Probe-specific DNA fingerprinting applied to the epidemiology of localized juvenile periodontitis

Although Actinobacillus actinomycetemcomitans has been recognized as a primary etiological agent in localized juvenile periodontitis, questions remain concerning the source of infection, mode of transmission, and relative virulence of strains. DNA fingerprinting analysis, using a randomly cloned chromosomal DNA fragment as a probe, revealed that previously characterized strains of A. actinomycetemcomitans displayed significant restriction site heterogeneity which could be applied to the typing of clinical isolates of this bacterium such that individual strains or variants could be traced within subjects from localized juvenile periodontitis families. Hybridization data derived from an analysis of bacterial isolates obtained from families participating in an ongoing longitudinal study of the disease showed that a single individual could be infected with more than one strain or variant of A. actinomycetemcomitans and that various members of the same family could harbor different strains or variants of the bacterium. In several cases the clinical isolates were matched to characterized laboratory strains by comparing hybridization patterns generated by digestion of the DNA with several restriction enzymes in independent reactions. Thus, probe-specific DNA fingerprinting of A. actinomycetemcomitans will permit us to determine if particular strains or variants are frequently associated with sites of periodontal destruction. Attention could then be focused on determining the virulence properties of those strains or variants that have in vivo significance.

Staphylococci in human periodontal diseases

The occurrence of subgingival staphylococci was determined in 506 individuals with advanced adult periodontitis, 108 with early-onset periodontitis, 13 with localized juvenile periodontitis, 18 with gingivitis, and 13 with 20 failing osseointegrated titanium dental implants. Subgingival samples were collected with paper points and transported in VMGA III. The bacterial samples were plated on Staphylococcus 110 medium which was incubated in 10% CO2, and on enriched brucella blood agar, which was incubated anaerobically. Staphylococcal isolates from 94 adult periodontitis subjects were speciated using the API STAPH Trac micromethod kit system and the Bacto Staph latex agglutination test for coagulase activity. Staphylococcus epidermidis comprised 45.8% and Staphylococcus aureus 22.3% of total staphylococcal isolates. At 1 microgram/ml, in vitro resistance by staphylococci was found to tetracycline (14.4% of isolates), penicillin (4.9%), erythromycin (12.1%), and metronidazole (31.9%). Subgingival staphylococci were isolated from approximately 50% of gingivitis and periodontitis patients. No statistically significant differences were found between these patient groups in the prevalence or mean proportions of staphylococci recovered. "Periimplantitis" lesions exhibited significantly higher proportions of staphylococci (15.1%) than gingivitis (0.06%) or periodontitis (1.2%) lesions. Staphylococci may play a role in some failing osseointegrated dental implants.

Genetic approach to the study of epidemiology and pathogenesis of Actinobacillus actinomycetemcomitans in localized juvenile periodontitis

Actinobacillus actinomycetemcomitans isolates from periodontal pockets were examined for restriction fragment-length polymorphism using a characterized 4.7-kb DNA probe. A total of 6 patterns of RFLP was found in 133 isolates originating from 12 subjects. No relatedness was found between RFLP types and serotypes. Different periodontal sites within the same subject and different individuals within the same family sometimes showed only one type of A. actinomycetemcomitans RFLP. When members among the same family showed 2 RFLP types, children were always infected with the A. actinomycetemcomitans strains found in at least one of the parents. These findings support the concept of familial spread of A. actinomycetemcomitans. A. actinomycetemcomitans RFLP type B, corresponding to reference strain JP2, seems to be particularly virulent, as indicated from the presence of RFLP type B in 3 subjects who converted from a healthy periodontal state to localized juvenile periodontitis. RFLP type B was not detected in any of the 21 A. actinomycetemcomitans-infected patients with adult periodontitis. The RFLP method seems to be useful in determining the epidemiology and possibly the potential virulence of periodontal strains of A. actinomycetemcomitans.

