Tat'Yana Victorovna Tsareva

A coronavirus infection can have a negative impact on periodontal tissues, contributing to the development and progression of inflammatory processes due to changes in the composition and structure of the periodontal microbiome. Therefore, the aim of the study was to characterize the dental status and periodontal microbiome in patients with chronic (generalized) periodontitis (CGP) who had a coronavirus infection, as well as to identify the features of the clinical course of the disease and microbiological changes in this group compared to patients who did not have COVID-19. Materials and methods. A total of 120 patients diagnosed with CGP were randomized into 2 groups: those with and those without COVID-19, as well as subgroups based on the severity of COVID-19 infection and the severity of CGP. All patients underwent an index assessment of the main indicators of periodontal status, microbiological examination using real-time PCR (PCR-RT) and cultivation for the detection and identification of Candida fungi. Results. In the sample of COVID-19 patients, the most common Type I periodontopathogens (PP-1) were P. gingivalis, T. forsythia, A. actinomycetemcomitans and F. alocis (frequency from 64 to 77%), less often T. denticola and P. micra (45 and 27% accordingly), indicating their significant role in the formation of pathogenic microbiota in patients with CGP. C. albicans (48%) and rarer species in C. krusei and C. glabrata (20%) were detected significantly more often than in the group of non-COVID-19 patients. No association was found between the frequency of PP-1 isolation and the severity of CGP, but there was an increase in the isolation of F. alocis and P. micra in patients with progressive pathology (severe periodontitis, moderate and severe COVID-19). Conclusions. Contribution of individual microbial species to the development and progression of CGP may vary significantly depending on the presence and severity of the previous coronavirus infection. There was a significant increase in the colonization of the gingival biofilm by P. gingivalis, T. forsythia, A. actinomycetemcomitans, and new species such as F. alocis and P. micra, as well as fungi such as C. albicans, C. krusei, and C. glabrata.

Relevance. The treatment of periodontal diseases currently requires professional oral hygiene procedures involving various antiseptics used as mouth rinses and irrigants. Objective. To provide an experimental and microbiological rationale for the use of domestically produced periodontal antiseptics and their combinations to enhance antimicrobial efficacy through the application of innovative microbiological culturomics technologies. Materials and methods. To study the antimicrobial effects of antiseptics, an advanced RTS bioreactor (BioSan, Latvia) was employed. Unlike the previous RTS-1 monocultivator, the new model comprises eight integrated units. Each unit incorporates an innovative agitation mechanism for mixing microbial cultures, with digital data processing and real-time display. The following quaternary ammonium compound (QAC) antiseptics were tested: benzyldimethyl [3-(myristoylamino)propyl]ammonium chloride (Miramistin), benzalkonium chloride, and cetylpyridinium chloride, as well as chlorhexidine digluconate, used as the most common reference agent. The test strains included S. aureus ATCC 25993, E. faecalis , P. intermedia , F. necrophorum 89-5 (Federal Scientific Centre VIEV, FSC VIEV, Moscow, Russia), C. albicans ATCC 10231, and C. krusei Harvard ATCC 625. Results. Miramistin demonstrated superior antimicrobial efficacy compared to other QAC antiseptics when analyzing microbial growth kinetics. Bacteriostatic effects were achieved at concentrations ranging from 0.012% to 0.05%, while bactericidal effects occurred within 0.05–0.10%. For fungal cultures, fungistatic activity was observed at 0.05–0.10% concentrations, and fungicidal activity at 0.1–0.2%. Conclusion. Chlorhexidine showed slightly lower efficacy than Miramistin, particularly against fungal isolates, though it outperformed other QAC-based agents. Our findings indicate that QAC antiseptics – especially miramistin – have a milder impact on the composition of the oral microbiota than chlorhexidine.

Products from titanium and its alloys are actively used for the reconstruction of the musculoskeletal and maxillofacial systems of the body. However, in some cases, their rejection is observed, which is associated with the addition of bacterial infections. To accelerate the process of osseointegration, various methods of surface treatment are used, including sandblasting, which creates a certain microrelief, as well as the deposition of a bioactive coating of titanium dioxide (TiO2) with the anatase structure. Since the method of TiO2 formation, namely atomic layer deposition (ALD), has a certain sensitivity to the structure and chemistry of the initial surface, especially in the low-thickness range, the characteristics of the coating may depend on the implant material. Therefore, the purpose of this study is to evaluate the antiadhesive and antimicrobial properties of titanium and its alloy samples, taking into account the differences in their structure and type of surface treatment, including the formation of a TiO2 coating with anatase crystalline structure. Materials and methods. In order to quantitatively evaluate the in vitro microbial adhesion to samples of Grade 4 titanium (ASTM F67) and Ti6Al4V (ASTM F136)/Ti6Al7Nb (ASTM F1295) alloys with different surface treatments, authors used microbiological, molecular biological methods and statistical analysis. Results. The work studies samples of titanium and its alloys with various surface preparation, that can be used for orthopedic treatment. Comparative assessment was carried out for the first time which included adhesion of sanitary-significant microorganisms (for example, S. aureus, E. coli) and anaerobic bacteria to the studied samples. The lowest level of adhesion was observed on Ti6Al4V samples coated with TiO2, which indicates their bactericidal and fungicidal properties. Samples containing niobium (Ti6Al7Nb) showed selective anti-adhesive properties, which confirms their activity against viable microbial cells. Conclusions. The results highlight the potential effectiveness of TiO2 coating with anatase crystalline structure for utilization in medical implants and structures.

