Periodontal Bacteria Research Articles

ВЛИЯНИЕ СТОМАТОЛОГИЧЕСКОГО ГЕЛЯ И ГЛИЦИНА НА ПСИХОЛОГО-СТОМАТОЛОГИЧЕСКИЙ СТАТУС КУРСАНТОВ ВЕДОМСТВЕННОГО ИНСТИТУТА ПРИ РАССТРОЙСТВЕ ПРИСПОСОБИТЕЛЬНЫХ РЕАКЦИЙ

Dental diseases are a frequent manifestation of disorders of adaptive reactions, since the negative impact on the immune status of cadets is reflected in changes in the microflora of the oral cavity and periodontal [2, 5, 7, 9]. 
 The goal is to improve the therapeutic and preventive measures of inflammatory periodontal diseases caused by a disorder of adaptive reactions in cadets of the departmental institute.
 Matherials and methods. The group of the examined consisted of 171 people – cadets of 1–4 courses of the Ufa Law Institute of the Ministry of Internal Affairs of the Russian Federation in the Republic of Bashkortostan, aged 18–23 years. The study consisted of psychological testing, determination of the state of their vegetative reactions and cortisol content in saliva, molecular genetic determination of the composition of frequently occurring periodontopathogenic bacteria of the dentoalveolar furrow and enzyme immunoassay of the content of cytokines in the oral fluid of proinflammatory, cellular regulatory and immunosuppressive action.
 Results. The antimicrobial effect of the course application of supravival applications of dental gel Phagodent, together with Glycine, is manifested by a decrease in the frequency of detection of periodontal pathogenic bacteria - Tanerella forsythia and Aggregatibacter actinomycetemcomitans in persons with periodontal diseases not associated with a disorder of adaptive reactions. The use of supramural applications of dental gel is accompanied by a significant decrease in the level of IL-4, IL-12, IL-1ß, TFR-β in the oral fluid of persons with a disorder of adaptive reactions and periodontal inflammation.
 Conclusion. After the use of dental gel Phagodent and Glycine, there was a 4-fold decrease in the possibility of recurrence of periodontal diseases, the frequency of detection of Aggregatibacter actinomycetemcomitans in the microflora of the dental sulcus decreased by 66% of the frequency and Tannerella forsythia – by 30%, a decrease in the levels of IL-4, IL-12, IL-1ß, TFR-β in the oral fluid in the group with disorder of adaptive reactions and periodontal inflammation, as well as IL-10, TNF-α and IL-1β in the group without disorder, but with periodontal inflammation.

Validity of a combination of periodontal pathogens and salivary biomarkers as predictors of periodontitis.

Chronic periodontitis is caused by multiple risk factors. To predict chronic periodontitis in older people, we evaluated the association between a combination of major periodontal pathogens and salivary biomarkers and the presence of periodontitis. Stimulated saliva samples were collected to analyze the prevalence of Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Prevotella intermedia, as well as four biomarkers: interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2). A total of 201 Japanese patients were recruited. Oral examinations ware performed to determine chronic periodontitis as measured by Community Periodontal Index. The sociodemographic and behavioral characteristics were also obtained, and the parameters were adjusted as potential confounders to employ statistical models. The odds ratio (OR) for the presence of P.gingivalis and the third tertile level of IL-1β as compared with the absence of P.gingivalis and the lowest tertile of IL-1β was highest in individuals with periodontitis (OR=13.98; 95% confidence interval [CI] 3.87-50.52) with the best level (0.79) of area under the curve (AUC) based on the receiver operating characteristic curve. The OR for the presence of P.gingivalis and the third tertile of PGE2 was 7.76 (CI 1.89-31.91) with an AUC of 0.78. The coexistence of more than two periodontal bacteria and the third tertile of PGE2 was also strongly associated with chronic periodontitis (OR=9.23, 95% CI 2.38-35.79) with an AUC of 0.76. The combined information of the presence of P.gingivalis in stimulated saliva, and higher levels of salivary IL-1β may play a vital role in the detection and prediction of chronic periodontitis in older adults.

Prevalence of Methicillin and β-Lactamase Resistant Pathogens Associated with Oral and Periodontal Disease of Children in Mymensingh, Bangladesh.

