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Objectives: The use of probiotics could promote the balance of the subgingival microbiota to contribute to periodontal health. This study aimed to identify the potential of bacteria commonly associated with healthy periodontal tissues as probiotic candidates. Material and methods: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the PubMed, Scopus, Science Direct, ProQuest, and Ovid databases as well as the combination of Medical Subject Headings (MeSH) and non-MeSH terms. Based on the selection criteria, original studies published in English and identifying the microorganisms present in the periodontium of healthy individuals and patients with periodontitis using the high-throughput 16S ribosomal gene sequencing technique were included. Results: Out of 659 articles, 12 met the criteria for this review. These articles were published from 2012 to 2020 and mainly originated from the United States, China, and Spain. Most of these studies reported adequate criteria for selecting participants, using standardized clinical criteria, and compliance with quality based on the tools used. In periodontal healthy tissue were identified species like Actinomyces viscosus, Actinomyces naeslundii, Haemophilus parainfluenzae, Rothia dentocariosa, Streptococcus sanguinis, Streptococcus mitis, Streptococcus oralis, Streptococcus gordonii, Streptococcus intermedius, and Prevotella nigrescens which have recognized strains with a capacity to inhibit periodontopathogens. Conclusions: S. sanguinis, S. oralis, S. mitis, and S. gordonii are among the bacterial species proposed as potential probiotics because some strains can inhibit periodontopathogens and have been reported as safe for humans. [ABSTRACT FROM AUTHOR]

No microbiological criteria were included in the 2018 EFP-AAP classification of periodontal diseases that could be used to differentiate between stages and grades. Furthermore, differences in the subgingival microbiome depending on stage and grade have not been established. Sixty subgingival biofilm samples were collected in Spain (n = 30) and Colombia (n = 30) from three distinct patient categories: those with periodontal health/gingivitis (n = 20), those with stage I-II periodontitis (n = 20), and those with stage III-IV periodontitis (n = 20). Patients were evaluated by 16S rRNA gene amplification sequencing. Amplicon sequence variants were used to assign taxonomic categories compared to the Human Oral Microbiome Database (threshold ≥97% identity). Alpha diversity was established by Shannon and Simpson indices, and principal coordinate analysis, ANOSIM, and PERMANOVA of the UNIFRAC distances were performed using QIIME2. Although differences in the alpha diversity were observed between samples according to country, Filifactor alocis, Peptostreptococcaceae [XI][G-4] bacterium HMT 369, Fretibacterium fastidiosum, Lachnospiraceae [G-8] bacterium HMT 500, Peptostreptococcaceae [XI][G-5] [Eubacterium] saphenum, Peptostreptococcus stomatis, and Tannerella forsythia were associated with periodontitis sites in all stages. However, only F. alocis, Peptostreptococcaceae [XI][G-4] bacterium HMT 369, Peptostreptococcaceae [XI][G-9] [Eubacterium] brachy, Peptostreptococcaceae [XI][G-5] [Eubacterium] saphenum, and Desulfobulbus sp. HMT 041 were consistent in stage III-IV periodontitis in both countries. Porphyromonas gingivalis and Tannerella forsythia were differentially expressed in severe lesions in the countries studied. Although some non-cultivable microorganisms showed differential patterns between the different stages of periodontitis, they were not the same in the two countries evaluated. Further studies using larger samples with advanced next-generation techniques for high-throughput sequencing of phyla and non-cultivable bacteria within the subgingival microbiome could provide more insight into the differences between stages of periodontitis. [ABSTRACT FROM AUTHOR]

Aim Destructive periodontitis is associated with a Th1-Th17 immune response and activation of RANKL-induced osteoclasts. In addition, Porphyromonas gingivalis K1 and K2 serotypes induce a strong Th1-Th17 response. This study aimed to investigate whether these P. gingivalis serotypes induce higher osteoclasts activation, by increased Th17-associated RANKL production, and an antigen-specific memory T-lymphocyte response. Material and Methods The RANKL production and TRAP+ osteoclast induction were quantified on naïve T lymphocytes stimulated with dendritic cells primed with the P. gingivalis serotypes. The T-bet, GATA-3, RORC2 and Foxp3 expression was correlated with RANKL production. The frequency of proliferating memory T lymphocytes in response to P. gingivalis serotypes was determined in both periodontitis and healthy subjects. Results T lymphocytes stimulated by K1 or K2-primed dendritic cells elicited higher levels of RANKL and TRAP+ osteoclasts than cells stimulated with the other serotypes. RANKL positively correlated with RORC2. Whereas periodontitis patients had a higher frequency of memory T lymphocytes responding to K1 or K2, healthy subjects had a higher frequency of memory T lymphocytes responding to K4 or K−. Conclusions P. gingivalis serotypes K1 and K2, but not others, are associated with an increased production of the osteoclastogenesis-related factor RANKL. This important information suggests that these serotypes could elicit a greater bone resorption in vivo and have a role in the periodontitis pathogenesis. [ABSTRACT FROM AUTHOR]

