Prevalence of periodontopathic bacteria in aggressive periodontitis patients in a Japanese population

Levels of specific immunoglobulin G to the forsythia detaching factor of Tannerella forsythia in gingival crevicular fluid are related to the periodontal status

BACKGROUND AND OBJECTIVE

Forsythia detaching factor (FDF) is a putative virulence factor of Tannerella forsythia that induces detachment of adherent cells and interleukin-8 production in human fibroblasts. The objective of the present study was to clarify the relationship between anti-FDF IgG levels in gingival crevicular fluid and the clinical status in patients with periodontitis and in healthy subjects.

MATERIAL AND METHODS

Gingival crevicular fluid and subgingival plaque samples were obtained from both the diseased and healthy sites of 37 patients with periodontitis and from 30 healthy subjects. Anti-FDF IgG levels were evaluated, and both the fdf gene and T. forsythia 16S ribosomal RNA (rRNA) were detected using the PCR.

RESULTS

Anti-FDF IgG levels (of both diseased and healthy sites) of patients with periodontitis were significantly higher than those of healthy subjects. Among the patients with periodontitis, anti-FDF IgG levels of healthy sites were significantly higher than those of diseased sites and the levels showed negative correlations with probing pocket depth and clinical attachment level. Among the patients with periodontitis, T. forsythia 16S rRNA was detected in 18 of 37 diseased sites and in 5 of 29 healthy sites, and the fdf gene was detected in 19 of 37 diseased sites and in 7 of 29 healthy sites. By contrast, no healthy subjects were positive for T. forsythia 16S rRNA or the fdf gene.

CONCLUSION

These data suggest that anti-FDF IgG levels in gingival crevicular fluid are related to the periodontal status.

Microbiological profile of untreated subjects with localized aggressive periodontitis

AIM

The microbial profile of localized aggressive periodontitis (LAgP) has not yet been determined. Therefore, the aim of this study was to evaluate the subgingival microbial composition of LAgP.

MATERIAL AND METHODS

One hundred and twenty subjects with LAgP (n=15), generalized aggressive periodontitis (GAgP, n=25), chronic periodontitis (ChP, n=30) or periodontal health (PH, n=50) underwent clinical and microbiological assessment. Nine subgingival plaque samples were collected from each subject and analysed for their content of 38 bacterial species using checkerboard DNA-DNA hybridization.

RESULTS

Red complex and some orange complex species are the most numerous and prevalent periodontal pathogens in LAgP. The proportions of Aggregatibacter actinomycetemcomitans were elevated in shallow and intermediate pockets of LAgP subjects in comparison with those with GAgP or ChP, but not in deep sites. This species also showed a negative correlation with age and with the proportions of red complex pathogens. The host-compatible Actinomyces species were reduced in LAgP.

CONCLUSION

A. actinomycetemcomitans seems to be associated with the onset of LAgP, and Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Campylobacter gracilis, Eubacterium nodatum and Prevotella intermedia play an important role in disease progression. Successful treatment of LAgP would involve a reduction in these pathogens and an increase in the Actinomyces species.

Relationship of neutrophil phagocytosis and oxidative burst with the subgingival microbiota of generalized aggressive periodontitis

INTRODUCTION

Polymorphonuclear neutrophil (PMN) dysfunctions have been associated with severe forms of periodontitis. This study evaluated the correlation between PMN phagocytosis and oxidative burst with the subgingival microbiota of patients with generalized aggressive periodontitis (GAgP).

METHODS

Heparinized peripheral blood samples were obtained from 18 GAgP patients and 11 periodontally healthy (PH) subjects, and PMNs were isolated on a Ficoll-Hypaque gradient. For phagocytosis analysis, PMNs were incubated with fluorescein-labeled Staphylococcus aureus. The oxidative burst was evaluated by incubation of PMNs with dihydroethidium and activation by S. aureus. The assays were examined using flow cytometry. Subgingival biofilm samples were obtained from periodontal sites with and without periodontitis and 24 species were detected by checkerboard.

RESULTS

A significantly lower phagocytosis rate was observed for patients with GAgP compared with PH subjects over time (P < 0.05). No differences between groups were found for superoxide production. GAgP patients presented significantly higher prevalence and levels of Porphyromonas gingivalis, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans serotype b than controls (P < 0.05). Significant negative correlations between T. forsythia and P. gingivalis and PMN functions were observed.

CONCLUSIONS

GAgP subjects presented diminished phagocytic activity of peripheral PMNs and high prevalence and levels of classical periodontal pathogens.

Detection of herpesviruses and periodontal pathogens in subgingival plaque of patients with chronic periodontitis, generalized aggressive periodontitis, or gingivitis

BACKGROUND

Herpesviruses may be related to the etiology of aggressive periodontitis (AgP) and chronic periodontitis (CP) by triggering periodontal destruction or by increasing the risk for bacterial infection. This case-control study evaluated the presence of herpes simplex virus type I (HSV-1), Epstein-Barr virus type I (EBV-1), human cytomegalovirus (HCMV), Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia (previously T. forsythensis) in patients with generalized AgP (AgP group), CP (CP group), or gingivitis (G group) and in healthy individuals (C group).

