Tannerella Forsythia Research Articles

Microbiological Effects of Sodium Hypochlorite/-Amino Acids and Cross-linked Hyaluronic Acid Adjunctive to Non-surgical Periodontal Treatment.

To investigate the microbiological outcomes obtained with either subgingival debridement (SD) in conjunction with a gel containing sodium hypochlorite and amino acids followed by subsequent application of a cross-linked hyaluronic acid gel (xHyA) gel, or with SD alone. Forty-eight patients diagnosed with stages II-III (grades A/B) generalised periodontitis were randomly treated with either SD (control) or SD plus adjunctive sodium hypochlorite/amino acids and xHyA gel (test). Subgingival plaque samples were collected from the deepest site per quadrant in each patient at baseline and after 3 and 6 months. Pooled sample analysis was performed using a multiplex polymerase chain reaction (PCR)-based method for the identification of detection frequencies and changes in numbers of the following bacteria: Aggregatibacter actinomycetemcomitans (A.a), Porphyromonas gingivalis (P.g), Tannerella forsythia (T.f), Treponema denticola (T.d), and Prevotella intermedia (P.i). In terms of detection frequency, in the test group, statistically significant reductions were found for P.g, T.f, T.d and P.i (p < 0.05) after 6 months. In the control group, the detection frequencies of all investigated bacterial species at 6 months were comparable to the baseline values (p > 0.05). The comparison of the test and control groups revealed statistically significant differences in detection frequency for P.g (p = 0.034), T.d (p < 0.01) and P.i (p = 0.02) after 6 months, favouring the test group. Regarding reduction in detection frequency scores, at 6 months, statistically significant differences in favour of the test group were observed for all investigated bacterial species: A.a (p = 0.028), P.g (p = 0.028), T.f (p = 0.004), T.d (p <0.001), and P.i (p = 0.003). The present microbiological results, which are related to short-term outcomes up to 6 months post-treatment, support the adjunctive subgingival application of sodium hypochlorite/amino acids and xHyA to subgingival debridement in the treatment of periodontitis.

Association of Periodontal Red Complex Bacteria With the Incidence of Gastrointestinal Cancers: A Systematic Review and Meta-Analysis.

Porphyromonas gingivalis is the primary microbe in the "periodontal red complex" bacteria (PRCB) along with Tannerella forsythia and Treponema denticola, which are linked to periodontal disease (PD). These pathogens are also implicated in various systemic disorders, but their association with the incidence of gastrointestinal (GI) cancer is less explored. A systematic review followed by a meta-analysis was conducted as per standard guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2022) to find this association between GI cancers and PRCB after a literature search for full-text papers in the English language (between 2010 and 2023) in databases (Cochrane Library, PubMed, and Web of Science) with suitable keywords using the Boolean search strategy. Data extraction involved titles, abstracts, and full texts retrieved and scored by the modified Newcastle-Ottawa Scale. The data were analyzed by the Review Manager (RevMan 5.2, Cochrane Collaboration, Denmark). Standard Cochran Q test and I2 statistics (for heterogeneity) and a random effects model (pooled OR with 95% CI) were applied to report results. P. gingivalis among the PRCB was linked to GI cancers (OR: 2.16; 95% CI: 1.34-3.47). T. forsythia and T. denticola did not show meaningful associations as per existing evidence for GI cancers.

Effect of quadrantwise versus full-mouth subgingival instrumentation on clinical and microbiological parameters in periodontitis patients: A randomized clinical trial.

