Periodontal Pathogen Porphyromonas Gingivalis Research Articles

Clinical and microbial evaluation of mouthwash containing Achyranthes aspera and Trachyspermum ammi: A randomized controlled non-inferiority trial

ObjectivesAchyranthes aspera (Apamarga) and Trachyspermum ammi (Ajwain) have been used in many clinical conditions, and it displays valuable properties as an alternative to Chlorhexidine (CHX) in the management of gingivitis. Therefore, this study aims to assess the effect of Achyranthes aspera and Trachyspermum ammi (AA + TA) based herbal mouthwash, 0.2 % CHX, and placebo mouthwash on gingival health, plaque control and antibacterial activity against specific periodontal pathogens (Porphyromonas gingivalis and Tannerella forsythia) using quantitative real-time PCR (RT-PCR). MethodsThis was a randomized controlled non-inferiority trial involving 108 children with plaque-induced gingivitis who were randomly assigned to three groups of 36 children each: Group A, AA + TA mouthwash; Group B, CHX mouthwash; and Group C, placebo mouthwash. Gingival index and plaque index were recorded at baseline, 7th and 21st day. RT-PCR was employed to determine the bacterial counts of each plaque sample at baseline and after 21 days. ResultsAll three groups exhibited a gradual and significant reduction in both gingival and plaque scores from baseline to days 7 and 21. However, the placebo group did not demonstrate a significant difference in scores between days 7 and 21. Furthermore, a significant reduction in bacterial counts of P. gingivalis and T. forsythia was observed in the groups receiving CHX and AA + TA mouthwash after 21 days of intervention compared to the placebo group. ConclusionAA + TA mouthwash demonstrated non-inferiority in anti-gingivitis and anti-plaque properties compared to CHX, suggesting its potential suitability as an alternative to CHX when used in conjunction with mechanical plaque control measures.

Comprehensive comparative analysis of the periodontal pathogen Porphyromonas gingivalis: exploring the pan-genome, the reconstruction of the gene regulatory network and genome-scale metabolic network.

Porphyromonas gingivalis is a nonmotile, obligate anaerobic, Gram-negative bacterium known for its association with periodontal disease and its involvement in systemic diseases such as atherosclerosis, cardiovascular disease, colon cancer, and Alzheimer's disease. This bacterium produces several virulence factors, including capsules, fimbriae, lipopolysaccharides, proteolytic enzymes, and hemagglutinins. A comparative genomic analysis revealed the open pangenome of P. gingivalis and identified complete type IV secretion systems in strain KCOM2805 and almost complete type VI secretion systems in strains KCOM2798 and ATCC49417, which is a new discovery as previous studies did not find the proteins involved in secretion systems IV and VI. Conservation of some virulence factors between different strains was observed, regardless of their genetic diversity and origin. In addition, we performed for the first time a reconstruction analysis of the gene regulatory network, identifying transcription factors and proteins involved in the regulatory mechanisms of bacterial pathogenesis. In particular, QseB regulates the expression of hemagglutinin and arginine deaminase, while Rex may suppress the release of gingipain through interactions with PorV and the formatum/nitrate transporter. Our study highlights the central role of conserved virulence factors and regulatory pathways, particularly QseB and Rex, in P. gingivalis and provides insights into potential therapeutic targets.