METHODS

Subgingival plaque samples were collected with paper points from 30 patients in each group. The nested polymerase chain reaction (PCR) method was used to detect HSV-1, EBV-1, and HCMV. Bacteria were identified by 16S rRNA-based PCR.

RESULTS

HSV-1, HCMV, and EBV-1 were detected in 86.7%, 46.7%, and 33.3% of the AgP group, respectively; in 40.0%, 50.0%, and 46.7% of the CP group, respectively; in 53.3%, 40.0%, and 20.0% of the G group, respectively; and in 20.0%, 56.7%, and 0.0% of the C group, respectively. A. actinomycetemcomitans was detected significantly more often in the AgP group compared to the other groups (P <0.005). P. gingivalis and T. forsythia were identified more frequently in AgP and CP groups, and AgP, CP, and G groups had higher frequencies of P. intermedia compared to the C group.

CONCLUSION

In Brazilian patients, HSV-1 and EBV-1, rather than HCMV, were more frequently associated with CP and AgP.

Persistence of extracrevicular bacterial reservoirs after treatment of aggressive periodontitis

BACKGROUND

The purpose of this study was to test the hypothesis that periodontal pathogens associated with aggressive periodontitis persist in extracrevicular locations following scaling and root planing, systemic antibiotics, and antimicrobial rinses.

METHODS

Eighteen patients with aggressive periodontitis received a clinical examination during which samples of subgingival plaque and buccal epithelial cells were obtained. Treatment consisted of full-mouth root planing, systemic antibiotics, and chlorhexidine rinses. Clinical measurements and sampling were repeated at 3 and 6 months. Quantitative polymerase chain reaction determined the number of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia (previously T. forsythensis), and Treponema denticola in the plaque. Fluorescence in situ hybridization and confocal microscopy determined the extent of intracellular invasion in epithelial cells.

RESULTS

Clinical measurements improved significantly following treatment. All bacterial species except P. gingivalis were significantly reduced in plaque between baseline and 3 months. However, all species showed a trend to repopulate between 3 and 6 months. This increase was statistically significant for log T. denticola counts. All species were detected intracellularly. The percentage of cells infected intracellularly was not affected by therapy.

CONCLUSIONS

The 6-month increasing trend in the levels of plaque bacteria suggests that subgingival recolonization was occurring. Because the presence of these species within epithelial cells was not altered after treatment, it is plausible that recolonization may occur from the oral mucosa. Systemic antibiotics and topical chlorhexidine did not reduce the percentage of invaded epithelial cells. These data support the hypothesis that extracrevicular reservoirs of bacteria exist, which might contribute to recurrent or refractory disease in some patients.

Disease severity associated with presence in subgingival plaque of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Tannerella forsythia, singly or in combination, as detected by nested multiplex PCR

This study used a nested multiplex PCR method to detect three periodontal pathogens in subgingival plaque collected before treatment and at 2 and 6 months posttreatment from 107 patients with severe, generalized periodontitis. The proportions of the patients who harbored these bacteria before periodontal treatment were as follows: Tannerella forsythia, 81%; Porphyromonas gingivalis, 78%; and Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans, 47%. At 2 months posttreatment there was a significant reduction in the numbers of patients harboring P. gingivalis (46%; P < 0.001) or T. forsythia (63%; P = 0.043) but not A. actinomycetemcomitans (50%) compared to pretreatment data. At 6 months posttreatment, significantly fewer patients harbored P. gingivalis (43%; P < 0.001); A. actinomycetemcomitans, (31%; P = 0.025), or T. forsythia (63%; P = 0.030). Interestingly, at baseline and at 2 months posttherapy, subjects who harbored only a single pathogen had a greater level of periodontal disease than subjects who harbored two, or all three, of these periodontal pathogens. These data suggest that a reduction in the number of species present may be associated with an increase in the severity of periodontal diseases.

Microbiological diversity of generalized aggressive periodontitis by 16S rRNA clonal analysis

BACKGROUND/AIM

The purpose of this study was to determine the bacterial diversity in the subgingival plaque of subjects with generalized aggressive periodontitis by using culture-independent molecular methods based on 16S ribosomal DNA cloning.

METHODS

Samples from 10 subjects with generalized aggressive periodontitis were selected. DNA was extracted and the 16S rRNA gene was amplified with the universal primer pairs 9F and 1525R. Amplified genes were cloned, sequenced, and identified by comparison with known 16S rRNA sequences.

RESULTS

One hundred and ten species were identified from 10 subjects and 1007 clones were sequenced. Of these, 70 species were most prevalent. Fifty-seven percent of the clone (40 taxa) sequences represented phylotypes for which no cultivated isolates have been reported. Several species of Selenomonas and Streptococcus were found at high prevalence and proportion in all subjects. Overall, 50% of the clone libraries were formed by these two genera. Selenomonas sputigena, the species most commonly detected, was found in nine of 10 subjects. Other species of Selenomonas were often present at high levels, including S. noxia, Selenomonas sp. EW084, Selenomonas sp. EW076, Selenomonas FT050, Selenomonas sp. P2PA_80, and Selenomonas sp. strain GAA14. The classical putative periodontal pathogens, such as, Aggregatibacter actinomycetemcomitans, was below the limit of detection and was not detected.

