Novel Demodex detection method involving non-invasive sebum collection and next-generation sequencing.

Introduction: Demodex mites are common human ectoparasites found across a broad geographical range. They reside in pilosebaceous units of the skin and feed on sebum, epithelial and glandular cells. D. folliculorum is the more common mite, inhabiting the upper end of the pilosebaceous unit while D. brevis resides deeper in the skin and meibomian glands. Until now, Demodex mites have been obtained by various techniques such as skin scraping, cellophane tape, plucking eyelashes, and also by invasive biopsies. Aim: To assess whether non-invasively collected sebum samples of patients suspected of rosacea or demodicosis are suitable for NGS DNA Demodex analysis. Material and methods: Suspicion of seborrheic dermatitis or rosacea was the inclusion criterion. The study group consisted of 20 males, 1 female, age: 33-83, median: 58. Nasal dorsum was moisturized and an adhesive strip was applied. DNA was isolated from the sebum and sequenced with the use of MiSeq® Reagent Kit v2 and MiSeq® System. Results: Out of 7 patients who were positive by microscopy, 6 were found positive by NGS. Additional 4 patients were found positive only by NGS, adding to a total of ten. The NGS approach showed superior sensitivity compared to light microscopy (63% and 44%, respectively). In 3 patients, both Demodex species were identified by NGS. Conclusions: We believe to have proven that it is possible to study Demodex mites by NGS with sebum as the input sample. Furthermore, it is possible to identify and distinguish Demodex folliculorum from D. brevis in individual patients.

Effect of exopolysaccharides from cariogenic bacteria on human gingival fibroblasts.

Bacterial biofilm (dental plaque) plays a key role in caries etiopathogenesis and chronic periodontitis in humans. Dental plaque formation is determined by exopolysaccharides (EPSs) produced by cariogenic and periopathogenic bacteria. The most frequent cariogenic bacteria include oral streptococci (in particular S. mutans) and lactobacilli (most frequently L. acidophilus). In turn, the dominant periopathogen in periodontitis is Porphyromonas gingivalis. Development of dental caries is often accompanied with gingivitis constituting the mildest form of periodontal disease. Basic cellular components of the gingiva tissue are fibroblasts the damage of which determines the progression of chronic periodontitis. Due to insufficient knowledge of the direct effect of dental plaque on metabolic activity of the fibroblasts, this work analyses the effect of EPSs produced by S. mutans and L. acidophilus strains (H2O2-producing and H2O2-not producing) on ATP levels in human gingival fibroblasts (HGF-1) and their viability. EPSs produced in 48-hours bacterial cultures were isolated by precipitation method and quantitatively determined by phenol - sulphuric acid assay. ATP levels in HGF-1 were evaluated using a luminescence test, and cell viability was estimated using fluorescence test. The tests have proven that EPS from S. mutans did not affect the levels of ATP in HGF-1. Whereas EPS derived from L. acidophilus strains, irrespective of the tested strain, significantly increased ATP levels in HGF-1. The analysed EPSs did not affect the viability of cells. The tests presented in this work show that EPSs from cariogenic bacteria have no cytotoxic effect on HGF-1. At the same time, the results provide new data indicating that EPSs from selected oral lactobacilli may have stimulating effect on the synthesis of ATP in gingival fibroblasts which increases their energetic potential and takes a protective effect.

Towards a more effective strategy for COVID-19 prevention (Review).

At the end of 2019, a new disease, similar to severe acute respiratory syndrome (SARS) associated with SARS-CoV was reported in Wuhan, China. It was quickly discovered that the etiological factor of the new disease (COVID-19) was a previously unknown SARS coronavirus 2 (SARS-CoV-2). The global spread of of COVID-19 has lead to the declaration of a pandemic status in 2019-2020 as declared by the World Health Organization and Public Health Emergency of International Concern. SARS-CoV-2 characterizes with high epidemic potential and is effectively disseminated between humans. SARS-CoV and SARS-CoV-2 are closely related pathogens. Their prime route of distribution is air-droplet transmission. Combating infectious diseases disseminated by inhalation is very difficult, and mainly relies on the use of vaccines. However, despite the lack of an effective anti-SARS-CoV vaccine and specific antiviral drugs, the strict sanitary procedures proved to be sufficient to stop the SARS epidemic in June 2003. However, epidemic research has indicated that SARS-CoV-2 is transmitted in humans significantly more effectively than SARS-CoV; therefore, the COVID-19 pandemic continues to expand. This indicates that the so far anti-epidemic activities to control COVID-19 are insufficient. In the current review, the possibility of using interferon α (IFN-α) as a preventive agent of COVID-19 is discussed. The current data concerning anti-COVID-19 vaccines and specific drugs against SARS-CoV-2 are also discussed. The aim of the current review is to contribute to the introduction of a more efficient strategy in the protection of the human population against COVID-19.

MUC7 Level As A New Saliva Risk Factor For Dental Caries In Adult Patients.

Purpose: Data currently available indicate the significance of salivary mucins MUC5B and MUC7 in the protection of teeth against caries. Our study aimed to determine the relationship between dental caries in adults and levels of MUC5B and MUC7. Methods: The studies were conducted on 45 adult subjects selected on the basis of dental examination and calculation of the DMFT (Decayed, Missing, and Filled Teeth) index. Among these patients, two research groups were distinguished: group 1 included 19 caries-free subjects (DMFT = 0); and group 2 included 26 patients with severe caries (DMFT > 13.9). Samples of whole unstimulated saliva were collected and centrifuged. MUC5B and MUC7 content in saliva supernatant were estimated using an enzyme-linked immunosorbent sandwich assay (ELISA). Analysis of the obtained data receiver operating characteristic (ROC) curves was employed to define relationships between the contents of the studied mucins and the detected dental caries. Results: In subjects from group 1, the mean level of MUC5B amounted to 0.63 ± 0.35 ng/ml and this was significantly higher than the concentration of mucin in patients of group 2, which amounted to 0.38 ± 0.32 ng/ml (p = 0.023). The mean level of MUC7 amounted to 5.47 ± 1.18 ng/ml and this was significantly higher than the level of the mucin in group 2, which was 1.39 ± 0.86 ng/ml (p< 0.0001). In parallel, a relationship was detected between levels of the examined mucins and manifestation of dental caries. For MUC7, the optimal cut-off value was obtained (i.e. corresponding to 100% sensitivity and specificity), amounting to 2.5 ng/ml for the detection of dental caries risk. Conclusions: Development of dental caries is linked to reduced concentrations of MUC5B and MUC7. The level of MUC7 may represent a significant parameter clinically suitable for evaluation of disease risk.