Correlation between chronic periodontitis and rheumatoid arthritis: A periodontist perspective

In this study, we evaluate the relationship between rheumatoid arthritis (RA) and chronic periodontitis on the basis of clinical attachment present and severity of attachment loss in both the cases. First of all Diagnosis of rheumatoid arthritis and chronic periodontitis was performed, thereafter bacterial DNA extraction from blood serum sample and subgingival dental plaque of each group through PCR and later DNA purification through Spin protocol was performed, oligonucleotide primer was used to detect t.forcythia and PCR amplification was done to detect T. Denticola for both the groups .PBDNA was detected in both SGP and serum samples of both the groups. In SGP samples, Tannerella forsythia was more frequently detected as compared to serum samples of both the groups. In result theclinical attachment Level (CAL) was observed to be higher in RA group as compared to CP group. Comparison of CAL according to severity was also observed in both the groups which suggested that RA group has mild periodontitis as compared to CP group in which moderate to severe periodontitis was seen, Detection of periodontal bacterial DNA by PCR assay PBDNA was detected in both SGP and serum samples. In SGP samples, Tannerella forsythia was more frequently detected as compared to serum samples of both the groups. So these are two common chronic inflammatory diseases with a similar host-mediated pathogenesis. Current evidence suggests that an association exists between periodontitis and RA. Well-designed multicenter longitudinal clinical trials and studies with sufficient sample sizes are needed to ascertain the relationship between these two diseases and whether periodontal treatment can reduce the severity of RA or prevent its onset.

NamZ1 and NamZ2 from the oral pathogen Tannerella forsythia are peptidoglycan processing exo-β-N-acetylmuramidases with distinct substrate specificity

ABSTRACTThe Gram-negative periodontal pathogen Tannerella forsythia is inherently auxotrophic for N-acetylmuramic acid (MurNAc), which is an essential carbohydrate constituent of the peptidoglycan (PGN) of the bacterial cell wall. Thus, to build up its cell wall, T. forsythia strictly depends on the salvage of exogenous MurNAc or sources of MurNAc, such as polymeric or fragmentary PGN, derived from cohabiting bacteria within the oral microbiome. In our effort to elucidate how T. forsythia satisfies its demand for MurNAc, we recognized that the organism possesses three putative orthologs of the exo-β-N-acetylmuramidase BsNamZ from Bacillus subtilis, which cleaves non-reducing end, terminal MurNAc entities from the artificial substrate pNP-MurNAc and the naturally-occurring disaccharide substrate MurNAc-β-1,4-N-acetylglucosamine (GlcNAc). TfNamZ1 and TfNamZ2 were successfully purified as soluble, pure recombinant His6-fusions and characterized as exo-lytic β-N-acetylmuramidases with distinct substrate specificities. The activity of TfNamZ1 was considerably lower compared to TfNamZ2 and BsNamZ, in the cleavage of pNP-MurNAc and MurNAc-GlcNAc. When peptide-free PGN glycans were used as substrates, we revealed striking differences in the specificity and mode of action of these enzymes, as analyzed by mass spectrometry. TfNamZ1, but not TfNamZ2 or BsNamZ, released GlcNAc-MurNAc disaccharides from these glycans. In addition, glucosamine (GlcN)-MurNAc disaccharides were generated when partially N-deacetylated PGN glycans from B. subtilis 168 were applied. This characterizes TfNamZ1 as a unique disaccharide-forming exo-lytic β-N-acetylmuramidase (exo-disaccharidase), and, TfNamZ2 and BsNamZ as sole MurNAc monosaccharide-lytic exo-β-N-acetylmuramidases.IMPORTANCETwo exo-β-N-acetylmuramidases from T. forsythia belonging to glycosidase family GH171 (www.cazy.org) were shown to differ in their activities, thus revealing a functional diversity within this family: NamZ1 releases disaccharides (GlcNAc-MurNAc/GlcN-MurNAc) from the non-reducing ends of PGN glycans, whereas NamZ2 releases terminal MurNAc monosaccharides. This work provides a better understanding of how T. forsythia may acquire the essential growth factor MurNAc by the salvage of PGN from cohabiting bacteria in the oral microbiome, which may pave avenues for the development of anti-periodontal drugs. On a broad scale, our study indicates that the utilization of PGN as a nutrient source, involving exo-lytic N-acetylmuramidases with different modes of action, appears to be a general feature of bacteria, particularly among the phylum Bacteroidetes.