CONCLUSION

These data suggest that other species, notably species of Selenomonas, may be associated with disease in generalized aggressive periodontitis subjects.

Detection of Treponema denticola in saliva obtained from patients with various periodontal conditions

The aim of the study was to determine the prevalence of Treponema denticola in saliva of periodontally diseased and healthy patients and its relationship with the periodontal status. A 16S rRNA-based polymerase chain reaction detection method was used to determine the prevalence of T. denticola in whole saliva samples from patients with chronic periodontitis (CP, n = 37), aggressive periodontitis (AgP, n = 24), and healthy subjects (n = 28). The periodontal status of each subject was assessed by criteria based on probing depth, clinical attachment loss, and extent of periodontal breakdown. Risk factors were assessed individually and adjusted for confounding using a binary logistic regression model. The results showed that the prevalence of T. denticola in CP patients was significantly higher than those in healthy and AgP subjects (P < 0.05). Odds ratio analysis revealed a positive association for CP group/T. denticola-positive and smoking/T. denticola-positive subjects. Furthermore, all clinical measurements were significantly greater (P < 0.05) for T. denticola-positive subjects compared to T. denticola-negative subjects. After binary logistic regression analysis, both T. denticola and smoking were independently and strongly associated with development of CP. It was concluded that when used in conjunction with an optimized clinical examination protocol, this assay may offer a rapid, useful, and cost-effective tool for monitoring the presence of T. denticola in noninvasive clinical samples from both healthy and diseased patients and correlating it with the amount and extent of periodontal breakdown.

Demographic, clinical, and microbial aspects of chronic and aggressive periodontitis in Colombia: a multicenter study

BACKGROUND

The microbial profile of periodontal disease varies among different human populations. This study evaluated the demographic, clinical, and microbiologic aspects of periodontitis in a multigeographic sample in Colombia.

METHODS

Three hundred twenty-five patients with chronic periodontitis (CP), 158 patients with aggressive periodontitis (AgP), and 137 healthy-gingivitis controls from five regions of the country were studied. Clinical, microbial, and sociodemographic data were collected. Microbiologic identification was performed using polymerase chain reaction 16S rRNA gene on pooled subgingival samples, and the presence of Gram-negative enteric rods was evaluated by culture. Bivariate and multivariate logistic regression analyses were conducted.

RESULTS

Porphyromonas gingivalis occurred in 71.5% of individuals with periodontitis, Tannerella forsythensis occurred in 58.5%, Campylobacter rectus occurred in 57.5%, Actinobacillus actinomycetemcomitans occurred in 23.6%, and enteric rods occurred in 34.5%. P. gingivalis was more common in CP and AgP than controls. A. actinomycetemcomitans was increased in AgP compared to controls and patients with CP. T. forsythensis, C. rectus, and Eikenella corrodens had a low presence in the West Pacific and Central regions, and enteric rods were increased in the Central region (P <0.05). Other sociodemographic factors were not associated with these microorganisms.

CONCLUSIONS

Geographic regions do not influence the microbiota, but the microbiota may vary by geographic region. P. gingivalis, T. forsythensis, and C. rectus are the most prevalent periodontophatic microorganisms in Colombia. A. actinomycetemcomitans was more common in AgP, and a large percentage of the population studied had enteric rods in the subgingival plaque.

Identification of periodontopathic bacteria in gingival tissue of Japanese periodontitis patients

INTRODUCTION

The identification of invading periodontopathic bacteria in tissues is important to determine their role in the pathogenesis of periodontal disease. The objective of this study was to identify periodontopathic bacteria in diseased gingival tissue of periodontitis patients.

METHODS

Subgingival plaque and gingival tissue were collected from 32 generalized chronic periodontitis (CP), 16 generalized aggressive periodontitis (GAgP) and eight localized aggressive periodontitis (LAgP) patients. Detection frequencies and quantities of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Tannerella forsythensis were investigated by polymerase chain reaction. The prevalences of Streptococcus oralis and Streptococcus sobrinus were also examined and the distribution of A. actinomycetemcomitans serotypes was observed.

RESULTS

P. gingivalis and T. forsythensis were detected in approximately 70% of tissue samples and 50% of plaque samples in the three periodontitis groups. Prevalence of A. actinomycetemcomitans in tissue samples was higher in the LAgP (63%) group than in either the CP (16%) or the GAgP (38%) group. A. actinomycetemcomitans serotype c was detected in 50% of LAgP patients. Detection frequencies of S. oralis and S. sobrinus were markedly low in both plaque and tissue samples from all three periodontitis groups. Amounts of P. gingivalis, A. actinomycetemcomitans and T. forsythensis in the tissue samples were not different among the three periodontitis groups.

CONCLUSION

P. gingivalis, A. actinomycetemcomitans and T. forsythensis can localize in diseased gingival tissue and may be involved in periodontal tissue destruction. Serotype c is the predominant serotype of A. actinomycetemcomitans in Japanese LAgP patients.

