Detection of Eight Periodontal Microorganisms and Distribution ofPorphyromonas gingivalis fimAGenotypes in Chinese Patients With Aggressive Periodontitis

The oral microbiome in autoimmune diseases: friend or foe?

The human body is colonized by abundant and diverse microorganisms, collectively known as the microbiome. The oral cavity has more than 700 species of bacteria and consists of unique microbiome niches on mucosal surfaces, on tooth hard tissue, and in saliva. The homeostatic balance between the oral microbiota and the immune system plays an indispensable role in maintaining the well-being and health status of the human host. Growing evidence has demonstrated that oral microbiota dysbiosis is actively involved in regulating the initiation and progression of an array of autoimmune diseases.Oral microbiota dysbiosis is driven by multiple factors, such as host genetic factors, dietary habits, stress, smoking, administration of antibiotics, tissue injury and infection. The dysregulation in the oral microbiome plays a crucial role in triggering and promoting autoimmune diseases via several mechanisms, including microbial translocation, molecular mimicry, autoantigen overproduction, and amplification of autoimmune responses by cytokines. Good oral hygiene behaviors, low carbohydrate diets, healthy lifestyles, usage of prebiotics, probiotics or synbiotics, oral microbiota transplantation and nanomedicine-based therapeutics are promising avenues for maintaining a balanced oral microbiome and treating oral microbiota-mediated autoimmune diseases. Thus, a comprehensive understanding of the relationship between oral microbiota dysbiosis and autoimmune diseases is critical for providing novel insights into the development of oral microbiota-based therapeutic approaches for combating these refractory diseases.

The Contribution of the Human Oral Microbiome to Oral Disease: A Review

The oral microbiome is an emerging field that has been a topic of discussion since the development of next generation sequencing and the implementation of the human microbiome project. This article reviews the current literature surrounding the oral microbiome, briefly highlighting most recent methods of microbiome characterization including cutting edge omics, databases for the microbiome, and areas with current gaps in knowledge. This article also describes reports on microorganisms contained in the oral microbiome which include viruses, archaea, fungi, and bacteria, and provides an in-depth analysis of their significant roles in tissue homeostasis. Finally, we detail key bacteria involved in oral disease, including oral cancer, and the current research surrounding their role in stimulation of inflammatory cytokines, the role of gingival crevicular fluid in periodontal disease, the creation of a network of interactions between microorganisms, the influence of the planktonic microbiome and cospecies biofilms, and the implications of antibiotic resistance. This paper provides a comprehensive literature analysis while also identifying gaps in knowledge to enable future studies to be conducted.

qPCR Detection and Quantification of Aggregatibacter actinomycetemcomitans and Other Periodontal Pathogens in Saliva and Gingival Crevicular Fluid among Periodontitis Patients

OBJECTIVE

The detection of special bacterial species in patients with periodontitis is considered useful for clinical diagnosis and treatment. The aim of this study was to investigate the presence of specific periopathogens and investigate whether there is a correlation between the results of different bacterial species in whole saliva and pooled subgingival plaque samples (healthy and diseased sites) from individuals with periodontitis and periodontally healthy subjects.

MATERIALS AND METHODS

In total, 52 patients were recruited and divided into two groups: non-periodontitis and periodontitis patients. For each group, the following periodontal pathogens were detected using real-time polymerase chain reaction: A. actinomycetemcomitans JP2 clone, A. actinomycetemcomitans non JP2 clone, Porphyromonasgingivalis, and total eubacteria.

RESULTS

Higher levels of the various studied bacteria were present in both saliva and plaque samples from the periodontitis group in comparison to non-periodontitis subjects. There were significant differences in P. gingivalis and A. actinomycetemcomitans JP2 clones in the saliva of periodontitis patient compared to the control group. Subgingival plaque of diseased sites presented a significant and strong positive correlation between A. actinomycetemcomitans and P. gingivalis. In saliva samples, there was a significant positive correlation between A. actinomycetemcomitans JP2 clone and P. gingivalis (p ≤ 0.002).

CONCLUSION

Quantifying and differentiating these periodontal species from subgingival plaque and saliva samples showed a good potential as diagnostic markers for periodontal disease. Regarding the prevalence of the studied bacteria, specifically A. actinomycetemcomitans JP2 clone, found in this work, and the high rate of susceptibility to periodontal species in Africa, future larger studies are recommended.

The role of pathogens in diabetes pathogenesis and the potential of immunoproteomics as a diagnostic and prognostic tool

Diabetes mellitus (DM) is a group of metabolic diseases marked by hyperglycemia, which increases the risk of systemic infections. DM patients are at greater risk of hospitalization and mortality from bacterial, viral, and fungal infections. Poor glycemic control can result in skin, blood, bone, urinary, gastrointestinal, and respiratory tract infections and recurrent infections. Therefore, the evidence that infections play a critical role in DM progression and the hazard ratio for a person with DM dying from any infection is higher. Early diagnosis and better glycemic control can help prevent infections and improve treatment outcomes. Perhaps, half (49.7%) of the people living with DM are undiagnosed, resulting in a higher frequency of infections induced by the hyperglycemic milieu that favors immune dysfunction. Novel diagnostic and therapeutic markers for glycemic control and infection prevention are desirable. High-throughput blood-based immunoassays that screen infections and hyperglycemia are required to guide timely interventions and efficiently monitor treatment responses. The present review aims to collect information on the most common infections associated with DM, their origin, pathogenesis, and the potential of immunoproteomics assays in the early diagnosis of the infections. While infections are common in DM, their role in glycemic control and disease pathogenesis is poorly described. Nevertheless, more research is required to identify novel diagnostic and prognostic markers to understand DM pathogenesis and management of infections. Precise monitoring of diabetic infections by immunoproteomics may provide novel insights into disease pathogenesis and healthy prognosis.

Structural and biochemical analyses of the tetrameric carboxypeptidase S9Cfn from Fusobacterium nucleatum

As one of the most abundant bacteria in the human oral cavity, Fusobacterium nucleatum is closely involved in various oral diseases and is also a risk factor for other diseases. The peptidases of F. nucleatum can digest exogenous peptides into amino acids to satisfy its nutrient requirements. Here, a putative F. nucleatum peptidase, termed S9Cfn, which belongs to the S9C peptidase family was identified. Enzymatic activity assays combined with mass-spectrometric analysis revealed that S9Cfn is a carboxypeptidase, but not an aminopeptidase as previously annotated. The crystal structure of the S9Cfn tetramer was solved at 2.6 Å resolution and was found to contain a pair of oligomeric pores in the center. Structural analysis, together with site-directed mutagenesis and enzymatic activity assays, revealed a substrate-entrance tunnel that extends from each oligomeric pore to the catalytic triad, adjacent to which three conserved arginine residues are responsible for substrate binding. Moreover, comparison with other S9 peptidase structures indicated drastic conformational changes of the oligomeric pores during the catalytic cycle. Together, these findings increase the knowledge of this unique type of tetrameric carboxypeptidase and provide insight into the homeostatic control of microbiota in the human oral cavity.

