Association between infection of different strains of Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in subgingival plaque and clinical parameters in chronic periodontitis

Treatment resistance of rheumatoid arthritis relates to infection of periodontal pathogenic bacteria: a case-control cross-sectional study

Recent studies have shown that periodontitis is associated with rheumatoid arthritis (RA) and periodontal bacteria, such as Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) are involved in the pathogenesis of RA via citrullinated proteins. Smoking has also been shown to be involved in the pathogenesis of RA; however, the extent of this involvement is still poorly understood. In addition, RA and polymyalgia rheumatica (PMR) are sometimes difficult to differentiate; however, the relationship between PMR and the factors from smoking and periodontal bacteria is unclear. The aim of this study was to clarify the relationship between periodontal pathogenic bacterial infections and smoking in patients with RA or PMR. This case–control study included 142 patients with untreated RA or PMR. This study evaluated the serum antibody titers against periodontal pathogenic bacterial antigens and an anti-citrullinated peptide antibody (ACPA). In patients with RA, the relationship between antibody titers and disease activity of RA and response after 3 months of treatment was also investigated. Additionally, the effects of smoking were evaluated. Although there was no significant difference in serum antibody titer against periodontal pathogenic bacteria between the ACPA-positive RA group and the ACPA-negative PMR group, we found an association between the elevated antibody titer against Pg and the degree of ACPA value, especially between negative group and high-value positive group (≥ 100 U/mL). The antibody titers against Aa and Pg did not differ depending on disease activity score 28 (DAS28) at baseline; however, patients with high antibody titers had poor RA therapeutic response as judged by DAS28 after 3 months. We could not find any association between smoking and any of these parameters. Periodontal pathogenic bacteria, especially Pg, are associated with elevated ACPA levels. Our findings suggest that Pg and Aa infections interfere with the therapeutic response of RA.

Impact of Adjunctive Diode Laser Application to Non-Surgical Periodontal Therapy on Clinical, Microbiological and Immunological Outcomes in Management of Chronic Periodontitis: A Systematic Review of Human Randomized Controlled Clinical Trials

Background

Due to the limitations of scaling and root planing (SRP) in chronic periodontitis (CP) management, research has been focused on utilising additional therapies to enhance conventional treatment methods. The present systematic review is aimed to appraise the accessible scientific evidence of in vivo human studies to establish the effectiveness of adjunctive diode (λ 808- λ 980nm) laser treatment to SRP in CP.

Methodology

This systematic review was conducted following the PRISMA statement guidelines. The review protocol is registered in PROSPERO (CRD 42021227695). The search strategies were based on structured electronic and manual (with appropriate keywords) and were conducted to collect the applicable published data on RCTs studies (in vivo human), spanning over ten years between August 2010 and August 2020. The articles were selected to address the following research focus question: “Does diode laser (λ 808- λ 980nm) therapy have superior effects as an adjunct to SPR, compared to SRP alone, in terms of clinical or microbiological or immunological profiles in the management of CP?”

Results

Fifteen articles met the eligibility criteria and are included in this review. A wide range of discrepancies and inconsistencies were shown in the outcomes of the laser and SPR treatment modality, compared to SRP alone. The data on standardised study protocol, optimal laser parameters and outcome measurements were inconclusive, and a high risk of bias in the majority of the studies observed, which are crucial in establishing a homogenous and reproducible protocol.

Conclusion

In light of the confined evidence-based data and critical evaluation of this systematic review, the efficacy of adjunctive diode laser treatment ranging between 808 and 980nm to SRP remains debatable. The observational quality of the present systematic review was emphasised after scrutinising the available data, and an attempt to propose a laser protocol for future RCTs consideration was a great challenge due to an absence of clear and standardised recommendations in delivering a reliable laser protocol which can be replicable by future investigators. RCTs with robust methodology are warranted.

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).