Oral and periodontal diseases (OPD) is considered one of the main problems of dentistry worldwide. This study aimed to estimate the prevalence of oral and periodontal pathogenic bacteria along with their antimicrobial resistance pattern in 131 children patients aged between 4–10 years who attended in Mymensingh Medical College Hospital during October 2019 to March 2020. OPD pathogens were identified through isolation, cultural and biochemical properties, and nucleic acid detection. The isolates were subjected to antimicrobial susceptibility to 12 antibiotics commonly used in dentistry. In addition, the isolates were analyzed molecularly for the presence of six virulence and three antibacterial resistance genes. Five pathogens were identified, of which Staphylococcus aureus (S. aureus) (49%) and S. salivarius (46%) were noticed frequently; other bacteria included S. mutans (16.8%), S. sobrinus (0.8%) and L. fermentum (13.7%). The virulence genes—clumping factor A (clfA) was detected in 62.5% isolates of S. aureus, and gelatinase enzyme E (gelE) gene was detected in 5% isolates of S. salivarius, while other virulence genes were not detected. All the tested isolates were multidrug-resistant. The overall prevalence of MDR S. aureus, Streptococcus spp. and L. fermentum was 92.2%, 95.1% and 100%, respectively. It was observed that a high proportion of isolates were found resistant to 5–8 antibiotics. A majority of S. aureus, Streptococcus spp., and L. fermentum isolates tested positive for the β−lactamase resistance genes blaTEM and cfxA, as well as the methicillin resistance gene mecA. Phylogenetically, the resistance genes showed variable genetic character among Bangladeshi bacterial pathogens. In conclusion, S. aureus and S. salivarius were major OPD pathogens in patients attended in Mymensingh Medical College Hospital of Bangladesh, and most were Beta-lactam and methicillin resistant.

Classifying Integrated Signature Molecules in Macrophages of Rheumatoid Arthritis, Osteoarthritis, and Periodontal Disease: An Omics-Based Study.

Rheumatoid arthritis (RA), osteoarthritis (OA), and periodontal disease (PD) are chronic inflammatory diseases that are globally prevalent, and pose a public health concern. The search for a potential mechanism linking PD to RA and OA continues, as it could play a significant role in disease prevention and treatment. Recent studies have linked RA, OA, and PD to Porphyromonas gingivalis (PG), a periodontal bacterium, through a similar dysregulation in an inflammatory mechanism. This study aimed to identify potential gene signatures that could assist in early diagnosis as well as gain insight into the molecular mechanisms of these diseases. The expression data sets with the series IDs GSE97779, GSE123492, and GSE24897 for macrophages of RA, OA synovium, and PG stimulated macrophages (PG-SM), respectively, were retrieved and screened for differentially expressed genes (DEGs). The 72 common DEGs among RA, OA, and PG-SM were further subjected to gene–gene correlation analysis. A GeneMANIA interaction network of the 47 highly correlated DEGs comprises 53 nodes and 271 edges. Network centrality analysis identified 15 hub genes, 6 of which are DEGs (API5, ATE1, CCNG1, EHD1, RIN2, and STK39). Additionally, two significantly up-regulated non-hub genes (IER3 and RGS16) showed interactions with hub genes. Functional enrichment analysis of the genes showed that “apoptotic regulation” and “inflammasomes” were among the major pathways. These eight genes can serve as important signatures/targets, and provide new insights into the molecular mechanism of PG-induced RA, OA, and PD.

Regulation of gingival keratinocyte monocyte chemoattractant protein-1-induced protein (MCPIP)-1 and mucosa-associated lymphoid tissue lymphoma translocation protein (MALT)-1 expressions by periodontal bacteria, lipopolysaccharide, and interleukin-1β.

