leukotoxin and Periodontal-Pocket

Mechanical debridement results in a shift of the bacterial composition in the periodontal pocket on the species level. It is unknown, however, whether a clonal change within a species could lead to the emergence of strains with different levels of virulence. Therefore, in the present study, the genetic variability of Actinobacillus actinomycetemcomitans was assessed and strains identified which were associated with periodontal disease progression following periodontal therapy, i.e., refractory periodontitis. Twenty adult patients with untreated periodontitis and subgingival colonization of A. actinomycetemcomitans were randomly assigned to receive full-mouth scaling alone or scaling with an adjunctive antimicrobial therapy. Both groups received supportive periodontal therapy at 3, 6, 9, 12, 18, and 24 months. Subgingival plaque samples were taken at every visit; venous blood was obtained at 24 months only. A. actinomycetemcomitans isolates were typed by the RAPD method, and antibody reactivity against outer membrane proteins was assessed by immunoblot analysis. Eleven distinct RAPD patterns were found in 18 patients completing the study. All patients harbored only one A. actinomycetemcomitans genotype, and within each patient this genotype persisted throughout the 24-month observation period. No differences in the expression of antibody reactivity against outer membrane proteins were found between strains isolated at baseline and at 24 months. Three genotypes were associated with reduced survival rates of teeth without probing attachment loss of 2 mm or more. The results indicated that (i) most patients harbored only one A. actinomycetemcomitans genotype; (ii) the genotype persisted following therapy; and (iii) only some genotypes were associated with refractory periodontitis.

Topics: Adult; Aggregatibacter actinomycetemcomitans; Amoxicillin; Anti-Bacterial Agents; Bacterial Outer Membrane Proteins; Bacterial Typing Techniques; Chronic Disease; Clone Cells; Dental Plaque; Disease Progression; DNA Fingerprinting; DNA, Bacterial; Exotoxins; Female; Genetic Variation; Humans; Male; Metronidazole; Middle Aged; Penicillins; Periodontal Pocket; Periodontitis; Random Amplified Polymorphic DNA Technique; Survival Analysis; Virulence

The aim of this study was to characterize the main periodontal bacterial species in Down syndrome (DS) patients with and without periodontitis.. This cross-sectional study involved 75 DS patients, 45 with and 30 without periodontitis. Informed consent, health and dental questionnaires and periodontitis diagnosis were performed PCR and LAMP assays were performed on subgingival dental plaque sample.. Tannerella forsythia was the most frequent bacteria detected in the group with and without periodontitis (95.5 and 63.3%) followed by Treponema denticola (88.8 and 50%) and Porphyromonas gingivalis (53.3 and 25% respectively). There were statistical differences between groups (p < 0.05). Pg fimA type I was the most frequent Porphyromonas gingivalis genotype. Two different sets of primers (Aa-F/Aa-R and ltx3/ltx4) were used to detect Aggregatibacter actinomycetemcomitans and different frequencies were obtained, (68% and 14.6% respectively), they had a weak correlation (Cohen Kappa = 0.16). After sequencing of PCR products, ltx3/ltx4 showed more specificity. JP2 clone of A. actinomycetemcomitans was not detected in any sample.. The composition of oral biofilm is fundamental for the development of periodontal disease independently of immunological alterations associated with DS. The frequency of detection of A. actinomycetemcomitans reported in the literature has a wide range, because the primers and probes applied

Topics: Aggregatibacter actinomycetemcomitans; Bacterial Toxins; Bacteroides; Biofilms; Cross-Sectional Studies; Dental Plaque; DNA Primers; DNA, Bacterial; Down Syndrome; Exotoxins; Female; Fimbriae Proteins; Genotype; Humans; Male; Microbial Consortia; Periodontal Attachment Loss; Periodontal Pocket; Periodontitis; Periodontium; Pili, Sex; Porphyromonas gingivalis; Tooth Loss; Treponema denticola; Young Adult

