[Study of the resistome of human microbial communities using a targeted panel of antibiotic resistance genes in COVID-19 patients]

AIM

To study overall drug resistance genes (resistome) in the human gut microbiome and the changes in these genes during COVID-19 in-hospital therapy.

MATERIALS AND METHODS

A single-center retrospective cohort study was conducted. Only cases with laboratory-confirmed SARS-CoV-2 RNA using polymerase chain reaction in oro-/nasopharyngeal swab samples were subject to analysis. The patients with a documented history of or current comorbidities of the hepatobiliary system, malignant neoplasms of any localization, systemic and autoimmune diseases, as well as pregnant women were excluded. Feces were collected from all study subjects for subsequent metagenomic sequencing. The final cohort was divided into two groups depending on the disease severity: mild (group 1) and severe (group 2). Within group 2, five subgroups were formed, depending on the use of antibacterial drugs (ABD): group 2A (receiving ABD), group 2AC (receiving ABD before hospitalization), group 2AD (receiving ABD during hospitalization), group 2AE (receiving ABD during and before hospitalization), group 2B (not receiving ABD).

RESULTS

The median number of antibiotic resistance (ABR) genes (cumulative at all time points) was significantly higher in the group of patients treated with ABD: 81.0 (95% CI 73.8-84.5) vs. 51.0 (95% CI 31.1-68.4). In the group of patients treated with ABD (2A), the average number of multidrug resistance genes (efflux systems) was significantly higher than in controls (group 2B): 47.0 (95% CI 46.0-51.2) vs. 21.5 (95% CI 7.0-43.9). Patients with severe coronavirus infection tended to have a higher median number of ABR genes but without statistical significance. Patients in the severe COVID-19 group who did not receive ABD before and during hospitalization also had more resistance genes than the patients in the comparison group.

CONCLUSION

This study demonstrated that fewer ABR genes were identified in the group with a milder disease than in the group with a more severe disease associated with more ABR genes, with the following five being the most common: SULI, MSRC, ACRE, EFMA, SAT.

[Composition of oropharyngeal microbiota in patients with COVID-19 of different pneumonia severity]

AIM

To identify features of the taxonomic composition of the oropharyngeal microbiota of COVID-19 patients with different disease severity.

MATERIALS AND METHODS

The study group included 156 patients hospitalized with confirmed diagnosis of COVID-19 in the clinical medical center of Yevdokimov Moscow State University of Medicine and Dentistry between April and June 2021. There were 77 patients with mild pneumonia according to CT (CT1) and 79 patients with moderate to severe pneumonia (CT2 and CT3). Oropharyngeal swabs were taken when the patient was admitted to the hospital. Total DNA was isolated from the samples, then V3V4 regions of the 16s rRNA gene were amplified, followed by sequencing using Illumina HiSeq 2500 platform. DADA2 algorithm was used to obtain amplicon sequence variants (ASV).

RESULTS

When comparing the microbial composition of the oropharynx of the patients with different forms of pneumonia, we have identified ASVs associated with the development of both mild and severe pneumonia outside hospital treatment. Based on the results obtained, ASVs associated with a lower degree of lung damage belong predominantly to the class of Gram-negative Firmicutes (Negativicutes), to various classes of Proteobacteria, as well as to the order Fusobacteria. In turn, ASVs associated with a greater degree of lung damage belong predominantly to Gram-positive classes of Firmicutes Bacilli and Clostridia. While being hospitalized, patients with severe pneumonia demonstrated negative disease dynamics during treatment significantly more often.

CONCLUSION

We have observed differences in the taxonomic composition of the oropharyngeal microbiota in patients with different forms of pneumonia developed outside hospital treatment against COVID-19. Such differences might be due to the presumed barrier function of the oropharyngeal microbiota, which reduces the risk of virus titer increase.

[The effectiveness of the drug Cholisal in the complex treatment of oral mucosa and periodontal diseases]

PURPOSE OF THE STUDY

Evaluation of the clinical efficacy of the drug holisal» according to the results of domestic and foreign studies on modern methods for treatment of inflammatory diseases of the oral mucosa mouth and periodontium.

MATERIALS AND METHODS

The study method was a comparative analysis of data obtained by various authors. The literature search was conducted on PubMed (www.ncbi.nlm.nih.gov), eLibrary (elibrary.ru) and ScienceDirect (www.sciencedirect.com).

RESULTS

The drug Cholisal reduces the duration of treatment, allows to increase the period of remission of the disease. It also promotes pain relief and accelerated mucosal epithelialization of the mouth mucosa.

CONCLUSION

Clinical studies of the drug Cholisal have shown that a wide range of its pharmacological action ensures the effectiveness of treatment of inflammatory diseases of the oral mucosa and periodontium by a combination of analgesic, antimicrobial, anti-inflammatory, and antifungal effects.