The aim of the study was to investigate and compare the primary and residual adhesion of microorganisms to the surface of dental prostheses made of Russian palladium-based alloys “Palladent” and “Palladent-UNI”. Samples of ceramic-coated and uncoated alloys were used. As a result of the study, the data were obtained that the ceramic-coated “Palladent-UNI” alloy samples showed a better statistically reliable result than the “Palladent” alloy samples. It was found that the zone of alloys and ceramic coating connection creates additional conditions for microorganisms fixation and increases the level of adhesion of some strains by 1.25—1.5 times. The obtained results showed low indices of primary adhesion of aggressive microbiota to the studied alloys.

INTRODUCTION: There are no sufficient numbers of studies in the modern literature devoted to investigation of the relationship between the use of fixed orthodontic appliances and changes in the qualitative and quantitative bacterial composition at certain periods of orthodontic treatment. AIM: To identify changes in the qualitative and quantitative composition of the microbiocenosis in the area of installed fixed appliances at different periods of orthodontic treatment. MATERIALS AND METHODS: The study included 40 participants aged 18–44 years. All patients had a history of occlusion pathologies, dento-alveolar anomalies, and needed orthodontic treatment with use of fixed metal bracket systems. Before installing a fixed ligature vestibular metal bracket system (OC Orthodontics, USA), all patients underwent sanitation by a dental therapist, professional oral hygiene (removal of hard and soft dental deposits, tooth polishing), and, if necessary, extraction of wisdom teeth/wisdom tooth germs. The microbiocenosis was assessed in the area of intended placement of braces before orthodontic treatment, in the area of installation of braces in the period of adaptation to the fixed appliance (at 1 month after fixing the appliance) and in the period of active treatment (at 6 months after fixing the appliance). RESULTS: On the initial examination, the frequency of detection of stabilizing microflora was 81.25%, periodontopathogenic microflora — 18.75%. In the period of adaptation, the frequency of detection of stabilizing microflora was 56.25%, the frequency of detection of periodontopathogens increased to 43.75% (p = 0.052). In the phase of active orthodontic treatment, a decrease in the frequency of detection of periodontopathogenic bacteria to 40.96% was observed, and the frequency of detection of stabilizing microflora was 59.04% (p = 0.007). The microbial number before the installation of fixed orthodontic appliances was 105 ± 102 CFU/cm2, in the adaptation phase — 107 ± 102 CFU/cm2, in the period of active treatment — 105 ± 102 CFU/cm2 (p = 0.008). CONCLUSION: In the course of clinical and laboratory study, species and quantitative composition of the oral microbiocenosis was found to have characteristic features at different stages of the orthodontic treatment: before installation of fixed orthodontic appliances, the so-called ‘stabilizing’ microorganisms prevail over representatives of the group of periodontopathogens, in the period of adaptation, the proportion of periodontopathogens increases significantly with a decrease in the proportion of stabilizing microflora, in the phase of active orthodontic treatment their ratio normalizes.