Clinical and microbiological characteristics of treated periodontitis patients on maintenance care

A population of 98 adults previously treated for moderate to advanced adult periodontitis and currently maintained in a recall program for at least one year were recruited for this study. The ultimate purpose of the study is to determine whether the presence of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Bacteroides intermedius in selected periodontal sites can predict the future clinical course of these patients, particularly with respect to disease recurrence. This report presents the clinical design of the study which allows comparisons between sites positive and negative for these species in infected patients, and between sites in infected patients and comparable sites in non-infected patients. In addition, some base line clinical and microbiological data for these patients are presented. The distribution of PII and GI scores tended to be highest for molars, with the remaining teeth having similar scores. Probing depth measurements were greater for mesio-distal than oro-vestibular recordings. A bilaterally symmetrical pattern of increasing probing depth was noted from the midline distally on mesio-distal as well as oro-vestibular surfaces. Sites positive for the target organisms listed above tended to have greater probing depths (mean: 4.14 +/- 0.1 mm) than non-infected sites in the same patients (mean: 3.76 +/- 0.1 mm) or comparable sites in non-infected patients (mean: 3.54 +/- 0.1 mm).

Immunomodulatory effects of Bacteroides products on in vitro human lymphocyte functions

Bacteroides spp. have been implicated in the pathogenesis of several diseases, including periodontal diseases. In this study sonic extracts of 6 Bacteroides spp. were examined for their abilities to alter human lymphocyte function. We found that soluble extracts from Bacteroides intermedius, Bacteroides endodontalis, Bacteroides asaccharolyticus, Bacteroides melaninogenicus, and to a lesser degree Bacteroides loescheii, caused dose-dependent inhibition of human lymphocyte responsiveness to both mitogens and antigens. Suppression involved altered DNA, RNA and protein synthesis as well as immunoglobulin production. In contrast, Bacteroides gingivalis did not suppress these responses; instead, it stimulated lymphocyte proliferation and enhanced immunoglobulin production. It has been proposed that impaired host defense may play a pivotal role in the pathogenesis of many infections. The data presented in this paper suggest that microbial mediated immunosuppression may conceivably alter the nature and consequences of host-parasite interactions in periodontal disease.

Experimental infections by Bacteroides gingivalis in non-immunized and immunized rabbits

The interactions between Bacteroides gingivalis and systemic antibodies were studied in tissue cages implanted in the backs of New Zealand white rabbits. Infectivity was evaluated according to clinical signs and to leukocyte and bacterial counts in material aspirated from the tissue cages. Pre- and post-inoculation antibody levels to sonicated whole bacterial cells were determined by enzyme-linked immunosorbent and agar immunodiffusion assays. Rabbits immunized against B. gingivalis and then challenged with pure cultures of B. gingivalis revealed complete elimination or markedly lower postinoculation bacterial counts and considerably weaker tissue reactions than non-immunized animals. B. gingivalis co-inoculated with Actinobacillus actinomycetemcomitans caused significantly more severe infections than observed in monoinfected animals. The present results suggest that the immune system acting through systemic antibodies and/or cellular mechanisms may modulate the pathogenic potential of infecting periodontal pathogens.

Bacteroides gingivalis, Bacteroides intermedius and Actinobacillus actinomycetemcomitans in human periodontal diseases

Bacteroides gingivalis, Bacteroides intermedius and Actinobacillus actinomycetemcomitans seem to be major pathogens in advancing periodontitis in man. First, these organisms are recovered in higher prevalence and proportions from progressive periodontitis lesions than from quiescent periodontal sites. Second, antibody levels against B. gingivalis and A. actinomycetemcomitans are markedly elevated in serum and gingival crevice fluid of periodontitis patients compared to normal controls. Third, B. gingivalis and B. intermedius elaborate potent proteases and A. actinomycetemcomitans various noxious substances which have the potential to perturb important host defenses and to disintegrate key constituents of the periodontal tissues. Monitoring these bacteria in advanced periodontal lesions may greatly assist the assessment of treatment efficacy and risk of further periodontal breakdown.