P. gingivalis in oral-prostate axis exacerbates benign prostatic hyperplasia via IL-6/IL-6R pathway.

Benign prostatic hyperplasia (BPH) is the most common disease in elderly men. There is increasing evidence that periodontitis increases the risk of BPH, but the specific mechanism remains unclear. This study aimed to explore the role and mechanism of the key periodontal pathogen Porphyromonas gingivalis (P. gingivalis) in the development of BPH. The subgingival plaque (Sp) and prostatic fluid (Pf) of patients with BPH concurrent periodontitis were extracted and cultured for 16S rDNA sequencing. Ligature-induced periodontitis, testosterone-induced BPH and the composite models in rats were established. The P. gingivalis and its toxic factor P. gingivalis lipopolysaccharide (P.g-LPS) were injected into the ventral lobe of prostate in rats to simulate its colonization of prostate. P.g-LPS was used to construct the prostate cell infection model for mechanism exploration. P. gingivalis, Streptococcus oralis, Capnocytophaga ochracea and other oral pathogens were simultaneously detected in the Pf and Sp of patients with BPH concurrent periodontitis, and the average relative abundance of P. gingivalis was found to be the highest. P. gingivalis was detected in both Pf and Sp in 62.5% of patients. Simultaneous periodontitis and BPH synergistically aggravated prostate histological changes. P. gingivalis and P.g-LPS infection could induce obvious hyperplasia of the prostate epithelium and stroma (epithelial thickness was 2.97- and 3.08-fold that of control group, respectively), and increase of collagen fibrosis (3.81- and 5.02-fold that of control group, respectively). P. gingivalis infection promoted prostate cell proliferation, inhibited apoptosis, and upregulated the expression of inflammatory cytokines interleukin-6 (IL-6; 4.47-fold), interleukin-6 receptor-α (IL-6Rα; 5.74-fold) and glycoprotein 130 (gp130; 4.47-fold) in prostatic tissue. P.g-LPS could significantly inhibit cell apoptosis, promote mitosis and proliferation of cells. P.g-LPS activates the Akt pathway through IL-6/IL-6Rα/gp130 complex, which destroys the imbalance between proliferation and apoptosis of prostate cells, induces BPH. P. gingivalis was abundant in the Pf of patients with BPH concurrent periodontitis. P. gingivalis infection can promote BPH, which may affect the progression of BPH via inflammation and the Akt signaling pathway.

Porphyromonas gingivalis aggravates colitis via a gut microbiota-linoleic acid metabolism-Th17/Treg cell balance axis

Periodontitis is closely related to inflammatory bowel disease (IBD). An excessive and non-self-limiting immune response to the dysbiotic microbiome characterizes the two. However, the underlying mechanisms that overlap still need to be clarified. We demonstrate that the critical periodontal pathogen Porphyromonas gingivalis (Pg) aggravates intestinal inflammation and Th17/Treg cell imbalance in a gut microbiota-dependent manner. Specifically, metagenomic and metabolomic analyses shows that oral administration of Pg increases levels of the Bacteroides phylum but decreases levels of the Firmicutes, Verrucomicrobia, and Actinobacteria phyla. Nevertheless, it suppresses the linoleic acid (LA) pathway in the gut microbiota, which was the target metabolite that determines the degree of inflammation and functions as an aryl hydrocarbon receptor (AHR) ligand to suppress Th17 differentiation while promoting Treg cell differentiation via the phosphorylation of Stat1 at Ser727. Therapeutically restoring LA levels in colitis mice challenged with Pg exerts anti-colitis effects by decreasing the Th17/Treg cell ratio in an AHR-dependent manner. Our study suggests that Pg aggravates colitis via a gut microbiota-LA metabolism-Th17/Treg cell balance axis, providing a potential therapeutically modifiable target for IBD patients with periodontitis.

Glucose-6-Phosphatase-Dehydrogenase activity as modulative association between Parkinson's disease and periodontitis.

https://www.bfarm.de/DE/Das-BfArM/Aufgaben/Deutsches-Register-Klinischer-Studien/_node.html, identifier DRKS00005388.