The aim of this study was to evaluate oral bacteria- and interleukin (IL)-1β-induced protein and mRNA expression profiles of monocyte chemoattractant protein-1-induced protein (MCPIP)-1 and mucosa-associated lymphoid tissue lymphoma translocation protein (MALT)-1 in human gingival keratinocyte monolayers and organotypic oral mucosal models. Human gingival keratinocyte (HMK) monolayers were incubated with Porphyromonas gingivalis, Fusobacterium nucleatum, P. gingivalis lipopolysaccharide (LPS) and IL-1β. The protein levels of MCPIP-1 and MALT-1 were examined by immunoblots and mRNA levels by qPCR. MCPIP-1 and MALT-1 protein expression levels were also analyzed immunohistochemically using an organotypic oral mucosal model. One-way analysis of variance followed by Tukey correction was used in statistical analyses. In keratinocyte monolayers, MCPIP-1 protein expression was suppressed by F. nucleatum and MALT-1 protein expression was suppressed by F. nucleatum, P. gingivalis LPS and IL-1β. P. gingivalis seemed to degrade MCPIP-1 and MALT-1 at all tested time points and degradation was inhibited when P. gingivalis was heat-killed. MCPIP-1 mRNA levels were increased by P. gingivalis, F. nucleatum, and IL-1β, however, no changes were observed in MALT-1 mRNA levels. Gingival keratinocyte MCPIP-1 and MALT-1 mRNA and protein expression responses are regulated by infection and inflammatory mediators. These findings suggest that periodontitis-associated bacteria-induced modifications in MCPIP-1 and MALT-1 responses can be a part of periodontal disease pathogenesis.

Oral Microbiota Profile in Patients with Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis.

Microbiota has been associated with autoimmune diseases, with nasal Staphylococcus aureus being implicated in the pathogenesis of anti-neutrophil cytoplasmic antibody–associated vasculitis (AAV). Little is known about the role of oral microbiota in AAV. In this study, levels of IgG antibodies to 53 oral bacterial species/subspecies were screened using immunoblotting in plasma/serum in pre-symptomatic AAV-individuals (n = 85), matched controls, and established AAV-patients (n = 78). Saliva microbiota from acute-AAV and controls was sequenced from 16s rDNA amplicons. Information on dental status was extracted from a national register. IgG levels against oral bacteria were lower in established AAV versus pre-AAV and controls. Specifically, pre-AAV samples had, compared to controls, a higher abundance of periodontitis-associated species paralleling more signs of periodontitis in established AAV-patients than controls. Saliva microbiota in acute-AAV showed higher within-sample diversity but fewer detectable amplicon-sequence variants and taxa in their core microbiota than controls. Acute-AAV was not associated with increased abundance of periodontal bacteria but species in, e.g., Arthrospira, Staphylococcus, Lactobacillus, and Scardovia. In conclusion, the IgG profiles against oral bacteria differed between pre-AAV, established AAV, and controls, and microbiota profiles between acute AAV and controls. The IgG shift from a pre-symptomatic stage to established disease cooccurred with treatment of immunosuppression and/or antibiotics.

Treatment resistance of rheumatoid arthritis relates to infection of periodontal pathogenic bacteria: a case–control cross-sectional study

Recent studies have shown that periodontitis is associated with rheumatoid arthritis (RA) and periodontal bacteria, such as Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) are involved in the pathogenesis of RA via citrullinated proteins. Smoking has also been shown to be involved in the pathogenesis of RA; however, the extent of this involvement is still poorly understood. In addition, RA and polymyalgia rheumatica (PMR) are sometimes difficult to differentiate; however, the relationship between PMR and the factors from smoking and periodontal bacteria is unclear. The aim of this study was to clarify the relationship between periodontal pathogenic bacterial infections and smoking in patients with RA or PMR. This case–control study included 142 patients with untreated RA or PMR. This study evaluated the serum antibody titers against periodontal pathogenic bacterial antigens and an anti-citrullinated peptide antibody (ACPA). In patients with RA, the relationship between antibody titers and disease activity of RA and response after 3 months of treatment was also investigated. Additionally, the effects of smoking were evaluated. Although there was no significant difference in serum antibody titer against periodontal pathogenic bacteria between the ACPA-positive RA group and the ACPA-negative PMR group, we found an association between the elevated antibody titer against Pg and the degree of ACPA value, especially between negative group and high-value positive group (≥ 100 U/mL). The antibody titers against Aa and Pg did not differ depending on disease activity score 28 (DAS28) at baseline; however, patients with high antibody titers had poor RA therapeutic response as judged by DAS28 after 3 months. We could not find any association between smoking and any of these parameters. Periodontal pathogenic bacteria, especially Pg, are associated with elevated ACPA levels. Our findings suggest that Pg and Aa infections interfere with the therapeutic response of RA.