To investigate the presence of A. actinomycetemcomitans, including the highly virulent JP2 clone, in young adult patients with aggressive periodontitis, and associate the findings with the two forms of the disease.. Seventy Moroccan subjects with aggressive periodontitis, aged less than 35 years, were recruited. Among these, 41 had LAgP and 29 had GAgP. Plaque samples were collected from periodontal pockets and examined using a PCR that detects the presence of A. actinomycetemcomitans and which differentiates between JP2 and non-JP2 genotypes of the bacterium.. total of 58 (83%) from the 70 AgP patients were positive for A. actinomycetemcomitans, among whom 77% were positives for the JP2 clone. The JP2 clone was detected in 34 (83%) of the LAgP patients compared to 20 (69%) of the GAgP patients (p = 0.17). Fourteen (20%) of the patients harbored non-JP2 genotypes of A. actinomycetemcomitans, although most of these patients (10/14) also harbored the JP2 clone.. The presence of the JP2 clone of A. actinomycetemcomitans is strongly associated with both LAgP and GAgP in young adults in Morocco. This implies that treatment of AgP in this population should include microbiological screening and aim at eradication of the bacterium when present.

Topics: Adolescent; Adult; Aggregatibacter actinomycetemcomitans; Aggressive Periodontitis; Bacterial Toxins; Chi-Square Distribution; Child; Dental Plaque; Exotoxins; Female; Genotype; Humans; Male; Morocco; Periodontal Pocket; Promoter Regions, Genetic; Virulence; Young Adult

Cross-sectional and longitudinal studies identify the JP2 clone of Aggregatibacter actinomycetemcomitans as an aetiological agent of aggressive periodontitis (AgP) in adolescents of northwest African descent. To gain information on why a significant part of Moroccan adolescents show clinical signs of periodontal disease in the absence of this pathogen we performed comprehensive mapping of the subgingival microbiota of eight young Moroccans, four of whom were diagnosed with clinical signs of AgP. The analysis was carried out by sequencing and phylogenetic analysis of a total of 2717 cloned polymerase chain reaction amplicons of the phylogenetically informative 16S ribosomal RNA gene. The analyses revealed a total of 173 bacterial taxa of which 39% were previously undetected. The JP2 clone constituted a minor proportion of the complex subgingival microbiota in patients with active disease. Rather than identifying alternative aetiologies to AgP, the recorded infection history of the subjects combined with remarkably high concentrations of antibodies against the A. actinomycetemcomitans leukotoxin suggest that disease activity was terminated in some patients with AgP as a result of elimination of the JP2 clone. This study provides information on the microbial context of the JP2 clone activity in a JP2-susceptible population and suggests that such individuals may develop immunity to AgP.

Topics: Actinobacillus Infections; Adolescent; Aggregatibacter actinomycetemcomitans; Aggressive Periodontitis; Antibodies, Bacterial; Bacterial Toxins; Case-Control Studies; Clone Cells; Disease Susceptibility; Exotoxins; Gingival Hemorrhage; Humans; Immunosuppressive Agents; Morocco; Nucleic Acid Amplification Techniques; Periodontal Attachment Loss; Periodontal Pocket; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Young Adult

Although certain serotypes of Aggregatibacter actinomycetemcomitans are associated more with aggressive periodontitis than are other serotypes, the correlation between distinct lineages and virulence traits in this species is poorly understood. This study aimed to evaluate the polymorphism of genes encoding putative virulence factors of clinical isolates, and to correlate these findings with A. actinomycetemcomitans serotypes, genotypes and periodontal status of the hosts.. Twenty-six clinical isolates from diverse geographic populations with different periodontal conditions were evaluated. Genotyping was performed using pulse-field gel electrophoresis. Polymorphisms in the genes encoding leukotoxin, Aae, ApaH and determinants for serotype-specific O polysaccharide were investigated.. The isolates were classified into serotypes a-f, and exhibited three apaH genotypes, five aae alleles and 25 macrorestriction profiles. Two serotype b isolates (7.7%), obtained from Brazilian patients with aggressive periodontitis, were associated with the highly leukotoxic genotype; these isolates showed identical fingerprint patterns and aae and apaH genotypes. Serotype c, obtained from various periodontal conditions, was the most prevalent among Brazilian isolates, and isolates were distributed in two aae alleles, but formed a genetically distinct group based on apaH analysis. Cluster analysis showed a close relationship between fingerprinting genotypes and serotypes/apaH genotypes, but not with aae genotypes.. Apart from the deletion in the ltx promoter region, no disease-associated markers were identified. Non-JP2-like strains recovered from individuals with periodontal disease exhibited considerable genetic variation regarding aae/apaH genotypes, serotypes and XhoI DNA fingerprints.

