Microbiological study of localized juvenile periodontitis in Panama

Periodontal Molecular Diagnostics: State of Knowledge and Future Prospects for Clinical Application

Periodontitis leads to immunologically mediated loss of periodontium and, if untreated, can result in tooth loss. Periodontal diseases are the most prevalent in the world and have a very strong impact on patients' well-being and general health. Their treatment generates enormous costs. Given the above, precise, prompt, and predictive diagnosis of periodontal disease is of paramount importance for clinicians. The aim of the study was to summarize the state-of-the-art knowledge of molecular periodontal diagnostics and the utility of its clinical application. There is a great need to have diagnostic tests that not only describe the periodontal destruction that has occurred in the tissues but also allow clinicians to detect disease at a subclinical level before the changes occur. A test that would enable clinicians to follow the course of the disease and detect areas prone to exacerbation could be used to evaluate the effectiveness of ongoing periodontal therapies. Unfortunately, there is no such diagnostic method yet. A hopeful prospect is molecular diagnostics. There are numerous studies on biomarkers of periodontal disease. Point-of-care tests are also emerging. There are possibilities for processing large biological datasets (omics data). However, all of the above have a minor role in the overall single-patient diagnostics process. Despite advances in microbiological, molecular, and genetic research, the basis of periodontal diagnosis is still clinical examination enriched by the evaluation of radiological images.

Clinical laboratory diagnostics in dentistry: Application of microbiological methods

Diagnosis and treatment in dentistry are based on clinical examination of the patients. Given that the major oral diseases are of microbial biofilm etiology, it can be expected that performing microbiological analysis on samples collected from the patient could deliver supportive evidence to facilitate the decision-making process by the clinician. Applicable microbiological methods range from microscopy, to culture, to molecular techniques, which can be performed easily within dedicated laboratories proximal to the clinics, such as ones in academic dental institutions. Periodontal and endodontic infections, along with odontogenic abscesses, have been identified as conditions in which applied clinical microbiology may be beneficial for the patient. Administration of antimicrobial agents, backed by microbiological analysis, can yield more predictable treatment outcomes in refractory or early-occurring forms of periodontitis. Confirming a sterile root canal using a culture-negative sample during endodontic treatment may ensure the longevity of its outcome and prevent secondary infections. Susceptibility testing of samples obtained from odontogenic abscesses may facilitate the selection of the appropriate antimicrobial treatment to prevent further spread of the infection.

Prevalence of Periodontal Destruction and Putative Periodontal Pathogens in the Same Lebanese Family

AIM

Periodontal diseases are associated with microorganisms rich in Gram-negative species. Several studies have indicated the presence of few a periodontopathic microorganisms in the same family. A parent with severe adult periodontitis, who is infected with bacteria associated with periodontal disease, may function as a source of infection. Their children may be at a greater risk to become colonized with bacteria. The purpose of this investigation was (1) to explore the presence of three bacteria, such as Porphyromonas gingivalis (PG), Prevotella intermedia (PI), and Aggregatibacter actinomycetemcomitans (AA) in the same Lebanese family and (2) to study the clinical destruction in the same family and their relations as members of this family due to the presence of PG.

MATERIALS AND METHODS

A total of 10 families were screened; only 5 (13 females and 5 males) were selected for this study, and at least one member of the family had untreated periodontal disease, chronic or aggressive. Every participant signed an informed consent form. A total of 18 available deoxyribonucleic acid (DNA) samples were taken to analyze the presence of three periodontal bacteria.

STATISTICS

Multiple logistic regression was used for the exact methods.

RESULTS

All 18 patients showed a positive result for PI. Also, PG. was recognized in 15 patients while AA was not detected in any of the subjects. All couples suffered from periodontitis, chronic or aggressive forms, five children suffered from gingivitis, three children had no clinical manifestation, and only one suffered from localized aggressive periodontitis. The statistical analysis showed with each 1 year of increase in age, the odds of having periodontal disease multiply by 1.39, i.e., age as a risk factor for periodontal disease due to the presence of PG and sharing the same plate.

CONCLUSION

This investigation demonstrates a high prevalence of periodontal microorganisms in children and young adults of Lebanese periodontitis parents and a microbiological similarity between the children and their mothers. All these factors could be a high risk of developing periodontal disease in the future.

CLINICAL SIGNIFICANCE

This article shows that vertical transmission of microorganisms is a possible risk factor for developing periodontal disease in the offspring.

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.

Viruses in periodontal disease - a review

The purpose of this review was to evaluate the evidence supporting the hypothesis that viral infection plays a role in the development of periodontitis. An involvement in periodontal diseases has been suspected specifically for human immunodeficiency virus (HIV) and herpes viruses. An association has been demonstrated between HIV infection and some distinct forms of periodontal infection, i.e. necrotizing lesions. Furthermore, reports of increased prevalence and severity of chronic periodontitis in HIV-positive subjects suggests that HIV infection predispose to chronic periodontitis. Several studies, most of them from the same research group, have demonstrated an association of herpesviruses with periodontal disease. Viral DNA have been detected in gingival tissue, gingival cervicular fluid (GCF) and subgingival plaque from periodontaly diseased sites. In addition markers of herpesviral activation have been demonstrated in the GCF from periodontal lesions. Active human cytomegalovirus (HCMV) replication in periodontal sites may suggest that HCMV re-activation triggers periodontal disease activity. Concerns regarding sampling, methods and interpretation cast doubts on the role of viruses as causes of periodontal disease.