СПЕКТР МИКРОФЛОРЫ ПАРОДОНТАЛЬНОГО КАРМАНА У ПАЦИЕНТОВ С ХРОНИЧЕСКИМ ПАРОДОНТИТОМ СРЕДНЕЙ СТЕПЕНИ ТЯЖЕСТИ

The purpose of the study. To evaluate the quantitative composition of the microflora of the periodontal pocket in patients with chronic generalized periodontitis of moderate severity. Materials and methods. The study group included 39 patients, of which: 41% (16/39) were men, 59% (23/39) were women, with chronic generalized periodontitis of moderate severity at the age of 48.9±2.3 years. To determine the dental status, clinical research methods were used (questioning, examination), determination of the Green-Vermillion Oral Hygiene Index (OHI-S), (PMA) modified by Parma, the Mulleman-Cowell bleeding index, the degree of pathological tooth mobility was determined using the Miller scale (Miller) modified by Flesar, the complex periodontal index (CPI), identified furcation defects according to the classification of Lindhe J. (1983).Quantitative assessment of the periodontal pockets microflora was performed. Reagent kits “RIBO-prep” (Next-Bio LLC, Russia), DENTOSKRIN® (NPF Litech LLC, Russia) were used to isolate RNA/DNA from clinical material and subsequent analysis by polymerase chain reaction. Spectrum of identifiable bacteria: Porphyromonas endodontalis, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia, Tannerella forsythia.The results of the study and their discussion. Fusobacterium nucleatum was found in 84.6% (33) of patients in periodontal pockets, 30.8% (12) – Treponema denticola, 28.2% (11) – Prevotella intermedia, 17.9% (7) – Porphyromonas gingivalis and Porhyromonas endodontalis. Aggregatibacter actinomycetemcomitans was isolated only in 5.1% (2) of individuals, Tannerella forsythia – in 2.6% (1). Combinations of 4 microorganisms were detected in 20.5% (8), from 3 - in 12.8% (5), from 2 - 15.4% (6). In 12.8% (5) of the examined patients were not isolated from any of the studied periodontal pathogens. When checking correlations between the level of hygiene and the number of pathogenic microorganisms detected, a moderate direct relationship was established between the value of the OHI-S index and the amount of Fusobacterium nucleatum r=0.36 (p<0.05) and Prevotella intermedia r=0.30 (p<0.05), as well as a moderate direct relationship between the value of the PMA index and the amount of Porphyromonas gingivalis r=0.33 (p<0.05), Porphyromonas endodontalis r=0.31 (p<0.05), Prevotella intermedia r=0.30.Conclusion. In patients with chronic periodontitis of moderate severity, a microbial biofilm is formed on the surface of the periodontium, represented by anaerobic bacteria. In periodontal pockets, the amount of Fusobacterium nucleatum and Prevotella intermedia increases with the deterioration of the hygienic condition of the oral cavty. With the development of inflammation in the gum tissues, periodontal pathogens Porphyromonas gingivalis and Porphyromonas endodontalis are more often detected, having more aggressive invasive and toxic properties in relation to periodontal tissues.

Extracellular vesicles from periodontal pathogens regulate hepatic steatosis via Toll-like receptor 2 and plasminogen activator inhibitor-1.

Plasminogen activator inhibitor-1 (PAI-1) is associated with nonalcoholic fatty liver disease (NAFLD) by lipid accumulation in the liver. In this study, we showed that extracellular vesicles (EVs) from the periodontal pathogens Filifactor alocis and Porphyromonas gingivalis induced steatosis by inducing PAI-1 in the liver and serum of mice fed a low-fat diet. PAI-1 induction was not observed in TLR2-/- mice. When tested using HEK-Blue hTLR2 cells, human TLR2 reporter cells, the TLR2-activating ability of serum from NAFLD patients (n=100) was significantly higher than that of serum from healthy subjects (n=100). Correlation analysis confirmed that PAI-1 levels were positively correlated with the TLR2-activating ability of serum from NAFLD patients and healthy subjects. Amphiphilic molecules in EVs were involved in PAI-1 induction. Our data demonstrate that the TLR2/PAI-1 axis is important for hepatic steatosis by EVs of periodontal pathogens.

Assessment of Minimum Inhibitory Concentration and Anti-biofilm Activity of Plectranthus Amboinicus Solvent Extract against Pure Strains of Putative Periodontal Pathogens: An In-vitro Study

Introduction: Antiseptic agents used in periodontics as anti-plaque and anti-gingivitis agents are primarily chemical substances such as Bis-biguanide derivatives (chlorhexidine) or essential oils. Herbal derivatives have gained prominence in the recent past due to their activity against putative periodontal pathogens; however, only a few have achieved commercialisation. This study focusses on determining the efficacy of an extract from a widely available herb, Indian mintPlectranthus Amboinicus Methanolic extract (PAM), which has known anti-microbial and anti-inflammatory properties against periodontal pathogens in-vitro. Aim: To assess the Minimum Inhibitory Concentration (MIC) and anti-biofilm property of PAM solvent extract against pure strains of putative periodontal pathogens, namely Porphyromonas gingivalis (American Type Culture Collection-ATCC 33277), Fusobacterium nucleatum (ATCC 25586), and Aggregatibacter actinomycetemcomitans (ATCC 43718). Materials and Methods: The extract of PA was prepared using methanol and a Soxhlet extractor. An in-vitro analysis of the MIC and anti-biofilm efficacy of the extract was performed against standard strains of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum using the broth dilution method and microtitre-crystal violet assay, respectively. The MIC activity of the PAM extracts was compared with Chlorhexidine as a standard. Results: The MIC value of P. amboinicus extract was nearly similar to Chlorhexidine as assessed by the broth dilution method. The MIC of P. amboinicus extract for A.a and P.g was 0.4 ug/mL, F.n was 0.8 ug/mL, and the Chlorhexidine values against all three periodontal pathogens were 0.2 ug/mL. The anti-biofilm activity of The extract of PAMwas evaluated using the microtitrecrystal violet assay, and the Optical Density (OD) values were reduced after exposure to the extract, with a significant reduction (p<0.001) of the biofilm-forming bacteria observed. Conclusion: The methanol extract of PAM demonstrated a noteworthy MIC, exhibiting effectiveness at a low concentration of 0.4 μg/mL against Aggregatibacter actinomycetemcomitans in three repeated trials. Moreover, this extract displayed significant inhibitory effects on the biofilm formation of periodontal pathogens Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum (Pg, Aa, Fn), suggesting its potential as an alternative to conventional chemical anti-microbials.