Relationship between Obesity, Gingival Inflammation, and Periodontal Bacteria after 4-Week Weight Control Program in 20’s

Relationship between Obesity, Gingival Inflammation, and Periodontal Bacteria after 4-Week Weight Control Program in 20’s

Peridontitis as a Risk Factor for Attention Deficit Hyperactivity Disorder: Possible Neuro-inflammatory Mechanisms.

Periodontitis is a condition caused mostly by the creation of a biofilm by the bacterium P. gingivalis, which releases toxins and damages the tooth structure. Recent research studies have reported association between dental health and neuropsychiatric illnesses. Neuroinflammation triggered by the first systemic inflammation caused by the bacterium present in the oral cavities is a plausible explanation for such a relationship. Substantial amount of evidence supports the role of neuroinflammation and dysfunction of the dopaminergic system in the pathology of ADHD (Attention deficit hyperactivity disorders). Recent epidemiological, microbiological and inflammatory findings strengthen that, periodontal bacteria, which cause systemic inflammation can contribute to neuroinflammation and finally ADHD. Although both diseases are characterized by inflammation, the specific pathways and crosslink's between periodontitis and ADHD remain unknown. Here, the authors describe the inflammatory elements of periodontitis, how this dental illness causes systemic inflammation, and how this systemic inflammation contributes to deteriorating neuroinflammation in the evolution of ADHD. Therefore, the aim of this review is to present possible links and mechanisms that could confirm the evidence of this association.

Teeth bleaching effect and anti-oral microbial activity of water-extracted apple (Malus asiatica)

Apple contains nutrients such as sugars, dietary fiber, and vitamins as well as bioactive phytochemicals such as organic acid, fatty acid and phenolic compounds. This study was conducted to confirm the applicability of apples as a bleaching agent and functional substances for the prevention of oral infectious diseases and maintenance of oral health by investigating the bovine teeth bleaching effect, anti-oral microbial activity, and inhibitory effect of halitosis of water-extracted apple (WEA). From the results of quantitative analysis of the surface color of bovine teeth, the application of WEA significantly increased the ΔE value, indicating a bleaching effect. In the case of 100mg/ml, the ΔE value increased as the WEA application time increased, and the bleaching effect was the greatest. Based on the results of the disk diffusion test and selective culture using CRT bacteria test kit, WEA showed anti-oral microbial activity against the dental caries bacteria, Streptococcus mutans and Latobacillus casei, the periodontal bacteria, Aggregatibacter actinomycetemcomitans, and Eschericha coli, but showed no antifungal effect against Candida albicans, causing oral candidiasis. From the results of colony formation and generation of halitosis from salivary microorganisms, WEA inhibited the growth of salivary microorganisms and generation of components inducing halitosis such as hydrogen sulfide, methyl mercaptan and dimethyl sulfide, that occur during the metabolic process of oral microorganisms. Therefore, WEA is a functional substance derived from a safe and useful natural product that can be used for the prevention of oral infectious diseases and maintenance of oral health

Association between Vitamin D Receptor Gene Polymorphisms and Periodontal Bacteria: A Clinical Pilot Study.

Background: Periodontitis is an inflammatory disease caused by microorganisms involving the supporting tissues of the teeth. Gene variants may influence both the composition of the biofilm in the oral cavity and the host response. The objective of the study was to investigate the potential correlations between the disease susceptibility, the presence and the quantity of periodontopathogenic oral bacterial composition and the VDR gene polymorphisms. Methods: Fifty (50) unrelated periodontal patients and forty-one (41) healthy controls were selected for genomic DNA extraction. DNA concentration was measured and analyzed. The periodontopathogenic bacterial species were identified and quantified using a Real Time PCR performed with species-specific primers and probes. Results: Genotype distribution showed a different distribution between the groups for BsmI rs1544410 genotypes (p = 0.0001) with a prevalence of the G(b) allele in periodontal patients (p = 0.0003). Statistical significance was also found for VDR TaqI rs731236 (p ≤ 0.00001) with a prevalence of the T(T) allele in periodontal patients (p ≤ 0.00001). The average bacterial copy count for the periodontitis group was significantly higher than that of control group. Dividing patients into two groups based on high or low bacterial load, FokI rs2228570 T allele (f) was statistically more represented in patients with high bacterial load. Conclusions: The findings of the study suggest the involvement of the VDR gene BsmI and TaqI polymorphisms in periodontal disease, while FokI and BsmI may be involved in determining an increased presence of periodontopathogens.