Subgingival microbiota of periodontally untreated Mexican subjects with generalized aggressive periodontitis

BACKGROUND AND AIM

Specific microbial profiles that may distinguish between generalized aggressive-periodontitis (GAgP) and generalized chronic-periodontitis (GCP) have, to date, not been described. The purpose of the present study was to describe the subgingival microbial composition of Mexican subjects with GAgP and compare it with that of individuals with GCP and periodontal health (PH).

MATERIAL AND METHODS

Seventy-seven subjects with GAgP (n=19), GCP (n=39) and PH (n=19) were selected. Clinical measurements included plaque accumulation, gingival erythema, bleeding on probing, suppuration, pocket depth and attachment level. Up to 28 subgingival plaque samples were obtained from each subject and analysed using the checkerboard DNA-DNA hybridization technique.

RESULTS

GAgP and GCP subjects harboured significantly higher levels and/or proportion of Porphyromonas gingivalis, Tannerella forsythia (levels: p<0.001, proportion: p<0.01), Prevotella nigrescens (p<0.05 levels) and "red" complex species (p<0.001 proportion) than PH subjects. All GAgP subjects were carriers of P. gingivalis and P. nigrescens. No significant differences in any of the 40 microbial species tested were detected between GAgP and GCP subjects.

CONCLUSIONS

Our results revealed that the microbial differences between GAgP and GCP subjects were only discrete and none of the bacterial species tested seemed to specifically differentiate the subgingival microbial profile of either periodontitis group.

Immunoglobulin G subclass antibody profiles in Porphyromonas gingivalis-associated aggressive and chronic periodontitis patients

BACKGROUND/AIMS

The immunoglobulin G (IgG) antibody response is considered to be protective and beneficial for the control of periodontal lesions. This study analysed IgG subclass antibody levels of Porphyromonas gingivalis in patients with both aggressive periodontitis (AgP) and chronic periodontitis (CP).

METHODS

Subgingival plaque and peripheral blood samples were collected from patients with localized AgP (n = 13), generalized AgP (n = 28) and generalized CP (n = 27) and from 14 periodontally healthy controls. P. gingivalis was identified in subgingival pockets using a polymerase chain reaction. Simultaneously, serum IgG subclass antibody against P. gingivalis whole cells/P. gingivalis fimbriae were measured using enzyme-linked immunosorbent assay.

RESULTS

P. gingivalis was frequently detected in periodontitis patients. Anti-P. gingivalis whole cell IgG1 was elevated in all P. gingivalis-positive patients in the three periodontitis groups. Although increased anti-P. gingivalis IgG1 was also observed in the bacterium-positive healthy controls, the level was lower than that found in the three periodontitis groups. Levels of IgG1, IgG2, IgG3 and IgG4 to P. gingivalis did not differ among bacterium-positive patients in the three periodontitis groups; a significant increase of IgG2 level was not observed in localized AgP. Anti-fimbriae IgG subclass levels of IgG1, IgG2 and IgG4 did not differ among bacterium-positive subjects in all groups, while the anti-fimbriae IgG3 level in generalized CP was significantly higher than that in localized and generalized AgP.

CONCLUSIONS

P. gingivalis infection elicited an IgG subclass antibody response in both periodontitis patients and healthy subjects, while higher anti-P. gingivalis IgG1 levels were found in the three periodontitis groups compared with the healthy control group.

Local Oxygen Therapy for Treating Acute Necrotizing Periodontal Disease in Smokers

BACKGROUND

The main aim of treatment for acute necrotizing periodontal disease is fast and effective reduction of anaerobic destructive microorganisms to avoid periodontal damage. The effect of adjunctive local oxygen therapy in the treatment of necrotizing periodontal disease was examined in this study.

METHODS

Thirty patients with acute necrotizing periodontal disease were treated with the systemic antibiotics amoxicillin, clavulanic acid, and metronidazole. In 15 out of 30 patients, adjunctive local oxygen therapy was administered. The patients were followed from the first to 10th day of treatment with clinical and bacteriological examinations. The clinical examination registered gingival bleeding, periodontal probing depth, and attachment loss; to follow up microbiological colonization of the periodontal sulcus, five representative bacteria were registered by a semiquantitative DNA polymerase chain reaction test.

RESULTS

In both groups of patients, colonization with Prevotella intermedia, Tannerella forsythensis, and Treponema denticola was initially positive. None of these three microorganisms were completely eradicated in any of the patients in the group without oxygen therapy within the first 10 days of treatment. In the group with adjunctive oxygen therapy, all patients either showed a reduction in or complete eradication of the microorganisms, resulting in more rapid clinical restitution with less periodontal destruction.

CONCLUSIONS

Adjunctive oxygen therapy results in early eradication of pathogenic anaerobic microorganisms in cases of acute necrotizing periodontal disease. The damage to periodontal tissue is reduced.

