O. O. Yanushevich’s research while affiliated with Federal State Budgetary Educational Institution of Higher Education "Russian Biotechnology University (ROSBIOTECH) and other places

Periodontitis is accompanied by inflammation that causes dysregulation of the Wnt/β-catenin and TGF-β signaling pathways. This leads to a violation of the homeostasis of periodontal tissues. Components of the extracellular matrix (ECM) are an important part of biomaterials used for the repair of periodontal tissue. The purpose of this study was to evaluate the components of the effect of ECM (hyaluronic acid (HA), fibronectin (Fn), and laminin (Lam)) on the osteogenic and odontogenic differentiation of periodontal ligament stem cells (PDLSCs) in the collagen I hydrogel under conditions of disruption of the Wnt/β-catenin and TGF-β signaling pathways. The study showed that the addition of components of the ECM restored the expression of odontogenic markers in PDLSCs, which was absent during inhibition of the canonical Wnt signaling pathway, and their multidirectional effect on the secretion of transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein 2 (BMP-2). Fn and Lam suppressed the expression of odontogenic markers in PDLSCs against the background of inhibition of the TGF-β signaling pathway. The addition of HA under the conditions of the TGF-β signaling pathway improved BMP-2 secretion, preserving odontogenic differentiation. Thus, our results demonstrated that disruption of the Wnt/β-catenin and TGF-β signaling pathways causes disorders in the differentiation of PDLSCs, preventing the regeneration of periodontal tissues. This should be taken into account when developing multicomponent scaffolds that recapitulate the ECM microenvironment at endogenic regeneration of the periodontium. Inclusion of hyaluronic acid as one of these components may enhance the therapeutic effect of such biomaterials.

Citation: Kuznetsova, A.V.; Popova, O.P.; Danilova, T.I.; Latyshev, A.V.; Yanushevich, O.O.; Ivanov, A.A.

The majority of metagenomic studies are based on the study of bacterial biota. At the same time, the COVID-19 pandemic has prompted interest in the study of both individual fungal pathogens and fungal communities (i.e., the mycobiome) as a whole. Here, in this work, we investigated the human gut mycobiome during COVID-19. Stool samples were collected from patients at two time points: at the time of admission to the hospital (the first time point) and at the time of discharge from the hospital (the second time point). The results of this study revealed that Geotrichum sp. is more represented in a group of patients with COVID-19. Therefore, Geotrichum sp. is elevated in patients at the time of admission to the hospital and underestimated at the time of discharge. Additionally, the influence of factors associated with the diversity of fungal gut microbiota was separately studied, including disease severity and age factors.

The purpose of this study was to analyze various literature sources, giving an exhaustive overview of the characteristics of all structural materials currently used in the manufacture of dental implants, which will also determine the trend of new developments in materials science in dental implantology. The research material included literary data presented in scientific publications indexed in the bibliographic databases PubMed, ScienceDirect and E-library, using the keywords isolated and their combinations in Russian and English « dental implants, titanium, zirconium, ceramics, tantalum, biocompatibility, osteointegration, graphene» as search terms. The results showed that the use of all existing materials and technological processes for the production of dental implants is justified. To date, the task of further scientific research in this field is to search for and/ or create a material that meets all the necessary operational requirements for a dental implant, has greater biocompatibility, less toxic effects on the body or its absence, providing optimal functional and aesthetic properties, at the lowest possible cost of manufacturing the product. Studies of ceramic-metal materials with the addition of graphene are promising, as currently studies show its high potential acceptability for integration in the development of new materials and technological processes for the production of dental implants.

Antimicrobial resistance poses a serious threat to global public health. The COVID-19 pandemic underscored the need to monitor the dissemination of antimicrobial resistance genes and understand the mechanisms driving this process. In this study, we analyzed changes to the oropharyngeal and fecal resistomes of patients with COVID-19 undergoing therapy in a hospital setting. A targeted sequencing panel of 4,937 resistance genes was used to comprehensively characterize resistomes. Our results demonstrated that the oropharyngeal resistome is homogeneous, showing low variability over time. In contrast, fecal samples clustered into two distinct resistotypes that were only partially related to enterotypes. Approximately half of the patients changed their resistotype within a week of therapy, with the majority transitioning to a less diverse and ermB-dominated resistotype 2. Common macrolide resistance genes were identified in over 80% of both oropharyngeal and fecal samples, likely originating from streptococci. Our findings suggest that the fecal resistome is a dynamic system that can exist in certain “states” and is capable of transitioning from one state to another. To date, this is the first study to comprehensively describe the oropharyngeal resistome and its variability over time, and one of the first studies to demonstrate the temporal dynamics of the fecal resistotypes.

