Effect of immunostimulation with bacterial lysate on the clinical course of allergic rhinitis and the level of γδT, iNKT and cytotoxic T cells in children sensitized to grass pollen allergens: A randomized controlled trial.

Background: There are many drugs for allergic rhinitis (AR), however, these drugs show variable clinical effectiveness and some side effects. Therefore, new methods of AR pharmacotherapy are being sought. Objectives: The objectives of this study were to evaluate the efficacy of polyvalent mechanical bacterial lysate (PMBL) therapy in improving the clinical course of grass pollen-induced AR (seasonal AR, SAR) in children and its effect on changes in the blood level of the γδT, iNKT and cytotoxic T cell subsets. Methods: Fifty children with SAR were enrolled in this study and were randomly assigned to either the PMBL group or the placebo group. The severity of SAR symptoms was assessed using the total nasal symptom score (TNSS) and visual analogue scale (VAS). During two visits (V1, V2), peak nasal inspiratory flow (PNIF) was measured and peripheral blood was collected for immunological analyses. The study also included 2 telephone contacts (TC1, TC2). Results: The severity of the nasal symptoms of SAR on the TNSS scale was revealed to have a significantly lower impact in the PMBL group vs the placebo group at measuring points TC1 and V2 (p = 0.01, p = 0.009, respectively). A statistically significantly lower mean severity of nasal symptoms of SAR on the VAS scale was recorded for children in the PMBL group compared to the placebo group at measuring points TC1, V2 and TC2 (p = 0.04, p = 0.04, p = 0.03, respectively). The compared groups do not show significant differences in terms of PNIF values at individual measuring points. There were no statistically significant changes in immune variables. For both groups, there was a statistically significant association between the level of Th1-like γδT cells and the severity of SAR symptoms expressed on the TNSS scale (p = 0.03) - the lower the level of Th1-like γδT cells, the higher the TNSS value. Conclusion: Administration of sublingual PMBL tablets during the grass pollen season proves to have a high efficacy in alleviating SAR symptoms in children sensitized to grass pollen allergens. Th1-like γδT cells may be used as potential markers for SAR severity in children. Clinical trial registration: ClinicalTrials.gov, identifier (NCT04802616).

Streptococcus sobrinus as a Predominant Oral Bacteria Related to the Occurrence of Dental Caries in Polish Children at 12 Years Old.

Dental caries is listed by the WHO as one of the major non-communicable diseases that need to be prevented and treated. The aim of the study was to evaluate the prevalence and severity of caries expressed as the Decayed, Missing and Filled Permanent Teeth (DMFT) index in 12-year-old Polish children and to verify bacterial species related to the occurrence of dental caries. Quantitative real-time PCR analysis of DNA isolated from saliva samples was performed to detect 8 cariogenic and periopathogenic bacterial strains. A total of 118 Polish children were enrolled in the study. They had low mean DMFT scores of 1.58 ± 1.98. The prevalence of dental caries in the children tested was low (53.4%), with a tendency to decrease compared to previous oral surveys. Bacterial abundance of other species in the dental caries and caries-free groups did not differ; however, periopathogenic Prevotella pallens, Fusobacterium nucleatum along with cariogenic Streptococcus mutans and Lactobacillus fermentum were significantly strongly correlated in the caries-active subjects. The prevalence of S. sobrinus was significantly higher in children with dental caries (p = 0.023) and correlated with higher DMFT. It may temporarily play an important role in the initiation of the cariogenic process or in its enhancement due to an ecological imbalance in dental microbiota.

Impact of Pneumococcal Vaccination on Nasopharyngeal Carriage of Streptococcus pneumoniae and Microbiota Profiles in Preschool Children in South East Poland.

In 2017, Poland introduced the 10-valent pneumococcal conjugate vaccine (PCV) into its national immunization schedule. This prospective study was conducted between March and June 2020 to determine the impact of vaccination on prevalence of the nasopharyngeal carriage of S. pneumoniae in 176 healthy children and to determine how conjugate vaccines indirectly affect colonization of nasopharyngeal microbiota. Pneumococcal isolates were analyzed by serotyping and antimicrobial resistance tests. Nasopharyngeal microbiota were detected and identified using the culture method and real-time PCR amplification primers and hydrolysis-probe detection with the 16S rRNA gene as the target. In the vaccinated group of children, colonization was in 24.2% of children, compared to 21.4% in the unvaccinated group. Serotypes 23A and 23B constituted 41.5% of the isolates. Serotypes belonging to PCV10 and PCV13 constituted 4.9% and 17.1% of the isolates, respectively. S. pneumoniae isolates were resistant to penicillin (34.1%), erythromycin (31.7%), and co-trimoxazole (26.8%). Microbial DNA qPCR array correlated to increased amounts of Streptococcus mitis and S. sanguinis in vaccinated children, with reduced amounts of C. pseudodiphtericum, S. aureus, and M. catarrhalis. Introduction of PCV for routine infant immunization was associated with significant reductions in nasopharyngeal carriage of PCV serotypes and resistant strains amongst vaccine serotypes, yet carriage of non-PCV serotypes increased modestly, particularly serotype 23B.