Clinical Responses to Mechanical Periodontal Treatment in Chinese Chronic Periodontitis Patients with and withoutActinobacillus actinomycetemcomitans

BACKGROUND

The purpose of this study was to compare 12-month clinical responses to mechanical periodontal treatment in Chinese chronic periodontitis patients at sites with and without Actinobacillus actinomycetemcomitans at baseline, and to investigate the ability of mechanical periodontal treatment to eliminate A. actinomycetemcomitans.

METHODS

Nineteen patients and a total of 76 selected sites with a mean probing depth (PD) of > or = 7 mm were studied. Whole mouth presence or absence of supragingival plaque (PI%), bleeding on probing (BOP%), probing depth (PD), and probing attachment level (PAL) were recorded at six sites per tooth at baseline and after 3, 9, and 12 months. Baseline subgingival plaque samples were taken from the deepest PD site in each quadrant using sterile paper points and were cultured on TSBV plates for 5 days in a 5% CO2-air incubator. All sites received mechanical periodontal treatment, which included oral hygiene instructions and supragingival and subgingival instrumentation with or without surgical access, with maintenance care being provided once every 3 months thereafter.

RESULTS

At baseline, A. actinomycetemcomitans was isolated in 13 of the 19 subjects (68%) and in 29 out of the 76 sampled sites (38%). At the end of 12 months, in three of the initially A. actinomycetemcomitans-positive subjects, A. actinomycetemcomitans was not detected in the sampled sites, while one subject, in whom A. actinomycetemcomitans was not initially found at the sampled sites was A. actinomycetemcomitans-positive at 12 months. Multi-level variance component models showed there was no statistically significant difference in all clinical parameters between A. actinomycetemcomitans-positive and -negative subjects (P > 0.05). In the sampled sites of the initially A. actinomycetemcomitans-positive subjects, the mean PD was reduced from 7.6 +/- 1.6 mm to 3.2 +/- 1.8 mm, the mean PAL gain was 1.4 +/- 2.0 mm, and the mean recession was 3.0 +/- 2.3 mm. The corresponding figures in the sampled sites of the initially A. actinomycetemcomitans-negative subjects were 7.5 +/- 1.6 mm to 2.7 +/- 1.0 mm, 2.3 +/- 2.6 mm and 2.4 +/- 2.2 mm for mean PD changes, PAL gain, and mean recession, respectively.

CONCLUSIONS

Favorable clinical responses to mechanical periodontal therapy may occur in Chinese chronic periodontitis patients at sites infected with A. actinomycetemcomitans. The mere detection of subgignival A. actinomycetemcomitans does not necessarily imply poorer treatment outcomes in the control of chronic periodontitis.

Can presence or absence of periodontal pathogens distinguish between subjects with chronic and aggressive periodontitis? A systematic review

OBJECTIVES

The purpose of this study was to determine to what extent the presence or absence of periodontal pathogens can distinguish between subjects with chronic and aggressive periodontitis.

MATERIAL AND METHODS

A systematic review of cross sectional and longitudinal studies providing microbiological data both from patients with chronic periodontitis (ChP) and aggressive periodontitis (AgP) at a subject level. Strict inclusion criteria were applied. The presence or absence of five microorganisms was selected as primary study parameters: Actinobacillus actinomycetemcomitans (AA), Porphyromonas gingivalis (PG), Prevotella intermedia (PI), Bacteroides forsythus (BF), and Campylobacter rectus (CR).

RESULTS

The presence or absence of AA could be evaluated in 11 papers. In seven papers the presence or absence of PG could be analysed. Subject specific data on PI were available from six studies. Two studies could be used regarding the presence or absence of BF, and two regarding CR. Sensitivity and specificity of every microbiological test were individually calculated for each selected study, assuming that the clinical diagnosis of AgP or ChP was the true status the tests attempted to detect. AgP was considered to be the condition of interest and ChP was considered equivalent to 'non-AgP'. Receiver Operator Characteristic (ROC) diagrams were constructed using these data. ROC diagrams indicated the limited discriminatory ability of all of the test parameters to identify subjects with AgP. An additional assessment showed that the highly leukotoxic variant of AA was uniquely associated with patients suffering from aggressive periodontitis. However, in a high proportion of patients diagnosed with AgP the presence of this variant could not be detected.

CONCLUSION

The presence or absence of AA, PG, PI, BF or CR could not discriminate between subjects with AgP from those with ChP.

Actinobacillus actinomycetemcomitans in a rural adult population in southern Thailand

The prevalence of Actinobacillus actinomycetemcomitans isolates was examined in a rural population of southern Thailand. Sixty individuals aged 30-39 and 50-59 years were randomly selected from a group of 363 persons, living in four villages, who had been clinically examined previously. A subgingival plaque sample was taken with a curette from the mesial aspect of the two upper and lower first molars. Each sample was dispersed in 3.3 ml of VMGA III transport medium and spread onto Trypticase Soy Broth with Bacitracin and Vancomycin (TSBV)-agar plates on the same day. After incubation in 10% CO2 for 5 days the plates were examined for typical A. actinomycetemcomitans colonies which were tested for catalase activity. Each strain was further tested for biochemical characteristics, serotyped against serotype-specific antisera a-e and ribotyped after DNA digestion using the restriction endonucleases HindIII and EcoRI. For 53 (88%) of the 60 individuals, A. actinomycetemcomitans was present in at least one subgingival sample, which is considerably higher than the prevalence in Western European adults. In 11 individuals, two or three different strains were found. Serotypes a and c were the most prevalent, and serotype b was found only once among 46 tested isolates. Eleven ribotypes were found among the 46 strains. While the same ribotype could be found among individuals of the same village, no ribotype of A. actinomycetemcomitans was unique for individuals of any one village. The study demonstrated a high prevalence of A. actinomycetemcomitans among adults of the rural population of southern Thailand and indicates that this species is present as part of the resident oral flora in this population.