Oleoresins and naturally occurring compounds of Copaifera genus as antibacterial and antivirulence agents against periodontal pathogens

Invasion of periodontal tissues by Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans can be associated with aggressive forms of periodontitis. Oleoresins from different copaifera species and their compounds display various pharmacological properties. The present study evaluates the antibacterial and antivirulence activity of oleoresins obtained from different copaifera species and of ten isolated compounds against two causative agents of periodontitis. The following assays were performed: determination of the minimum inhibitory concentration (MIC), determination of the minimum bactericidal concentration (MBC), and determination of the antibiofilm activity by inhibition of biofilm formation and biofilm eradication tests. The antivirulence activity was assessed by hemagglutination, P. gingivalis Arg-X and Lis-X cysteine protease inhibition assay, and A. actinomycetemcomitans leukotoxin inhibition assay. The MIC and MBC of the oleoresins and isolated compounds 1, 2, and 3 ranged from 1.59 to 50 μg/mL against P. gingivalis (ATCC 33277) and clinical isolates and from 6.25 to 400 μg/mL against A. actinomycetemcomitans (ATCC 43717) and clinical isolates. About the antibiofilm activity, the oleoresins and isolated compounds 1, 2, and 3 inhibited biofilm formation by at least 50% and eradicated pre-formed P. gingivalis and A. actinomycetemcomitans biofilms in the monospecies and multispecies modes. A promising activity concerning cysteine protease and leucotoxin inhibition was also evident. In addition, molecular docking analysis was performed. The investigated oleoresins and their compounds may play an important role in the search for novel sources of agents that can act against periodontal pathogens.

Detection of Tannerella forsythia bspA and prtH genotypes among periodontitis patients and healthy subjects-A case-Control study

BACKGROUND

T. forsythia a gram negative, anaerobe inhabits the mature biofilm present at sites expressing progressive periodontitis. It is a part of "red complex" group which contributes to the pathogenesis of periodontitis. The BspA protein and prtH gene encoded cysteine protease play a vital role in the virulence of T. forsythia. The present study aims to detect the two genotypes (bspA and prtH) in periodontitis and healthy subjects.

MATERIALS & METHOD

Subgingival plaque samples were collected from periodontitis patients and healthy subjects (Chronic Periodontitis n = 128, Aggressive Periodontitis n = 72, healthy subjects n = 200). The samples were screened for the presence of T. forsythia 16S rRNA, bspA and prtH genotypes by Polymerase Chain Reaction. The prevalence of the genotypes between periodontitis patients and healthy subjects was compared with Pearson's Chi-square test. A P value of < 0.05 was considered to be statistically significant.

RESULTS

The prevalence for T. forsythia in Chronic Periodontitis (n = 128), Aggressive Periodontitis (n = 72) and health (n = 200) was 73.4%, 59.7% and 10.5% respectively. The prevalence of T.forsythia bspA/prtH genotypes was 81.90%/43.60%, 88.40%/53.50% and 33.30%/14.3% in Chronic Periodontitis, aggressive Periodontitis and health respectively. Compared to healthy subjects, the odds of detecting T.forsythia 16S rRNA was 18.53 times high in individuals with periodontitis (P = 0.0001).

CONCLUSION

The high odds ratio of T.forsythia 16S rRNA among periodontitis strongly suggests its role in periodontitis. In addition, the high prevalence of T. forsythia bspA genotype among Chronic Periodontitis signifies it as a useful marker for chronic periodontitis.

Prevalence of Anaerobic Bacteria (P.gingivalis) as Major Microbial Agent in the Incidence Periodontal Diseases by Meta-analysis

STATEMENT OF THE PROBLEM

Periodontal diseases are complex oral diseases characterized by bacterial-induced inflammatory destruction of tooth-supporting tissues. Porphyromonas gingivalis (P. gingivalis) is a common gram-negative anaerobic oral bacteria strongly associated with periodontal disease.

PURPOSE

The present study was conducted to estimate prevalence of P. gingivalis in patients with periodontal diseases by using meta-analysis method.

MARTIALS AND METHOD

Different databases including PubMed, EmBase, Scopus, the Institute for Scientific Information (ISI) Web of Science, and the Cochrane Library were searched to identify original English-language studies addressing prevalence of P. gingivalis in periodontal diseases up to December 2014. The random effects model was applied in the meta-analysis and the heterogeneity between studies was assessed using a Cochran test and the I² index. Funnel plots and Egger test were used to examine publication bias. Statistical analyses were performed using STATA version 12.

RESULTS

Forty-two eligible studies published during 1993- 2016 were selected for meta-analysis. Considering all the included studies, the total sample size was 5,884 individuals containing 2,576 healthy people with a mean age of 37.21±7.45 years and 3,308 periodontal patients with a mean age of 44.16±8.35 years. Overall, the prevalence of P. gingivalis was 78% [95% CI: 74-81] in periodontal diseases group and 34% [95% CI: 26-41] in healthy individuals. There was a significantly higher prevalence of P.gingivalis in individuals with periodontal diseases compared to healthy subjects [78% versus 34%, respectively].