Activation of liver X receptors suppresses the abundance and osteoclastogenic potential of osteoclast precursors and periodontal bone loss.

Liver-X receptors (LXRs) are essential nuclear hormone receptors involved in cholesterol and lipid metabolism. They are also believed to regulate inflammation and physiological and pathological bone turnover. We have previously shown that infection with the periodontal pathogen Porphyromonas gingivalis (Pg) in mice increases the abundance of CD11b+c-fms+Ly6Chi cells in bone marrow (BM), spleen (SPL), and peripheral blood. These cells also demonstrated enhanced osteoclastogenic activity and a distinctive gene profile following Pg infection. Here, we investigated the role of LXRs in regulating these osteoclast precursors (OCPs) and periodontal bone loss. We found that Pg infection downregulates the gene expression of LXRs, as well as ApoE, a transcription target of LXRs, in CD11b+c-fms+Ly6Chi OCPs. Activation of LXRs by treatment with GW3965, a selective LXR agonist, significantly decreased Pg-induced accumulation of CD11b+c-fms+Ly6Chi population in BM and SPL. GW3965 treatment also significantly suppressed the osteoclastogenic potential of these OCPs induced by Pg infection. Furthermore, the activation of LXRs reduces the abundance of OCPs systemically in BM and locally in the periodontium, as well as mitigates gingival c-fms expression and periodontal bone loss in a ligature-induced periodontitis model. These data implicate a novel role of LXRs in regulating OCP abundance and osteoclastogenic potential in inflammatory bone loss.

Emergence of Antibiotic-Resistant Porphyromonas gingivalis in United States Periodontitis Patients.

Antibiotic resistance patterns of the major human periodontal pathogen Porphyromonas gingivalis were assessed over a 20-year period in the United States. Subgingival P. gingivalis was cultured pre-treatment from 2193 severe periodontitis patients during three time periods: 1999-2000 (936 patients), 2009-2010 (685 patients), and 2019-2020 (572 patients). The clinical isolates were tested for in vitro resistance to 4 mg/L for clindamycin and doxycycline, 8 mg/L for amoxicillin, and 16 mg/L for metronidazole, with a post hoc combination of data for metronidazole plus amoxicillin. Clindamycin-resistant P. gingivalis was significantly more prevalent in 2009-2010 (9.1% of patients) and 2019-2020 (9.3%; 15-fold increase) as compared to 1999-2000 (0.6%). P. gingivalis resistance to amoxicillin also significantly increased from 0.1% of patients in 1999-2000 to 1.3% in 2009-2010 and 2.8% (28-fold increase) in 2019-2020. P. gingivalis resistance to metronidazole, metronidazole plus amoxicillin, and doxycycline was low (≤0.5% prevalence), and statistically unchanged, over the 20-year period. These findings are the first to reveal marked increases over 20 years in clindamycin-resistant and amoxicillin-resistant P. gingivalis in United States periodontitis patients. Increased antibiotic resistance of P. gingivalis and other periodontitis-associated bacteria threatens the efficacy of periodontal antimicrobial chemotherapy.

Immunometabolic capacities of nutritional fatty acids in regulation of inflammatory bone cell interaction and systemic impact of periodontal infection.