Virtual Screening to Identify the Protein Network Interaction of Triclosan in Red Complex Pathogens

Background: Antimicrobial drug resistance is the major problem encountered world-wide. Novel therapeutic leads have been identified and are regularly tested for their activity against microbial pathogens. Aim: To identify the protein network interactions of triclosan in red complex pathogens. Materials and Methods: The present study follows an observational study design which aims to screen for the interaction of triclosan in red complex pathogens. The interaction was analyzed using the STITCH v.5 pipeline. The functional class of proteins identified were assessed using VICMPred and VirulentPred softwares. The microbial pathogens Treponema denticola ATCC 35405, Tannerella forsythia ATCC 43037, Porphyromonas gingivalis ATCC 33277 are the strains of red complex pathogens that are included in the present study. Results and Discussion: Several proteins were found to interact with triclosan. Among the protein interactions, interactions of triclosan with virulent proteins seems to have a greater impact. The NAD-dependent nucleotide-diphosphate-sugar epimerase [PGN_1370], Putative NAD dependent epimerase [PGN_1886], GDP-fucose synthetase [PGN_1079], Probable oxidoreductase [PGN_1360] of Porphyromonas gingivalis, Conserved hypothetical protein [TDE_2401], Epimerase/dehydratase family protein [TDE_1439] of Treponema denticola, NAD dependent epimerase/dehydratase family protein [BFO_2919], Hypothetical protein [BFO_1782], Nitroreductase family protein [BFO_1604] and Nitroreductase family protein [BFO_1516] Tannerella forsythia were found to be exhibit virulence nature. Conclusion: This study identifies the molecular targets of triclosan on red complex pathogens. As triclosan interacts with the red complex pathogens, in future it can be used as a primary medicine for periodontitis and some oral conditions.

Characterization of the O-Glycoproteome of Tannerella forsythia

Tannerella forsythia is an oral pathogen associated with severe forms of periodontal disease characterized by destruction of the tooth’s supporting tissues, including the bone. The bacterium releases a variety of proteins associated with virulence on the surface of outer membrane vesicles.

DETECTION OF BACTERIAL SPECIES ASSOCIATED WITH PERIODONTAL DISEASE IN A GROUP OF PATIENTS

Objectives. The study aimed to detect the presence/quantification of the 12 bacterial strains more frequently involved in the occurrence and aggravation of periodontal disease in a group of patients. Material and method. The study included 55 patients of both sexes, from the portfolio of the „Dr. Vodiță“ Dental Clinic, with chronic marginal periodontitis, who had not been under regular dental control and hygiene for at least 2 years. During the first treatment session, fluid was collected from each patient from the periodontal bags using sterile paper cones from the collection putty. Subsequently, fluid-soaked paper cones from periodontal bags were sent to the Genetic Lab in Bucharest for DNA extraction and quantification of 12 bacterial species, more common in the etiology of periodontal disease. For the correctness of the results obtained, it is necessary that patients have not taken antibiotics in the last 3 weeks. The data were analyzed and statistically processed with the Microsoft Excel 2016 program. Results. The least common bacteria found were from the species: Capnocytophaga ochracea, Aggregatibacter actinomycetemcomitans, Eikanella corrodens and Campylobacter rectus, closely followed by Capnocytophaga gingivalis, Prevotella intermedia and Capnocytophaga sputigena. The rest of the bacterial species were detected much more frequently. Discussions. In the analyzed group there was no monoinfection with Aggregatibacter actinomycetemcomitans. Porphyromonas gingivalis had an important presence in the studied group, registering increased levels in 89% of cases. In our group, Treponema denticola was present in increased amounts in 76.36% of cases. Tannerella forsythia was present in 92.72% of cases in elevated concentrations. Eikanella corrodens and Campylobacter rectus were present in 18.18% of the cases studied in high quantities. Prevotella intermedia was present in significant amounts in 34.54% of cases. Fusobacterium nucleatum was present in high concentrations in 98.18% of the cases studied. Prevotella nigrescens was present in increased amounts in 56.36% of cases. Capnocytophaga ochracea was present in 9.09% of cases in high amounts, Capnocytophaga sputigena in 38.18% of cases, and Capnocytophaga gingivalis was detected in 24.45% of cases. Conclusions. From the class of bacteria with high pathogenicity, we most frequently encountered in the studied group Tannerella forsythia. From the class of bacteria with moderate pathogenicity, we encountered the most common Fusobacterium nucleatum. From the class of bacteria with low pathogenicity, we encountered the most common Capnocytophaga sputigena. In order to validate the results obtained, it is necessary to extend the study to a larger number of patients.