Prevalence and microbiology of localized prepubertal periodontitis

Loss of crestal alveolar bone at primary teeth was ascertained radiographically in a dental school clinical population of 2264 children. 19 patients (0.84%) demonstrated distinct periodontal bone destruction around one or more primary teeth; in only 2 of these patients had periodontal disease been identified in previous clinical examinations. A microbiological study of 35 subgingival samples from 9 available patients revealed a high prevalence of black-pigmented Bacteroides spp., mainly Bacteroides intermedius. Actinobacillus actinomycetemcomitans and Capnocytophaga spp. were predominant organisms in some samples. The present data indicate that localized prepubertal periodontitis is more common than previously realized and is associated with bacteria generally regarded as major periodontal pathogens.

The capability of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius to indicate progressive periodontitis; a retrospective study

This study evaluated the statistical association of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius with progressive periodontitis. 146 adults with a history of advanced periodontitis contributed 105 "nonprogressing" and 130 "progressing" periodontal sites. Periodontal disease activity was assessed by radiographic changes in crestal alveolar bone level. The subgingival proportion of the 3 test bacteria was determined by selective and nonselective culturing. The relationship between bacterial proportions and disease progression was evaluated using subgrouping and multiple-regression analyses. All 3 test bacteria had to be considered in order to distinguish nonprogressing and progressing periodontitis with a reasonably high sensitivity. A recovery rate below 0.01% for A. actinomycetemcomitans, 0.1% for B. gingivalis and 2.5% for B. intermedius defined a site with nonprogressing disease with 87% sensitivity and 84% specificity. By utilizing transformed values of the bacterial recovery rates and optimal test criteria determined by multiple regression analysis, it was possible to obtain sensitivities between 83% and 95% and specificities between 86% and 69%. These 3 bacterial species might serve as valuable components of a periodontitis activity test based on microbiological variables.

Purification and properties of hemagglutinin from culture supernatant of Bacteroides gingivalis

The hemagglutinating factor (hemagglutinin) of Bacteroides gingivalis was prepared from the supernatant of a 5-day diffusate broth culture by ammonium sulfate precipitation and column chromatography with a hydrophobic column of Phenyl-Sepharose CL-4B, DEAE-Sephadex A-50, and Sephadex G-100 gel filtration. The hemagglutinating activity of the preparation was 53.3 times higher than that of ammonium sulfate precipitate. In electron microphotographs, hemagglutinin appears to have a vesicle or tubelike structure. The hemagglutinating activity of intact cells was completely destroyed by heating at 100 degrees C for 10 min, but the activity of extracted hemagglutinin was heat stable. The activity of hemagglutinin was inhibited by L-arginine and L-lysine and partially inhibited by phospholipase D, but it was not affected by proteolytic enzymes, neuraminidase, hyaluronidase, lipase, phospholipase A and C, or sugars. The B. gingivalis hemagglutinin appeared to be comprised mainly of a 40,000-molecular-weight material. The Fab fragment of immunoglobulin G prepared from rabbit antiserum to whole cells of B. gingivalis and monoclonal antibody against the hemagglutinin bound to the cell surface and inhibited the hemagglutinating activity of both the cells and the purified hemagglutinin.