Topics: Actinobacillus Infections; Adhesins, Bacterial; Aggregatibacter actinomycetemcomitans; Aggressive Periodontitis; Alleles; Bacterial Outer Membrane Proteins; Bacterial Toxins; Base Pairing; Chronic Periodontitis; Deoxyribonucleases, Type II Site-Specific; DNA Fingerprinting; Exotoxins; Genetic Variation; Genotype; Humans; O Antigens; Periodontal Index; Periodontal Pocket; Periodontitis; Periodontium; Polymorphism, Genetic; Promoter Regions, Genetic; Serotyping; Virulence Factors

To look for clinical signs of periodontal disease in young adults who exhibited radiographic bone loss and detectable numbers of Aggregatibacter actinomycetemcomitans in their primary dentition.. Periodontal status and radiographic bone loss were examined in each of the subjects 16 years after the baseline observations. Techniques for anaerobic and selective culture, and checkerboard, were used to detect periodontitis-associated bacterial species. The isolated A. actinomycetemcomitans strains were characterized by polymerase chain reaction.. Signs of localized attachment loss were found in three out of the 13 examined subjects. A. actinomycetemcomitans was recovered from six of these subjects and two of these samples were from sites with deepened probing depths and attachment loss. Among the isolated A. actinomycetemcomitans strains, serotypes a-c and e, but not d or f, were found. None of the isolated strains belonged to the highly leucotoxic JP2 clone, and one strain lacked genes for the cytolethal distending toxin.. This study indicates that the presence of A. actinomycetemcomitans and early bone loss in the primary dentition does not necessarily predispose the individual to periodontal attachment loss in the permanent dentition.

Topics: Adult; Aggregatibacter actinomycetemcomitans; Aggressive Periodontitis; Alveolar Bone Loss; Bacterial Toxins; Bacteroides; Clone Cells; Colony Count, Microbial; Cytotoxins; Dental Calculus; Dental Plaque; DNA, Bacterial; Exotoxins; Female; Follow-Up Studies; Genotype; Humans; Male; Nucleic Acid Hybridization; Peptostreptococcus; Periodontal Attachment Loss; Periodontal Pocket; Porphyromonas gingivalis; Prevotella intermedia; Prevotella nigrescens; Serotyping; Young Adult

The identification of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) serotypes may add some important information to the understanding of the pathogenetic background of severe periodontal infections. This study compared serotypes of A. actinomycetemcomitans in two groups of periodontal patients with different ethnic backgrounds.. A total of 194 patients (96 Germans and 98 Koreans) with aggressive or severe chronic periodontitis participated in the study. Microbiologic analysis of pooled samples from subgingival plaque was performed by using a real-time polymerase chain reaction (PCR) test for A. actinomycetemcomitans. In patients who tested positive for A. actinomycetemcomitans, serotypes (a through f) were determined by nucleic acid-based methods.. The prevalence of patients who tested positive for A. actinomycetemcomitans with the real-time PCR was comparable in both groups (Germans: 27.0%; Koreans: 22.2%). In German patients, the serotypes detected most frequently were b (33.3%), c (25.0%), and a (20.8%), whereas in Korean patients, the serotype distribution was different, with serotypes c (61.9%) and d (19.0%) accounting for >80% of the complete serotype spectrum.. Even if the percentage of patients who tested positive for A. actinomycetemcomitans was identical in patients with generalized aggressive and severe chronic periodontitis and different ethnic backgrounds, the distribution of A. actinomycetemcomitans serotypes may exhibit marked differences.