Разработка современных технологий дезинфекции и стерилизации инструментов медицинского назначения является крайне актуальной задачей, что определяется агрессивным воздействием используемых физических и химических агентов. Для повышения срока службы инструментов медицинского назначения в последние годы применяются защитные покрытия на основе нитрида титана, которые существенно повышают стоимость изделия по сравнению с аналогами без покрытия. Цель исследования — сравнительная оценка коррозионной стойкости образцов с защитными покрытиями под влиянием щелочных дезинфектантов с учетом оценки применения оригинальной методики микробной адгезии и конфокальной электронной микроскопии в эксперименте in vitro. Исследовали варианты формирования оптимальных металлокерамических покрытий, устойчивых к коррозионному действию дезинфектантов на основе TiC-NiCr, с использованием метода электроискрового лигирования для образцов стоматологических инструментов. Были использованы щелочные дезинфектанты «Венделин», «Мегадез Орто», «Трилокс» отечественного производства. Для контроля эффекта дезинфектантов до и после воздействия проводили стандартное исследование микробной адгезии со штаммами S. aureus, B. cereus, C. albicans, C. glabrata. Шероховатость и рельеф поверхности оценивали с помощью сканирующей электронной микроскопии. Установлено, что сформированные защитные покрытия не подвергаются коррозии при воздействии изучаемых растворов ДС при комнатной температуре. Напротив, на контрольных образцах (без покрытия) определяли увеличение микробной адгезии и признаки, указывающие на деструкцию и коррозию, зависимые от концентрации ДС. Оптимальные результаты по показателям микробной адгезии S. aureus и C. albicans были получены с III образцом (Ra=3,26 мкм), и, напротив, худшие показатели оказались у IV образца, который отличался самой значительной толщиной (40 мкм) и степенью шероховатости покрытия (Ra=3,73 мкм). Защитные покрытия из твердых растворов на основе железа: Fe241Ti9, Fе47C3, Cr-Ni-Fe-C и упрочняющей фазы карбида титана TiC на поверхности образцов обеспечивают их коррозионную стойкость при воздействии рабочими растворами щелочных ДС, а при использовании ДС «Трилокс» также концентратом. The development of modern technologies for disinfection and sterilization of medical instruments is an extremely urgent task, which is determined by the aggressive effects of the physical and chemical agents used. In recent years, titanium nitride-based protective coatings have been used to increase the life of medical instruments, which significantly increase the cost of the product compared to uncoated counterparts. The purpose of the study is to compare the corrosion resistance of samples with protective coatings under the influence of alkaline disinfectants, taking into account the assessment of the use of the original microbial adhesion technique and confocal electron microscopy in an in vitro experiment. . Options for forming optimal cermet coatings of TiC-NiCr-based corrosion-resistant disinfectants using the electrospark ligation method for dental instrument samples were investigated. Have been used alkaline disinfectants “Wendelin”, “Megadez Orto”, “Trilox” of domestic production were used. To control the effect of disinfectants before and after exposure, a standard microbial adhesion study was performed with strains of S. aureus, B. cereus, C. albicans, C. glabrata. Surface roughness and topography were evaluated by scanning electron microscopy. . It was found that the formed protective coatings are not subject to corrosion when exposed to the studied ET solutions at room temperature. In contrast, the control samples (uncoated) showed an increase in microbial adhesion and signs indicating degradation and corrosion dependent on the concentration of ET. Optimal results for the microbial adhesion of S. aureus and C. albicans were obtained with sample 3 (Ra=3.26 μm), and on the contrary, the worst results were obtained with sample 4, which had the most significant thickness (40 μm) and the degree of roughness of the coating (Ra=3.73 μm). . Protective coatings made of solid solutions based on iron: Fe241Ti9, Fe47C3, Cr-Ni-Fe-C and the...

Микробиологическое обоснование комбинированного подхода к антимикробной терапии инфекции пародонта, ассоциированной с пародонтопатогенными анаэробами

The problem of chronic periodontitis (CP) is actively discussed due to the recognition of the fact that periodontal microbial damage is closely related to a number of systemic diseases and probably plays an important role in the occurrence of comorbid pathology. The aim of the meta-analysis was to characterize the composition of the subgingival microbiome and to determine the peculiarities of the formation of associations of the new periodontal pathogen Filifactor alocis with other I and II order periodontal pathogenic bacteria, as well as with the commensal bacteria colonizing this biotope. The study presents data of patient examination with obligatory use of polymerase chain reaction methods and sequencing of 16S rRNA genes in 1529 healthy individuals and 2394 patients with CP, 136 patients with CP and concomitant atherosclerosis, 258 patients with CP and concomitant type 2 diabetes mellitus. It was confirmed that the basis of the oral microbiome under normal circumstances is composed of representatives of microaerophilic streptococci, corynebacteria, lactobacilli, as well as representatives of the Veillonella and Sphingobacterium genera. 16S sequencing and bioinformatic analysis allowed us to specify the taxonomic place of the new pathogen F. alocis, as well as representatives of normal microbiota in CP and comorbid somatic pathology.