Transmission of periodontal bacteria and models of infection

BACKGROUND

Bacteria play an essential role in the aetiology of periodontitis. Most bacterial species isolated from subgingival plaque are indigenous to the oral cavity. Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis are detected infrequently in periodontal health, which makes these species prime candidates to study person-to-person transmission. The aim of the present study was to review the literature on transmission of these periodontal bacterial species.

METHOD

We review the literature on bacterial typing techniques and summarize the information on clonal distribution of A. actinomycetemcomitans and P. gingivalis in family units based on different typing techniques in order to establish the likelihood for person-to-person transmission of these periodontal pathogens.

RESULTS

Vertical transmission of A. actinomycetemcomitans is estimated to be between 30% and 60%, whereas vertical transmission of P. gingivalis has rarely been observed. Horizontal transmission between spouses ranges between 14% and 60% for A. actinomycetemcomitans and between 30% and 75% for P. gingivalis. There is some evidence to show that cohabitation with a periodontitis patient influences the periodontal status of the spouse; however, substantially more information is needed to prove this hypothesis.

CONCLUSIONS

Transmission of putative periodontal pathogens between family members has been shown. The clinical consequences of these events have been poorly documented. Based on the current knowledge, screening for and prevention of transmission of specific virulent clones of A. actinomycetemcomitans may be feasible and effective in preventing some forms of periodontal disease. P. gingivalis is usually recovered from diseased adult subjects, and transmission of this pathogens seems largely restricted to adult individuals. Horizontal transmission of P. gingivalis may therefore be controlled by periodontal treatment involving elimination or significant suppression of the pathogen in diseased individuals and by a high standard of oral hygiene.

Adjunctive benefits of systemic amoxicillin and metronidazole in non-surgical treatment of generalized aggressive periodontitis: a randomized placebo-controlled clinical trial

BACKGROUND

The objective of this study was to assess the adjunctive clinical effect of the administration of systemic amoxicillin and metronidazole in the non-surgical treatment of generalized aggressive periodontitis (GAP).

METHODS

Forty-one systemically healthy subjects with GAP were included in this 6-month double-blind, placebo-controlled, randomized clinical trial. Patients received a course of full-mouth non-surgical periodontal treatment delivered over a 24 h period using machine-driven and hand instruments. Test subjects received an adjunctive course of systemic antibiotic consisting of 500 mg amoxicillin and 500 mg metronidazole three times a day for 7 days. Clinical parameters were collected at baseline, and at 2 and 6 months post-treatment.

RESULTS

In both the test and the placebo groups, all clinical parameters improved at 2 and 6 months. In deep pockets (> or =7 mm), the test treatment resulted in an additional 1.4 mm (95% confidence interval 0.8, 2.0 mm) in full-mouth probing pocket depth (PPD) reduction and 1 mm (0.7, 1.3 mm) of life cumulative attachment loss (LCAL) gain at 6 months. In moderate pockets (4-6 mm), the adjunctive benefit was smaller in magnitude: PPD reduction was 0.4 mm (0.1, 0.7 mm) and LCAL gain was 0.5 mm (0.2, 0.8 mm). In addition, the 6-month data showed LCAL gains > or =2 mm at 25% of sites in test patients compared with 16% in placebo (p=0.028). Similarly, PPD reductions of 2 mm or more were observed in 30% of sites in test and 21% of sites in placebo patients. Seventy-four percent of pockets with PPD > or =5 mm at baseline were 4 mm or shallower at 6 months in the test group. This compared with 54% in the placebo group (p=0.008). Disease progression at 6 months was observed at 1.5% of test and 3.3% of sites in test and placebo, respectively (p=0.072).

CONCLUSIONS

These data indicate that a 7-day adjunctive course of systemic metronidazole and amoxicillin significantly improved the short-term clinical outcomes of full-mouth non-surgical periodontal debridement in subjects with GAP.

Elevated serum IgG titer and avidity to Actinobacillus actinomycetemcomitans serotype c in Japanese periodontitis patients

AIM

The purpose of this study was to characterize serum antibody responses to different serotypes of Actinobacillus actinomycetemcomitans strains in various forms of periodontitis and to determine whether any specific type of A. actinomycetemcomitans was associated with any specific form of periodontitis in a Japanese population.

METHODS

Sonicated whole cell and autoclaved serotype antigens of A. actinomycetemcomitans were used. Serum IgG titer and avidity to A. actinomycetemcomitans were measured by enzyme-linked immunoabsorbant assay (ELISA) and ammonium thiocyanate-dissociation ELISA, respectively, in 46 aggressive periodontitis patients (8 localized, 38 generalized), 28 chronic periodontitis patients, and 18 periodontally healthy subjects. The presence of A. actinomycetemcomitans in plaque and saliva samples was determined using polymerase chain reaction.

RESULTS

Generalized aggressive and chronic periodontitis patients exhibited significantly higher IgG titers than healthy subjects to both sonicated and autoclaved antigens of serotype c strains, while IgG titer to serotype b (Y4) was significantly higher in localized aggressive periodontitis patients compared to healthy subjects. No A. actinomycetemcomitans was detected in localized aggressive periodontitis patients. A. actinomycetemcomitans-positive patients exhibited significantly higher IgG titer and avidity to serotype c than A. actinomycetemcomitans-negative patients. In A. actinomycetemcomitans-positive patients, a significantly positive correlation was observed between antibody titer and avidity to serotype c. A. actinomycetemcomitans-positive patients with generalized aggressive periodontitis showed lower IgG avidities to serotype c than those with chronic periodontitis, though no statistically significant difference was found.