Topics: Actinobacillus Infections; Adult; Aggregatibacter actinomycetemcomitans; Aggressive Periodontitis; Asian People; Bacterial Toxins; Chronic Periodontitis; Dental Plaque; Dental Plaque Index; Ethnicity; Exotoxins; Female; Germany; Gingival Hemorrhage; Humans; Korea; Male; Middle Aged; Operon; Periodontal Attachment Loss; Periodontal Index; Periodontal Pocket; Polymerase Chain Reaction; Promoter Regions, Genetic; Serotyping; White People

beta2-Glycoprotein I (beta 2GPI) is important in the suppression of coagulation, and antibodies against TLRVYK peptides on the beta 2GPI molecule are related to thrombosis. According to the Swiss-Prot database, Aggregatibacter actinomycetemcomitans leukotoxin c has sequences (SIRVYK) that are homologous to the TLRVYK peptides. The aim of this study was to investigate the effects of A. actinomycetemcomitans infection on the antibody response against SIRVYK peptides in patients with periodontitis.. Serum immunoglobulin G (IgG) antibody and IgG subclass antibody titers against SIRVYK or TLRVYK peptides were measured by enzyme-linked immunosorbent assay in 46 patients with aggressive periodontitis (eight with localized disease, 38 with generalized disease), 28 patients with chronic periodontitis, and 20 periodontally healthy subjects. The presence of A. actinomycetemcomitans in plaque and saliva samples was determined using polymerase chain reaction.. The level of anti-SIRVYK antibodies was significantly higher in patients who were A. actinomycetemcomitans-positive than in A. actinomycetemcomitans-negative patients (P < 0.05) in the chronic periodontitis group. A similar trend was found in the antibody response to TLRVYK peptide; however, no statistically significant difference was seen between A. actinomycetemcomitans-positive and -negative patients. The A. actinomycetemcomitans-positive patients displayed significantly higher levels of anti-SIRVYK IgG2 and IgG3 antibodies than A. actinomycetemcomitans-negative patients (P < 0.05 and P < 0.05, respectively). The level of IgG2 was highest among the four IgG subclasses and it predominantly increased in patients who were A. actinomycetemcomitans-positive. Anti-TLRVYK antibody levels were significantly correlated with anti-SIRVYK IgG antibody levels.. The results suggest that A. actinomycetemcomitans infection may elicit anti-SIRVYK IgG antibodies and modify the anti-TLRVYK antibody response in patients with periodontitis by molecular mimicry with beta2GPI.

Topics: Adult; Aggregatibacter actinomycetemcomitans; Antibodies, Bacterial; Anticoagulants; Bacterial Toxins; beta 2-Glycoprotein I; Chronic Disease; Dental Plaque; Exotoxins; Gingival Hemorrhage; Humans; Immunoglobulin G; Middle Aged; Molecular Mimicry; Peptide Fragments; Periodontal Pocket; Periodontitis; Periodontium; Polymerase Chain Reaction; Saliva

The highly leukotoxic JP2 clone of Actinobacillus actinomycetemcomitans is strongly associated with periodontitis in adolescents. Availability of the DNA sequence of the complete genome of A. actinomycetemcomitans strain HK1651, a representative strain of the JP2 clone (http://www.genome.ou.edu/act.html), has provided new possibilities in basic research regarding the understanding of the pathogenesis of A. actinomycetemcomitans in periodontitis. This case report describes the periodontal treatment of the original source of A. actinomycetemcomitans HK1651, a 16-year-old Ghanaian adolescent girl with aggressive periodontitis. The bacterial examination involved polymerase chain reaction analysis for presence of JP2 and non-JP2 types of A. actinomycetemcomitans. The treatment, including periodontal surgery supplemented by antibiotics, arrested the progression of periodontitis for more than 10 years. Initially, infection by A. actinomycetemcomitans, including the JP2 clone, was detected at various locations in the oral cavity and was not limited to the periodontal pockets. Post-therapy, the JP2 clone of A. actinomycetemcomitans disappeared, while the non-JP2 types of A. actinomycetemcomitans remained a part of the oral microflora.