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

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

Occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia in progressive adult periodontitis

BACKGROUND

Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia are the major periodontal bacteria species in most forms of progressive periodontitis in Scandinavia and the United States. The occurrence of periodontal pathogens appears to be different in subjects of different ethnic origin, and geographical factors may influence the distribution of these species.

METHODS

The occurrence of A. actinomycetemcomitans, P. gingivalis, and P. intermedia was determined using a DNA probe in progressive adult periodontitis in Chileans. Sixty patients (mean age 43.6 +/- 8 years) who had not previously received any type of periodontal therapy were selected. Bleeding on probing, probing depth, and clinical attachment level measurements were made with an automated probe. Patients were monitored at 2-month intervals until at least 2 sites exhibited > or =2 mm attachment loss. Two subgingival plaque samples from active sites were taken in 56 subjects and matched with 2 plaque samples from inactive sites in the same individuals.

RESULTS

P. gingivalis was found in 75% of active sites and in 59.7% of inactive sites in 96% of the patients (P = 0.022). P. gingivalis at high levels of detection was significantly more frequent in active sites (48.2%) than in inactive sites (31.2%) (P = 0.014). A. actinomycetemcomitans was detected in 6.25% of active sites and in 12.5% of inactive sites in 11.6% of patients. P. intermedia was found in 33% of patients and at a significantly higher proportion in active sites (49.1%) than in inactive sites (30.3%) (P = 0.006). There was a significantly higher proportion of inactive sites (34.8%) than active sites (19.6%) without any of the 3 pathogens (P = 0.016). Bleeding on probing was significantly more associated with active sites with high levels of P. gingivalis and with active sites with P. intermedia than with inactive sites.

CONCLUSIONS

A high prevalence of P. gingivalis and P. intermedia was found in adult periodontitis, and the occurrence of these bacteria appears to be higher in Chileans than in other populations. No apparent association exists between A. actinomycetemcomitans and progressive adult periodontitis in Chileans.

Early-onset periodontitis

In 1993, the 1st European Workshop on Periodontology explicitly recognized that there was insufficient knowledge to differentiate truly different forms of periodontal disease from differences in the presentation/severity of the same disease. In spite of recent progress in our understanding of periodontal diseases, the issue is far from having been resolved. Classification of periodontal diseases, therefore, remains based upon the definition of specific clinical syndromes. Early-onset periodontitis (EOP) is one such syndrome and comprises a group of pathological conditions leading to loss of periodontal tissues early in life. The notion that classifies periodontitis syndromes as "early-onset" or "adult" is primarily epidemiological in nature and is based on the observation that periodontitis is rather infrequent in children and young adults. Nevertheless, considerable epidemiological evidence indicates that periodontitis does affect children and young adults to a level of severity that may lead to premature exfoliation of primary and/or permanent teeth. Clinical presentation of periodontitis early in the life of an individual is thought to indicate that the etiologic agents have been able to cause considerable tissue damage over a relatively short period of time. It also implies either infection with highly virulent bacteria and/or a highly susceptible subject. The purpose of this review is to discuss the criteria generally utilized to classify EOP, provide the rationale to designate EOP as a distinct disease entity, and to review the evidence justifying a subclassification into particular subgroups of EOP.

Clinical and microbiological effects of adjunctive antibiotics in treatment of localized juvenile periodontitis. A controlled clinical trial

The aim of this study was to assess the clinical and microbiologic effects of the combination of amoxicillin and metronidazole therapy as an adjunct to mechanical treatment in the management of localized juvenile periodontitis. Twenty-five localized juvenile periodontitis (LJP) patients from a Brazilian population were randomly allocated into an experimental group receiving mechanical treatment and antibiotics, and a control group receiving mechanical treatment and placebo. Clinical and radiographic assessments, as well as microbiologic sampling for Actinobacillus actinomycetemcomitans, were performed at baseline and one year after the end of the treatment. At the termination of the study A. actinomycetemcomitans could be isolated from the oral cavity of all patients in the control group who harbored the bacterium at baseline and in 4 out of 8 patients in the experimental group. Both treatment modalities resulted in significant benefit on an individual basis. The experimental group, however, displayed better results than did the control group regarding gingival index (GI), probing depth (PD), clinical attachment level (CAL), and radiographic analysis of crestal alveolar bone mass, but not with respect to plaque index (PI). No serious adverse effects of the antibiotic treatment were observed in the present study.

Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in young Chinese adults

The aim of this study was to determine the presence or absence of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in young Chinese adults and to examine the A. actinomycetemcomitans isolates from positive subjects with regard to the serotype distribution, presence of the leukotoxin gene lktA and the promoter for the leukotoxin operon as well as the incidence of phage Aa phi 23. Sixty subjects, working in a knitting factory in the Province of Guangzhou, People's Republic of China, were investigated. Subgingival microbial samples were taken from both upper first molars. They were cultured both anaerobically and in 5% CO2. P. gingivalis was found in 33 subjects. On average, it constituted 7% of the total anaerobic cultivable counts. A. actinomycetemcomitans was detected in 37 subjects of which seven yielded counts > 10(5). Twenty-one subjects were positive for both organisms. A. actinomycetemcomitans serotype a was found in 9 subjects, serotype c was found in 23 and serotype e in 5. A. actinomycetemcomitans serotypes b and d were not detected in any subjects. Presence of the leukotoxin gene lktA was demonstrated for all A. actinomycetemcomitans isolates; however, none of the A. actinomycetemcomitans strains from the present study had a deletion in the promoter region of the leukotoxin operon. The results of this investigation show a high frequency of the putative periodontal pathogens P. gingivalis and A. actinomycetemcomitans and corroborate the concept that there is variation in virulence and pathogenic potential among isolates from different subjects.