Comparison of Red-Complex Bacteria Between Saliva and Subgingival Plaque of Periodontitis Patients: A Systematic Review and Meta-Analysis

The development of periodontitis is associated with an imbalanced subgingival microbial community enriched with species such as the traditionally classified red-complex bacteria (Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola). Saliva has been suggested as an alternative to subgingival plaque for the microbial analysis due to its easy and non-invasive collection. This systematic review aims to determine whether the levels of red-complex bacteria assessed using saliva reflect those in subgingival plaque from periodontitis patients. The MEDLINE, EMBASE, and Cochrane Library databases were searched up to April 30, 2021. Studies were considered eligible if microbial data of at least one of the red-complex species were reported in both saliva and subgingival plaque from periodontitis patients, based on DNA-based methods. Of the 17 included studies, 4 studies used 16S rRNA gene sequencing techniques, and the rest used PCR-based approaches. The detection frequency of each red-complex species in periodontitis patients was reported to be > 60% in most studies, irrespective of samples types. Meta-analyses revealed that both detection frequencies and relative abundances of red-complex bacteria in saliva were significantly lower than those in subgingival plaque. Moreover, the relative abundances of all 3 bacterial species in saliva showed significantly positive correlation with those in subgingival plaque. In conclusion, current evidence suggests that one-time saliva sampling cannot replace subgingival plaque for microbial analysis of the red-complex bacteria in periodontitis patients. Given the positive microbial associations between saliva and subgingival plaque, a thorough review of longitudinal clinical studies is needed to further assess the role of saliva.

Oral Microbiota Identifies Patients in Early Onset Rheumatoid Arthritis

Rheumatoid arthritis (RA) is the most common autoimmune inflammatory disease, and single periodontitis-associated bacteria have been suggested in disease manifestation. Here, the oral microbiota was characterized in relation to the early onset of RA (eRA) taking periodontal status into consideration. 16S rRNA gene amplicon sequencing of saliva bacterial DNA from 61 eRA patients without disease-modifying anti-rheumatic drugs and 59 matched controls was performed. Taxonomic classification at 98.5% was conducted against the Human Oral Microbiome Database, microbiota functions were predicted using PICRUSt, and periodontal status linked from the Swedish quality register for clinically assessed caries and periodontitis. The participants were classified into three distinct microbiota-based cluster groups with cluster allocation differences by eRA status. Independently of periodontal status, eRA patients had enriched levels of Prevotella pleuritidis, Treponema denticola, Porphyromonas endodontalis and Filifactor alocis species and in the Porphyromonas and Fusobacterium genera and functions linked to ornithine metabolism, glucosylceramidase, beta-lactamase resistance, biphenyl degradation, fatty acid metabolism and 17-beta-estradiol-17-dehydrogenase metabolism. The results support a deviating oral microbiota composition already in eRA patients compared with healthy controls and highlight a panel of oral bacteria that may be useful in eRA risk assessment in both periodontally healthy and diseased persons.

Antibacterial Activity of Boswellia sacra Flueck. Oleoresin Extract against Porphyromonas gingivalis Periodontal Pathogen

Boswellia sacra Flueck. oleoresin extract (frankincense) has traditionally been used in the treatment of different diseases, but there are no sufficient studies on its potential activity against periodontal pathogens. Therefore, antibacterial and antibiofilm activity of frankincense extract against Porphyromonas gingivalis clinical isolates were studied. The phytochemical composition of the volatile components of the extract was identified by GC-MS analysis revealing 49 compounds as trans-nerolidyl formate, cycloartenol acetate, ursenoic acid 3-oxomethyl ester, bisabolene epoxide, and kaur-16-ene. It decreased the growth and increased the leakage of nucleotides in 58.3% and 33.3% of isolates, respectively. Additionally, it reduced the extracellular polysaccharide production and the cell surface hydrophobicity in 41.67% and 50% of the isolates, respectively. Crystal violet assay revealed inhibition of biofilm formation by the tested isolates. Light microscope and scanning electron microscope were used to examine the biofilms and they confirmed the reduction of biofilm formation by frankincense extract. Downregulation of the genes linked to biofilm formation (fimA, hagA, and hagB) was observed using qRT-PCR after treatment with the frankincense extract. This study suggested that the frankincense extract could exhibit antibacterial and antibiofilm activity against P. gingivalis isolates. Thus, the frankincense extract could be used as a treatment approach for periodontitis.

Determination of the Role of Fusobacterium Nucleatum in the Pathogenesis in and Out the Mouth

INTRODUCTION

One of the most important types of microorganisms in the oral cavity in both healthy and non-healthy individuals is Fusobacterium nucleatum. Although present as a normal resident in the oral cavity, this Gram-negative pathogen is dominant in periodontal disease and it is involved in many invasive infections in the population, acute and chronic inflammatory conditions, as well as many adverse events with a fatal outcome.

AIM

To determine the role of F. nucleatum in the development of polymicrobial biofilms thus pathogenic changes in and out of the oral media.

MATERIAL AND METHOD

A systematic review of the literature concerning the determination and role of F. nucleatum through available clinical trials, literature reviews, original research and articles published electronically at Pub Med and Google Scholar.

CONCLUSION

The presence of Fusobacterium nucleatum is commonly associated with the health status of individuals. These anaerobic bacteria plays a key role in oral pathological conditions and has been detected in many systemic disorders causing complex pathogenethic changes probably due to binding ability to various cells thus several virulence mechanisms. Most common diseases and conditions in the oral cavity associated with F.nucleatum are gingivitis (G), chronic periodontitis (CH), aggressive periodontitis (AgP), endo-periodental infections (E-P), chronic apical periodontitis (PCHA). The bacterium has been identified and detected in many systemic disorders such as coronary heart disease (CVD) pathological pregnancy (P); polycystic ovary syndrome (PCOS), high-risk pregnancy (HRP), colorectal cancer (CRC); pre-eclampsia (PE); rheumatoid arthritis (RA); osteoarthritis (OA).