This study evaluated the efficacy of quadrantwise subgingival instrumentation (Q-SI) versus one-stage full-mouth subgingival instrumentation (FM-SI) on probing depth and periodontal pathogen reduction over a 6-month follow-up period, as well as whether baseline periodontal pathogens influenced the impact of periodontal treatment protocols on outcomes. Patients with periodontitis were randomized to receive Q-SI (n = 43) or FM-SI (n = 45). Patients were instructed and motivated to maintain optimal oral hygiene during the treatment sessions. Clinical (probing pocket depth [PPD], clinical attachment loss [CAL], and bleeding on probing [BOP]) and periodontal pathogens were assessed at baseline and after 30, 90, and 180 days. Total bacterial load and periodontal pathogens were analysed via real-time PCR. At the 6-month follow-up, the median PPD decreased from 4.8 mm (interquartile range [IQR]: 4.3-5.2) to 2.6 mm (IQR: 2.3-2.9) in FM-SI patients and from 4.7 mm (IQR: 4.1-5.2) to 3.2 mm (IQR: 2.4-3.5) in Q-SI patients (p < .001). At 6 months, FM-SI was more effective at reducing the median proportions of Porphyromonas gingivalis (Pg), Aggregatibacter actinocomyctemcomitans, and Tannerella forsythia (Tf) (p < .001 for each value). Multilevel linear regression analysis demonstrated that high baseline PPD (p = .029), Pg (p = .014), and Tf (p < .001) levels and the FM-SI protocol (p < .001) were statistically significant predictors of PPD reduction at 6 months. Furthermore, PPD reduction was significantly greater in the FM-SI group when lower baseline Pg levels were detected. The FM-SI was more effective than the Q-SI in reducing the mean PPD and number of periodontal pathogens in periodontitis patients over a 6-month follow-up period. Higher baseline PPD and Pg levels had a negative impact on PPD reduction at 6 months after FM-SI.

Biofilm and clinical data between volunteers with self-ligating and conventional brackets: an observational study

Introduction: Fixed orthodontic appliances can lead to enamel demineralization and gingival changes due to increased biofilm. Aim: To detect the presence of Prevotella intermedia, Tannerella forsythia, Streptococcus mutans, Scardovia wiggsiae, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis in oral biofilm and presence of white spot lesions and gingivitis in users of self-ligating and conventional brackets. Design: This observational controlled study was conducted from January to December 2020. The participants used fixed orthodontic therapy for 6 months and were divided into a conventional and a self-ligating bracket group. The participants underwent clinical examination, and biofilm samples were collected from their lower incisors. Results: No differences were found in the bacteria detection between the groups (p&gt;0.05). However, white spot lesions were more common in users of self-ligating brackets (p=0.019). There was no association between clinical data and the detection of any microorganism (p&gt;0.05). The fluorescence intensity of A. actinomycetemcomitans was higher in self ligating brackets than in conventional brackets (p&lt;0.05). Implications: The microbial diversit did not differ between the types of brackets; however, the presence of white spot lesions and the amount of A. actinomycetemcomitans were higher in patients with self-ligating brackets.

Oral anaerobe bacteria-a common risk for cardiovascular disease and mortality and some forms of cancer?

This review explores the results of research on oral health concerning cardiovascular diseases and some forms of cancer and is based on results from published systematic reviews and some studies. The research results will have a strong focus on exploring the relationship between different aspects of oral infections. The relationship between oral health parameters, cardiovascular diseases (CVD), and certain cancers was examined from different angles, including prospective analyses, in a population-based health study in Oslo from the year 2000 (Oslo II study). A major finding was that low levels of antibodies to the oral anaerobe Tannerella forsythia predict both CVD mortality in men with a history of myocardial infarction and incidence of bladder cancer in a random sample of men in the study. Low levels of antibodies to Treponea denticola predict the incidence of bladder and colon cancer in a random sample of men in the study. Both anaerobe bacteria are part of the so-called red complex of bacteria in chronic periodontitis together with Pophyromonas gingivalis. These three bacteria have different properties and are causal in chronic periodontitis. They migrate into the local tissues by adhering to the oral epithelium, break down soft and hard tissues, and spread via the circulation to organs distant from the mouth. This paper will give an overview of which oral health measures have been explored and associated with different CVD and cancer diagnoses and what scientific literature supports or contravenes our hypothesis. The oral microbiome is described with the most relevant bacteria related to microbiology, serum, autopsies, and associated causes such as alcohol. There will be a mention of the possibilities and limitations of different study designs. There seems to be a causal relationship between oral anaerobe bacteria and systemic diseases regulated by the immune system. This is seen alongside other well-known risk factors, especially for CVD. The prospective finding of a relation to the incidence of certain cancers and CVD is particularly intriguing. However, further research is needed to determine the biological mechanisms underpinning these associations.