The distribution and transmission of Actinobacillus actinomycetemcomitans in families with localized juvenile periodontitis

The prevalence and distribution of A. actinomycetemcomitans in families where at least one family member (proband) suffered from localized juvenile periodontitis was investigated. 25 probands with localized juvenile periodontitis (LJP) and their 78 close family members were screened for the presence of A. actinomycetemcomitans. Among these 25 families, 10 contained at least one additional family member colonized with oral A. actinomycetemcomitans. Genomic DNA from subgingival A. actinomycetemcomitans strains from each of the probands and their family members were amplified and characterized by the polymerase chain reaction (PCR) using a single primer known to distinguish A. actinomycetemcomitans strains. The PCR products from each strain were separated by electrophoresis on a 1% submarine agarose gel containing ethidium bromide and visualized by UV light transillumination. The studies showed that 41.2% of the parents and 58% of the siblings in this LJP-based population harbored the bacterium. Comparison of the PCR generated amplitypes showed that there was a wide distribution of amplitypes among the probands and immediate relatives. No clear transmission paths were observed in this specific population.

Attachment loss and serum antibody levels against autologous and reference strains of Actinobacillus actinomycetemcomitans in untreated localized juvenile periodontitis patients

Immunological data have been suggested to be a potential tool in the diagnosis, classification and monitoring of periodontal diseases. However, the role of circulating antibodies in periodontal patients is poorly understood. Patients suffering from localized juvenile periodontitis (LJP) are often reported to show high titers of serum IgG antibodies against Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), but several affected patients do not. Most studies use well-known reference strains of the bacterium for testing against the patients' sera. The aim of the present investigation was to study the relationship between serum IgG antibody levels to autologous A. actinomycetemcomitans strains and clinical attachment loss (CAL). In addition, we wanted to assess the patients' serum titers against 4 well-known reference strains of the bacterium as well as their general potential immunoglobulin response. Intravenous blood samples were taken from 23 LJP patients and 10 healthy individuals, and autologous A. actinomycetemcomitans strains were cultured from 18 of the LJP patients. CAL was measured at 4 different sites around all present teeth and assessed as a % of teeth with at least 1 site moderately > or = 2 < 5 mm) or severely (> or = 5 mm) involved. An enzyme-linked immunosorbent assay (ELISA) was performed to evaluate the serum titers of IgG antibodies to A. actinomycetemcomitans antigens. No significant correlation was found between serum IgG antibody titers to autologous strains and CAL. However, there was a trend that low responders had more moderately affected teeth than had high responders and patients with undetectable A. actinomycetemcomitans levels, which is in agreement with a hypothetically protective role of the antibodies. The total counts of immunoglobulin assessed in all participants showed that the predominant class was IgG and the reference group displayed significantly less (p < 0.05) IgG and IgG1 counts than the LJP patients. Both the reaction pattern against reference and autologous strains varied widely. We conclude that the specific antibody response against A. actinomycetemcomitans shows a weak correlation to clinical attachment levels in LJP patients.

Serum immunoglobulin G responses to various Actinobacillus actinomycetemcomitans serotypes in a young ethnographically heterogeneous periodontitis patient group

Sera from young patients with periodontal diseases have been shown to often contain highly elevated antibody levels to Actinobacillus actinomycetemcomitans, in particular serotype b. Such responses were reportedly predominated by antibodies of the immunoglobulin G2 (IgG2) subclass. The aim of this study was to investigate an ethnically diverse group of 14 early-onset periodontitis and 15 rapidly progressive periodontitis patients for the occurrence of elevated antibody titers against the five known A. actinomycetemcomitans serotypes, and to compare the patient's IgG subclass response profiles. Enzyme-linked immunosorbent assays were used to measure both total IgG and subclass specific IgG titers. Twenty-four subjects had markedly elevate total IgG levels against at least one serotype. The frequencies of high responses against serotypes a, b, c, d and e were 7, 11, 6, 4, and 4, respectively. Elevated antibody responses were predominated by IgG2, regardless of the serotype to which the response was directed. The serotype specificity of the host responses was further investigated by competitive binding studies with serotype-specific monoclonal antibodies. Twelve sera were found to contain antibodies capable of strongly inhibit the binding of monoclonal antibodies against a single serotype; four other sera had antibodies against epitopes of two, and one serum against those of three serotypes. The findings document broad serotype diversity in an ethnically heterogeneous group of patients and indicate that strong antibody responses to A. actinomycetemcomitans are predominated by IgG2 regardless of the serotype of the infective agent.