The prevalence of fimA genotypes of Porphyromonas gingivalis in patients with chronic periodontitis: A meta-analysis

FimA is an important virulence factor of Porphyromonas gingivalis (P. gingivalis). According to its DNA sequence, the fimA genotype of P. gingivalis can be divided into six categories (I, Ib, Ⅱ, III, IV, V). The fimA gene may be a key factor in the diversity of virulence found in P. gingivalis. Moreover, the role fimA plays in the pathogenesis of P. gingivalis is closely associated with periodontitis, making it an important factor of study for disease prevention and treatment. In this study, the prevalence of fimA genotypes of P. gingivalis in patients with periodontal diseases was evaluated by meta-analysis. The Embase and PubMed databases were searched for articles from 1999 to 2019 using the following search terms: Porphyromonas gingivalis or P. gingivalis; periodontitis or chronic periodontal disease; fimA or fimA genotype. The reference lists of relevant published articles were searched manually. A total of 17 studies were included in this report. A statistical software package (Stata, version 11.0/mp, StataCorp) was utilized to calculate and analyze the P. gingivalis fimA genotypes for each combined incidence estimate. The pooled rates of fimA Ⅰ, fimA Ib, fimA Ⅱ, fimA Ⅲ, fimA Ⅳ and fimA Ⅴ genotypes of P. gingivalis were 8.4% (95% CI: 5.7-11.1), 11.7% (95% CI: 7.4-16), 42.9% (95% CI: 34.2-51.7), 6.5% (95% CI: 5.1-7.9), 17.8% (95% CI: 9.0-26.5), and 3.2% (95% CI: 1.6-4.9), respectively. This study showed that the fimA Ⅱ and fimA Ⅳ genotypes of P. gingivalis are highly present in patients with periodontal disease. Therefore, these two genotypes may be related to the pathogenesis and progress of periodontal disease, one of the main risk factors of periodontitis.

Clinical and Microbiological Profiles of Aggressive and Chronic Periodontitis in Congolese Patients: A Cross-sectional Study

Background:

Chronic and aggressive periodontitis were the main forms of periodontitis according to the 1999 classification of periodontal diseases and conditions. Their profile in Congolese patients is still undescribed.

Aim:

The aim of this study was to compare the profile of chronic periodontitis (ChP) with that of aggressive periodontitis (AgP) in Congolese patients.

Materials and Methods:

Thirty-two patients with ChP and 20 with AgP who consulted the dental services at any of the four medical centers in Kinshasa, from April 2017 to April 2018, were enrolled in the cross-sectional study. All patients underwent a full mouth examination, including assessment of the probing pocket depth and clinical attachment level at six sites per tooth. Microbial samples were collected in the deepest pocket in the maxilla and the deepest pocket in the mandible. A deoxyribonucleic acid (DNA) analysis was performed using DNA strip technology. Fisher exact test, the chi-square test, the t test, and the Mann–Whitney test were used for the statistical analysis.

Results:

Patients with AgP were significantly younger than those with ChP (P < 0.001). There was no significant difference in the prevalence of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, or Prevotella intermedia between the AgP and ChP groups (P > 0.05). Aggregatibacter actinomycetemcomitans was detected in 10% of cases in the AgP group and in none of those in the ChP group (P = 0.143).

Conclusion:

This study shows that the clinical profiles of ChP and AgP are similar in Congolese patients. There were no microbiological differences between these two forms of periodontitis.

Analysis of Porphyromonas gingivalis fimA genotypes in severe periodontitis patients

The aim of this study was to i) evaluate the prevalence of P. gingivalis and the genotypes fim A I, Ib, II, III, IV, and V in Brazilian patients with periodontitis stage III and IV, grades B and C, ii) compare periodontitis grades B and C with regard to the prevalence of P. gingivalis and fim A genotypes, and iii) correlate the presence of these pathogens with clinical periodontal variables. Two samples of subgingival biofilm were collected from the interproximal sites with the greatest clinical attachment loss (CAL) of each patient (grade B = 38; grade C = 54) and submitted to polymerase chain reaction (PCR) for the identification of P. gingivalis and fim A genotypes. The collected periodontal clinical parameters included gingival index, plaque index, probing depth (PD), bleeding on probing (BoP) and CAL. P. gingivalis was present in 61.96% of the samples, but more prevalent in patients with grade C periodontitis (p = 0.048) and higher CAL (p < 0.001), PD (p < 0.001), and BoP (p = 0.01) values, and at sites with high CAL values (p = 0.01). The fim A II genotype was more prevalent in patients with greater mean PD (p = 0.04) and a higher proportion of bleeding sites (p = 0.006). Thus, in this sample of Brazilian periodontitis patients, the presence of P. gingivalis was associated with grade C periodontitis and periodontal destruction, while the fim A II genotype was associated with increased PD and BoP, supporting the notion that P. gingivalis fim A II is an important virulence factor in periodontal tissues.

Specific Anti-biofilm Activity of Carbon Quantum Dots by Destroying P. gingivalis Biofilm Related Genes

Introduction

Biofilms protect bacteria from antibiotics and this can produce drug-resistant strains, especially the main pathogen of periodontitis, Porphyromonas gingivalis. Carbon quantum dots with various biomedical properties are considered to have great application potential in antibacterial and anti-biofilm treatment.

Methods

Tinidazole carbon quantum dots (TCDs) and metronidazole carbon quantum dots (MCDs) were prepared by a hydrothermal method with the clinical antibacterial drugs tinidazole and metronidazole, respectively. Then, TCDs and MCDs were characterized by transmission electron microscopy, UV–visible spectroscopy, infrared spectroscopy and energy-dispersive spectrometry. The antibacterial effects were also investigated under different conditions.

Results

The TCDs and MCDs had uniform sizes. The results of UV–visible and energy-dispersive spectrometry confirmed their important carbon polymerization structures and the activity of the nitro group, which had an evident inhibitory effect on P. gingivalis, but almost no effect on other bacteria, including Escherichia coli, Staphylococcus aureus and Prevotella nigrescens. Importantly, the TCDs could penetrate the biofilms to further effectively inhibit the growth of P. gingivalis under the biofilms. Furthermore, it was found that the antibacterial effect of TCDs lies in its ability to impair toxicity by inhibiting the major virulence factors and related genes involved in the biofilm formation of P. gingivalis, thus affecting the self-assembly of biofilm-related proteins.