THE EFFECTIVENESS OF METRONIDAZOLE GELS IN THE MANAGEMENT OF PERIODONTAL DISEASE

Introduction : Metronidazole is one of the antimicrobial and antimicrobial that has been widely used as antibacterial and antiprotozoal agent for treatment. Metronidazole is antimicrobial have been used as an adjuvant to mechanical plaque removal. Periodontal disease is a chronic inflammatory disease that develops from dental plaque that affects periodontal supporting tissues. Many chemical agents that have been evaluated to determine their effect on plaque, gingivitis and periodontitis, one of which is metronidazole, has been successfully introduced and studied extensively. This literature review explains effectiveness of metronidazole gels in the management of periodontal disease. Review : Metronidazole (MTZ) is frequently used in the treatment for periodontal diseases since it can be against several Gram-negative anaerobic rods, the pathogenesis of periodontitis. It can be administered via oral and topical routes. However, the systemic adverse effects may in the oral cavity if used peroral. Hence, topical administration is preferable. The bacterial reservoirs not eliminated by conventional periodontal therapy can be further suppressed with the use of chemotherapeutic agents. Localized antimicrobial therapy, in particular, has evoked growing interest because of the site‑specific nature of periodontal infections, the higher concentration of anti‑microbial agent subgingivally and reduced side‑effects of systemic antibiotic use. Among the various locally delivered chemotherapeutic agents metronidazole, a has bactericidal action against anaerobes, such as Prevotela intermedia, Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium species and spirochetes like Treponema denticola, Treponema vincentii, which are generally believed to be the main pathogens associated with periodontitis. Conclusion : Treatment of periodontal pockets with metronidazole gel in addition to scaling and root planning, provides a significant increase in reducing pocket depth and microbial count and effective in the treatment of periodontal disease.

Effect of sleeve gastrectomy on the levels of oral volatile sulfur compounds and halitosis-related bacteria

BackgroundThe association between sleeve gastrectomy and halitosis remains relatively unknown. Therefore, this study aimed to evaluate the effect of sleeve gastrectomy on halitosis and the oral bacterial species associated with halitosis in patients with obesity. MethodsThis was a prospective longitudinal cohort study that examined patients before and after sleeve gastrectomy and followed the patients at three time intervals (1, 3, and 6 months) after sleeve gastrectomy. Clinical periodontal measurements (plaque index [PI], gingival index [GI], and probing depth [PD]) were obtained. In addition, plaque samples were collected for quantification of the periodontopathogenic bacteria: Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Fusobacterium nucleatum using real-time quantitative polymerase chain reaction (qPCR). In addition, breath samples were collected to analyze the concentration of volatile sulfur compounds (VSCs), namely hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and dimethyl sulfide (CH3SCH3), via portable gas chromatography (Oral Chroma™). ResultsOf the 43 patients initially included, 39 completed the study, with a mean age of 32.2 ± 10.4 years. For PI and GI repeated measurements one way analysis of variance showed a significant increase (p-value < 0.001 for both) one month after surgery, with mean values of 1.3 and 1.59, respectively, compared to the baseline. During the same period, the number of P. gingivalis increased, with a p-value = 0.04. Similarly, the levels of hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) increased significantly in the first month after surgery (p-value = 0.02 and 0.01, respectively). ConclusionThis study demonstrated that sleeve gastrectomy may lead to increased halitosis one month post-surgery, attributed to elevated and P. gingivalis counts, contributing to the development of gingivitis in obese patients who underwent sleeve gastrectomy. This emphasizes the importance of including oral health professionals in the multidisciplinary team for the management of patients undergoing bariatric surgery

Comparative analysis of antibodies to four major periodontal bacteria in respiratory diseases: a cohort study

ObjectivesTo make a descriptive comparison of antibodies to four major periodontal bacteria and their relation to the respiratory diseases asthma and bronchitis/emphysema, and to cancer incidence.MethodsThe serum of a random...

Comparative Evaluation of 0.2% Chlorhexidine and Oxygenated Mouthwash as an Adjunct to Scaling and Root Planing in Chronic Periodontitis Patients - A Clinico-microbiological Study

ABSTRACT Background and Objective: Oxygen therapy has been proven to be beneficial in the treatment and healing of chronic wounds. Oxygenated mouthwash could help in the management of oral infections like periodontal disease by reducing the levels of reactive oxygen species. The current study was designed to evaluate the effectiveness of Blue M, an oxygenated mouthwash as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis (CP). Materials and Methods: Forty-two CP patients were randomly divided into 3 groups (Group A – only SRP, Group B – SRP with oxygenated blue®m mouthwash, and Group C-SRP with 0.2% chlorhexidine [CHX] mouthwash). Clinical parameters-plaque index, gingival index, probing pocket depth, and relative attachment level were evaluated at baseline, 1 month, and 3 months while microbial analysis was carried out, using chairside N-benzoyl-DL-arginine-2-naphthylamide Assay for detection of either presence or absence of Treponema denticola, Porphyromonas gingivalis, and/or Tannerella forsythia at baseline and 3 months. Results: All groups showed a significant reduction in clinical and microbiologic parameters from baseline to 3 months (P &lt; 0.05). Intergroup analysis showed Group B and Group C to be significantly better than Group A (P &lt; 0.05) while Group B showed similar results when compared to Group C (P &gt; 0.05). Conclusion: Blue M mouthwash showed better improvement as compared to SRP alone while it showed similar improvements in clinical as well as microbiologic parameters when compared with CHX. It can be concluded that Blue M mouthwash could well be a futuristic prospect as an alternative to chemical agents like CHX in the treatment of CP.