Localized juvenile periodontitis and Actinobacillus actinomycetemcomitans in a Brazilian population

Localized juvenile periodontitis (LJP) has been used as a model for studying periodontal disease, and its prevalence is considered to be higher in third-world countries (0.3-8%) than in industrialized countries (0.1%). Mostly, the disease has been associated with Actinobacillus actinomycetemcomitans (A.a.) but lack of association has also been reported. The aim of this study was to identify LJP patients in geographically different Brazilian populations and assess the presence of A.a. in their periodontal lesions. 7843 children, 12-19-years of age, from the cities of Rio de Janeiro, Votorantim and Belo Horizonte were screened, and LJP patients were identified by strict clinical and radiographical criteria. A final LJP prevalence of 0.3%, with a 99% confidence interval between 0.16% to 0.47%, was found. The prevalence in the subpopulations varied between 0.1-1.1% in the different areas. Subgingival bacterial samples were obtained from the oral cavity of 25 patients and their family members. 80% of these patients, 39.5% of their family members, 35.3% of their parents, and 43.9% of all siblings were culture positive for A.a. All but one of the families had at least one member in addition to the patient who was culture positive for A.a. In 3 families, > 1 member showed radiographic and clinical signs of LJP. 30% of non-LJP subjects coming from one of the areas with higher LJP prevalence harbored A.a. We conclude that LJP is highly associated with A.a. in this Brazilian population.

Comparison between 2 surgical techniques for the treatment of early-onset periodontitis

The objective of this study was to compare guided tissue regeneration (GTR) and osseous surgery (OS) in treatment of early-onset periodontitis. Six patients participated in this research, presenting 15 paired defects randomly assigned to 1 of the surgical groups. Pre-operative clinical parameters (probing depth and attachment loss) between the two groups were not significantly different. Results 1 year following surgery showed probing depth reduction (2.60 +/- 1.30 mm) and clinical attachment gain (2.20 +/- 1.42 mm) were significantly greater in the GTR group than in the osseous surgery group (P < 0.05). The gingival recession was -0.53 +/- 0.52 mm and -0.40 +/- 0.74 mm for the osseous and the guided tissue regeneration group, respectively (no significant difference, P > 0.05). Radiographic analysis by two techniques illustrated that the interproximal alveolar bone changes at the margin of the defects in the OS group were slightly decreased (-0.20 +/- 1.15; 0.26 +/- 0.74 mm) and those in the GTR group were slightly increased (0.16 +/- 0.96; 0.26 +/- 0.68 mm), but showed no significant difference (P > 0.05). The base of the GTR-treated defects showed significant increase in bone fill (1.67 +/- 0.68; 1.97 +/- 0.74 mm; P < 0.05). At a follow-up reexamination 1 year following surgery, oral hygiene and gingival conditions in both groups were at satisfactory levels and gingiva was clinically healthy throughout the entire study period, except the first 4 to 6 weeks following surgery.

Occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in juvenile periodontitis

The occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in subgingival plaque in 24 juvenile periodontitis patients was determined using DNA probe. 36 samples of subgingival plaque from 36 pockets having > or = 6 mm depth, > or = 3 mm of loss of attachment, and bleeding on probing and/or suppuration were taken from 18 patients with localized juvenile periodontitis (LJP, age range 12-24 years); and 12 samples from 6 patients with generalized juvenile periodontitis (GJP, age range 23-26 years). As control, an equal numbers of samples from healthy sites in the same patients were studied. P. gingivalis was found in 17 of 18 LJP patients, and in 31 of 36 diseased sites in those patients. P. intermedia was found in 15 out of the 18 LJP patients and in 28 of the 36 diseased sites. A. actinomycetemcomitans was present in 7 of the 18 LJP patients, and in 9 of the 36 diseased sites, and was not found in any GJP patients. All GJP patients had P. gingivalis (11 out of 12 diseased sites) and P. intermedia (all of the diseased sites). None of the three bacterial species was detected in healthy sites of GJP patients, and were found in healthy sites in only 2 of 18 LJP patients. The high prevalence and high levels of P. gingivalis and P. intermedia found in the LJP and GJP patients studied, suggest that there are populations affected by juvenile periodontitis in which this type of periodontitis is more associated with these species than with A. actinomycetemcomitans.

Temperate bacteriophages are common among Actinobacillus actinomycetemcomitans isolates from periodontal pockets

Actinobacillus actinomycetemcomitans is a suspected etiologic agent in destructive periodontal diseases. The detection of bacteriophages in A. actinomycetemcomitans in the subgingival plaque of patients with rapidly destructive forms of periodontitis led to the hypothesis that bacteriophage infection might increase the virulence of this bacterium (19). A. actinomycetemcomitans was isolated from 68 subjects from the Netherlands and Switzerland with localized juvenile periodontitis, rapidly progressing periodontitis, or adult periodontitis, and was tested for the presence of temperate bacteriophage with the overlay plate technique. More than half of the A. actinomycetemcomitans strains were found to release bacteriophage which formed individual plaques on indicator strains. Electron microscopy of preparations from 7 strains revealed virions with an icosahedral head and a contractile tail typical for double-stranded DNA bacteriophages. The presence of A. actinomycetemcomitans carrying temperate bacteriophage was not correlated with the composition of the subgingival microflora nor with the clinical form of periodontal disease. Destructive periodontal disease of subjects with phage-carrying A. actinomycetemcomitans was not more severe than of subjects with phage-free A. actinomycetemcomitans as determined by several clinical parameters. In contrast, the pocket depth and the attachment loss were significantly lower for adult periodontitis subjects with phage-carrying A. actinomycetemcomitans. It seems unlikely that the frequently occurring temperate bacteriophages increase significantly the virulence of A. actinomycetemcomitans.