Conclusion

The findings demonstrate a promising new method for improving the efficiency of periodontitis treatment by penetrating the P. gingivalis biofilm with preparations of nano-level antibacterial drugs.

TLR4 polymorphisms may increase susceptibility to periodontitis in Pg-positive individuals

Objective

To investigate the correlation between the single nucleotide polymorphisms (SNPs) in the toll-like receptor 4 (TLR4) gene and the susceptibility to chronic periodontitis.

Design

241 Chinese subjects from the cohort of Beijing Shijingshan Community were recruited. Buccal swab samples, the whole unstimulated saliva and periodontal clinical parameters were collected. Human DNA extracted from buccal swab samples were used for genotyping eight SNPs of the TLR4 gene (rs11536889, rs1927906, rs1927911, rs2149356, rs4986790, rs4986791, rs2737190, rs787384) by the Sequenom MassARRAY system. Porphyromonas gingivalis (P. gingivalis) was detected from the deposition of the whole unstimulated saliva through polymerase chain reaction (PCR) method based on 16S rRNA. The correlation between SNPs of TLR4 and chronic periodontitis susceptibility in the whole subjects and the patients detected with P. gingivalis was investigated.

Results

The variants of rs4986790 and rs4986791 were not found in 241 Chinese subjects. Moreover, there was no significant difference in the distribution of theother6 SNPs of TLR4 between groups of none/mild -periodontitis and moderate/severe-periodontitis subjects. When combined with P. gingivalis infection, rs1927911 (TT/CC+CT), rs2149356 (TT/GG+GT) and rs2737190 (GG/AA+AG) were independent risk factors of chronic periodontitis.

Conclusion

Three SNPs of TLR4, i.e., rs1927911 (TT/CC+CT), rs2149356 (TT/GG+GT) and rs2737190 (GG/AA+AG), were associated with moderate/severe chronic periodontitis in Chinese population infected with P. gingivalis. P. gingivalis, which interacted with TLR4 gene plays an important role in the pathogenesis of periodontitis.

Variability in Genomic and Virulent Properties of Porphyromonas gingivalis Strains Isolated From Healthy and Severe Chronic Periodontitis Individuals

Porphyromonas gingivalis has been extensively associated with both the onset and progression of periodontitis. We previously isolated and characterized two P. gingivalis strains, one from a patient exhibiting severe chronic periodontitis (CP3) and another from a periodontally healthy individual (H3). We previously showed that CP3 and H3 exhibit differences in virulence since H3 showed a lower resistance to cationic peptides compared with CP3, and a lower ability to induce proliferation in gingival epithelial cells. Here, we aimed to determine whether differences in virulence between these two strains are associated with the presence or absence of specific genes encoding virulence factors. We sequenced the whole genomes of both P. gingivalis CP3 and H3 and conducted a comparative analysis regarding P. gingivalis virulence genetic determinants. To do so, we performed a homology search of predicted protein sequences in CP3 and H3 genomes against the most characterized virulence genes for P. gingivalis available in the literature. In addition, we performed a genomic comparison of CP3 and H3 with all the 62 genomes of P. gingivalis found in NCBI's RefSeq database. This approach allowed us to determine the evolutionary relationships of CP3 and H3 with other virulent and avirulent strains; and additionally, to detect variability in presence/absence of virulence genes among P. gingivalis genomes. Our results show genetic variability in the hemagglutinin genes. While CP3 possesses one copy of hagA and two of hagC, H3 has no hagA and only one copy of hagC. Experimentally, this finding is related to lower in vitro hemmaglutination ability of H3 compared to CP3. Moreover, while CP3 encodes a gene for a major fimbrium subunit FimA type 4 (CP3_00160), H3 possess a FimA type 1 (H3_01400). Such genetic differences are in agreement with both lower biofilm formation ability and less intracellular invasion to oral epithelial cells exhibited by H3, compared with the virulent strain CP3. Therefore, here we provide new results on the genome sequences, comparative genomics analyses, and phenotypic analyses of two P. gingivalis strains. The genomics comparison of these two strains with the other 62 genomes included in the analysis provided relevant results regarding genetic determinants and their association with P. gingivalis virulence.

De novo synthesis of novel bacterial monosaccharide fusaminic acid

Fusobacterium nucleatum is an oral bacteria related to various types of diseases. As Gram-negative bacteria, lipopolysaccharide (LPS) of Fusobacterium nucleatum could be a potential virulence factor. Recently, the structure of O-antigen in LPS of Fusobacterium nucleatum strain 25586 was elucidated to contain a trisaccharide repeating unit -(4-β-Nonp5Am-4-α-L-6dAltpNAc3PCho-3-β-D-QuipNAc)-. The nonulosonic acid characterized as 5-acetamidino-3,5,9-trideoxy-L-glycero-L-gluco-non-2-ulosonic acid (named as fusaminic acid), and 2-acetamido-2,6-dideoxy-L-altrose are the novel monosaccharides isolated. Herein we report the de novo synthesis of 5-N-acetyl fusaminic acid and the thioglycoside derivative in order to further investigate the biological significance of nonulosonic acids for bacterial pathogenesis.

Recombinant fimbriae protein of Porphyromonas gingivalis induces an inflammatory response via the TLR4/NF‑κB signaling pathway in human peripheral blood mononuclear cells

Porphyromonas gingivalis (P. gingivalis) is a periodontal pathogen that may accumulate with other organisms in subgingival plaque biofilms and is associated with periodontal disease. P. gingivalis fimbriae (FimA) is a filamentous structure on the surface of bacteria that is closely associated with bacterial adhesion to and colonization of host tissues, and serves an essential role in biofilm formation. The present study aimed to construct P. gingivalis FimA prokaryotic expression plasmids, purify a FimA fusion protein and explore the effect of a recombinant FimA protein on the inflammatory response in human peripheral blood mononuclear cells (PBMCs). P. gingivalis FimA prokaryotic expression plasmids were constructed by gene cloning and recombination technology. SDS-PAGE was used to evaluate the purified recombinant FimA protein. The cell proliferation rate and inflammatory cytokine expression of PBMCs treated with the FimA fusion protein with or without transfection with toll-like receptor 4 (TLR4) small interfering (si)RNA were detected by CCK-8 assays and ELISAs, respectively. The expression levels of TLR4, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and myeloid differentiation primary response 88 (MyD88) in PBMCs were detected by western blot analysis and reverse transcription quantitative polymerase chain reaction. A FimA fusion protein with high purity was obtained. FimA fusion protein treatment significantly increased PBMC proliferation and promoted the release of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, matrix metalloproteinase (MMP)-8 and MMP-9 in PBMCs. TLR4 interference reversed the effects of the FimA fusion protein on PBMC proliferation and inflammatory cytokine release. The expression levels of TLR4, NF-κB and MyD88 in PBMCs were significantly increased following treatment with the FimA fusion protein, while the expression levels of these genes at the mRNA and protein levels decreased significantly in PBMCs following FimA fusion protein treatment and TLR4 interference. The FimA fusion protein increased PBMC proliferation and promoted the release of the inflammatory cytokines TNF-α, IL-6, MMP-8 and MMP-9 via the TLR4/NF-κB signaling pathway. FimA may serve as a promising therapeutic strategy for periodontal disease.