Microbial Composition of the Periodontal Pocket in Chronic Generalized Periodontitis

The aim of the study was to evaluate the microbiocenosis of the periodontal pocket in chronic generalized periodontitis. Materials: The study included 106 patients with chronic generalized paradontitis of varying severity who were on an outpatient appointment with a dentist-surgeon. Methods: the study was performed by PCR method with real-time detection of the results, on the DT-96 detecting amplifier of NPO DNA Technology LLC Periodontoscreen kit. Statistical processing of the obtained results was carried out using the SPSS Statistics 11.0 program. Results: Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, Treponema denticola were found in etiologically significant concentrations in patients with chronic generalized periodontitis. At the same time, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythensis were most often verified in patients, Prevotella intermedia was detected in a smaller number. Given this fact, it remains relevant to study the identified microorganisms in patients with chronic generalized paradontitis in order to establish their role in the etiopathogenesis of this disease.

Influence of obesity on subgingival microbiota composition in subjects with different periodontal status: a systematic review.

This systematic review aimed to investigate the changes in the composition of the subgingival microbiota among subjects with normo-weight, overweight and obesity, in conditions of periodontal health and disease. The protocol for this study was designed following PRISMA guidelines. Records were identified using different search engines (PubMed/MedLine, Scopus and Web of Science). Observational studies, in human subjects diagnosed with obesity (BMI >30kg/m2) and periodontal disease (gingivitis and periodontitis), on the analysis of subgingival microbiota were selected. Eight articles were included. The subgingival microbiota of 1,229 subjects (n=894 exposure group and n=335 control group) was analyzed. Periodontal pathogens were the most common bacteria detected in subjects with obesity and periodontitis (Porphyromonas gingivalis, Tannerella forsythia, Campylobacter gracilis, Eubacterium nodatum, Fusobacterium nucleatum spp. vincentii, Parvimonas micra, Prevotella intermedia, Campylobacter rectus, and Aggregatibacter actinomycetemcomitans), as along with some accessory pathogens such as: Streptococcus gordonii, and Veillonella parvula that favor the virulence of late colonizers. Although there are evident alterations in the composition of the subgingival microbiota in subjects with obesity and periodontitis, it is still a challenge to identify a specific pattern of microbiota in these subjects. If associations between subgingival plaque microorganisms and obesity are confirmed, microbiome analysis could be a useful tool to improve preventive measures and the management of people with obesity.

Glycolanguage of the oral microbiota.

The oral cavity harbors a diverse and dynamic bacterial biofilm community which is pivotal to oral health maintenance and, if turning dysbiotic, can contribute to various diseases. Glycans as unsurpassed carriers of biological information are participating in underlying processes that shape oral health and disease. Bacterial glycoinfrastructure-encompassing compounds as diverse as glycoproteins, lipopolysaccharides (LPSs), cell wall glycopolymers, and exopolysaccharides-is well known to influence bacterial fitness, with direct effects on bacterial physiology, immunogenicity, lifestyle, and interaction and colonization capabilities. Thus, understanding oral bacterias' glycoinfrastructure and encoded glycolanguage is key to elucidating their pathogenicity mechanisms and developing targeted strategies for therapeutic intervention. Driven by their known immunological role, most research in oral glycobiology has been directed onto LPSs, whereas, recently, glycoproteins have been gaining increased interest. This review draws a multifaceted picture of the glycolanguage, with a focus on glycoproteins, manifested in prominent oral bacteria, such as streptococci, Porphyromonas gingivalis, Tannerella forsythia, and Fusobacterium nucleatum. We first define the characteristics of the different glycoconjugate classes and then summarize the current status of knowledge of the structural diversity of glycoconjugates produced by oral bacteria, describe governing biosynthetic pathways, and list biological roles of these energetically costly compounds. Additionally, we highlight emerging research on the unraveling impact of oral glycoinfrastructure on dental caries, periodontitis, and systemic conditions. By integrating current knowledge and identifying knowledge gaps, this review underscores the importance of studying the glycolanguage oral bacteria speak to advance our understanding of oral microbiology and develop novel antimicrobials.