[Comparative evaluation of the shear bond strength of a universal adhesive system in different etching modes and a total etch adhesive system]

OBJECTIVE

To determine a comparative evaluation between the shear bond strength (SBS) of total etch adhesive system and the SBS of universal adhesive system in various etching techniques.

MATERIAL AND METHODS

There were made 60 sections of teeth for the laboratory research. The studied samples had been divided into 4 groups (15 samples in each group). The control group of the study was the Adper SingleBond 2 total etch adhesive system. The SingleBondUniversal adhesive system had been used in three comparison groups: the first group was the total etch technique; the second group was selective etch technique; the third group was self-etching techinque. The Zwick Roell Z010 testing machine had been used for the study. The received results were fixed. The statistical data were processed. Comparison of researched groups were performed in pairs using the nonparametric Mann-Whitney U test.

RESULTS

In the control group the average value of the shear bond strength (SBS) was 15.01±5.2 MPa, in the first comparison group - 15.6±4.8 MPa, in the second comparison group - 19.7±6.04 MPa, in the third comparison group - 17.9±5.85 MPa. The groups with SingleBondUniversal adhesive system in selective etch technique (19.74 MPa) and self-etching (17.9 MPa) technique had the highest average values of the shear bond strength. The universal adhesive system with total etch technique and the total etch adhesive system had statistically similar data (p≥0.05). The control group with Adper SingleBond 2 total etch adhesive system had the lowest shear bond strength (15.01 MPa).

CONCLUSIONS

The universal adhesive system had high average values of SBS in all etching techniques. During the comparative evaluation there were established correspondence between average values of SBS of universal adhesive system and SBS of total etch adhesive system. The universal adhesive system in selective etch technique had the highest shear bond strength (SBS) with enamel and dentin.

Analysis of the implementation of dental disease prevention programs in the pediatric dental service in several constituent entities of the Russian Federation

Relevance. High dental disease incidence in children is still a relevant problem of public health care in Russia. Regional or national oral disease incidence rates may decrease via the introduction of state or Regional prevention programs. School dentistry is crucial in the pediatric dental care system. Different socio-economic, climatic and geographical conditions of various Regions of the Russian Federation affect the possibilities of preventive program implementation in the child population. Purpose – to evaluate the implementation of dental disease prevention programs in pediatric dental services in several constituent entities of the Russian Federation.

Materials and methods. In 2020, employees of Moscow State University of Medicine and Dentistry visited the Regions of the Russian Federation 39 times within the implementation of the national project "Healthcare" and national medical centre activities. In these Regions, the study examined the following parameters: availability of a Regional dental disease prevention program, the functioning of dental offices in educational institutions, dental checkup coverage rate in children.

Results. The study revealed that most Regions have school-based dental offices in the pediatric dental service. School-based dental offices provide treatment and prevention procedures. The analysis showed that all studied constituent entities carry out dental checkups. However, the dental checkup coverage rate in children varies greatly.

Conclusions. A small number of Regions (23.07%) have approved and are implementing a Regional prevention program, several entities (20.51%) are validating similar programs. And the majority of the studied constituent entities (56.41%) don’t have Regional prevention programs.

[The effectiveness of parodontax toothpaste in the complex treatment of chronic gingivitis]

THE AIM OF THE STUDY

Was to evaluate the clinical efficacy of parodontax Comprehensive Protection (GlaxoSmithKline, London, UK) toothpaste in the complex therapy of chronic gingivitis.

MATERIALS AND METHODS

The study involved 119 volunteers; group 1 (n=59, age range 18 to 32 years) and group 2 (n=60, age range 20 to 35 years) with a diagnosis of chronic gingivitis (K05.1). The criterion for inclusion in the study was sulcus bleeding index (SBI) more than 1 point. Dental examination included SBI, papillary-marginal-alveolar index (PMA), and Green-Vermillion oral hygiene index (OHI-S). After determining the indices, all patients underwent professional oral hygiene and controlled tooth cleaning. Patients in group 1 (parodontax) were prescribed parodontax Comprehensive Protection toothpaste (GlaxoSmithKline, London, UK), patients in group 2 - a toothpaste that did not contain sodium bicarbonate. Repeated clinical examinations with the determination of the SBI, PMA, OHI-S were carried out after week 2 and 4.

RESULTS

After 4 weeks, SBI scores in group 1 were 63% lower than at baseline, and in group 2 - by 30%. PMA values at 4 weeks in group 1 were 58% and in group 2 30% lower, compared to baseline levels. The results of the analysis of the OHI-S index showed a statistically significant decrease in group 1 by 75%, while in group 2 by only 8% from the initial values. The difference in all index values between groups at 4 weeks of the study was statistically significant (p<0.05).

CONCLUSION

The use of parodontax Comprehensive Protection Toothpaste (GlaxoSmithKline, London, UK) has been shown to reduce the clinical signs of biofilm-associated gingivitis and effectively maintain optimal oral hygiene in patients.