Periopathogenic bacteria in dental plaque of Congolese patients with periodontitis: A pilot study

Background

Periopathogenic bacteria play an important role in the etiology of periodontal disease. At present, no study screening for periopathogens in the DR Congo was carried out. The aim of this pilot study was to investigate the prevalence of five periopathogens in Congolese patients with periodontitis and to determine the association between these bacteria.

Material and Methods

Twelve patients (eight women and four men) with a mean age of 45 ± 19 years from those consulted in dental services of two medical centers of Kinshasa from April 2017 to October 2017 were included. Full mouth examination was registered, the probing pocket depth and clinical attachment level were assessed at six sites per tooth. Dental subgingival plaque samples were taken in the deepest pocket per arch in the maxilla and mandible. DNA analysis was performed using DNA-strip technology. The Fisher Exact test and Pearson correlation were used for statistical analysis.

Results

Porphyromonas gingivalis and Tannerella forsythia were detected at high level of 92%, Prevotella intermedia at a rate of 75% whereas Treponema denticola was detected in all patients. Aggregatibacter actinomycetemcomitans was not detected. Strong associations were found between three bacteria of the red complex and between T. denticola and P. intermedia (r=1).

Conclusions

This first study investigating periopathogens in subgingival plaque of Congolese with periodontitis demonstrated a high prevalence of the red complex (P. gingivalis, T. forsythia and T. denticola). Associations between different bacteria of this complex were strong.

Key words:Association, bacteria, periopathogen, periodontitis, prevalence.

Profiling of Aggregatibacter actinomycetemcomitans Serotypes B and C and the genotypes in periodontal health and disease

BACKGROUND

A. actinomycetemcomitans is prevalent in periodontitis but is found in some periodontally healthy individuals as well. Certain serotypes of the organism have shown to determine severity of the disease. The distribution of serotype and genotype is affected by geographic and ethnic variation. Therefore, the present study was aimed to detect serotypes b & c of A. actinomycetemcomitans and the genotypes and find its correlation with periodontal status.

MATERIALS AND METHODS

A total of 75 subjects (25 aggressive periodontitis, 25 chronic periodontitis and 25 periodontally healthy) in age range of 14-55 yrs were included. Subgingival plaque samples were collected and checked for the presence of A. actinomycetemcomitans. Following isolation of the organism, detection of the serotype b or c was done by multiplex PCR. Genotyping of A. actinomycetemcomitans was done by arbitrarily primed PCR(polymerase chain reaction).

RESULTS

Out of 75 plaque samples, 35(46.66%) tested positive for A. actinomycetemcomitans. Serotype c was detected in 19/35 (54.28%), whereas serotype b alone was not detected in any of the samples. Two samples were positive for both the serotypes (b and c) (5.71%) and 14 (40%) were untypeable. 14 different arbitrarily primed PCR genotypes were obtained among 35 A. actinomycetemcomitans isolates.

CONCLUSION

Serotype c was predominant in periodontally diseased as well as periodontally healthy individuals. An association could be present between genotype - serotype and genotype - periodontal status.

Serotypes of Aggregatibacter actinomycetemcomitans in relation to periodontal status and assessment of leukotoxin in periodontal disease: A clinico-microbiological study

Context:

Aggregatibacter actinomycetemcomitans (A.a) serotypes may add some important information of the pathogenetic background of periodontal infections. A.a leukotoxin is an important virulence factor in the pathogenesis of periodontal disease and its rate of progression. When compared to minimally leukotoxic strains, variants of A.a highly leukotoxic strains produce 10–20 times more leukotoxin.

Aims:

The aim of the present study was to detect serotypes a, b, c, d, and e of A.a its leukotoxin and find its correlation with periodontal status.

Settings and Design:

Microbiological analysis and cross-sectional study.

Materials and Methods:

A total of 80 subjects (40 chronic periodontitis and 40 aggressive periodontitis) in the age range of 14–55 years were selected. Subgingival plaque samples were collected and checked for the presence of A.a. Following isolation of the organism, detection of the serotypes and leukotoxin assessment was done.

Statistical Analysis Used:

The proportions of A.a were calculated using descriptive statistics in terms of percentage. Chi-square test was used to find association between serotype, leukotoxin, and periodontal disease in individual group.

Results:

Out of 80 plaque samples, 45% tested positive for A.a. serotype b was detected in 33.33%, whereas serotype e in 8.33% samples and serotype c in 2.77% samples. Serotypes a and d were not detected in any of the samples. A combination of serotypes was seen in 47.22% of the sites. Of these 76.47% showed a combination of 2 serotypes, while 23.52%showed a combination of 3 serotypes. 8.33% showed untypable serotype. All samples had low-toxic variants of A.a.

Conclusions:

Serotype b and serotype e were predominant in chronic periodontitis, and serotype b was predominant in aggressive periodontitis. An association could be present between serotype and periodontal disease.

Prevalence of fimA genotypes of Porphyromonas gingivalis in adolescent orthodontic patients

Background

The placement of fixed orthodontic appliances may alter the composition of oral microbiota and has the potential risk of periodontal complication. Porphyromonas gingivalis fimbriae play a critical role in colonization of P. gingivalis in subgingival regions. In this study, we investigated the association between the prevalence of P. gingivalis-specific fimA genotypes and periodontal health status in adolescent orthodontic patients, to identify the pathogencity of P. gingivalis during orthodontic therapy.

Methods

Sixty-one adolescent orthodontic patients were enrolled in the case group, while the control group consisted of 56 periodontally healthy adolescents. At baseline (T0), clinical parameter (gingival index) was tested, and subgingival plaque samples were obtained from the lower incisors. The incidences of P. gingivalis and fimA genotypes were detected by polymerase chain reaction. All parameters were reassessed after 1 month (T1), 2 months (T2), 3 months (T3), and 6 months (T4) in the case group and then compared with those of the controls.