Oral and gut microbial profiling in periodontitis and Parkinson’s disease

ABSTRACT Objectives We tested the hypothesis that Parkinson’s disease (PA) alters the periodontitis-associated oral microbiome. Method Patients with periodontitis with Parkinson’s disease (PA+P) and without PA (P) and systemically and periodontally healthy individuals (HC) were enrolled. Clinical, periodontal and neurological parameters were recorded. The severity of PA motor functions was measured. Unstimulated saliva samples and stool samples were collected. Next-generation sequencing of 16S ribosomal RNA (V1-V3 regions) was performed. Results PA patients had mild-to-moderate motor dysfunction and comparable plaque scores as those without, indicating that oral hygiene was efficient in the PA+P group. In saliva, there were statistically significant differences in beta diversity between HC and PA+P (p = 0.001), HC and P (p = 0.001), and P and PA+P (p = 0.028). The microbial profiles of saliva and fecal samples were distinct. Mycoplasma faucium, Tannerella forsythia, Parvimonas micra, and Saccharibacteria (TM7) were increased in P; Prevotella pallens, Prevotella melaninogenica, Neisseria multispecies were more abundant in PA+P group, Ruthenibacterium lactatiformans, Dialister succinatiphilus, Butyrivibrio crossotus and Alloprevotella tannerae were detected in fecal samples in P groups compared to healthy controls. Conclusions No significant differences were detected between Parkinson’s and non-Parkinson’s gut microbiomes, suggesting that Parkinson’s disease modifies the oral microbiome in periodontitis subjects independent of the gut microbiome.

Assessment of the Antibacterial Effect of Vitamin D3 against Red Complex Periodontal Pathogens: A Microbiological Assay.

The study aims is to evaluate the antibacterial effect of vitamin D3 against the red complex bacteria, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia in chronic periodontitis patients. The study comprised 98 participants with chronic periodontitis. All clinical parameters including plaque index (PI), gingival bleeding index (GBI), probing pocket depth (PPD), clinical attachment level (CAL), and a microbiological assay of P. gingivalis, T. denticola, T. forsythia were assessed at the baseline. All study participants who underwent scaling and root planning were divided into two groups, A and B, each with 49 patients and only group B patients were advised to take vitamin D supplementation of 60,000 IU granules, once daily for 2 months. All the patients of both the groups were recalled at the end of 2nd month and all the clinical and microbiological parameters were reassessed. After two months, there was a reduction in all the clinical markers in both groups, but the group B patients showed more improvement following non-surgical treatment vitamin D intake. There was also a statistical reduction in P. gingivalis, T. denticola, and T. forsythia following administration of vitamin D in group B patients compared to group A. These discoveries proposed that vitamin D has a superb antimicrobial impact against red complex periodontal microbes and might be considered a promising compound in the counteraction of periodontal disease. Vitamin D is considered to possess anti-inflammatory and antimicrobial activity, which may help to delay the progression of periodontitis. So, vitamin D3 can be used as a potential supplement that could be employed to stop the advancement of periodontal disease. How to cite this article: Govindharajulu R, Syed NK, Sukumaran B, et al. Assessment of the Antibacterial Effect of Vitamin D3 against Red Complex Periodontal Pathogens: A Microbiological Assay. J Contemp Dent Pract 2024;25(2):114-117.

Antimicrobial effect of indocyanine green-mediated photodynamic therapy in patients with periodontal disease: A systematic review