CONCLUSION

This study indicates that P. gingivalis is highly present in subjects with periodontal diseases and it also appears in periodontally healthy people, although to a lesser extent. Thus, the presence of P. gingivalis increases the chance of periodontal disease and it can be considered as a main potential risk factor.

Detection of Aggregatibacter actinomycetemcomitans leukotoxin and fimbria-associated protein gene genotypes among periodontitis patients and healthy controls: A case-control study

BACKGROUND

Aggregatibacter actinomycetemcomitans has been reported in higher proportions in subgingival microbiota of individuals with aggressive periodontitis (AgP) compared with those with chronic periodontitis (ChP) and healthy controls. The major virulence factors are the ones that help in colonization and evasion of host's defenses. Hence, this study was aimed to assess the prevalence of A. actinomycetemcomitans 16S rRNA and its virulent genotypes (leukotoxin [lktA] and fimbria-associated protein [fap]).

MATERIALS AND METHODS

In this case- control study We performed periodontal examination and measured probing depth and clinical attachment level (CAL). Subgingival plaque samples from 200 (ChP: n = 128 and AgP: n = 72) periodontitis patients and 200 healthy controls were screened for the presence of A. actinomycetemcomitans 16S rRNA, lktA, and fap genotypes by polymerase chain reaction. The prevalence of genotypes between periodontitis patients and healthy controls was compared with Pearson's Chi-square test. P < 0.05 was considered statistically significant.

RESULTS

Mean pocket probing depth and CAL were high as compared to the healthy controls. The prevalence of A. actinomycetemcomitans in ChP (n = 128), AgP (n = 72), and healthy individuals (n = 200) was 32.0%, 61.1%, and 2.5%, respectively. A. actinomycetemcomitans lktA genotype prevalence was 71.8% among periodontitis patients, while A. actinomycetemcomitans fap genotype showed 31.8% prevalence. The prevalence of these genotypes was insignificant in healthy controls.

CONCLUSION

The high odds ratio for A. actinomycetemcomitans prevalence suggests its strong link to periodontitis. Detection of A. actinomycetemcomitans lktA + genotype may be a useful marker for AgP as its prevalence was found to be high in AgP.

Diode laser therapy in the management of chronic periodontitis - A clinico-microbiological study

Introduction

Chronic periodontitis (CP) is an infectious disease resulting in inflammation of the supporting tissues of the teeth with progressive attachment loss and bone loss. This study aimed to evaluate the effect of 980-nm diode laser, as an adjunct to scaling and root planing (SRP) in the management of CP.

Methodology

A total of 40 systemically healthy subjects diagnosed with CP were randomly assigned into two groups G1 (SRP and sham application of laser) and G2 (SRP and laser irradiation) with equal numbers in each. The levels of Porphyromonas gingivalis (Pg) were estimated from plaque samples using real-time polymerase chain reaction. Clinical and microbiological parameters were assessed at baseline, 4–6, and 12–14 weeks posttreatment in both groups.

Results

A gradual reduction in the levels of Pg and improvement in clinical parameters were observed from baseline to 4–6 and 12–14 weeks in both groups. However, the comparison between groups, although clinically relevant, was not found to be statistically significant.

Conclusion

Although a 980-nm diode laser may not have any added benefit compared with SRP, it may emerge as an effective non-surgical treatment option in advanced periodontitis with complex inaccessible subgingival niches where comprehensive periodontal care may not be feasible.

Study of Porphyromonas gingivalis in periodontal diseases: A systematic review and meta-analysis

Background: The mouth cavity hosts various types of anaerobic bacteria including Porphyromonas gingivalis, which causes periodontal inflammatory diseases. P. gingivalis is a gram-negative oral anaerobe and is considered as a main etiological factor in periodontal diseases. Several studies have reported a relationship between P. gingivalis in individuals with periodontal diseases and a critical role of this bacterium in the pathogenesis of periodontal diseases. The present study aimed at estimating this probability using a meta-analysis.

Methods: We searched several databases including PubMed, Scopus, Google Scholar, and Web of Science to identify case-control studies addressing the relationship between P. gingivalis with periodontal diseases. A total of 49 reports published from different countries from 1993 to 2014 were included in this study. I² (heterogeneity index) statistics were calculated to examine heterogeneity. Data were analyzed using STATA Version 11.