Results

Both microbiological and clinical parameters from orthodontic patients started to increase after placement of fixed appliances. Maximum values were reached at 3 months after placement and followed by their decreases at six months. However, the microbiological and clinical parameters in the case group were significantly higher than those of the control group. The GI of fimA II, IV-positive samples was significantly higher than that of negative samples.

Conclusion

P. gingivalis carrying fimA II or IV was closely related to orthodontic gingivitis. In addition, proper oral hygiene control could lead to little increase in dental plaque accumulation, and exert a beneficial effect to periodontal tissues.

Fusobacterium nucleatum in gastroenterological cancer: Evaluation of measurement methods using quantitative polymerase chain reaction and a literature review

The human microbiome Fusobacterium nucleatum, which primarily inhabits the oral cavity, causes periodontal disease and has also been implicated in the development of colorectal cancer. However, whether F. nucleatum is present in other gastroenterological cancer tissues remains to be elucidated. The present study evaluated whether quantitative polymerase chain reaction (qPCR) assays were able to detect F. nucleatum DNA and measure the quantity of F. nucleatum DNA in esophageal, gastric, pancreatic and liver cancer tissues. The accuracy of the qPCR assay was determined from a calibration curve using DNA extracted from cells from the oral cavity. Formalin-fixed paraffin-embedded (FFPE) tumor tissues from 20 patients with gastroenterological [esophageal (squamous cell carcinoma), gastric, colorectal, pancreatic and liver] cancer and 20 matched normal tissues were evaluated for F. nucleatum DNA content. The cycle threshold values in the qPCR assay for F. nucleatum and solute carrier organic anion transporter family member 2A1 (reference sample) decreased linearly with the quantity of input DNA (r²>0.99). The F. nucleatum detection rate in esophageal, gastric and colorectal cancer tissues were 20% (4/20), 10% (2/20) and 45% (9/20), respectively. F. nucleatum was not detected in liver and pancreatic cancer tissues. The qPCR results from the frozen and FFPE tissues were consistent. Notably, F. nucleatum was detected at a higher level in superficial areas compared with the invasive areas. F. nucleatum in esophageal, gastric and colorectal cancer tissues was evaluated by qPCR using FFPE tissues. F. nucleatum may be involved in the development of esophageal, gastric and colorectal cancer.

Prevalence of Periodontal Pathogens in a Group of Participants from the Middle East and North Africa Geographic Region with Minimal Periodontal Disease

Aim and Objectives:

To assess the prevalence of the three putative periodontal pathogens such as Aggregatibacter actinomycetemcomitans (A. a), Porphyromonas gingivalis (P. g), and Prevotella intermedia (P. i) in a group of Arab participants from the Middle East and North Africa (MENA) region who had minimal periodontal disease and no history of periodontal treatment and further to analyze the association among these three microorganisms.

Materials and Methods:

Eighty-four participants of varied demographics and oral/dental care habits were screened for this study. Twenty-one participants who eventually gave their consent to fully participate in the study provided a balanced representation of the screened universe.

Results:

Seventy-eight microbiological samples were taken from the deepest pockets. Twenty-three percent of all samples were found to be A. a positive and so were 79% for P. g and 82% for P. i. A highly remarkable association was observed between the presence of P. i along with P. g (P < 0.00l; Fisher's exact test). Of all samples, merely six cases were P. i positive but not P. g and eight cases were vice versa. There was a statistically significant association between A. a and P. g (P = 0.016). No significant relationship was detected between P. i and A. a.

Conclusions:

This qualitative study shows very high frequency of the three periodontal pathogens (A. a, P. g, and P. i) in a group of Arab nationals with minimal periodontal disease. The lack of oral hygiene, minimal use of antimicrobial drugs and antiseptics, and the absence of dental care may partly explain the high prevalence of periodontal pathogens.

Pathogenicity and genetic profile of oral Porphyromonas species from canine periodontitis

OBJECTIVE

In this study, the presence of the prtC and fimA genes involved in the pathogenicity of oral Porphyromonas spp. isolated from dogs with periodontitis and healthy, as well as their genetic diversity was investigated.

DESIGN

Thirty-two Beagle dogs, 24 with periodontitis and 8 healthy were evaluated. Subgingival samples from only one gingival site of both groups were collected. Bacteria grown in anaerobiosis were identified by RAPID ID 32A kits. From each strain the respective DNA was obtained and used to genotyping by conventional PCR and AP-PCR.

RESULTS

Dogs with periodontitis harbored 28 P. gulae, 2 P. creviocaricanis, 1 P. cangingivalis and 7 P. macacae; and from healthy dogs, 11 P. gulae and 5 P. circumdentaria. In P. gulae isolated from periodontal dogs the gene prtC was observed in 19 (67.85%) and in 7 (63.63%) from healthy dogs. P. gulae strains from periodontal dogs harbored either the gene fimA I or fimA II; while strains from healthy dogs harbored the gene fimA I, fimA II, fimA III or fimA IV, as well as 1 P. circumdentaria the gene fimA II. By AP-PCR strains were grouped in different clusters suggesting heterogeneity of these microorganisms.

CONCLUSIONS

The results presented herein inform that Porphyromonas spp. isolated from dogs with and without periodontitis harbored the prtC and fimA genes and it could be a role in the establishment of the infectious process.

Root abnormalities and nonsurgical management of generalized aggressive periodontitis

To investigate long-term nonsurgical treatment outcomes in patients with generalized aggressive periodontitis (GAgP) and the impact of root abnormalities (RAs) and other patient-level factors in relation to GAgP progression. Patients (n = 64) from a GAgP cohort who completed active nonsurgical periodontal treatment and consented to re-evaluation after 3 to 11 (mean 5.3) years, were enrolled. RAs were identified using radiographs. Periodontal parameters (e.g., probing depths [PDs], and tooth loss [TL]) were investigated. Multivariate analysis was performed to identify factors contributing to TL and bone level alteration (∆BL). After treatment, the mean number of sites with PDs > 5 mm decreased from 54.3 to 17.2. Annual TL was 0.11/patient. Twenty-one patients (32.8%) had >4 teeth with root abnormalities (RA-teeth) and exhibited a higher risk for TL (univariate odds ration [OR] = 3.52, multivariate logistic OR = 6.57). Factors correlated to ∆BL were sites with residual PD > 5 mm (β = -0.400) and observation time (β = -0.210). Nonsurgical treatment provides beneficial outcomes in GAgP patients. Higher incidence of RAs and high prevalence of residual deep pockets have a negative impact on long-term outcomes.