Abstract Aim: This systematic review assessed the antimicrobial effect of indocyanine green-mediated photodynamic therapy (ICG-PDT) in patients with periodontal disease. Materials and Methods: Four electronic databases that is, MEDLINE, MEDLINE-In-Process, EMBASE, and Cochrane Library were systematically searched from their inception until December 22, 2022. Randomized controlled trials (RCTs) reporting the antimicrobial effect of ICG-PDT in patients with periodontal disease and published in English were included. The Cochrane risk of bias tool was used to assess the quality of the included RCTs. Two independent reviewers performed all the steps involved in a systematic review (primary and secondary screening, data extraction, and quality assessment). As the data extracted was not suitable for meta-analysis, the evidence was synthesized qualitatively. Results: Overall, seven RCTs from seven publications were included. All included studies had PDT, laser, or photothermal with ICG as the test group while the control group included low-level laser therapy, root surface debridement, and scaling and root planning. The bacterial species assessed across the included studies included Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Fusobacterium nucleatum, and Treponema denticola. With subtle exceptions, ICG-PDT in combination with root surface debridement and scaling and root planning significantly reduced the growth of periodontal pathogens from baseline. Conclusion: Based on the evidence from the limited studies, ICG-PDT seems to exhibit potent antimicrobial activity against an array of periodontal pathogens in patients with periodontal disease.

Periodontal Health in Children with Juvenile idiopathic arthritis.

To investigate gingival inflammation and prevalence of four specific periodontal associated pathogens in Juvenile idiopathic arthritis (JIA) in relation to orofacial pain, jaw function and systemic inflammatory activity in JIA. Forty-five children with JIA and 16 healthy children as controls, were enrolled. Subjects were examined and classified according to the diagnostic criteria for temporomandibular disorders (DC/TMD). Pain, pain-related disability and jaw function were also assessed. A clinical periodontal examination was performed. Subgingival plaque samples were collected and analyzed for semiquantitative levels of the following periodontal pathogens; Aggregatibacter actinomycetemcomintans, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola. This study suggests that the periodontal disease-associated bacteria P. gingivalis and T. forsythia do not contribute to neither periodontal disease, systemic inflammatory activity nor orofacial pain and jaw dysfunction, including TMJ arthritis, in JIA patients in Sweden.

Ancient Genomes From Bronze Age Remains Reveal Deep Diversity and Recent Adaptive Episodes for Human Oral Pathobionts.

Ancient microbial genomes can illuminate pathobiont evolution across millenia, with teeth providing a rich substrate. However, the characterization of prehistoric oral pathobiont diversity is limited. In Europe, only preagricultural genomes have been subject to phylogenetic analysis, with none compared to more recent archaeological periods. Here, we report well-preserved microbiomes from two 4,000-year-old teeth from an Irish limestone cave. These contained bacteria implicated in periodontitis, as well as Streptococcus mutans, the major cause of caries and rare in the ancient genomic record. Despite deriving from the same individual, these teeth produced divergent Tannerella forsythia genomes, indicating higher levels of strain diversity in prehistoric populations. We find evidence of microbiome dysbiosis, with a disproportionate quantity of S. mutans sequences relative to other oral streptococci. This high abundance allowed for metagenomic assembly, resulting in its first reported ancient genome. Phylogenetic analysis indicates major postmedieval population expansions for both species, highlighting the inordinate impact of recent dietary changes. In T. forsythia, this expansion is associated with the replacement of older lineages, possibly reflecting a genome-wide selective sweep. Accordingly, we see dramatic changes in T. forsythia's virulence repertoire across this period. S. mutans shows a contrasting pattern, with deeply divergent lineages persisting in modern populations. This may be due to its highly recombining nature, allowing for maintenance of diversity through selective episodes. Nonetheless, an explosion in recent coalescences and significantly shorter branch lengths separating bacteriocin-carrying strains indicate major changes in S. mutans demography and function coinciding with sugar popularization during the industrial period.

Subgingival microbial changes in Down Syndrome adults with periodontitis after chlorhexidine adjunct non-surgical therapy and monthly recalls–A 12-month case series study