Novel preventive strategies in periodontal disease target the bacterial-induced inflammatory host response to reduce associated tissue destruction. Strategies focus on the modulation of tissue-destroying inflammatory host response, particularly the reduction of inflammation and promotion of resolution. Thereby, nutrition is a potent immunometabolic non-pharmacological intervention. Human studies have demonstrated the benefit of olive oil-containing Mediterranean-style diets (MDs), the main component of which being mono-unsaturated fatty acid (FA) oleic acid (OA (C18:1)). Hence, nutritional OA strengthened the microarchitecture of alveolar trabecular bone and increased circulating pro-resolving lipid mediators following bacterial inoculation with periodontal pathogen Porphyromonas gingivalis, contrary to saturated FA palmitic acid (PA (C16:0)), which is abundant in Western-style diets. Additionally, the generalized distribution of inflammatory pathway mediators can occur in response to bacterial infection and compromise systemic tissue metabolism and bone homeostasis distant from the side of infection. Whether specific FA-enriched nutrition and periodontal inoculation are factors in systemic pathology that can be immune-modulatory targeted through dietary substitution is unknown and of clinical relevance. Normal-weight C57BL/6-mice received OA-or PA-enriched diets (PA-ED, OA-ED, PA/OA-ED) or a normal-standard diet (n=12/group) for 16 weeks and were orally infected with P. gingivalis/placebo to induce periodontal disease. Using histomorphometry and LC-MS/MS, systemic bone morphology, incorporated immunometabolic FA-species, serological markers of bone metabolism, and stress response were determined in addition to bone cell inflammation and interaction in vitro. In contrast to OA-ED, PA-ED reduced systemic bone microarchitecture paralleled by increased lipotoxic PA-containing metabolite accumulation in bone. Substitution with OA reversed the bone-destructive impact of PA, which was accompanied by reduced diacylglycerols (DAG) and saturated ceramide levels. Further, PA-associated reduction in mineralization activity and concomitant pro-inflammatory activation of primary osteoblasts were diminished in cultures where PA was replaced with OA, which impacted cellular interaction with osteoclasts. Additionally, PA-ED increased osteoclast numbers in femurs in response to oral P. gingivalis infection, whereas OA-ED reduced osteoclast occurrence, which was paralleled by serologically increased levels of the stress-reducing lipokine PI(18:1/18:1). OA substitution reverses the bone-destructive and pro-inflammatory effects of PA and eliminates incorporated lipotoxic PA metabolites. This supports Mediterranean-style OA-based diets as a preventive intervention to target the accumulation of PA-associated lipotoxic metabolites and thereby supports systemic bone tissue resilience after oral bacterial P. gingivalis infection.

Metronidazole Potentiation by Panax Ginseng and Symphytum officinale: A New Strategy for P. gingivalis Infection Control.

The important periodontal disease pathogen Porphyromonas gingivalis produces thick biofilms that increase its pathogenicity. Finding natural antimicrobial agents is crucial because of the rise in antibiotic resistance. The purpose of this study was to determine if plant extracts such as Symphytum officinale (S) and Panax Ginseng (G) were effective against P. gingivalis separately and in combination with a common antibiotic, metronidazole (F). Six different dilutions were produced using the plant extracts in different concentrations and antibiotics separately and in combination with F, G, and S using the two-fold serial dilution technique. To evaluate the effects of these substances, biofilm inhibition experiments were conducted. Plaque samples were collected from periodontitis patients to isolate P. gingivalis, and a standard strain of P. gingivalis (ATCC 33277) was purchased. Additionally, Acylated Homoserine Lactones (AHLs) detection was carried out to look for any activity that would interfere with quorum sensing. GraphPad Prism was used for statistical analysis with a p-value < 0.05. The combinations of Symphytum officinale and metronidazole (S+F) showed the maximum effectiveness in biofilm inhibition (98.7%), which was slightly better than G+F (98.2%), with substantial variations in biofilm inhibition levels in different treatment regimes. Notably, the patient isolate was more active than the standard strain. Additionally, the plant extracts and their combinations at particular dilutions had notable inhibitory effects on the generation of AHL (p < 0.05). The study highlights the possibility of Symphytum officinale and Panax Ginseng as effective treatments for P. gingivalis biofilm and AHLs, both on their own and in combination with metronidazole. These organic substances may open the door to cutting-edge methods of treating periodontal disorders.

Unexpected lower level of oral periodontal pathogens in patients with high numbers of systemic diseases.