Introduction. Periodontal diseases are a common pathology with chronic periodontitis (CP) being the most severe form. This polymicrobial disease has become a problem of great importance in recent years due to the possibility of development of systemic effects associated with this condition. CP is often combined with type 2 diabetes (T2D). The main cause of the occurrence and development of periodontal pathology is played by the bacteria Filifactor alocis, the least studied and most recently discovered periodontal pathogen. The objective of this study was to identify bacteria of genus Filifactor as part of the periodontal microbiome associated with CP and T2D and to clarify the mechanisms of their possible influence on associated metabolic processes according to comparative metagenomic analysis. Materials and methods. A metagenomic study of the microbiome of periodontal pocket samples from 28 patients with CP associated with T2D and 22 patients with CP, as well as the microbiome of dental gingival sulcus samples from 19 clinically healthy individuals was performed. 16S-sequencing of the ribosomal RNA gene was used to determine the taxonomic composition of the microbiome. Prediction of metabolic pathways involving the microbiome was performed with the help of the shotgun method. Results. Filifactor bacteria were the one of the most frequent microorganisms only in patients with CP associated with T2D. The rate of identification of these bacteria was correlated with low predicted metagenomic levels of fatty acid biosynthesis and pyrimidine metabolism in the affected area. Conclusion. The detection frequency of Filifactor bacteria in patients associated with CP and T2D is negatively correlated with the selected features of putative metabolic pathways of the microbiome, which include fatty acid biosynthesis and pyrimidine metabolism.

Микробное поражение тканей пародонта тесно связано с рядом системных заболеваний; возможно, оно играет важную роль в возникновении коморбидной патологии. Цель работы — идентификация патогена Filifactor alocis в качестве нового диагностического индикатора заболеваний пародонта у больных с хроническим пародонтитом (ХП) и ишемической болезнью сердца (ИБС). Обследовано 180 пациентов с ХП и сердечно-сосудистыми заболеваниями (ССЗ), в том числе острым инфарктом миокарда (ОИМ), стенокардией напряжения I—II функциональных классов, ИБС с постинфарктным кардиосклерозом и показаниями к реваскуляризации миокарда. Контрольную группу составили 60 больных с ХП средней степени тяжести без ССЗ. Проведена оценка стоматологического и кардиологического статуса, эндотелиальной дисфункции, состава ДНК основных видов пародонтопатогенных бактерий, включая новый маркер пародонтита F. alocis, в субгингивальной биопленке пациентов, биохимический анализ крови. Установлена статистически достоверная взаимосвязь между колонизацией субгингивальной биопленки пародонтопатогенными бактериями F. alocis и P. gingivalis с наличием ССЗ. У больных с ИБС частота выявления F. alocis и P. gingivalis, в том числе совместного, выше, чем у людей без ССЗ. Отношение рисков наличия F. alocis и P. gingivalis у больных с ОИМ — 2,76 (95% ДИ 1,24—6,15; p<0,05); у больных с ИБС — 2,25 (95% ДИ 1,00—5,03; p0,05). Выявлены взаимосвязи F. alocis и P. gingivalis с клиническими проявлениями острых и хронических ССЗ, что может указывать на их роль в качестве ключевых патогенов воспалительных заболеваний тканей пародонта и вспомогательных патогенов при ССЗ. Результаты проведенного проспективного исследования подтверждают важную роль ключевых пародонтопатогенных видов в рассматриваемой патологии и свидетельствуют о практической необходимости идентификации F. alocis и P. gingivalis у больных ХП, в том числе с коморбидными ССЗ. Microbial damage to periodontal tissues is closely associated with a number of systemic diseases and, possibly, plays an important role in the occurrence of comorbid pathology. The aim of the work is to identify the pathogen Filifactor alocis as a new diagnostic indicator of periodontal disease in patients with chronic periodontitis with coronary heart disease (CHD). . We examined 180 patients with chronic periodontitis (CP) and cardiovascular diseases (CVD), including: acute myocardial infarction (AMI), angina pectoris I—II FC classes (AP), coronary artery disease with postinfarction cardiosclerosis (CAD) and indications for myocardial revascularization. Control group — 60 patients with chronic periodontitis of moderate severity without CVD. Dental and cardiological status, endothelial dysfunction, DNA composition of the main types of periodontal pathogens, including a new marker of periodontitis F. alocis in the subgingival biofilm of patients, and a biochemical blood test were assessed. . Statistically significant relationship found between the colonization of the subgingival biofilm by periodontal pathogens F. alocis and P. gingivalis with the presence of CVD. In patients with coronary artery disease, the frequency of detection of F. alocis and P. gingivalis, including the joint, is higher than in people without CVD. The risk ratio for the presence of F. alocis and P. gingivalis in patients with AMI was 2.76 (95% CI 1.24—6.15; p<0.05); CAD patients — 2.25 (95% CI 1.00—5.03; p0.05). Relationships of F. alocis and P. gingivalis with clinical manifestations of acute and chronic cardiovascular diseases were revealed, which may indicate their role as key pathogens of inflammatory periodontal diseases and auxiliary pathogens in CVD. . The results of a prospective study confirm the important role of key periodontal pathogenic species in the pathology under consideration and indicate the practical need to identify F. alocis and P. gingivalis in patients with CP, including those with comorbid CVD.