ObjectivesDown Syndrome (DS) adults are at risk for periodontitis. Previous reports indicated difficulties in periodontopathogen reduction or eradication in DS individuals after periodontal treatment. This case series follows the subgingival microbial changes in adult DS individuals with periodontitis who received chlorhexidine adjunct non-surgical therapy plus 12-month recalls. MethodsTwenty periodontitis DS participants (7 females; 25.5 ± 5.6 years of age; 3 with generalized periodontitis) partook in a study involving non-surgical mechanical periodontal therapy, twice daily chlorhexidine gel toothbrushing, chlorhexidine mouthwash, and monthly recalls. The subgingival microbiota profile was followed at baseline, 6-, and 12-months post-operation. ResultsDesulfobulbus, Saccharibacteria (TM7), Tannerella, and Porphyromonas were the major subgingival genera in this DS cohort. Favorable chlorhexidine adjunct non-surgical treatment outcomes were observed, with the relative abundance of Desulfobulbus sp. HMT 041, Saccharibacteria (TM7) [G-1] bacterium HMT 346 or 349, and Tannerella forsythia significantly reduced at the end of the study, but no significant reduction of Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans could be observed. Relative abundance of Desulfobulbus sp. HMT 041 and T. forsythia were also found to be significantly associated with plaque, bleeding on probing, and probing pocket depth (PPD, in mm) at a site level, while the relative abundance of Halomonas pacifica was negatively associated with PPD. ConclusionsSuccessful chlorhexidine adjunct non-surgical treatment with hygiene care was accompanied by a subgingival microbial shift involving certain periodontopathogenic species, except P. gingivalis and A. actinomycetemcomitans. Further investigations are required to clarify the mechanism underpinning the unchanged relative abundance of the above two pathogens despite favorable clinical responses. Clinical SignificanceDS adults face challenges achieving optimal home care or hygiene for periodontal healing and disease prevention. Chemical adjunct mechanical periodontal therapy plus regular recalls appeared promising clinically and microbiologically, with subgingival periodontopathogenic species reduction. The persistence of A. actinomycetemcomitans and P. gingivalis in subgingival niches post-treatment warrants further investigation.

Molecular Characterization of the glyA Gene From the Clinical Isolates of Tannerella forsythia.

TheglyA gene in Tannerella forsythia is attributed for its virulence by producing the enzyme serine hydroxymethyltransferase (SHMT), which plays a vital role in bacterial cell metabolism. The study is thus aimed to determine the frequency of the glyA gene from the clinical strains of T. forsythia isolated from periodontitis patients. Forty-five patients with varying degrees of periodontitis were included in the study, and the plaque samples collected from them were anaerobically processed by inoculating onto sterile anaerobic blood agar plates using a gaspak system, with incubation at 37°C for 5-7 days. The DNA was extracted from the obtained isolated colony, and PCR was performed to confirm the presence of the glyA gene. In total, 46.6% (n= 7) of the cases in group III aggressive periodontitis (n = 15) and 6.66% (n =1) in group II stage II periodontitis (n = 15) showed the presence of T. forsythia,and among them, 57.14% (n= 4) showed the presence of theglyA gene. Conclusion: The findings of the study showed that theglyA gene may be associated with the pathogenesis of T. forsythia and could be thus a novel candidate for the future theragnostic approach to combat periodontitis.

Ultrastructural and glycoproteomic characterization of Prevotella intermedia: Insights into O-glycosylation and outer membrane vesicles.

Prevotella intermedia, a Gram-negative bacterium from the Bacteroidota phylum, is associated with periodontitis. Other species within this phylum are known to possess the general O-glycosylation system. The O-glycoproteome has been characterized in several species, including Tannerella forsythia, Porphyromonas gingivalis, and Flavobacterium johnsoniae. In our study, we used electron cryotomography (cryoET) and glycoproteomics to reveal the ultrastructure of P. intermedia and characterize its O-glycoproteome. Our cryoET analysis unveiled the ultrastructural details of the cell envelope and outer membrane vesicles (OMVs) of P. intermedia. We observed an electron-dense surface layer surrounding both cells and OMVs. The OMVs were often large (>200 nm) and presented two types, with lumens being either electron-dense or translucent. LC-MS/MS analyses of P. intermedia fractions led to the identification of 1655 proteins, which included 62 predicted T9SS cargo proteins. Within the glycoproteome, we identified 443 unique O-glycosylation sites within 224 glycoproteins. Interestingly, the O-glycosylation motif exhibited a broader range than reported in other species, with O-glycosylation found at D(S/T)(A/I/L/M/T/V/S/C/G/F/N/E/Q/D/P). We identified a single O-glycan with a delta mass of 1531.48 Da. Its sequence was determined by MS2 and MS3 analyses using both collision-induced dissociation and high-energy collisional dissociation fragmentation modes. After partial deglycosylation with trifluoromethanesulfonic acid, the O-glycan sequence was confirmed to be dHex-dHex-HexNAc (HPO3 -C6 H12 O5 )-dHex-Hex-HexA-Hex(dHex). Bioinformatic analyses predicted the localization of O-glycoproteins, with 73 periplasmic proteins, 53 inner membrane proteins, 52 lipoproteins, 26 outer membrane proteins, and 14 proteins secreted by the T9SS.