Results: After a detailed analysis of the selected articles, 49 case-control studies with 5924 individuals fulfilled the inclusion criteria for the meta-analysis. The healthy controls included 2600 healthy individuals with a Mean±SD age of 36.56±7.45 years. The periodontal diseases group included 3356 patients with a mean age of 43.62±8.35 years. There was a statistically significant difference between P. gingivalis in periodontal patients and healthy controls; 9.24 (95% CI: 5.78 to 14.77; P = 0.000). In the other word, there was a significant relationship between the presence of P. gingivalis and periodontal diseases.

Conclusion: Analyzing the results of the present study, we found a strong association between the presence of P. gingivalis and periodontal diseases. This result suggests that another research is needed to further assess this subject.

"Association of periodontopathic anaerobic bacterial co-occurrence to atherosclerosis" - A cross-sectional study

BACKGROUND

Epidemiological studies have shown a link between periodontitis and atherosclerosis. Hence the present study was chosen to assess the presence of eight anaerobic periodontal pathogens and their virulence genes in subgingival plaque (SGP) and atheromatous plaque (AP) of patients with Ischaemic heart disease.

METHODS

SGP and AP collected from 65 Ischaemic heart disease patients were screened for the presence of periodontal bacterial pathogens by Polymerase chain reaction. The samples positive for Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia were screened for virulence genes. Chronic periodontitis patients (ChP) without any systemic disease (n = 59) and healthy subjects free of both periodontitis and systemic disease were included as control groups (n = 100).

RESULTS AND DISCUSSION

Statistical significance was observed for the prevalence of 16S rRNA of P. gingivalis, T. forsythia, T. denticola and P. nigrescens both in SGP and AP. Nine different periodontal bacterial co-occurrences were observed in SGP and AP of Ischaemic heart disease patients. Besides, the prevalence of these nine different bacterial co-occurrence was high in SGP OF Ischaemic heart disease patients compared to ChP without systemic disease. Among the nine different bacterial co-occurrence, only four were observed in SGP of ChP without systemic disease in spite of high prevalence of these anaerobic bacterial species. While, bacterial co-occurrences was completely absent among healthy subjects. Significant odds and risk ratio to atherosclerosis were observed for P. gingivalis, T. forsythia, T. denticola and P. nigrescens. Among the virulence genes, significance to atherosclerosis was observed for P. gingivalis type II fimA and T. forsythia bspA.

CONCLUSION

The results of this study strongly correlate periodontal bacterial co-occurrence and periodontal bacterial adhesion factor to atherosclerosis.

Detection of Porphyromonas gingivalis fimA Type I Genotype in Gingivitis by Real-Time PCR-A Pilot Study

INTRODUCTION

Published literature till date reveals a high prevalence of Porphyromonas gingivalis fimA type I genotype among healthy subjects. Quite a few studies have reported its prevalence also in periodontitis patients. Nevertheless incidence of this genotype in gingivitis is lacking in adult population.

AIM

The present study was chosen to detect P. gingivalis fimA type I genotype among chronic gingivitis patients.

MATERIALS AND METHODS

A total of 46 subgingival plaque samples collected from chronic marginal gingivitis (n=23) and chronic periodontitis subjects (control group) (n=23) were subjected to Real-Time Polymerase Chain Reaction to detect the P. gingivalis fimA type I gene. Statistical analysis was performed using chi-square test.

RESULTS

Prevalence of P. gingivalis fimA type I gene among chronic periodontitis and chronic gingivitis patients were 8.7% and 30.4% respectively. P. gingivalis fimA type I genotype prevalence was found to be statistically insignificant between the two study groups (p=0.135).

CONCLUSION

The avirulent P. gingivalis fimA type I genotype, occurred in high prevalence among chronic gingivitis patients, while its presence was low in chronic periodontitis patients. Presence of this avirulent genotype in chronic marginal gingivitis signifies its reversible condition.