Gastroesophageal reflux disease (GERD) is a common chronic disease leading to a spontaneous and regular retrograde flow of gastric and/or duodenal contents into the esophagus. Reflux of the gastric contents into the oral cavity refers to the extraesophageal presentation of the disease, which, in the absence of timely treatment, can result in erosion of dental hard tissue (EDHT) through repeated exposure of the dental tissue to acidic contents. EDHT are non-carious lesions of the dental hard tissues (mainly enamel, and in some cases dentin), induced by a chemical reaction involving acids, which results in demineralization processes. The incidence rates of EDHT in adult patients with GERD are 32.5–51.5%. The EDHT in GERD develops in stages. Initially, the gradual degradation of tooth pelicula happens when it gradually becomes decayed by repeated acidic attacks. The loss of the pelicula results in direct contact of hydrochloric acid refluxate with the enamel surface and initiation of its demineralization at pH < 5.5 with dissolution of hydroxyapatite crystals. Given the high prevalence of GERD in the population, it seems important to update an integrated approach to the treatment of such patients, which involves pharmacotherapy provided by the gastroenterologist, as well as prevention and minimally invasive treatment of presentations in the oral cavity by the dentist. Patients with EDHT due to GERD need to maintain individual oral hygiene (use mouth washes with a neutral pH level, avoid abrasive toothpastes), use remineralization therapy at home applying remogels (Tooth Mousse), and also be observed by a dentist as part of the follow-up care. Minimally invasive treatment by the dentist involves restorations using composite tooth filling materials and ceramic veneers. It is reasonable to empirically use proton pump inhibitors twice a day for 3 months for the direct treatment of GERD in patients with EDHT.

Relevance. The COVID-19 pandemic caused by the SARS-CoV-2 virus has demonstrated the critical importance of understanding the mechanisms of transmission and finding effective methods of prevention. Particular attention has been paid to the role of oral hygiene, as the oral cavity serves as a major route of transmission. Studies show that the composition of the oral microbiota can influence the course and outcome of COVID-19 disease. Therefore, there is a need to study the effects of oral antiseptics on the microbiome, which may offer new opportunities for the prevention and treatment of this disease. Objective. The aim of this study is to evaluate the effectiveness of the oral cleansing foam «Parodontol PROF» in reducing the pathogenic microflora of the oral cavity in patients with COVID-19 and to assess its effect on the risk of secondary infections. Materials and methods. The study was conducted on the basis of the Clinical Medical Centre «Kuskovo» of Russian University of Medicine. It included 450 patients with a confirmed diagnosis of COVID-19. The participants were divided into two groups: the test group used oral cleansing foam, while the control group used no additional oral hygiene. Comparative analyses of the taxonomic composition of the oropharyngeal microbiota and dental plaque before and after the use of the cleansing foam were performed. Results . The study showed that patients who regularly used the cleansing foam «Parodontol PROF» had a significant decrease in the representation of pathogens, including Mycoplasma, and an increase in the number of beneficial commensals such as Lactococcus and Lactobacillus. These changes indicate the potential efficacy of this product to improve oral hygiene and reduce the risk of secondary infections. Conclusion. The study supports the hypothesis that improving oral hygiene with specialised antiseptic agents, such as a cleansing foam, may help to reduce pathogenic microflora in the oral cavity in patients with COVID-19. This, in turn, may reduce the risk of pathogen migration into the lower respiratory tract and the development of secondary infections. The findings emphasise the importance of further research in this area and the development of comprehensive approaches to oral hygiene management in the context of infectious diseases.

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has significantly impacted global healthcare, underscoring the importance of exploring the virus’s effects on infected individuals beyond treatments and vaccines. Notably, recent findings suggest that SARS-CoV-2 can infect the gut, thereby altering the gut microbiota. This study aimed to analyze the gut microbiota composition differences between COVID-19 patients experiencing mild and severe symptoms. We conducted 16S rRNA metagenomic sequencing on fecal samples from 49 mild and 43 severe COVID-19 cases upon hospital admission. Our analysis identified a differential abundance of specific bacterial species associated with the severity of the disease. Severely affected patients showed an association with Enterococcus faecium, Akkermansia muciniphila, and others, while milder cases were linked to Faecalibacterium prausnitzii, Alistipes putredinis, Blautia faecis, and additional species. Furthermore, a network analysis using SPIEC-EASI indicated keystone taxa and highlighted structural differences in bacterial connectivity, with a notable disruption in the severe group. Our study highlights the diverse impacts of SARS-CoV-2 on the gut microbiome among both mild and severe COVID-19 patients, showcasing a spectrum of microbial responses to the virus. Importantly, these findings align, to some extent, with observations from other studies on COVID-19 gut microbiomes, despite variations in methodologies. The findings from this study, based on retrospective data, establish a foundation for future prospective research to confirm the role of the gut microbiome as a predictive biomarker for the severity of COVID-19.