Bacterial specificity in adult periodontitis. A summary of recent work

3 studies investigated the importance of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius in progressive adult periodontitis. A total of 196 adults with advanced periodontitis and 475 periodontal sites were examined. The periodontal disease activity was assessed by changes in probing periodontal attachment level and crestal alveolar bone level. The composition of the subgingival microflora was determined by nonselective and selective culturing and indirect immunofluorescence of direct smears. A. actinomycetemcomitans occurred in 50% of progressing lesions and in only 6% of nonprogressing sites. B. gingivalis was detected in 42-52% of progressing lesions and in 14% of nonprogressing sites. The median B. gingivalis recovery in culture-positive sites was more than 10-fold higher in progressing than in nonprogressing sites. B. intermedius was recovered from 59-89% of progressing lesions and from 36-53% of nonprogressing sites. B. intermedius averaged 5-10 higher recovery in infected progressing lesions than in infected nonprogressing sites. 1 progressing lesion only failed to reveal any of the above organisms. Assessment of the overall results indicates that A. actinomycetemcomitans, B. gingivalis and B. intermedius are major suspected pathogens in destructive periodontal disease in adults.

Topical antimicrobial therapy and diagnosis of subgingival bacteria in the management of inflammatory periodontal disease

Bacterial specificity in human periodontal diseases suggests the possibility of diagnosing and treating periodontitis as specific infections and using microbiological diagnostic means to evaluate the efficacy of periodontal therapy. In a series of clinical trials, the usefulness of topical antimicrobial agents in combination with surgical and non-surgical conventional periodontal therapy were tested. The healing result was estimated by monitoring probing attachment levels (PAL). The usefulness of clinical and microbiological parameters to evaluate post-treatment healing result was tested. 9 of the patients exhibiting sites with recurrent periodontal disease were then evaluated for clinical and microbiological parameters to define accurate means to differentiate between active and inactive periodontal disease. The results showed that the frequency of periodontal lesions with significant loss of PAL after treatment was less in patients treated with antimicrobial agent. Specific microbiological parameters showed stronger correlation than clinical parameters with gain and/or loss of PAL post-treatment. Thus Actinobacillus actinomycetemcomitans and Bacteroides gingivalis occurred in periodontal lesions with progressing disease after treatment, but were rarely detected in samples from pockets of the same depths which did not exhibit further loss of PAL over a study period of 1 year. This study points to the usefulness of topical antimicrobial agent as an adjunct to mechanical subgingival debridement in the treatment of periodontitis in adults. The results also indicate the utility of diagnostic microbiology in the assessment of periodontal disease activity post-treatment.

The occurrence of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius in destructive periodontal disease in adults

A total of 235 subgingival sites, including 104 progressive deep lesions from 61 untreated patients, 26 progressive deep lesions from 10 treated patients, 33 nonprogressive deep sites from 20 untreated patients, and 72 nonprogressive sites from 55 treated patients were examined for Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius. The periodontal disease progression was mainly determined on the basis of radiographic changes in the crestal alveolar bone level. A. actinomycetemcomitans isolation was carried out using the selective TSBV medium and B. gingivalis and B. intermedius isolations were performed using a nonselective blood agar medium. 1 or more of the 3 bacteria studied appeared in 99.2% of progressive periodontal lesions but only in 40.0% of nonprogressive sites. Culture-positive progressive periodontal sites in comparison with culture-positive nonprogressive sites showed higher median recovery rates of A. actinomycetemcomitans (0.5% vs 0.3%), B. gingivalis (30.5% vs 0.3%) and B. intermedius (4.9% vs 0.5%). Of total progressive lesions, 12.3% yielded solely A. actinomycetemcomitans, 21.5% demonstrated solely B. gingivalis, and 20.8% revealed solely B. intermedius. The A. actinomycetemcomitans--B. intermedius combination was found in 24.6% of progressive lesions. A. actinomycetemcomitans appeared in significantly higher prevalence in treated-progressive lesions (80.8%) than in nontreated-progressive lesions (42.3%). 32 of the 42 culture-positive nonprogressive sites yielded B. intermedius as the sole test organism. The main conclusion is that A. actinomycetemcomitans, B. gingivalis and B. intermedius are closely related to disease-active periodontitis, and more closely than to periodontal pocket depth. This finding is important in understanding periodontal disease etiology and pathogenesis and may also aid in a clinical setting to differentiate progressing and nonprogressing periodontal sites.