Aim Porphyromonas gingivalis can synthesize an extracellular capsule and different serotypes have been described based on capsular antigenicity. On dendritic cells ( DCs), the type of capsule present plays a role on the strength of the developed immune response. This study aimed to investigate the T-lymphocyte responses when stimulated with autologous mature DCs exposed to different P. gingivalis K-serotypes. Materials and Methods Naïve CD4+T-lymphocytes were obtained from healthy subjects and stimulated with autologous DCs primed with increasing multiplicity of infections of the different P. gingivalis K-serotypes. The Th1, Th2, Th17 and T-regulatory cytokines and transcription factor levels were quantified. Results Distinct types of response were detected when T-lymphocytes were stimulated by DCs primed with the different P. gingivalis K-serotypes. T-lymphocytes stimulated by K1 or K2-primed DCs elicited higher levels of Th1 and Th17-associated cytokines, T-bet and RORC2 than T-lymphocytes stimulated with DCs primed with the other serotypes. Conversely, the serotypes K3-K5 induced higher levels of Th2-associated cytokines and GATA-3 than the others. Conclusions These results demonstrate that DCs primed with the different P. gingivalis K-serotypes elicited distinct T-cell responses. Strains K1 (W83) and K2 ( HG184) induced a Th1/Th17 pattern of immune response and K3 (A7A1-28), K4 ( ATCC®49417™), and K5 ( HG1690) a Th2 response. [ABSTRACT FROM AUTHOR]

Background and Objectives One of the major disadvantages of DNA-based microbial diagnostics is their inability to differentiate DNA between viable and dead microorganisms, which could be important when studying etiologically relevant pathogens. The aim of this investigation was to optimize a method for the selective detection and quantification of only viable Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis cells by combining quantitative real-time polymerase chain reaction (q PCR) and propidium monoazide ( PMA). Material and Methods Three different concentrations of PMA (10, 50 or 100 μ m) were added to suspensions of 106 (CFU)/mL of viable/dead A. actinomycetemcomitans and P. gingivalis cells. After DNA isolation, q PCR was carried out using specific primers and probes for the tested bacteria. PMA was further tested with different mixtures containing varying ratios of viable and dead cells. The efficacy of PMA to detect viable/dead cells was tested by analysis of variance. Results For these specific bacterial pathogens, 100 μ m PMA resulted in a significant reduction of q PCR amplification with dead cells (106 CFU/mL), while with viable cells no significant inhibition was detected. PMA was also effective in detecting selectively viable cells by q PCR detection, when mixtures of varying ratios of viable and dead bacteria were used. Conclusions This study demonstrated the efficiency of PMA for differentiating viable and dead A. actinomycetemcomitans and P. gingivalis cells. This method of PMA-q PCR may be useful for monitoring new antimicrobial strategies and for assessing the pathogenic potential of A. actinomycetemcomitans and P. gingivalis in different oral conditions when using molecular diagnostic methods. [ABSTRACT FROM AUTHOR]

The objective was to characterize and compare the subgingival microbiota in patients diagnosed according to the World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions 2018. For this cross-sectional study, Spanish and Colombian subjects (characterized as health/gingivitis, periodontitis in stages I-II or stages III-IV) were clinically assessed, and subgingival samples were taken and processed by culture. The comparisons among patients with periodontal status (and between countries) was made using Mann–Whitney, Kruskal–Wallis, ANOVA and chi-square tests. The final sample consisted of 167 subjects. Eikenella corrodens and Parvimonas micra were more frequently detected in health/gingivitis and Porphyromonas gingivalis in periodontitis (p < 0.05). Higher total counts were observed in Colombia (p = 0.036). In Spain, significantly higher levels of P. gingivalis and Campylobacter rectus were observed, and of Tannerella forsythia, P. micra, Prevotella intermedia, Fusobacterium nucleatum, Actinomyces odontolyticus and Capnocytophaga spp. in Colombia (p < 0.001). P. micra was more prevalent in health/gingivitis and stage I-II periodontitis in Colombia, and P. gingivalis in all periodontitis groups in Spain (p < 0.05). As conclusions, significant differences were detected in the microbiota between health/gingivitis and periodontitis, with minor differences between stages of periodontitis. Differences were also relevant between countries, with Colombia showing larger counts and variability of bacterial species. [ABSTRACT FROM AUTHOR]

Objective: This study was aimed to compare the presence and amounts of bacteremia induced by interdental brushing in periodontally healthy (H) and periodontitis (P) individuals using culture based (direct culture [DC]) and molecular based techniques (real-time quantitative polymerase chain reaction [qPCR]) in a cross-sectional study model., Materials and Methods: After a full mouth periodontal evaluation, blood samples were taken before and 1 min after professionally-administered interdental brushing. These samples were analyzed by DC and qPCR, targeting Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Subgingival samples were also collected and analyzed. Student t-test, chi-squar tests and correlations were used for analyzing the data., Results: Thirty individuals per group were included. P. gingivalis and A. actinomycetemcomitans were detected with qPCR methods, but not with DC. At baseline, bacteremia was observed in 5 P patients (16.7%) and in 2 H individuals (6.6%) (p = 0.421). After interdental brushing, bacteremia was only observed in 2 P patients (6.6%) (p = 0.901). A positive correlation between subgingival and blood levels of A. actinomycetemcomitans was observed (r = 0.3; p = 0.013)., Conclusion: Bacteremia related to A. actinomycetemcomitans and P. gingivalis did not significantly increase after a single session of use of interdental brushes., (Copyright © 2018 Elsevier Ltd. All rights reserved.)