Association of oral spirochetes from periodontally healthy sites with development of gingivitis

The association between gingivitis and oral spirochetes in young cats and dogs

Although gingivitis frequently occurs in young cats, spirochetes are often found in the early stages of periodontal disease. This study was conducted to determine the association between gingivitis and oral spirochetes in young cats and dogs. The degree of gingivitis was evaluated in a total of 68 cats and 31 dogs under one year of age, and plaques were collected from each carnassial. To detect spirochetes or Porphyromonas gulae in plaque samples, 16S rRNA gene was amplified by polymerase chain reaction (PCR) using specific primers. All data were analyzed using Fisher's exact probability test and odds ratio (OR) with a 95% confidence interval (95% CI). The prevalence of gingivitis was significantly higher in young cats (92.6%) than in young dogs (45.2%). The positive rate of spirochetes by PCR in gingivitis cases was 85.4% in young cats and 15.4% in young dogs, and the positive rate of P. gulae was 66.7% in young cats and 15.4% in young dogs. Both results were significantly higher in young cats than in young dogs. In young cats, spirochetes were significantly associated with gingivitis (OR = 7.95; 95% CI = 1.17, 53.83; P < 0.05), but P. gulae was not (OR = 2.44; 95% CI = 0.38, 15.66; P = 0.23). These results suggest that spirochetes may be associated with the early stages of periodontal disease in cats.

Short-term effect of removal of fixed orthodontic appliances on gingival health and subgingival microbiota: a prospective cohort study

OBJECTIVE

The aim of this prospective longitudinal study was to assess and compare the microbiological and clinical parameters of patients wearing a fixed orthodontic appliance, as opposed to 10 days after the bracket had been removed following treatment.

MATERIALS AND METHODS

In total, 122 patients participated in this study; 61 of the subjects were assessed at baseline (wearing a fixed orthodontic appliance: T1) and 10 days after bracket removal (T2). The other 61 individuals had never worn an orthodontic appliance before and these subjects served as controls (CT). Subgingival plaque samples were assessed for bleeding on probing (GBI) and plaque index (VPI). PCR of 16s rDNA, followed by reverse species-specific hybridization for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Treponema denticola were performed. A descriptive analysis was conducted; chi-squared, Student's matched and unmatched t-tests, the point biserial correlation coefficient and the McNemar test were used to test for differences between groups (p < 0.05).

RESULTS

The GBI and VPI clinical parameters showed statistical differences (p < 0.05) between T1-T2, T1-CT and T2-CT. The prevalence of T. denticola had significantly decreased (p = 0.039) 10 days after appliance removal. At T2, a significant positive correlation was found between GBI and A. actinomycetemcomitans (p < 0.01) and between clinical parameters and P. intermedia. In patients without a fixed orthodontic appliance (T2 and CT), there was a significant positive correlation between T. forsythia and VPI.

CONCLUSION

Local factors associated with the wearing of a fixed orthodontic appliance influence changes in subgingival plaque that leads to more inflammation and bleeding.

Characterization of a novel family of fibronectin-binding proteins with M23 peptidase domains from Treponema denticola

Interactions with fibronectin are important in the virulence strategies of a range of disease-related bacteria. The periodontitis-associated oral spirochaete Treponema denticola expresses at least two fibronectin-binding proteins, designated Msp (major surface protein) and OppA (oligopeptide-binding protein homologue). To identify other T. denticola outer membrane fibronectin-binding proteins, the amino acid sequence of the Treponema pallidum fibronectin-binding protein Tp0155 was used to survey the T. denticola genome. Seven T. denticola genes encoding orthologous proteins were identified. All but two were expressed in Escherichia coli and purified recombinant proteins bound fibronectin. Using antibodies to the N-terminal region of Tp0155, it was demonstrated that T. denticola TDE2318, with highest homology to Tp0155, was cell surface localized. Like Tp0155, the seven T. denticola proteins contained an M23 peptidase domain and four (TDE2318, TDE2753, TDE1738, TDE1297) contained one or two LysM domains. M23 peptidases can degrade peptidoglycan whereas LysM domains recognize carbohydrate polymers. In addition, TDE1738 may act as a bacteriocin based on homology with other bacterial lysins and the presence of an adjacent gene encoding a putative immunity factor. Collectively, these results suggest that T. denticola expresses fibronectin-binding proteins associated with the cell surface that may also have cell wall modifying or lytic functions.