Molecular Detection of Porphyromonas gingivalis in COVID-19 Patients

Background:SARS-CoV-2 infection has caused a global pandemic that continues to negatively impact human health. A large group of microbial domains including bacteria co-evolved and interacted in complex molecular pathogenesis along with SARS-CoV-2. Evidence suggests that periodontal disease bacteria are involved in COVID-19, and are associated with chronic inflammatory systemic diseases. This study was performed to investigate the association between bacterial loads of Porphyromonas gingivalis and pathogenesis of SARS-CoV-2 infection. Fifty patients with confirmed COVID-19 by reverse transcriptase-polymerase chain reaction, their age ranges between 20-76 years, and 35 healthy volunteers (matched accordingly with age and sex to the patients) participated in this case control study. Oral hygiene status was determined by the simplified oral hygiene index. Blood and saliva samples were obtained from patients and controls, Porphyromonas gingivalis quantification from extracted DNA of blood and saliva samples performed by means of real-time polymerase chain reaction. The present result revealed that the quantity of salivary Porphyromonas gingivalis was significantly higher (p=0.003) in the patients’ group than in the controls group, while there was no significant difference in the number of bacteria in the blood samples between the two groups. Moreover, the number of bacteria in severe cases was higher than that in moderate and mild with no significant differences, and there was a significant increase in the number of bacteria among patients with poor oral hygiene compared to patients with good oral hygiene. This study demonstrated that the high level of salivary Porphyromonas gingivalis in patients increases in number with disease severity, which may indicate that bacterial infections contribute to the spread of the disease.

Periodontitis and pregnancy outcomes

Placental and Periodontal environment have common aspects which suggests that periodontal microorganisms that enter the circulation and seed the placenta may find a niche that can support infection. When periodontal pathogens are being assessed, the timing of the seeding of the placenta for their possible contribution to adverse pregnancy outcomes can be challenging to determine. Samples from the placenta are generally taken at the time of delivery, and therefore when infection occurred, it is unknown. If a woman is considering becoming pregnant, and periodontitis is present, periodontal treatment should occur prior to the pregnancy as seeding occurs in the first trimester. The presence of periodontal bacteria (i.e. F.nucleatum and P.gingivalis) in the placenta does not itself constitute evidence of cause and effect regarding adverse pregnancy outcomes.

Oral microbiome dysbiosis triggers gestational periodontal disease and adverse pregnancy outcomes

Oral microbiome dysbiosis, triggered by increased oral pathogens or decreased commercial bacteria, leads to oral and systemic diseases. Recent ecological events suggest that periodontal disease is a risk factor of adverse pregnancy outcomes. The oral microbiome dysbiosis is believed to be associated with oral disease and adverse pregnancy outcomes (APO). However, the pathogenic mechanisms have not yet been elucidated. In this review, we summarize the recent literature on how pregnancy associated pathogenic oral microbiome dysbiosis can trigger gestational periodontal diseases and poor birth outcomes, especially the role of periodontal pathogenic bacteria in the mechanisms of how gestational periodontal diseases cause APO, and the effect of periodontal therapy during pregnancy on birth outcomes.

Utilization of Rhizosphere Earthworm Extracts to Support the Immune System

Periodontitis is an inflammatory condition caused by periodontal bacteria that are recognized by Toll-like receptors on neutrophils, macrophages, and other immune cells. As a result of this interaction, immune cells produce inflammatory molecules like cytokines and chemokines. In addition to the pathogenic effects of periodontitis, dysregulation of neutrophil activity can occur. The neutrophil acts as a double-edged sword in periodontitis, mobilizing defence mediators and tissue repair mechanisms while also causing further tissue damage. The goal of this study was to determine how Lumbricus luberus worm extract (EEW) affected the number of neutrophil cells in rats with periodontitis. A post-test design was used. Five Wistar rats, each infected with P. gingivalis, were divided into groups: a control group (no earthworm extract), an oral EEW (200 mg/kg/body weight) group, and a topical EEW gel group (20%). The number of neutrophil cells was measured on days 3, 7, 14, and 21. The study was carried out at the Udayana University Analytical Laboratory and the Veterinary Medicine Laboratory. The differences between control, oral, and topical Lumbricus rubellus extract administration on days 3 and 7 were significant (p < 0.05). On days 14 and 21, there was a significant difference (p < 0.05) between the control vs. oral administration groups and between the control vs. earthworm extract gel groups. However, on days 14 and 21, there was no significant difference between the oral administration and L. rubellus gel extract groups (p > 0.05). The number of neutrophils was significantly lower following the oral administration of L. rubellus earthworm extracts.
 Keywords: Wistar periodontitis rats, Lumbricus rubellus earthworm extract, neutrophil