[Clinic and treatment of the oral candidiasis]

OBJECTIVE

The aim of the study is to clarify the stages of examination of patients with various clinical manifestations of nosological forms of candidiasis and to evaluate the effectiveness of the ongoing antifungal therapy in the complex treatment of oral candidiasis, considering all factors and background diseases.

MATERIAL AND METHODS

56 patients were examined and treated, of which 41 were women and 15 were men with a clinical course of candidiasis (acute pseudomembranous candidiasis, chronic hyperplastic candidiasis, angular candidiasis cheilitis). The patients' age is from 33 to 78 years. All patients underwent a bacterioscopic examination of plaque. All patients diagnosed with oral candidiasis were prescribed complex treatment, which included both general and local therapy. The diagnosis and treatment of the patient's main diseases (diabetes mellitus, hypoparathyroidism, diseases of the gastrointestinal tract, blood diseases, etc.) were mandatory.

RESULTS

All patients taking antifungal therapy reported a significant improvement in the clinical condition of the oral mucosa. Burning sensation, pain, sensation of enlargement of the tongue, dryness in the oral cavity disappeared in the patients. After 2 weeks of drug therapy with fungicidal preparations, the patients were prescribed a second bacterioscopic examination. The results of laboratory studies showed the presence of single, non-budding Candida cells in the field of view and a minimal, diagnostically significant, degree of contamination, which corresponded to the candidacy.

CONCLUSIONS

The study showed that antifungal therapy for oral mucosa candidiasis should always be pathogenetically justified and should be carried out considering the patient's underlying disease.

[Autofluorescence visualization of the oral malignant lesions]

OBJECTIVE

The aim of the present paper was to observe the main features of the autofluorescence emission of the oral epithelial carcinomas.

MATERIAL AND METHODS

The study included four patients aged 38-61 years with the oral epithelial carcinomas located at a cheek, a floor of the mouth, a bottom lip. All the diagnoses were later confirmed histologically. The oral cavity was inspected traditionally and then using autofluorescence visualization. For autofluorescence emission excitation we used the home-made LED-based device emitting near 400 nm.

RESULTS

The tissue autofluorescence was visualized in the broad and narrow spectral bands. In comparison with the healthy mucosa the pathological lesions showed the large losses of the green autofluorescence emissions ("dark sport effect") which have been visualized at both spectral bands. The visualization in the broad spectral band allowed to reveal that three lesions had the local sites of red fluorescence of the endogenous porphyrins traditionally connected with the local inflammation.

CONCLUSION

Autofluorescence stomatoscopy is not only important but also mandatory for oncological screening and should be widely used as the additional method of oral mucosa examination in the common dental practice.

[Subjective, functional and microbiological parameters of the oral cavity in gastroesophageal reflux patients with acidic and subacidic refluctant]

The aim of the study was to compare dental and periodontal status, oral hygiene, salivation rate, functional parameters of saliva and oral microbiota composition in patients with gastroesophageal reflux disease (GERD) with acidic and subacidic refluctant. The study comprised 69 participants divided in 3 groups: 22 healthy volunteers (controls) and 2 main groups: 25 GERD patients with acidic (group 2) and 22 patients with subacidic refluctant (group 3). Poor dental and periodontal condition was revealed in group 3 patients probably because of aggressive intestinal content reflux in the oral cavity resulting in higher PMA an saliva pH values, Escherichia coli species in oral microbiota and low buffer capacity of saliva. The results show that GERD may be suspected due to oral manifestations thus promoting it's prompt treatment.

[The effectiveness of Sensodyne Instant effect toothpaste for dentin hypersensitivity treatment]

The article presents an analysis of the clinical efficacy of Sensodyne Instant Effect toothpaste containing sodium fluoride and tin fluoride for the treatment of increased sensitivity of hard dental tissues. The study proved long-term efficiency of Sensodyne Instant Effect toothpaste designed to reduce tooth hyperesthesia. Toothpaste Sensodyne Instant Effect can be widely recommended to reduce the hypersensitivity of dentin.

[Mineral composition of mixed saliva in patients with dental fluorosis]

The aim of the study was to assess the mineral composition of mixed saliva in dental fluorosis patients undergoing treatment with microabrasion and bleaching. The study included 60 patients aged 18-35 years with various forms of dental fluorosis. Group 1 included 40 patients in which enamel microabrasion was performed, group 2 - 20 patients with microabrasion and bleaching. Mixed saliva composition was analyzed with Olimpus automatic analyzing device. Dental fluorosis treatment in both groups resulted in saliva mineral composition changed associated with enamel demineralization which proves the necessity for calcium and phosphate containing compositions in these treatment groups.

[Clinical and laboratory evidence for effectiveness of whitening toothpastes]

The article presents clinical and laboratory data concerning application of whitening toothpastes "Rembrandt". The effects of these pastes on the soft tissues status, the content of mineral substances in enamel biopsy liquid, enamel surface were evaluated. The results confirm the necessity of differential application of agents for tooth whitening and also of using whitening toothpastes for improvement of teeth color.