Role of Treponema denticola in periodontal diseases

Among periodontal anaerobic pathogens, the oral spirochetes, and especially Treponema denticola, have been associated with periodontal diseases such as early-onset periodontitis, necrotizing ulcerative gingivitis, and acute pericoronitis. Basic research as well as clinical evidence suggest that the prevalence of T denticola, together with other proteolytic gram-negative bacteria in high numbers in periodontal pockets, may play an important role in the progression of periodontal disease. The accumulation of these bacteria and their products in the pocket may render the surface lining periodontal cells highly susceptible to lysis and damage. T. denticola has been shown to adhere to fibroblasts and epithelial cells, as well as to extracellular matrix components present in periodontal tissues, and to produce several deleterious factors that may contribute to the virulence of the bacteria. These bacterial components include outer-sheath-associated peptidases, chymotrypsin-like and trypsin-like proteinases, hemolytic and hemagglutinating activities, adhesins that bind to matrix proteins and cells, and an outer-sheath protein with pore-forming properties. The effects of T. denticola whole cells and their products on a variety of host mucosal and immunological cells has been studied extensively (Fig. 1). The clinical data regarding the presence of T. denticola in periodontal health and disease, together with the basic research results involving the role of T. denticola factors and products in relation to periodontal diseases, are reviewed and discussed in this article.

Treponema socranskii, Treponema denticola, and Porphyromonas gingivalis are associated with severity of periodontal tissue destruction

BACKGROUND

The aim of the present study was to identify Treponema socranskii in addition to Treponema denticola and Porphyromonas gingivalis by polymerase chain reaction (PCR), and to clarify the relationship between the presence of these microorganisms and the severity of clinical periodontal parameters.

METHODS

Saliva and subgingival plaque collected from 123 subjects (38 aggressive periodontitis patients, 65 chronic periodontitis patients, 20 healthy patients) were subjected to PCR to detect the aforementioned 3 microorganisms.

RESULTS

Detection frequencies of T. socranskii, T. denticola, and P. gingivalis in plaque samples from aggressive periodontitis patients (71.1%, 73.7%, 84.2%, respectively) and chronic periodontitis patients (89.2%, 93.8%, 95.3%) were much higher than those from healthy subjects (30%, 5.0%, 10.0%). In aggressive and chronic periodontitis patients, these 3 species of bacteria were detected frequently at sites that showed deep periodontal pockets and severe attachment loss. The percentage of these bacteria-positive sites increased as the gingival index score of chronic periodontitis patients increased. T. socranskii was frequently detected together with T. denticola or P. gingivalis at the same sites, and coexistence of these microorganisms was frequently observed in deep periodontal pockets of aggressive periodontitis patients.

CONCLUSIONS

T. socranskii, T. denticola, and P. gingivalis were frequently detected in periodontitis patients by PCR. The prevalence of these 3 microorganisms was correlated with various clinical parameters. Taken together, our findings suggest that T. socranskii, T. denticola, and P. gingivalis are associated with the severity of periodontal tissue destruction.

Periodontal disease as a specific, albeit chronic, infection: diagnosis and treatment

Periodontal disease is perhaps the most common chronic infection in adults. Evidence has been accumulating for the past 30 years which indicates that almost all forms of periodontal disease are chronic but specific bacterial infections due to the overgrowth in the dental plaque of a finite number of mostly anaerobic species such as Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola. The success of traditional debridement procedures and/or antimicrobial agents in improving periodontal health can be associated with the reduction in levels of these anaerobes in the dental plaque. These findings suggest that patients and clinicians have a choice in the treatment of this overgrowth, either a debridement and surgery approach or a debridement and antimicrobial treatment approach. However, the antimicrobial approach, while supported by a wealth of scientific evidence, goes contrary to centuries of dental teaching that states that periodontal disease results from a "dirty mouth." If periodontal disease is demonstrated to be a risk factor for cardiovascular disease and stroke, it will be a modifiable risk factor since periodontal disease can be prevented and treated. Since the antimicrobial approach may be as effective as a surgical approach in the restoration and maintenance of a periodontally healthy dentition, this would give a cardiac or stroke patient and his or her physician a choice in the implementation of treatment seeking to improve the patient's periodontal condition so as to reduce and/or delay future cardiovascular events.

