dermcidin levels, and acne severity in male professional hockey players compared with amateur athletes and non-athletes. One hundred men (18–57 years) were examined and allocated to six subgroups by exercise intensity and acne status. Microbiota composition was assessed by culture-based methods and MALDI-TOF identification, antimicrobial activity measured spectrophotometrically, dermcidin quantified by ELISA, and sweat proteome characterised by HPLC-MS. Staphylococcus epidermidis and Micrococcus luteus predominated in all groups. Exercise intensity, rather than acne, was the main determinant of total bacterial colonisation, which increased approximately tenfold from non-athletes to professional hockey players. In non-athletes, higher antimicrobial activity correlated with greater acne severity, whereas in professionals this relationship was absent and dermcidin levels showed an inverse association with acne severity. Proteomic analysis identified 17 polypeptides; dermcidin and prolactin-inducible protein were dominant in all groups, and calprotectin (S100-A8/A9) was detected exclusively in healthy professionals.

Relevance. Nowadays, in oral surgery, it is still relevant to increase the effectiveness of collagen membranes in the oral cavity in the condition of potential microbial contamination of the wound.Purpose. The study aimed to conduct a comparative analysis of the growth of opportunistic oral bacteria on various collagen membranes.Material and methods. Based on the I.I. Mechnikov Research Institute for Vaccines and Sera, the study conducted a comparative analysis of the growth of opportunistic oral bacteria on the surface of resorbable collagen membranes developed by the Institute of Regenerative Medicine of the Sechenov University and an already existing foreign alternative. Microbial growth was assessed for S. aureus, S. mutans and C. albicans as the most significant microorganisms isolated from the oral cavity. The quantitative composition of microorganisms was analyzed in the control group without membranes and in groups with membranes (Group 2 – customized collagen membrane 2, Group 3 – membrane 3 with recombinant human lactoferrin, Group 4 – Mucograft membrane) on days 3, 5, and 7 from the start of membrane surface colonization. In all groups, we also evaluated the pH change in a 10% sucrose solution under the influence of biofilm microorganisms. Statistical data processing included the calculation of mean, standard deviations and medians, and comparison between groups was carried out using the Kruskal-Wallis test after assessing the samples' distribution normality. The results were statistically significant at a minimum of 95%.Results. The performed analysis showed statistically significant differences in the quantitative composition of the microbial biofilm on the surface of all three membranes. The developed collagen membrane with lactoferrin showed the best result at all times, while the customized collagen membrane did not significantly differ from the Mucograft membrane in CFU values and medium pH change. This provision was statistically significant for all three studied microorganisms.Conclusion. The study showed the potential of using manufactured collagen membranes to eliminate soft tissue defects in the oral cavity under the condition of their surfaces' possible contamination as an alternative to foreign membranes.