Periodontal disease is associated with systemic conditions such as diabetes, arthritis, and cardiovascular disease, all diseases with large inflammatory components. Some, but not all, reports show periopathogens Porphyromonas gingivialis and Tannerella forsythia at higher levels orally in people with one of these chronic diseases and in people with more severe cases. These oral pathogens are thought to be positively associated with systemic inflammatory diseases through induction of oral inflammation that works to distort systemic inflammation or by directly inducing inflammation at distal sites in the body. This study aimed to determine if, among patients with severe periodontal disease, those with multi-morbidity (or many chronic diseases) showed higher levels of periodontal pathogens. A total of 201 adult subjects, including 84 with severe periodontal disease were recruited between 1/2017 and 6/2019 at a city dental clinic. Electronic charts supplied self-reported diseases and conditions which informed a morbidity index based on the number of chronic diseases and conditions present. Salivary composition was determined by 16S rRNA gene sequencing. As expected, patients with severe periodontal disease showed higher levels of periodontal pathogens in their saliva. Also, those with severe periodontal disease showed higher levels of multiple chronic diseases (multimorbidity). An examination of the 84 patients with severe periodontal disease revealed some subjects despite being of advanced age were free or nearly free of systemic disease. Surprisingly, the salivary microbiota of the least healthy of these 84 subjects, defined here as those with maximal multimorbidity, showed significantly lower relative numbers of periodontal pathogens, including Porphyromonas gingivalis and Tannerella Forsythia, after controlling for active caries, tobacco usage, age, and gender. Analysis of a control group with none to moderate periodontal disease revealed no association of multimorbidity or numbers of medications used and specific oral bacteria, indicating the importance of severe periodontal disease as a variable of interest. The hypothesis that periodontal disease patients with higher levels of multimorbidity would have higher levels of oral periodontal pathogens is false. Multimorbidity is associated with a reduced relative number of periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia.

Protective effects of tanshinone IIA on Porphyromonas gingivalis-induced atherosclerosis via the downregulation of the NOX2/NOX4-ROS mediation of NF-κB signaling pathway

Tanshinone IIA (TSA), an active component isolated from Danshen, possess high medicinal values against atherosclerosis by reducing vascular oxidative stress, inhibiting platelet aggregation, and protecting the endothelium from damage. The periodontal pathogen Porphyromonas gingivalis (P. gingivalis) has been proven to accelerate the development of atherosclerosis. We aim to determine the effects of TSA on P. gingivalis-induced atherosclerosis in ApoE-knockout (ApoE−/−) mice. After feeding with a high-lipid diet and infected with P. gingivalis three times per week for four weeks, TSA-treated (60 mg/kg/d) mice greatly inhibited atherosclerotic lesions both morphologically and biochemically and exhibited significantly reduction ROS, 8-OHdG, and ox-LDL levels in serum compared with P. gingivalis-infected mice. Additionally, TSA-treated mice were observed a marked reduction of ROS, 8-OHdG and ox-LDL in the serum, mRNA levels of COX-2, LOX-1, NOX2 and NOX4 in the aorta, as well as the levels of NOX2, NOX4, and NF-κB. These results suggest that TSA attenuates oxidative stress by decreasing NOX2 and NOX4 and downregulating NF-κB signaling pathway, which might be contributed to the amelioration of atherosclerosis.

Structural and antigenic characterization of a novel genotype of Mfa1 fimbriae in Porphyromonas gingivalis

ABSTRACT Background Mfa1 fimbriae of the periodontal pathogen Porphyromonas gingivalis are responsible for biofilm formation and comprise five proteins: Mfa1–5. Two major genotypes, mfa170 and mfa153, encode major fimbrillin. The mfa170 genotype is further divided into the mfa170A and mfa170B subtypes. The properties of the novel mfa170B remain unclear. Methods Fimbriae were purified from P. gingivalis strains JI-1 (mfa170A), 1439 (mfa170B), and Ando (mfa153), and their components and their structures were analyzed. Protein expression and variability in the antigenic specificity of fimbrillins were compared using Coomassie staining and western blotting using polyclonal antibodies against Mfa170A, Mfa170B, and Mfa153 proteins. Cell surface expression levels of fimbriae were analyzed by filtration enzyme-linked immunosorbent assays. Results The composition and structure of the purified Mfa1 fimbriae of 1439 was similar to that of JI-1. However, each Mfa1 protein of differential subtype/genotype was specifically detected by western blotting. Mfa170B fimbriae were expressed in several strains such as 1439, JKG9, B42, 1436, and Kyudai-3. Differential protein expression and antigenic heterogeneities were detected in Mfa2–5 between strains. Conclusion Mfa1 fimbriae from the mfa170A and mfa170B genotypes indicated an antigenic differencesuggesting the mfa170B, is to be utilized for the novel classification of P. gingivalis.