The Application of Antimicrobial Photodynamic Therapy (aPDT) in the Treatment of Peri-Implantitis

Background This literature review evaluates the mechanisms and efficacy of different types of antimicrobial photodynamic therapy (aPDT) for treating peri-implantitis by reviewing existing experimental studies to provide guidance for the clinical application of antibacterial photodynamic therapy (aPDT) in oral implants. Materials and Methods From February 2001 to February 2021, we have collected 152 randomized controlled trials of aPDT for peri-implantitis by searching the experimental studies and clinical trials published in PubMed, Embase, Web of Science, and Google Scholar databases via online search. After screening the retrieved literature, we finally selected 10 statistically significant literature for evaluation and review. Results Compared with the traditional nonsurgical treatment of peri-implantitis, the aPDT was superior to the traditional mechanical irrigation treatment group in terms of periodontal indexes PD, BOP, PLI, and postoperative effect, and the difference was statistically significant (P < 0.05). Furthermore, the combination of the aPDT and other treatments shows the synergistic antibacterial effect, signifying better clinical effect in many aspects (P < 0.05). In these 10 papers, by comparing the probe depth (PD), bleeding on probing (BOP), synosteosis, and periodontal pathogenic bacteria detection, etc., obtained after treating peri-implantitis by application of the antimicrobial photodynamic therapy, and using the SPSS data analysis software for statistical data processing, we found that the antimicrobial photodynamic therapy combined with other periodontal treatments has a more prominent postoperative effect. Meanwhile, the antibacterial photodynamic therapy with targeted action of photosensitizer has strong specificity to some bacteria, while the synthetic photosensitize for antibacterial photodynamic therapy can show good inactivation effect on broad-spectrum periodontal anaerobes without side effect. Conclusion The experimental studies and clinical data of antibacterial photodynamic therapy for treating peri-implantitis show a good postoperative treatment effect. In addition, it did not develop resistance due to the use of antibiotic drugs. Owing to multiple advantages from combining antibacterial photodynamic therapy and other treatments, it is applicable for clinical treatment.

Profiling volatile compounds from culture supernatants of periodontal bacteria using gas chromatography/mass spectrometry/olfactometry analysis with a monolithic silica gel adsorption device

Halitosis is formed mainly by the volatile compounds produced by periodontal bacteria. Three volatile sulfur compounds (VSCs), hydrogen sulfide, methanethiol, and dimethyl sulfide, have attracted attention as major components of halitosis. However, these compounds cannot account for all odors. In this study, we profiled volatile compounds from the culture supernatants of periodontal bacteria using gas chromatography/mass spectrometry/olfactometry analysis with a monolithic silica gel adsorption device to investigate the potential odorous compounds. Periodontal bacteria have been found to produce volatile compounds belonging to various classes, such as alcohols, ketones, fatty acids, and aromatic compounds, in addition to VSCs. In addition, VSCs different from hydrogen sulfide and methanethiol, which are considered important causative compounds, may also influence to halitosis.

Immune Responses Regulated by Key Periodontal Bacteria in Germ-Free Mice.

The immune dysregulation induced by periodontal bacteria has important roles in the development of periodontitis. However, the role of key periodontal bacteria in local and systemic immunity has not been comprehensively studied. Herein, to explore immunoregulation maps of key periodontal bacteria, a mono-colonized germ-free mice model with P. gingivalis, F. nucleatum, and T. denticola for two weeks was designed in this study. The alveolar bone loss was determined by micro-CT. A total of 14 types of innate and adaptive immune cells of the gingiva, spleen, and colon were detected by multi-color flow cytometry. P. gingivalis induced the strongest innate immune response in gingiva and mononuclear phagocytes (MNPs) changed most significantly, compared to F. nucleatum and T. denticola. Immune dysregulation of the colon was widely induced by F. nucleatum. T. denticola mainly induced immune disorder in spleen. ILC3s, Tregs, CD11B+ dendritic cells s, MNPs, macrophages, and plasmacytoid dendritic cells were the main types in response to key periodontal bacteria. However, the alveolar bone loss was not induced by key periodontal bacteria. In conclusion, the overall immunoregulation of monomicrobial stimuli to decipher the complexities of periodontitis was provided in this study. P. gingivalis, F. nucleatum, and T. denticola have different effects on local and systemic immunity in gingiva, colon, and spleen of germ-free mice.