Occurrence of certain bacterial species and morphotypes in juvenile periodontitis in Chile

The occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Eikenella corrodens, Fusobacterium nucleatum, Campylobacter rectus, Capnocytophaga species, and certain bacterial morphotypes was determined in 18 affected and 18 unaffected sites in 10 localized juvenile periodontitis (LJP) patients, and in 10 affected and 10 unaffected sites in 5 generalized juvenile periodontitis (GJP) patients. The subgingival proportion of the 7 bacterial species was determined by selective and nonselective culturing. The results showed that when considering the pure prevalence of bacteria ( > 0%) there were significant differences (P < 0.05) in the subgingival plaque microflora of the affected sites versus those of the unaffected sites for P. gingivalis, A. actinomycetemcomitans, P. intermedia, E. corrodens, C. rectus, and F. nucleatum in LJP, and for P. gingivalis, P. intermedia, and F. nucleatum in GJP. The mean proportions of cocci, motile rods and spirochetes were also significantly different (P < 0.05) in affected sites compared to unaffected sites. Capnocytophaga sp, F. nucleatum, P. intermedia, and E. corrodens were found in more than 75% of affected sites in LJP. When taking the approach that an organism, to be associated with periodontal disease, has to be detected above a certain minimum threshold, the results indicated that bacteria most frequently associated with LJP and GJP in Chile are P. gingivalis (66% of LJP and 80% of GJP affected sites), and A. actinomycetemcomitans (44% of LJP and 50% in GJP affected sites). Different bacterial species may be judged to be important in the disease process depending upon whether a pure bacterial prevalence, or a prevalence above a certain detection level, is considered.

The effect of plaque control in subjects with shallow pockets and high prevalence of periodontal pathogens

In a previous study, it was shown that professional tooth cleaning 3x a week had a significant influence on the subgingival microbiota of shallow pockets. The purpose of this investigation was to study the effect of a single episode of full-mouth supragingival cleaning and oral hygiene instructions in subjects with minimal periodontal disease but high prevalence of putative periodontal pathogens. 10 subjects from Arabic countries, aged between 22 and 48 years, which had previously not been exposed to any dental care other than extractions and fillings, were selected for this trial. DNA probe analysis of subgingival samples, taken in the deepest pocket of each quadrant, showed presence of Porphyromonas gingivalis and Prevotella intermedia in all patients, and presence of Actinobacillus actinomycetemcomitans in 5 individuals. 85% of all samples were P. gingivalis-positive, 83% were positive for P. intermedia and 43% were A. actinomycetemcomitans-positive. 4 weeks after treatment, subgingival microbiological samples were again taken in the same sites. In 8 patients, P. gingivalis could still be detected after treatment. However, the number of P. gingivalis positive samples was reduced from 85% to 38%, and the bacterial counts in positive samples were markedly lower than at baseline. P. intermedia-positive samples were obtained from 7 patients after treatment. 33% of all samples were still positive, but showed markedly reduced bacterial counts. 4 patients still yielded A. actinomycetem comitans-positive samples after treatment. Here, the number of positive samples was reduced to 15%, and the bacterial counts were barely exceeding the detection limit.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative detection frequency of 6 putative periodontal pathogens in Sudanese and Norwegian adult periodontitis patients

Twenty-five sudanese and 18 norwegian adult periodontitis patients were selected to participate in this study. The purpose was to compare cultivation results of Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, and Capnocytophaga species as well as various enteric rods in both populations. In addition, DNA probe analysis was used to identify P. gingivalis, P. intermedia, A. actinomycetemcomitans, F. nucleatum, and Bacteroides forsythus in the Sudanese patients and results were compared with those obtained by cultivation. The paper point technique was used to sample 99 sites in the Sudanese group (4 paper points/site) and 119 sites in the Norwegian patients (3 paper points/site). In the Sudanese subjects, the fourth paper point was used for the DNA probe analysis. The chi-square test and the Wilcoxon signed rank test were used to test for statistically significant differences between Sudanese and Norwegian cultivation results as well as between cultivation and DNA results in the Sudanese group. Cultivation results indicated that the Sudanese subjects had significantly lower prevalence of P. gingivalis, P. intermedia, and F. nucleatum (P < 0.01), significantly higher prevalence of Capnocytophaga species (P < 0.05), and similar prevalence of A. actinomycetemcomitans. Almost all Sudanese subjects tested positive for various enteric rods, while none of the Norwegians did so. The extent to which unrestricted use of antibiotics and transport media influenced the levels of enteric species is not known, however.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation frequency and serotype distribution of mutans streptococci and Actinobacillus actinomycetemcomitans, and clinical periodontal status in Finnish and Vietnamese children

The isolation frequency and serotype distribution of mutans streptococci and A. actinomycetemcomitans (A.a.) were investigated in a group of Finnish (n = 16) and Vietnamese (n = 16) children, matched by sex, age, and caries status. In the Vietnamese children, the isolation frequencies were higher than in the Finnish children: 100%/62% for mutans streptococci and 78%/13% for A.a. Isolates (n = 3-8) from plaque and saliva were serotyped by immunodiffusion technique using serotype-specific antisera against serotypes c, e, f, d, and g for mutans streptococci and a, b, c, d, and e for A.a. The distribution of mutans streptococci serotypes in Finnish/Vietnamese children was: c 100%/50%; e 10%/31%; d 0%/56%; g 20%/38%. The frequency of plural serotypes was 30%/75%, respectively. In the Vietnamese group the serotype distribution of A.a. was: a 36%, b 27%, and c 63%; 45% of children carried two serotypes. One Finnish child harbored serotype a and one serotype b. The mean percentage of bleeding gingival sites was 7.4 in the Finnish and 15.1 in the Vietnamese group. Calculus and clinically deepened gingival pockets were more frequent findings in the Vietnamese children. The results indicate considerable differences in bacteriologic status and in clinical periodontal status between these Finnish and Vietnamese children.