Actinobacillus actinomycetemcomitans Keratitis After Glaucoma Infiltration Surgery: A Clinical Report and Literature Review

Actinobacillus actinomycetemcomitans infection is a rare and easily misdiagnosed ocular disease. In this article, the authors report a chronic, purulent, and difficult-to-treat case of A actinomycetemcomitans keratitis following a glaucoma infiltration surgery.A 56-year-old man with a long-standing history of open-angle glaucoma in both eyes presented with a 12-week history of ocular pain, redness, and blurred vision in his right eye. He underwent a glaucoma infiltration surgery in his right eye 6 months ago. Three months postoperatively, he developed peripheral corneal stromal opacities associated with a white, thin, cystic bleb, and conjunctival injection. These opacities grew despite topical treatment with topical tobramycin, levofloxacin, natamycin, amikacin, and metronidazole eye drops.Multiple corneal scrapings revealed no organisms, and no organisms grew on aerobic, anaerobic, fungal, or mycobacterial cultures. The patient's right eye developed a severe purulent corneal ulcer with a dense hypopyon and required a corneal transplantation. Histopathologic analysis and 16S ribosomalribonucleic acid polymerase chain reaction sequencing revealed A actinomycetemcomitans as the causative organism. Postoperatively, treatment was initiated with topical levofloxacin and cyclosporine, as well as oral levofloxacin and cyclosporine. Graft and host corneal transparency were maintained at the checkup 1 month after surgery.Although it is a rare cause of corneal disease, A actinomycetemcomitans should be suspected in patients with keratitis refractory to topical antibiotic therapy. Delay in diagnosis and appropriate treatment can result in vision loss.

Porphyromonas gingivalis: major periodontopathic pathogen overview

Porphyromonas gingivalis is a Gram-negative oral anaerobe that is involved in the pathogenesis of periodontitis and is a member of more than 500 bacterial species that live in the oral cavity. This anaerobic bacterium is a natural member of the oral microbiome, yet it can become highly destructive (termed pathobiont) and proliferate to high cell numbers in periodontal lesions: this is attributed to its arsenal of specialized virulence factors. The purpose of this review is to provide an overview of one of the main periodontal pathogens—Porphyromonas gingivalis. This bacterium, along with Treponema denticola and Tannerella forsythia, constitute the “red complex,” a prototype polybacterial pathogenic consortium in periodontitis. This review outlines Porphyromonas gingivalis structure, its metabolism, its ability to colonize the epithelial cells, and its influence upon the host immunity.

Association of three bacterial species and periodontal status in Chinese adults: an epidemiological approach

Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia are oral pathogens associated with periodontitis. The association between these three bacteria and periodontal disease has been reported in populations of many countries. However, corresponding data in Chinese populations are still lacking. The aim of this study was to detect these pathogens in subgingival plaque collected from 468 subjects with chronic periodontitis in a group of Chinese adults by using a PCR method and to determine the degree of association between the target bacteria and periodontal status based on logistic regression analysis. A. actinomycetemcomitans, P. gingivalis, and T. forsythia were found in 20.5%, 70.7%, and 77.1% of the subjects, respectively. About one-third (36.1%) of subjects had chronic periodontitis. Upon univariate analysis, age, male gender, current smoking status, diabetes, and the presence of A. actinomycetemcomitans or P. gingivalis were positively associated with chronic periodontitis, whereas education and income exhibited inverse associations with chronic periodontitis. Upon multivariate analysis, education, current smoking status, diabetes, and the presence of A. actinomycetemcomitans and P. gingivalis remained significant. The adjusted odds ratios for having chronic periodontitis were 2.5 and 3.4 in subjects positive for A. actinomycetemcomitans and P. gingivalis, respectively. However, no significant association was observed between the presence of T. forsythia and periodontal status. This study assesses the prevalence of periodontal pathogens and chronic periodontitis and the associations with sociodemographic characteristics among this group of Chinese adults. These findings also suggest that PCR should be considered for field oral epidemiologic studies and may be necessary in investigations presenting major logistic challenges.

Occurrence of Aggregatibacter actinomycetemcomitans in Brazilian Indians from Umutina Reservation, Mato Grosso, Brazil

Aggregatibacter actinomycetemcomitans is associated with periodontal disease, especially localized aggressive periodontitis, produces a potent leukotoxin and its distribution is influenced by ethnic characteristics of the population.

Interleukin-6 polymorphisms modify the risk of periodontitis: a systematic review and meta-analysis

OBJECTIVE

To clarify the association of IL-6 polymorphisms and periodontitis, a meta-analysis of case-control studies and a systemic review were conducted.