PRACTICAL IMPLICATIONS

in cases of GAgP with residual deep pockets and high incidence of RAs, clinicians must emphasize that long-term outcomes of nonsurgical treatment may be compromised.

Profiling of subgingival plaque biofilm microbiota in adolescents after completion of orthodontic therapy

Background

Fixed orthodontic treatment is the most common method for malocclusion but has the potential risk of periodontal complication with unclear outcomes of whether microbiologic and clinical changes could be reversible in adolescents after orthodontic therapy.

Methods

Twenty adolescents with orthodontic treatment were enrolled in the study as the case group at end of the therapy, while 19 periodontally healthy adolescents were involved in the control group. At baseline (T₀), clinical parameters including gingival index, probing depth and sulcus bleeding index were tested, and subgingival plaque samples were collected from the lower incisors. The counts of A. actinomycetemcomitans, P. gingivalis, P. intermedia, T. forsythia and total bacteria were determined by real-time PCR. All parameters were reassessed after 1 month (T₁) and 3 months (T₂) in the case group and compared with that of the controls.

Results

At baseline (T₀), clinical parameters (including GI, PD, SBI) of the test sites in the case group were significantly higher than that of the control group (P<0.05 or P<0.01). At 3 months (T₂), no differences were noticed in GI and SBI between two groups. The prevalence and counts of periodontopathogens tend to be normal (P>0.05), while PD and the amount of P.intermedia were still significantly higher compared with that of the control group (P<0.05 or P<0.01).

Conclusion

After removal of appliances, the periodontal changes induced by orthodontic therapy are only partially reversible at 3 months after removal.

Porphyromonas gingivalis Uses Specific Domain Rearrangements and Allelic Exchange to Generate Diversity in Surface Virulence Factors

Porphyromonas gingivalis is a keystone pathogen of chronic periodontitis. The virulence of P. gingivalis is reported to be strain related and there are currently a number of strain typing schemes based on variation in capsular polysaccharide, the major and minor fimbriae and adhesin domains of Lys-gingipain (Kgp), amongst other surface proteins. P. gingivalis can exchange chromosomal DNA between strains by natural competence and conjugation. The aim of this study was to determine the genetic variability of P. gingivalis strains sourced from international locations over a 25-year period and to determine if variability in surface virulence factors has a phylogenetic basis. Whole genome sequencing was performed on 13 strains and comparison made to 10 previously sequenced strains. A single nucleotide polymorphism-based phylogenetic analysis demonstrated a shallow tri-lobed phylogeny. There was a high level of reticulation in the phylogenetic network, demonstrating extensive horizontal gene transfer between the strains. Two highly conserved variants of the catalytic domain of the major virulence factor the Kgp proteinase (Kgp_catI and Kgp_catII) were found. There were three variants of the fourth Kgp C-terminal cleaved adhesin domain. Specific variants of the cell surface proteins FimA, FimCDE, MfaI, RagAB, Tpr, and PrtT were also identified. The occurrence of all these variants in the P. gingivalis strains formed a mosaic that was not related to the SNP-based phylogeny. In conclusion P. gingivalis uses domain rearrangements and genetic exchange to generate diversity in specific surface virulence factors.

Molecular identification of black-pigmented bacteria from subgingival samples of cats suffering from periodontal disease

OBJECTIVES

To characterise the black-pigmented bacterial species found in the subgingival samples of cats with periodontal disease using molecular-based microbiological techniques.

METHODS

Sixty-five subgingival samples obtained from 50 cats with periodontal disease were analysed by polymerase chain reaction amplified ribosomal DNA restriction analysis and cloning and sequencing of the 16S rRNA genes.

RESULTS

Among the 65 subgingival samples, eight phylogenetic profiles were obtained, of which the most prevalent species were: Porphyromonas gulae (40%), P. gingivalis/P. gulae (36 · 9%), P. gulae/Porphyromonas sp. UQD 406 (9 · 2%), Odoribacter denticanis (6 · 2%), P. gulae/Porphyromonas sp. UQD 348 (1 · 5%) and P. circumdentaria (1 · 5%). When compared with the species resulting from biochemical diagnosis, the identification of P. gulae was congruent in 70% of the cases, while colonies identified as P. intermedia-like corresponded in 80% of cases to P. gulae.

CLINICAL SIGNIFICANCE

The use of molecular-based microbiological diagnostic techniques resulted in a predominance of Porphyromonas spp. in the subgingival plaque of cats suffering from periodontal disease. Further characterisation of these bacteria identified P. gulae, O. denticanis and P. circumdentaria. The more frequently detected phylogenetic profiles corresponded to P. gingivalis and P. gulae.

Deoxyribonucleic Acid Probes Analyses for the Detection of Periodontal Pathogens

BACKGROUND

In clinical microbiology several techniques have been used to identify bacteria. Recently, Deoxyribonucleic acid (DNA)-based techniques have been introduced to detect human microbial pathogens in periodontal diseases. Deoxyribonucleic acid probes can detect bacteria at a very low level if we compared with the culture methods. These probes have shown rapid and cost-effective microbial diagnosis, good sensitivity and specificity for some periodontal pathogens in cases of severe periodontitis.

MATERIALS AND METHODS

Eighty-five patients were recruited for the study. Twenty-one subjects ranging between 22 and 48 years of age fulfilled the inclusion and exclusion criteria. Seventy-eight samples became available for DNA probe analysis from the deepest pockets in each quadrant.

RESULTS

All 21 patients showed positive results for Prevotella intermedia; also, Prevotella gingivalis was identified in 19 subjects, Aggregatibacter actinomycetemcomitans in 6 subjects. P. intermedia was diagnosed positive in 82% of the subgingival samples taken, 79% for P. gingivalis, and 23% for A. actinomycetemcomitans.

CONCLUSION

This study shows a high frequency of putative periodontal pathogens by using DNA probe technology, which is semi-quantitative in this study. Deoxyribonucleic acid probes can detect bacteria at very low level about 10(3) which is below the detection level of culture methods. The detection threshold of cultural methods.

CLINICAL SIGNIFICANCE

The three types of bacteria can be detected rapidly with high sensitivity by using the DNA probe by general practitioners, and thus can help in the diagnosis process and the treatment.

The expression of NLRP3, NLRP1 and AIM2 in the gingival tissue of periodontitis patients: RT-PCR study and immunohistochemistry

OBJECTIVE

Detecting the distribution and intensity of NLRP3, NLRP1 and AIM2 expression in different types of periodontitis gingival tissues.