The diversity of periodontal spirochetes by 16S rRNA analysis

The purpose of this study was to examine the diversity of spirochetes in the subgingival pocket of multiple subjects with a range of periodontal conditions, including two healthy, one adult periodontitis, three acute necrotizing ulcerative gingivitis, eight refractory periodontitis, and one human immunodeficiency virus (HIV) periodontitis. The 16S rRNA genes of spirochetes in plaque were amplified by polymerase chain reaction using spirochete selective primers. Over 500 clones were sequenced and subjected to phylogenetic analysis. The sequences clustered into the 10 known cultivated Treponema species and into 47 as-yet-uncultivated Treponema species. Most of these Treponema species were identified from multiple clones and subjects. The human periodontal pocket harbors a highly diverse treponeme population. Of the cultivated species, Treponema denticola, Treponema maltophilum and Treponema sp. Smibert-3 were most commonly encountered in diseased subjects but rarely in healthy subjects. Molecular tools based on the sequence data from this study will allow determination of the prevalence of cultivable and uncultivable treponemes in oral diseases.

Phenotypic and genotypic heterogeneity among cultivable pathogen-related oral spirochetes and Treponema vincentii

Recent findings challenge the assumption that pathogen-related oral spirochetes (PROS) are related to Treponema pallidum. Treponema vincentii, grown in OMIZ-Pat media, cross-reacted with monoclonal antibody H9-2 against T. pallidum, and cultivable PROS had 16S rRNA gene sequences similar to those of T. vincentii (C.-B. Choi, C. Wyss, and U. B. Göbel. J. Clin. Microbiol. 34:1922-1925, 1996). Aims of the present study were to determine whether antigen phenotypes of oral treponemas were influenced by growth conditions and to evaluate the genetic relatedness of cultivable PROS to T. pallidum and T. vincentii. Results show that three T. pallidum monoclonal antibodies (H9-1, H9-2, and F5) cross-reacted with whole cells from four Treponema species grown in modified OMIZ-Pat medium, but not with treponemas grown in NOS medium. Only H9-2 reacted in immunoblots with reduced proteins from cultivable PROS and T. vincentii. Three of five PROS isolates were amplified by T. vincentii-specific PCR, and one was amplified by Treponema medium-specific PCR. None were amplified by T. pallidum-specific PCR. Three of five PROS isolates had 16S ribosomal DNA restriction fragment length polymorphism patterns identical to that of T. vincentii, and the patterns of two isolates resembled that of T. medium. Arbitrarily primed-PCR profiles from whole genomic DNA were distinct among five PROS isolates and two T. vincentii strains. Thus, PROS isolates represent a heterogeneous group of treponemas that share some 16S rRNA gene sequences with T. vincentii and T. medium, but not with T. pallidum. It is proposed that the PROS nomenclature be dropped.

Detection of Treponema socranskii associated with human periodontitis by PCR

A PCR technique was used to detect and identify Treponema socranskii associated with periodontitis. A species-specific forward primer was designed for a variable region within its 16S rRNA gene and was used in conjunction with a conserved reverse primer. This primer pair was tested for specificity against 44 oral bacterial strains. Sensitivity was determined using a serial dilution of T. socranskii cells. Amplification products were obtained from all T. socranskii strains tested, but not from other oral bacteria associated with periodontal disease. The detection limit of PCR was 5 T. socranskii cells per PCR. T. socranskii was detected by PCR in subgingival plaque and saliva samples from patients with periodontitis.