MATERIAL AND METHODS

We performed a literature search using PubMed and Medline database to May 2009, with no restrictions. We also reviewed references from all retrieved articles. Six case-control studies involving 1 093 periodontitis cases and 574 controls were selected for meta-analysis to assess the purported associations between IL-6 polymorphisms and the risk of periodontitis. IL-6 -174 G/C and -572 C/G polymorphisms were included in the present meta-analysis, and the association between IL-6 -6331 T/C polymorphism and the risk of periodontitis was adequately reviewed as well.

RESULTS AND CONCLUSION

The present meta-analysis indicates that the IL-6 -174 G allele could not modify the risk of chronic periodontitis, but increased the risk of aggressive periodontitis. And -572 C/G polymorphism is associated with the pathogenesis of periodontitis, including chronic periodontitis or aggressive periodontitis.

Virulence genes of Porphyromonas gingivalis W83 in chronic periodontitis

OBJECTIVE

To identify virulence genes found in highly virulent strains of Porphyromonas gingivalis (P. gingivalis) among Chinese patients with chronic periodontitis and to evaluate the association of these virulence genes with clinical parameters and with periodontal tissue destruction.

MATERIAL AND METHODS

Suppression subtractive hybridization was applied to acquire short gene fragments harbored only in virulent strains of P. gingivalis W83. Eighteen genes, which were present in P. gingivalis W83 but absent from P. gingivalis ATCC 33277, were labeled with Cy5 and used as probes in DNA microarray hybridization to analyze DNA of P. gingivalis isolated from chronic periodontitis patients.

RESULTS

Spearman correlation analysis revealed 10 genes correlated with probing depth, clinical attachment loss, and tooth mobility (p<0.05).

CONCLUSION

These genes may provide an important clue towards our understanding the mechanism of occurrence and the development of periodontal disease.

Diminished treatment response of periodontally diseased patients infected with the JP2 clone of Aggregatibacter (Actinobacillus) actinomycetemcomitans

This longitudinal study evaluated the response to periodontal treatment by subjects infected with either JP2 (n = 25) or non-JP2 (n = 25) Aggregatibacter (Actinobacillus) actinomycetemcomitans. Participants were treated during the first 4 months by receiving (i) scaling and root planing, (ii) systemic antibiotic therapy, and (iii) periodontal surgery. Probing depth (PD), clinical attachment level (CAL), and gingival and plaque indices (GI and PI, respectively) were monitored at baseline and at 12 months, along with DNA-PCR-based subgingival detection of JP2 or non-JP2 A. actinomycetemcomitans. At baseline, PD, CAL, and GI scores were statistically higher in the JP2 strain-positive group than the non-JP2-strain-positive group. At 12 months, PD, CAL, and GI scores had decreased significantly for both groups, but the reduction rates of PD and CAL were higher in the non-JP2-strain-positive group. Among JP2-strain-positive patients in the baseline, patients who remained JP2 strain positive at 12 months showed significantly higher GIs than did the patients who had lost the detectable JP2 clone. Patients who remained JP2 strain positive at 12 months appeared to be more resistant to mechanical-chemical therapy than did those who were still non-JP2 strain positive, while the elimination of JP2 A. actinomycetemcomitans remarkably diminished gingival inflammation. Early identification and elimination of the JP2 clone of A. actinomycetemcomitans will enable practitioners to effectively predict the outcome of treatments applied to periodontal patients.

Prevalence and distribution of principal periodontal pathogens worldwide

BACKGROUND

Detailed genetic analysis of bacteria has demonstrated an unanticipated genetic diversity within species, which often reveals evolutionary lineages that are disproportionately associated with infection. There is evidence that some evolutionary lineages of bacteria have adapted to particular ethnic groups.

AIM

This review analyzes to what extent observed differences in periodontal disease prevalence among ethnically or geographically distinct populations may be explained by restricted host adaptation of clones of principal periodontal pathogens.

RESULTS

Carriage rates of several putative periodontal pathogens and particular subsets of these species vary between ethnic groups. Few of these differences can, with the limited information available, be directly related to differences in periodontal disease prevalence. Asian populations are regularly colonized with Actinobacillus actinomycetemcomitans serotype c with questionable pathogenic potential. Conversely, the JP2 clone of A. actinomycetemcomitans has enhanced virulence and causes significantly higher prevalence of aggressive periodontitis in adolescents whose descent can be traced back to the Mediterranean and Western parts of Africa. Some genetically distinct types of Porphyromonas gingivalis are more associated with disease than others, but additional work is required to relate this to clinical differences.