MATERIALS AND METHODS

A total of 65 gingival tissues were collected from clinic and been divided into three groups: patients with chronic periodontitis (CP), patients with generalized aggressive periodontitis (G-AgP) and healthy control subjects. Real-time polymerase chain reaction (RT-PCR) was performed to detect mRNA expression of NLRP3, NLRP1 and AIM2 in full-thickness tissue. In the meanwhile, immunohistochemistry was used to detect distribution of NLRP3, NLRP1 and AIM2 in the periodontal epithelium and in the connective tissue cells.

RESULTS

The overall intensity of NLRP3 expression was significantly higher in CP or G-AgP than healthy tissue. A more significant difference was observed in the periodontal epithelium layer. NLRP1 was barely expressed in the healthy and periodontitis gingival tissues, whereas AIM2 was expressed at a higher level in the chronic periodontitis group than others.

CONCLUSION

The NLRP3, NLRP1 and AIM2 proteins were differentially expressed in gingival tissues from patients with CP and G-AgP and may play vital roles in the progression of periodontal inflammation to different degrees. Our studies may provide a new direction for personalized periodontal treatment.

16S rRNA based microarray analysis of ten periodontal bacteria in patients with different forms of periodontitis

DNA microarray analysis is a computer based technology, that a reverse capture, which targets 10 periodontal bacteria (ParoCheck) is available for rapid semi-quantitative determination. The aim of this three-year retrospective study was to display the microarray analysis results for the subgingival biofilm samples taken from patient cases diagnosed with different forms of periodontitis. A total of 84 patients with generalized aggressive periodontitis (GAP,n:29), generalized chronic periodontitis (GCP, n:25), peri-implantitis (PI,n:14), localized aggressive periodontitis (LAP,n:8) and refractory chronic periodontitis (RP,n:8) were consecutively selected from the archives of the Oral Microbiological Diagnostic Laboratory. The subgingival biofilm samples were analyzed by the microarray-based identification of 10 selected species. All the tested species were detected in the samples. The red complex bacteria were the most prevalent with very high levels in all groups. Fusobacterium nucleatum was detected in all samples at high levels. The green and blue complex bacteria were less prevalent compared with red and orange complex, except Aggregatibacter actinomycetemcomitas was detected in all LAP group. Positive correlations were found within all the red complex bacteria and between red and orange complex bacteria especially in GCP and GAP groups. Parocheck enables to monitoring of periodontal pathogens in all forms of periodontal disease and can be alternative to other guiding and reliable microbiologic tests.

Fusobacterium nucleatum: a commensal-turned pathogen

Fusobacterium nucleatum is an anaerobic oral commensal and a periodontal pathogen associated with a wide spectrum of human diseases. This article reviews its implication in adverse pregnancy outcomes (chorioamnionitis, preterm birth, stillbirth, neonatal sepsis, preeclampsia), GI disorders (colorectal cancer, inflammatory bowel disease, appendicitis), cardiovascular disease, rheumatoid arthritis, respiratory tract infections, Lemierre's syndrome and Alzheimer's disease. The virulence mechanisms involved in the diseases are discussed, with emphasis on its colonization, systemic dissemination, and induction of host inflammatory and tumorigenic responses. The FadA adhesin/invasin conserved in F. nucleatum is a key virulence factor and a potential diagnostic marker for F. nucleatum-associated diseases.

Real-time PCR quantification of six periodontal pathogens in saliva samples from healthy young adults

OBJECTIVE

The use of saliva as a diagnostic fluid for the evaluation of periodontal health has gained attention recently. Most published real-time PCR assays focused on quantification of bacteria in subgingival plaque, not in saliva. The aims of this study were to develop a real-time PCR assay for quantification of six periodontal pathogens in saliva and to establish a relationship between the amount of DNA (fg) and colony-forming unit (CFU).

MATERIALS AND METHODS

TaqMan primers/probe sets were used for the detection of Aggregatibacter actinomycetemcomitans (Aa), Eikenella corrodens (Ec), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythia (Tf), and total bacteria. Six periodontal pathogens and total bacteria in saliva from 24 periodontally healthy individuals were determined. The relationship between the amount of DNA (fg) and CFU was established by measuring the concentrations of extracted bacterial DNA and CFU per milliliter of bacteria on agar plates.

RESULTS

Fn, Ec, and Pi were detected in all saliva samples, while 58.5, 45.8, and 33.3% were detected for Tf, Pg, and Aa, respectively. Numbers of Ec and Fn in saliva were highly correlated (R(2) = 0.93, P < 0.01). The values of DNA (fg) per CFU ranged from 64 for Ec to 121 for Pg.

CONCLUSION

The real-time PCR assay in combination with the relationship between DNA (fg) and CFU can be used to quantitate periodontal pathogens in saliva and estimate the number of live bacteria (CFU).

CLINICAL RELEVANCE

This real-time PCR assay in combination with the relationship between DNA (fg) and CFU has the potential to be an adjunct in evaluation of periodontal health status.

Detection of fusobacterium nucleatum and fadA adhesin gene in patients with orthodontic gingivitis and non-orthodontic periodontal inflammation

Fusobacterium nucleatum is one of the most abundant gram-negative bacilli colonizing the subgingival plaque and closely associated with periodontal disease. However it is unclear whether F. nucleatum is involved in gingival inflammation under orthodontic appliance. A novel adhesin, FadA, which is unique to oral Fusobacteria, is required for F. nucleatum binding and invasion to epithelial cells and thus may play an important role in colonization of Fusobacterium in the host. In this study, we evaluated the prevalence of F. nucleatum and its virulence factor FadA adhesion gene (fadA) in 169 subgingival biofilm samples from 55 cases of gingivitis patients with orthodontic appliances, 49 cases of gingivitis patients without orthodontic treatment, 35 cases of periodontitis patients and 30 cases of periodontally healthy people via PCR. The correlations between the F. nucleatum/fadA and gingivitis index(GI)was also analyzed. The detection rate of F. nucleatum/fadA in periodontitis group and non-orthodontic gingivitis group was higher than the other two groups (p<0.01) while it was higher in orthodontic gingivitis group than in health people (p<0.05). An obviously positive correlation was observed between the prevalence of F. nucleatum/fadA and GI. F. nucleatum carrying fadA may be more closely related to the development of gingivitis and periodontal disease compared with orthodontic gingivitis.