Dynamic Production of Soluble Extracellular Polysaccharides by Streptococcus mutans

Caries development in the presence of Streptococcus mutans is associated not only with the production of extracellular water-insoluble polymers but also is based on water-soluble polysaccharides. The aim of this study was the evaluation of a novel glucan-specific Lectin assay for monitoring water-soluble EPS produced by S. mutans during several growth periods in different media. S. mutans cultures were grown for 24 h, 48 h, and 144 h in medium deficient of sucrose (A) and medium supplemented with 5% sucrose (B). Microtiter well plates were coated with cell-free supernatants followed by the addition of labeled Concanavalin-A and enzyme substrate. The substrate reactions were kinetically detected at 405 nm. The validation of the assay was performed using carbohydrates dextran, xanthan, and sucrose as reference. This new Concanavalin-A-based assay showed the highest sensitivity for dextran and revealed that the glucan production of S. mutans reached its maximum at 144 h in medium B according to bacterial maturation

Dynamic Production of Soluble Extracellular Polysaccharides by Streptococcus mutans

Caries development in the presence of Streptococcus mutans is associated not only with the production of extracellular waterinsoluble polymers but also is based on water-soluble polysaccharides. The aim of this study was the evaluation of a novel glucanspecific Lectin assay for monitoring water-soluble EPS produced by S. mutans during several growth periods in different media. S. mutans cultures were grown for 24 h, 48 h, and 144 h in medium deficient of sucrose (A) and medium supplemented with 5% sucrose (B). Microtiter well plates were coated with cell-free supernatants followed by the addition of labeled Concanavalin-A and enzyme substrate. The substrate reactions were kinetically detected at 405 nm. The validation of the assay was performed using carbohydrates dextran, xanthan, and sucrose as reference. This new Concanavalin-A-based assay showed the highest sensitivity for dextran and revealed that the glucan production of S. mutans reached its maximum at 144 h in medium B according to bacterial maturation

Characteristics and outcomes of SARS-CoV-2 breakthrough infections among double-vaccinated and triple-vaccinated patients with inflammatory rheumatic diseases

Objective To analyse the clinical profile of SARS-CoV-2 breakthrough infections in at least double-vaccinated patients with inflammatory rheumatic diseases (IRDs).Methods Data from the physician-reported German COVID-19-IRD registry collected between February 2021 and July 2022 were analysed. SARS-CoV-2 cases were stratified according to patients’ vaccination status as being not vaccinated, double-vaccinated or triple-vaccinated prior to SARS-CoV-2 infection and descriptively compared. Independent associations between demographic and disease features and outcome of breakthrough infections were estimated by multivariable logistic regression.Results In total, 2314 cases were included in the analysis (unvaccinated n=923, double-vaccinated n=551, triple-vaccinated n=803, quadruple-vaccinated n=37). SARS-CoV-2 infections occurred after a median of 151 (range 14–347) days in patients being double-vaccinated, and after 88 (range 14–270) days in those with a third vaccination. Hospitalisation was required in 15% of unvaccinated, 8% of double-vaccinated and 3% of triple-vaccinated/quadruple-vaccinated patients (p<0.001). Mortality was 2% in unvaccinated, 1.8% in the double-vaccinated and 0.6% in triple-vaccinated patients. Compared with unvaccinated patients, double-vaccinated (OR 0.43, 95% CI 0.29 to 0.62) and triple-vaccinated (OR 0.13, 95% CI 0.08 to 0.21) patients showed a significant lower risk of COVID-19-related hospitalisation. Using multivariable analysis, the third vaccination was significantly associated with a lower risk for COVID-19-related death (OR 0.26; 95% CI 0.01 to 0.73).Conclusions Our cross-sectional data of COVID-19 infections in patients with IRD showed a significant reduction of hospitalisation due to infection in double-vaccinated or triple-vaccinated patients compared with those without vaccination and even a significant reduction of COVID-19-related deaths in triple-vaccinated patients. These data strongly support the beneficial effect of COVID-19 vaccination in patients with IRD.Trial registration number EuDRACT 2020-001958-21