CONCLUSION

A. actinomycetemcomitans serotype c may play a significant role in chronic and generalized aggressive periodontitis, while A. actinomycetemcomitans serotype b may be associated with localized aggressive periodontitis in a Japanese population.

Antimicrobial susceptibility variation of 50 anaerobic periopathogens in aggressive periodontitis: an interindividual variability study

BACKGROUND/AIMS

The frequent use of antibiotics in developed countries has led to the emergence of widespread bacterial resistance. In this study, the interindividual variability of the antibiotic susceptibility of 50 putative microorganisms in aggressive periodontitis patients has been evaluated by means of VC (variation coefficient).

MATERIAL AND METHODS

A total of 60 microbial samples were collected from 20 adult patients diagnosed with aggressive periodontitis (2-4 samples by patient). Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, and Peptostreptococcus micros were isolated according to Slots' rapid identification method. The susceptibilities to 10 antibiotics were studied: penicillin G (PEN), ampicillin (AMP), amoxicillin (AMX), amoxicillin/clavulanate (AMC), tetracycline (TET), doxycycline (DOX), ciprofloxacin (CIP), erythromycin (ERY), spiramycin (SPI) and clindamycin (CLIN), using the Disk Diffusion Susceptibility test (DDS test: Kirby-Bauer's modified method for anaerobic bacteria). The broth microdilution Minimum Inhibitory Concentration test was carried out as a control test.

RESULTS

Among the 50 identified bacteria, 15 were P. gingivalis, 12 P. intermedia, 8 T. forsythia, 9 F. nucleatum, and 6 P. micros. The results of the DDS test show that penicillins (especially AMC, AMP, and AMX), cyclines (especially DOX) and CLIN are highly effective against the 50 anaerobic studied bacteria. CIP and ERY have the lowest efficacy against those bacteria. CIP shows a very variable activity according to anaerobic bacteria species, being particularly inactive against P. gingivalis and very efficient against T. forsythia and P. micros. SPI is also highly efficient but not against P. micros.

CONCLUSIONS

The interindividual susceptibility of principal periodontal pathogens to antibiotics is not homogeneous and seems to vary according to bacterial species and antimicrobial molecules. This variability seems to be greater with older molecules (PEN, TET, ERY) than with more recent ones, which indicates more stable results (AMC, AMX, AMP, and DOX). P. intermedia appeared to be the bacteria most resistant to penicillins and showed the highest coefficient variation. Together with scaling and root planing, the combination of two antibiotics would therefore seem to be recommended in the treatment of aggressive periodontitis, particularly in the presence of P. intermedia.

Etiology and pathogenesis of periodontal diseases

The two most prevalent and most investigated periodontal diseases are dental plaque-induced gingivitis and chronic periodontitis. The last 10 to 15 years have seen the emergence of several important new findings and concepts regarding the etiopathogenesis of periodontal diseases. These findings include the recognition of dental bacterial plaque as a biofilm, identification and characterization of genetic defects that predispose individuals to periodontitis, host-defense mechanisms implicated in periodontal tissue destruction, and the interaction of risk factors with host defenses and bacterial plaque. This article reviews current aspects of the etiology and pathogenesis of periodontal diseases.

Subgingival distribution of Campylobacter rectus and Tannerella forsythensis in healthy children with primary dentition

OBJECTIVE

It is important to know how many subgingival plaque samples should be assayed from a child to ascertain infection with a periodontal pathogen. Plaque samples from several sites may fail to detect some important bacteria if only a limited number of gingival sites are sampled. The purpose of this study was to evaluate the detection of periodontal pathogens in a large number of subgingival sites in the same children in order to determine the number of samples necessary.

METHODS

Ten children, aged 4-6 years, with complete primary dentition were enrolled in this study. Plaque samples from the mesio-buccal aspect of each erupted tooth were first collected by gently inserting a sterile paper point for 10s. Purified genomic DNA from all plaque samples was prepared for polymerase chain reaction. The primers for species-specific 16S ribosomal RNA sequence were selected as the target sequence. Standard strains of Campylobacter rectus and Tannerella forsythensis (formerly Bacteroides forsythus) were used as control strains.

RESULTS

All subjects were found positive for C. rectus and T. forsythensis with the mean of positive sites at 17.6 +/- 2.4 (range: 12-20 sites) for C. rectus and 9.3 +/- 5.0 (range: 1-19) for T. forsythensis. The mean number of positive sites was 1.7 +/- 0.8 for C. rectus and 6.5 +/- 4.9 for T. forsythensis, with a confidence ratio of 95%.

CONCLUSIONS

We concluded that two or more random sites for C. rectus and seven or more random sites for T. forsythensis from children to detect those bacteria at 95% probability.