Antimicrobial Behavior and Cytotoxicity of Indocyanine Green in Combination with Visible Light and Water-Filtered Infrared A Radiation against Periodontal Bacteria and Subgingival Biofilm.

The widespread increase of antibiotic resistance highlights the need for alternative treatments such as antimicrobial photodynamic therapy (aPDT). This study aimed to evaluate the antimicrobial behavior and cytotoxicity of aPDT with indocyanine green (ICG) in combination with visible light (Vis) and water-filtered infrared A (wIRA). Representative periodontal bacteria (Parvimonas micra, Atopobium riame, Slackia exigua, Actinomyces naeslundii, Porphyromonas gingivalis, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, and Prevotella nigrescens) and subgingival in situ biofilms from periodontal patients were treated with aPDT for 5 min. ICG was used at different concentrations (50–500 µg/mL) and the number of viable cells was determined in colony forming units (CFU). Untreated negative controls and 0.2% chlorhexidine as a positive control were also prepared. The cytotoxicity test on human keratinocytes in vitro was analyzed with the AlamarBlue assay after 5, 10, and 20 min, with four ICG concentrations, and at two temperatures (room temperature and 37 °C). The tested periodontal pathogens treated with aPDT were eliminated in a range between 1.2 and 6.7 log10 CFU, except for A. naeslundii, which was killed at a lower range. The subgingival biofilm treated with aPDT expressed significant differences to the untreated controls except for at 300 µg/mL ICG concentration. The cytotoxicity was directly related to the concentration of ICG and irradiation time. These observations raise questions concerning the use of this specific aPDT as an adjuvant to periodontal treatments due to its possible toxicity towards human gingival cells.

Antibodies to a Citrullinated Porphyromonas gingivalis Epitope Are Increased in Early Rheumatoid Arthritis, and Can Be Produced by Gingival Tissue B Cells: Implications for a Bacterial Origin in RA Etiology.

Based on the epidemiological link between periodontitis and rheumatoid arthritis (RA), and the unique feature of the periodontal bacterium Porphyromonas gingivalis to citrullinate proteins, it has been suggested that production of anti-citrullinated protein antibodies (ACPA), which are present in a majority of RA patients, may be triggered in the gum mucosa. To address this hypothesis, we investigated the antibody response to a citrullinated P. gingivalis peptide in relation to the autoimmune ACPA response in early RA, and examined citrulline-reactivity in monoclonal antibodies derived from human gingival B cells. Antibodies to a citrullinated peptide derived from P. gingivalis (denoted CPP3) and human citrullinated peptides were analyzed by multiplex array in 2,807 RA patients and 372 controls; associations with RA risk factors and clinical features were examined. B cells from inflamed gingival tissue were single-cell sorted, and immunoglobulin (Ig) genes were amplified, sequenced, cloned and expressed (n=63) as recombinant monoclonal antibodies, and assayed for citrulline-reactivities by enzyme-linked immunosorbent assay. Additionally, affinity-purified polyclonal anti-cyclic-citrullinated peptide (CCP2) IgG, and monoclonal antibodies derived from RA blood and synovial fluid B cells (n=175), were screened for CPP3-reactivity. Elevated anti-CPP3 antibody levels were detected in RA (11%), mainly CCP2+ RA, compared to controls (2%), p<0.0001, with a significant association to HLA-DRB1 shared epitope alleles, smoking and baseline pain, but with low correlation to autoimmune ACPA fine-specificities. Monoclonal antibodies derived from gingival B cells showed cross-reactivity between P. gingivalis CPP3 and human citrullinated peptides, and a CPP3+/CCP2+ clone, derived from an RA blood memory B cell, was identified. Our data support the possibility that immunity to P. gingivalis derived citrullinated antigens, triggered in the inflamed gum mucosa, may contribute to the presence of ACPA in RA patients, through mechanisms of molecular mimicry.