Antimicrobial Efficacy of Blended Essential Oil and Chlorhexidine against Periodontal Pathogen (P.gingivalis)-An In Vitro Study.

Essential oils (EOs) have a considerable amount of therapeutic and preventive effect in treating dental diseases due to their wider potential as antibacterial and anti-inflammatory agents. EOs like virgin coconut oil, eucalyptus oil, peppermint oil thyme oil, and clove oil, when used in combination, may further have enhanced antimicrobial effects. However, limited information exists on the synergistic effect of these oils when used in combination, especially on the primary periodontal pathogen Porphyromonas gingivalis. The current study aims to compare the antimicrobial efficacy of commercially available EO on the periodontal pathogen, P. gingivalis, in comparison to chlorhexidine (CHX). Antimicrobial efficacy of EO and CHX was assessed at various concentrations against the periodontal pathogen P. gingivalis, by evaluating the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). P. gingivalis was seen to be sensitive at a MIC of 100 μg/ml and 50 μg/ml concentration of the EO, which is regarded as the MIC of EO against P. gingivalis and CHX effectively inhibited microbial growth at 0.4 μg/ml. A combination of EOs possesses a potent antibacterial activity against P. gingivalis, and the antibacterial efficacy increases with increasing concentration of EOs.

Molecular Iodine Mouthrinse Antimicrobial Activity Against Periodontopathic Bacteria.

This study compared two molecular iodine mouthrinses for their in vitro bactericidal effects against subgingival biofilm bacteria from severe periodontitis patients. In a subgingival biofilm eradication assay, dilution aliquots of subgingival microbial specimens from 32 adults with severe periodontitis were mixed in vitro with either a mouthrinse containing 100 parts per million (ppm) molecular iodine (Iorinse®) or one containing 150 ppm molecular iodine (iClean®), followed by mouthrinse neutralization after 60 seconds with 3% sodium thiosulfate. The mixtures, along with unexposed subgingival biofilm aliquots, were inoculated onto enriched Brucella blood agar and incubated anaerobically for 7 days to quantitate total viable bacterial counts and selected red/orange complex periodontal pathogens (Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia/nigrescens, Parvimonas micra, Campylobacter rectus, and Fusobacterium nucleatum). Both molecular iodine mouthrinses significantly reduced total viable bacterial counts in the subgingival biofilm samples, with iClean® providing significantly greater in vitro suppression than Iorinse®. Both molecular iodine mouthrinses also significantly reduced total red/orange complex periodontal pathogens, with significantly greater suppression also exhibited by iClean®. The molecular iodine mouthrinses exerted marked bactericidal activity in vitro against human subgingival biofilm microbial species, including red/orange complex periodontal pathogens associated with severe periodontitis, with iClean® providing significantly better antimicrobial activity than Iorinse®. These findings suggest potential value of molecular iodine mouthrinses in the treatment and prevention of periodontal diseases.

Cyclic di-AMP Rescues Porphyromonas gingivalis–Aggravated Atherosclerosis

Growing evidence demonstrates the relationship between periodontitis and atherosclerotic cardiovascular diseases. The periodontal pathogen Porphyromonas gingivalis (Pg) has been shown to contribute to the progression of atherosclerosis. Cyclic diadenylate monophosphate (c-di-AMP) has been widely studied as an immune adjuvant for tumor immunotherapy, given its ability to activate the stimulator of interferon genes (STING) and regulate trained immunity. This study sought to elucidate the role of c-di-AMP in Pg-associated atherosclerosis. Periodontitis and atherosclerosis mouse models were established by ligature application around maxillary second molars and feeding ApoE knockout mice with a high-fat diet. We found that periodontitis and atherosclerosis were more severe in mice exposed to Pg than mice that underwent ligature placement only, while prophylactic treatment with c-di-AMP activated trained immunity and elicited significant alleviation of alveolar bone resorption, as well as reduced blood lipid levels and atherosclerotic plaque accumulation. After 3 mo of intervention, c-di-AMP limited the elevation of cytokines interleukin (IL)–6, IL-1β, tumor necrosis factor α, and interferon β; extracellular matrix remodeling enzymes MMP-2 and MMP-9; and adhesion molecules ICAM-1 and VCAM-1 gene expression. The mechanism underlying Pg-aggravated atherosclerosis may be attributed to changes in microbiota composition in oral and aortic plaques and excess inflammatory response, whereas c-di-AMP could prevent the effects of Pg infection due to its potential ability to activate trained immunity and regulate microecological balance. Our findings suggest a positive role of c-di-AMP in alleviating Pg-aggravated atherosclerosis by regulating the immune response and influencing the local microenvironment.