Subgingival distribution of A. actinomycetemcomitans in periodontitis

This investigation developed an experimental design that (1) detailed the distribution of A. actinomycetemcomitans in subgingival plaque related to the level of serum antibody to this pathogen; (2) used broad based subgingival plaque sampling to allow a definition of the distribution of A. actinomycetemcomitans infection in periodontitis patients; (3) described the distribution of A. actinomycetemcomitans serotypes in patients and within sites; and, (4) assessed how this infection impacted upon local clinical symptoms of disease. We noted a significant positive relationship between the level of IgG anti-A. actinomycetemcomitans antibody and the frequency of teeth infected until nearly 13 teeth demonstrated an infection. Furthermore, the results showed a generally negative relationship between the antibody level and the burden of A. actinomycetemcomitans in the infected sites. Interproximal sites associated with first molar teeth were the predominant sites for subgingival colonization; incisors were also frequently infected in this population. The first molar teeth also exhibited the greatest level of A. actinomycetemcomitans, while the incisors demonstrated a high level of A. actinomycetemcomitans in individual sites. The results clearly indicated the majority of the sites sampled were colonized by a single serotype of A. actinomycetemcomitans. We detected A. actinomycetemcomitans nearly 2 x times more frequently and a significant increase in the proportion of A. actinomycetemcomitans was found in samples obtained from teeth with bleeding on probing. The results also showed a significant trend for both pocket depth and attachment levels to be related to the presence and proportion of A. actinomycetemcomitans in the subgingival plaque. These findings detail the microbiological, immunological and clinical characteristics of a unique subset of periodontitis patients that appear to exhibit disease associated (caused?) with A. actinomycetemcomitans infection irrespective of clinical categorization. The results support a unique distribution of this microorganism in the subgingival ecology that is related to active host immune responses and clinical presentation of the tooth.

Transmission of Actinobacillus actinomycetemcomitans in families of adult periodontitis patients

At present Actinobacillus actinomycetemcomitans is regarded as an important microorganism in the etiology of some forms of periodontitis. The purpose of the present investigation was to study the number of Restriction Endonuclease Analysis (REA)-types present in the oral cavity of A. actinomycetemcomitans positive subjects and to study the possibility of transmission of A. actinomycetemcomitans within families of adult periodontitis patients. DNA of A. actinomycetemcomitans isolates was digested with a combination of the restriction endonucleases PstI and BamHI, after which the DNA fragments were separated by agarose gel-electrophoresis. To study the number of REA-types, multiple A. actinomycetemcomitans isolates obtained from 8 different sites in the oral cavity of five subjects were typed. The results showed that in most cases only one REA-type is present. In the 13 families investigated in 4 of the 26 children (15%) and in 1 of the 13 spouses (8%) of the adult periodontitis patients an indistinguishable REA-type was found within the families. This suggests that also in the case of adult periodontitis transmission of A. actinomycetemcomitans is possible, but does not seem to occur easily.

Identification of Actinobacillus actinomycetemcomitans: polymerase chain reaction amplification of lktA-specific sequences

Actinobacillus actinomycetemcomitans has been strongly implicated in the etiology of localized juvenile periodontitis. Techniques used in the identification of this periodontal pathogen include cultural, biochemical, immunological and DNA hybridization analysis. In this study, we report the use of polymerase chain reaction (PCR) to amplify unique sequences of A. actinomycetemcomitans. Specific oligonucleotide primers LKT2 and LKT3 were designed to hybridize to the A. actinomycetemcomitans lktA gene, which encodes leukotoxin, a putative A. actinomycetemcomitans virulence factor. The LKT2 and LKT3 primers amplified lktA-specific sequences from all 12 A. actinomycetemcomitans strains tested. In another set of experiments, 13 other bacterial species, most of which are normal residents of the oral cavity, were tested with these primers. These PCR amplifications also contained 2 additional primers, RRN4 and RRN5, which served as positive controls; RRN4 and RRN5 were designed to amplify specific sequences of eubacterial 16S ribosomal DNA (rDNA). PCR amplifications of all bacterial species tested, including A. actinomycetemcomitans, yielded 16S rDNA-specific DNA fragments. Furthermore, each bacterial species tested, with the exception of A. actinomycetemcomitans, failed to amplify lktA sequences. The LKT and RRN primers were used in further PCR experiments to detect A. actinomycetemcomitans directly from gingival fluid samples. The results clearly demonstrate the simplicity, rapidity, specificity and accuracy of the LKT primers in the identification of A. actinomycetemcomitans.

Seroclassification of hitherto nontypeable Actinobacillus actinomycetemcomitans strains: evidence for a new serotype e

Serotyping of 89 Actinobacillus actinomycetemcomitans isolates by indirect immunofluorescence with serotype-specific monoclonal antibodies yielded 10 nontypeable strains. The aim of the present study was to re-evaluate the seroclassification of these strains with a different assay. Electroblotted antigens of nontypeable isolates and selected reference strains were immunostained with 37 human sera containing high antibody titers to A. actinomycetemcomitans. Such immunoblots typically showed an immunodominant, serotype-specific antigen smear. Twelve human sera were found to recognize specifically serotype a, 10 serotype b and 9 serotype c. Three sera contained antibodies to 2 or all 3 serotype antigens; 3 sera had no activity to any reference strain smear antigen. There was complete agreement between the seroclassification of the reference strains with the monoclonal and the polyclonal reagents. Seven of the 10 strains, nontypeable with monoclonal antibodies, could also not be typed by the human sera. Of the remaining 3 strains, one belonged to a previously unrecognized serovar of serotype a, and 2 isolates expressed a novel smear antigen detected by the 3 human sera containing no antibodies to the serotype a, b, or c antigens. We propose that these 2 strains be assigned to a new A. actinomycetemcomitans serotype, designated serotype e.