Peptidoglycan Salvage Enables the Periodontal Pathogen Tannerella forsythia to Survive within the Oral Microbial Community

<i>Tannerella forsythia</i> is an anaerobic, fusiform Gram-negative oral pathogen strongly associated with periodontitis, a multibacterial inflammatory disease that leads to the destruction of the teeth-supporting tissue, ultimately causing tooth loss. To survive in the oral habitat, <i>T. forsythia</i> depends on cohabiting bacteria for the provision of nutrients. For axenic growth under laboratory conditions, it specifically relies on the external supply of <i>N</i>-acetylmuramic acid (MurNAc), which is an essential constituent of the peptidoglycan (PGN) of bacterial cell walls. <i>T. forsythia</i> comprises a typical Gram-negative PGN; however, as evidenced by genome sequence analysis, the organism lacks common enzymes required for the <i>de novo</i> synthesis of precursors of PGN, which rationalizes its MurNAc auxotrophy. Only recently insights were obtained into how <i>T. forsythia</i> gains access to MurNAc in its oral habitat, enabling synthesis of the own PGN cell wall. This report summarizes <i>T. forsythia</i>’s strategies to survive in the oral habitat by means of PGN salvage pathways, including recovery of exogenous MurNAc and PGN-derived fragments but also polymeric PGN, which are all derived from cohabiting bacteria either via cell wall turnover or decay of cells. Salvage of polymeric PGN presumably requires the removal of peptides from PGN by an unknown amidase, concomitantly with the translocation of the polymer across the outer membrane. Two recently identified exo-lytic <i>N</i>-acetylmuramidases (Tf_NamZ1 and Tf_NamZ2) specifically cleave the peptide-free, exogenous (nutrition source) PGN in the periplasm and release the MurNAc and disaccharide substrates for the transporters Tf_MurT and Tf_AmpG, respectively, whereas the peptide-containing, endogenous (the self-cell wall) PGN stays unattached. This review also outlines how <i>T. forsythia</i> synthesises the PGN precursors UDP-MurNAc and UDP-<i>N</i>-acetylglucosamine (UDP-GlcNAc), involving homologs of the <i>Pseudomonas</i> sp. recycling enzymes AmgK/MurU and a monofunctional uridylyl transferase (named Tf_GlmU*), respectively.

Localization of Porphyromonas gingivalis and Tannerella Forsythia In vivo and In vitro

Porphyromonas gingivalis and Tannerella forsythia have been identified as pathogenic bacteria associated with periodontal disease. Also, there are reports describing possible association of periodontal disease with other systemic diseases and some studies have revealed the presence of these bacterial species or their genomic content in sites distal to oral cavity in human body. There have been various studies investigating on possible pathogenic mechanisms that these bacteria device in healthy and disease conditions. Majority of the studies have been focused on possible molecular mechanisms and investigating the end products that are released as a result of bacteria coming into contact with the human tissues/ cells. Up to date only a limited number of studies have visualized direct histo-pathological and cellular events of these bacteria with time lapse information. In this mini review we tried to narrow down our focus on the visualization P. gingivalis and T. forsythia, starting from the oldest possible publications to current advancements, their contribution on understanding the histo-morpho-pathological changes during bacterial invasion, the pros and cons in these methods and how future research should be shaped to reveal the possible translocation of these bacteria from periodontal tissues to distal sites of the human body.