Topics: Adolescent; Aggregatibacter actinomycetemcomitans; Aggressive Periodontitis; Alveolar Bone Loss; Exotoxins; Female; Humans; Immunosuppressive Agents; Mandibular Diseases; Maxillary Diseases; Periodontal Pocket; Radiography

Eighteen (18) members of an extended family in which numerous individuals have Papillon-Lefèvre syndrome (PLS) were examined. In all, 6 affected members and 12 non-affected members were included. All patients underwent a clinical examination which, in the dentate persons, included plaque index, bleeding on probing, probing depth, and periodontal attachment loss and a set of full mouth periapical x-rays. Subgingival bacterial samples were also collected from 2 teeth in the dentate patients for cultures and identification of Actinobacillus actinomycetemcomitans. Serum samples were collected from all participants and assayed for antileukotoxin antibodies. The results indicate that there is a high prevalence of leukotoxic strains of A. actinomycetemcomitans in persons suffering from PLS, as well as in unaffected family members. The ubiquitous presence of A. actinomycetemcomitans in the family units suggests a close association between A. actinomycetemcomitans and the periodontal disease associated with the syndrome; it also suggests that A. actinomycetemcomitans by itself is not sufficient for the expression of periodontal disease and that other factors, some of which must be genetic, are necessary for lesion development.

Topics: Adolescent; Adult; Aggregatibacter actinomycetemcomitans; Antibodies, Bacterial; Bacteria; Bacterial Toxins; Child, Preschool; Colony Count, Microbial; Cytotoxins; Dental Plaque Index; Exotoxins; Female; Gingival Hemorrhage; Humans; Male; Middle Aged; Papillon-Lefevre Disease; Periodontal Attachment Loss; Periodontal Diseases; Periodontal Pocket

In a previous population-based study of 3896 7-9-year-old children living in Sweden, it was found that 32 children (0.8%) exhibited radiographic, periodontal bone loss at > or = 2 proximal surfaces of their deciduous teeth. In the present study, 26 of the 32 children were subjected to additional oral and systemic health examination. 20 other children without any radiographic evidence of bone loss in their primary dentition served as referents. None of the cases or the referents were detected to have any systemic disease. The frequency of bleeding and suppuration on probing, radiographic proximal calculus and probing attachment loss was higher among the cases than the referents. Actinobacillus actinomycetemcomitants was found subgingivally in 14 of the cases but in none of the referents. 11 of 22 cases analysed for presence of serum antibodies against A. actinomycetemcomitans leukotoxin were sero-positive compared to none of 7 referents available for analysis. Evaluation of the data from each child revealed wide variations in clinical parameters among the children in the case group. In this group, there were children with deep probing depths, probing attachment loss, suppuration on probing, proximal calculus and presence of subgingival A. actinomycetemcomitans, indicating current periodontitis. However, in the case group there were also children without positive signs of inflammatory disease, similar to the children in the reference group. In fact, the findings suggest that less than half of the number of individuals with > or = 2 proximal sites with bone loss had current periodontitis.

Topics: Aggregatibacter actinomycetemcomitans; Alveolar Bone Loss; Antibodies, Bacterial; Bacterial Toxins; Case-Control Studies; Child; Dental Calculus; Dental Plaque; Exotoxins; Female; Gingival Hemorrhage; Health Status; Humans; Male; Periodontal Attachment Loss; Periodontal Pocket; Periodontitis; Suppuration; Tooth, Deciduous