Molecular analysis of human oral microbiota

OBJECTIVES

The application of molecular, mainly 16S ribosomal RNA (rRNA)-based approaches enables researchers to bypass the cultivation step and has proven its usefulness in studying the microbial composition in a variety of ecosystems, including the human oral cavity. In this mini-review, we describe the impact of these culture-independent approaches on our knowledge of the ecology of the human oral cavity and provide directions for future studies that should emphasize the role of specific strains, species and groups of microbes in periodontal disease.

MATERIALS AND METHODS

Recent findings are summarized to elucidate the relationship between periodontal disease and human oral microbiota, including as-yet-to-be-cultured organisms.

RESULTS

The real-time polymerase chain reaction (PCR) method was developed to detect and quantify periodontopathic bacteria, such as Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis (formerly Bacteroides forsythus) and Treponema denticola. The checkerboard DNA-DNA hybridization technique allowed enumeration of large numbers of species in very large numbers of samples. 16S rRNA gene clone library analysis revealed the diversity of human oral microbiota and the existence of as-yet-to-be-cultured organisms that are presumed periodontal pathogens. In addition, terminal restriction fragment length polymorphism (T-RFLP) analysis was applied for assessment of diversity of human oral microbiota.

CONCLUSION

Culture-independent approaches are useful for studying the microbial ecology in the human oral cavity and should be useful in the future to elucidate the etiology of periodontal disease.

Clinical and microbiological evaluation of the effectiveness of the Nd:Yap laser for the initial treatment of adult periodontitis. A randomized controlled study

BACKGROUND

Enhancement of the results obtained by scaling and planing is most often sought by using antimicrobial therapies. Laser beams have been shown to be bactericidal and could possibly target pathogens more effectively and with fewer compliance problems than antiseptic solutions.

METHODS

Thirty subjects 20-60 years old presenting periodontal pockets at least 5 mm deep in each quadrant received initial periodontal treatment. The study had a split-mouth design. The control side (SRP) only received scaling and planing, and the test side (SRP+laser) was treated by both SRP and Nd:Yap (yttrium aluminum perovskite doped with neodym) laser. Clinical conditions were evaluated at day 0 and day 90 using the plaque index, gingival index, bleeding on probing, pocket probing depth, and clinical attachment level. Microbial sampling was also performed on days 0 and 90, and the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Treponema denticola was analysed by polymerase chain reaction in a commercial laboratory. Post-operative pain or discomfort was measured by the patient using a linear visual scale. Pearson's chi-squared test was used to compare bacterial presence.

RESULTS

There was no statistically significant difference concerning clinical data between test and control groups at baseline. Both treatments enhanced the clinical situation compared to baseline; however, results were not significantly different between the two groups. T. forsythensis was the organism most numerous in both groups. Though initial treatment diminished the numbers of all the pathogens it did not do so statistically significantly. Differences between test and control groups were very small and bore no significance. Evaluation of the post-operative pain did not reveal any differences between the groups.

CONCLUSIONS

Scaling and root planing was effective in reducing levels of plaque, inflammation, and bleeding upon probing. No additional advantage was achieved by using the Nd:Yap laser.

The prevalence and pathogenic differences of Porphyromonas gingivalis fimA genotypes in patients with aggressive periodontitis

BACKGROUND

The fimA gene, which encodes fimbrillin (FimA), is found in Porphyromonas gingivalis and has been classified into six genotypes based on nucleotide sequence. P. gingivalis that possesses the type II fimA gene is prevalent in adult periodontitis.

OBJECTIVES

The aim of this study was to investigate the prevalence of P. gingivalis fimA genotypes in Japanese aggressive periodontitis patients, and to examine their virulence.

METHODS

Subgingival plaque samples were obtained from 223 sites in 18 aggressive periodontitis patients and 95 sites in 22 periodontally healthy young adults. Actinobacillus actinomycetemcomitans, P. gingivalis and Tannerella forsythensis detection, determination of the fimA genotype in P. gingivalis, and the quantification of P. gingivalis were analyzed by polymerase chain reaction (PCR) methods. The proteolytic activities of the P. gingivalis fimA type I and fimA type II were also examined.

RESULTS

In aggressive periodontitis patients, the most prevalent fimA genotype was the type II (46.7%), followed by the type Ib and type I, whereas in healthy subjects, the type I fimA was the only genotype detected. The number of P. gingivalis pathogens was the greatest in the type I fimA positive sites, and the frequency of coexisting A. actinomycetemcomitans and T. forsythensis was highest in the type II fimA positive sites in the aggressive periodontitis patients. Both the arginine-specific cysteine proteinase (Arg-gingipain) and lysine-specific cysteine proteinase (Lys-gingipain) activity of the P. gingivalis fimA type I strain were significantly higher than those of the fimA type II strains.

CONCLUSIONS

These results suggest that differences in virulence exist among different fimA genotypes. Coadherence with other pathogens in P. gingivalis fimA type II-associated aggressive periodontitis and quantitative increases in P. gingivalis in fimA type I-associated aggressive periodontitis are related to this virulence.