Inhibitory effect of Porphyromonas gingivalis-derived phosphoethanolamine dihydroceramide on acid ceramidase expression in oral squamous cells.

The maintenance of diminished acid ceramidase (ASAH1) gene expression leading to the accumulation of antiproliferative intracellular ceramides in oral squamous cell carcinoma (OSCC) has emerged as a prospective oral cancer therapeutic regimen. Our published study demonstrated that the key periodontal pathogen Porphyromonas gingivalis downregulates the expression patterns of ASAH1 mRNA in normal epithelial cells in vitro. Therefore, P. gingivalis may also beneficially diminish the expression of ASAH1 in OSCC. Because a uniquely structured P.gingivalis-derived phosphoethanolamine dihydroceramide (PEDHC) inhibits the proliferation of normal human fibroblasts, this study aimed to test the effect of PEDHC on the survival of human oral squamous OECM-1 cells in vitro. We demonstrated that the P. gingivalis dihydroceramide-null (ΔPG1780) strain upregulates the expression of ASAH1 mRNA and promotes aggressive proliferation and migration of OECM-1 cells compared to the parent P. gingivalis-W83 strain. In addition, the intracellular concentration of ceramides was dramatically elevated in OECM-1 cells exposed to PEDHC in vitro. Furthermore, PEDHC inhibited expression patterns of ASAH1 mRNA as well as some genes associated with degradation of the basement membranes and extracellular matrix, for example, MMP-2, ADAM-17 and IL-6, in OECM-1 cells. Altogether, these data indicated that PEDHC produced by P. gingivalis inhibits acid ceramidase expression, promotes intracellular ceramide accumulation and suppresses the survival and migration of OSCC cells in vitro. Further studies are needed to determine molecular mechanisms of PEDHC-mediated inhibitory effect(s) on OSCC using in vivo models of oral cancer.

The First Domestic Experience of Detecting the Association of Anaerobic Bacteria &lt;i&gt;Filifactor Alocis&lt;/i&gt; and &lt;i&gt;Porphyromonas Gingivalis&lt;/i&gt; by Molecular Biological Methods in Periodontal Diseases and Comorbid Pathology (Comparative Research)

Background. The widespread global increase in the incidence of periodontitis and the role of its pathogens in comorbid pathology and systemic complications determines the need to create new molecular genetic systems for diagnosis and the use of metagenomic and bioinformatic analysis methods. Aims to use methods of microbiological genodiagnostics and bioinformatic analysis to prove the etiological role of the key periodontal pathogens Filifactor alocis and Porphyromonas gingivalis, characterizing the degree of progression of chronic periodontitis, and its association with a systemic pathological process (type 2 diabetes mellitus). Methods. A comparative assessment of the identification of key periodontopathogenic species P. gingivalis and F. alocis in different forms of periodontitis according to the degree of progression (84 people) using a previously patented system of primers in patients in 4 comparison groups, differing in the degree of progression. 16S sequencing and bioinformatic analysis were performed in 69 patients (including 38 with type 2 diabetes mellitus). All nondiabetic patients were required to have HbA1c level 6.0%. Results. A higher frequency of detection of periodontal pathogens was established in patients of group C with a pronounced tendency to progression (93 and 100% respectively). The simultaneous presence of P. gingivalis and F. alocis in chronic periodontitis of grade B was noted in 20% of cases, and in grade C in 93% of cases. Conclusions. The proposed method can be used to effectively determine the degree of periodontitis progression based on the determination of oligonucleotide primers of P. gingivalis and F. alocis, including comorbid pathology periodontitis and type 2 diabetes mellitus.