CONCLUSIONS

Studies that take into account differences linked to the genetics of both patients and potential pathogens are likely to give better insight into the aetiology of periodontal diseases.

Distribution of biotypes and leukotoxic activity of Aggregatibacter actinomycetemcomitans isolated from Brazilian patients with chronic periodontitis

Aggregatibacter actinomycetemcomitans is an important etiologic agent of the periodontitis and is associated with extra-oral infections. In this study, the detection of the ltxA gene as well as the ltx promoter region from leukotoxic A. actinomycetemcomitans isolated from 50 Brazilian patients with periodontitis and 50 healthy subjects was performed. The leukotoxic activity on HL-60 cells was also evaluated. Leukotoxic activity was determined using a trypan blue exclusion method. The 530 bp deletion in the promoter region was evaluated by PCR using a PRO primer pair. A. actinomycetemcomitans was detected by culture and directly from crude subgingival biofilm by PCR using specific primers. By culture, A. actinomycetemcomitans was detected in nine (18%) of the periodontal patients and one (2%) healthy subject. However, by PCR, this organism was detected in 44% of the periodontal patients and in 16% of the healthy subjects. It was verified a great discrepancy between PCR detection of the ltx operon promoter directly from crude subgingival biofilm and from bacterial DNA. Only one periodontal sample harbored highly leukotoxic A. actinomycetemcomitans. Moreover, biotype II was the most prevalent and no correlation between biotypes and leukotoxic activity was observed. The diversity of leukotoxin expression by A. actinomycetemcomitans suggests a role of this toxin in the pathogenesis of periodontal disease and other infectious diseases.

Invasive differences among Porphyromonas gingivalis strains from healthy and diseased periodontal sites

BACKGROUND AND OBJECTIVE

The purpose of this study was to determine any difference between Porphyromonas gingivalis isolates from periodontally healthy sites as compared to those from diseased sites with respect to the ability to invade host cells.

MATERIAL AND METHODS

Subgingival plaque samples were obtained from periodontally healthy and diseased sites using paper points. P. gingivalis colonies were isolated and tested, using an antibiotic protection assay, for their ability to invade KB cells. P. gingivalis 381 and Escherichia coli MC1061 were used as controls.

RESULTS

Mean values of 16.79 +/- 0.86 x 10(3) colony-forming units/mL and 26.14 +/- 2.11 x 10(3) colony-forming units/mL were observed in invasion assays for isolates from periodontally healthy and diseased sites, respectively. P. gingivalis present in diseased sites had significantly greater invasive abilities than strains isolated from healthy sites. No statistical difference was noted between male or female subjects concerning the degree of invasion; isolates from diseased sites from both genders had significantly greater invasion abilities than those from healthy sites. A significant correlation was found between the increased invasive capabilities of P. gingivalis isolates vs. an increased probing depth.

CONCLUSION

The increased invasion noted with P. gingivalis isolates from diseased sites vs. healthy sites, and the increased invasive capabilities with increasing probing depth, indicate that P. gingivalis isolates have a varying ability to invade host cells in the periodontal pocket.

Fimbrial proteins of porphyromonas gingivalis mediate in vivo virulence and exploit TLR2 and complement receptor 3 to persist in macrophages

Porphyromonas gingivalis is an oral/systemic pathogen implicated in chronic conditions, although the mechanism(s) whereby it resists immune defenses and persists in the host is poorly understood. The virulence of this pathogen partially depends upon expression of fimbriae comprising polymerized fimbrillin (FimA) associated with quantitatively minor proteins (FimCDE). In this study, we show that isogenic mutants lacking FimCDE are dramatically less persistent and virulent in a mouse periodontitis model and express shorter fimbriae than the wild type. Strikingly, native fimbriae allowed P. gingivalis to exploit the TLR2/complement receptor 3 pathway for intracellular entry, inhibition of IL-12p70, and persistence in macrophages. This virulence mechanism also required FimCDE; indeed, mutant strains exhibited significantly reduced ability to inhibit IL-12p70, invade, and persist intracellularly, attributable to failure to interact with complement receptor 3, although not with TLR2. These results highlight a hitherto unknown mechanism of immune evasion by P. gingivalis that is surprisingly dependent upon minor constituents of its fimbriae, and support the concept that pathogens evolved to manipulate innate immunity for promoting adaptive fitness and thus their capacity to cause disease.