Diabetes and Periodontal Disease: A Case-Control Study

BACKGROUND

Periodontitis is often associated with diabetes and might be considered one of the chronic complications of diabetes mellitus, both in Type 1 (T1DM) and Type 2 (T2DM). This case-control study was designed to evaluate the possible association between non-insulin-dependent diabetes (T2DM) and clinical and microbiological periodontal disease among adult Sardinians.

METHODS

A total of 212 individuals participated in this study: 71 T2DM patients aged 61.0 +/- 11.0 years and 141 non-diabetic controls in good general health aged 59.1 +/- 9.2 years. All subjects were given a clinical periodontal examination for probing depth, attachment level, presence of calculus, bleeding on probing, and assessment of plaque. Subgingival plaque samples were obtained, and P. gingivalis, P. intermedia, and T. forsythensis were identified using multiplex polymerase chain reaction.

RESULTS

T2DM patients showed a significantly lower number of teeth present (P = 0.002); a significant increase in number of probing depths >4 mm, and percent of pocket depths >4 mm (P = 0.04 and P = 0.05, respectively); periodontitis (P = 0.046); bleeding on probing (P = 0.02); and plaque index (P = 0.01). A significant association with diabetes was detected for plaque (X2= 4.46; P <0.05) and bleeding on probing (X2= 3.60; P <0.05). Concerning bacteria prevalence, a positive association was detected for P. gingivalis (X2= 2.80; P <0.05) and T. forsythensis (X2= 3.87; P <0.05). Presence of plaque was positively associated with case status (odds ratio [OR] = 1.3; 95% confidence interval [CI]: 1.2, 3.6) and with prevalence of P. gingivalis and T. forsythensis (OR = 1.2, 95% CI: 1.3, 2.2; and 1.2, 95% CI: 1.2, 1.8, respectively).

CONCLUSION

Patients with T2DM undoubtedly have a susceptibility for more severe periodontal disease.

Prevalence of Periodontopathic Bacteria in Aggressive Periodontitis Patients in a Chilean Population

BACKGROUND

Actinobacillus actinomycetemcomitans is considered a major etiologic agent of aggressive periodontitis (AgP). Other periodontopathic bacteria such as Porphyromonas gingivalis are also suspected of participating in aggressive periodontitis although the evidence to support this is controversial. The aim of the present study was to determine the prevalence of eight periodontopathic bacteria in Chilean patients with AgP.

METHODS

Subgingival plaque samples were collected from 36 aggressive, 30 localized, and six generalized periodontitis patients. Samples from 17 advanced chronic periodontitis (CP) patients were taken as controls. Samples collected from the four deepest periodontal pockets in each patient were pooled in prereduced transport fluid (RTF) and cultured. Periodontal bacteria were primarily identified by colony morphology under stereoscopic microscope and rapid biochemical tests. The identity of some bacterial isolates was confirmed by colony polymerase chain reaction (PCR).

RESULTS

AgP showed a significatively higher prevalence of C. rectus than CP (P = 0.036). The only statistical difference found was for C. rectus. Patients with AgP showed a higher, but not statistically significant, prevalence of P. gingivalis, E. corrodens, P. micros, and Capnocytophaga sp. A similar prevalence in both groups of patients was observed for F. nucleatum and P. intermedia/nigrescens, and A. actinomycetemcomitans was less prevalent in AgP than CP patients. In localized AgP, P. intermedia/nigrescens, E. corrodens, F. nucleatum, and P. micros were the more prevalent pathogens in contrast to generalized AgP patients who harbored A. actinomycetemcomitans, P. gingivalis, and Capnocytophaga sp. as the most prevalent bacteria.

CONCLUSIONS

C. rectus, P. gingivalis, E. corrodens, P. micros, and Capnocytophaga sp. were the most predominant periodontopathic bacteria of AgP in this Chilean population, but the only statistical difference found here between AgP and CP was for C. rectus, suggesting that the differences in clinical appearance may be caused by factors other than the microbiological composition of the subgingival plaque of these patients. In this study, the prevalence of A. actinomycetemcomitans was much lower than that of P. gingivalis.

Monocyte activation by Porphyromonas gingivalis LPS in aggressive periodontitis with the use of whole-blood cultures

In this study, we re-visited the issue of hyper-responsiveness of monocytes to bacterial lipopolysaccharide (LPS) in aggressive periodontitis patients. We used whole-blood cultures to compare monocyte activation by Porphyromonas gingivalis LPS between Thai subjects with generalized aggressive periodontitis and those without periodontitis. Upon stimulation with P. gingivalis LPS, expression of co-stimulatory molecules on monocytes and expression of CD69 on NK and gamma delta T-cells were analyzed by flow cytometry, and the production of interleukin-1 beta and prostaglandin E(2) was monitored by ELISA. LPS stimulation resulted in a dose-dependent up-regulation of CD40, CD80, and CD86 on monocytes, and up-regulation of CD69 on NK cells and gamma delta T-cells in both the periodontitis and non-periodontitis groups. The levels of activation markers and the mediator production after LPS stimulation were quite similar for both groups. In conclusion, we did not observe hyper-responsiveness of monocytes to P. gingivalis LPS challenge in Thai patients with aggressive periodontitis.