Titer and subclass distribution of serum IgG antibody reactive with Actinobacillus actinomycetemcomitans in localized juvenile periodontitis

Most patients with localized juvenile periodontitis (LJP) manifest serum IgG antibodies specifically reactive with antigens of Actinobacillus actinomycetemcomitans serotype b (Aa-b). Whether these antibodies are protective, destructive, or irrelevant to the progress of the disease remains unclear. We report results of studies aimed at assessing the subclass IgG responses in 35 LJP patients and 35 periodontally normal control subjects using well-characterized monoclonal antibody subclass reagents in an enzyme-linked immunosorbent assay. Our data show that the mean value for total IgG reactive with antigens of Aa-b was more than sevenfold higher for patients than for normal control sera (2349.6 micrograms/ml for patients vs 332.2 micrograms/ml for controls). Individual patients and control subjects were classified as high- or low-titer, using twice the median value for total anti-Aa-b IgG in control sera as the cutoff. Of 35 patients, 26 (74%) were high-titer, and 9 (26%) were low-titer. This compares to 5 normal control subjects (14%) high-titer and 30 (86%) low-titer. IgG2 accounted for the major quantitative response in both patients and control subjects. Indeed, the mean IgG2 values for both concentration and percentage of total specific IgG were greater than the combined values for specific anti-Aa-b IgG1, IgG3, and IgG4. Of the 26 high-titer sera, IgG2 predominated in 24, with IgG1 and IgG3 predominating in 1 each; IgG2 predominated in only 2 of the low-titer sera.

Periodontal pathogens in the shallow pockets of immigrants from developing countries

The aim of this study was to examine the distribution of typical periodontitis-associated microorganisms in refugees arriving from non-industrialized countries, and to relate the presence of these organisms to the periodontal condition of the subjects. Thirty males between 35-44 years of age were surveyed. Dental plaque, calculus, gingivitis, loss of attachment, and probing depths were recorded for all surfaces. A total of 90 microbiological samples were taken with paper points from mesial sites of teeth 16, 36 and 41. Microbiological test sites were grouped by probing depths and loss of attachment. Only 16.8% of all surfaces had probing depths > 3 mm, although 90.7% of surfaces had loss of attachment > 1 mm. Twenty-one sites with obvious periodontal destruction (PD > 3 mm, LA > 2 mm) showed the greatest recovery of Porphyromonas gingivalis (66.7%). However, 51 sites with minimal periodontal disease (PD < or = 3 mm, LA < 2 mm) and with no gingival recession also showed a relatively high detection frequency of P. gingivalis (34.1%). Twenty-four of these samples came from 12 patients with no pockets > 5 mm and with less than 10% of all sites yielding pockets > 3 mm. The detection frequencies of Prevotella intermedia (91.6%), Bacteroides forsythus (25.0%), Wolinella spp. (33.3%) and Actinobacillus actinomycetemcomitans (50.0%) were similar in these sites compared with periodontitis sites. Morphologically distinct isolates, from 19 individuals positive for A. actinomycetemcomitans, were serotyped by indirect immunofluorescence.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteriological study of juvenile periodontitis in China

The predominant cultivable bacteria associated with juvenile periodontitis (JP) in China were studied for the first time. Subgingival plaque samples were taken on paper points from 23 diseased sites in 15 JP patients and from 7 healthy sites in 7 control subjects. Serially diluted plaque samples were plated on nonselective blood agar and on MGB agar, a selective medium for the isolation of Actinobacillus actinomycetemcomitans. Fifteen or more isolated colonies from each sample (in sequence without selection) were purified for identification. The results indicated that the microflora in healthy sulci of the 7 control subjects was significantly different from that in diseased sites of JP patients. The predominant species in healthy sulci were Streptococcus spp. and Capnocytophaga gingivalis. In JP patients, Eubacterium sp. was found in significantly higher frequency and proportion. Actinobacillus actinomycetemcomitans was not detected in any samples. It appears that this species is not associated with juvenile periodontitis in China.

Serum antibody in Actinobacillus actinomycetemcomitans-infected patients with periodontal disease

This study was designed to (i) delineate the characteristics of serum antibody responses to Actinobacillus actinomycetemcomitans in patients with periodontitis who are infected with A. actinomycetemcomitans; irrespective of disease classification; (ii) assess the relationship of the elevated antibody levels to colonization of the oral cavity by A. actinomycetemcomitans; and (iii) describe the serotype distribution of A. actinomycetemcomitans and antibodies to the microorganism in infected patients with various clinical classifications. To compare the levels of various isotype-specific antibodies to the different antigens, studies were performed that allowed quantitation of each isotype-specific antibody in a human reference standard. By using this reference standard, it was shown that the levels of immunoglobulin G (IgG), IgM, and IgA responses to A. actinomycetemcomitans were similar among the infected patients, irrespective of disease classification. Also, we demonstrated that the serum antibody response to serotype b was quantitatively greater in all isotypes. Our findings indicate that b was the most frequent A. actinomycetemcomitans serotype detected in the patients and appears to be capable of initiating a substantial serum IgG antibody response that may contain cross-reactive antibodies to other serotypes of A. actinomycetemcomitans. Generally, in cases in which the response to a single serotype was elevated, only that type of A. actinomycetemcomitans was detected in the plaque. Individuals exhibiting elevated antibodies to multiple serotypes were most consistently colonized by the serotype b microorganism. This study represents the first report detailing the distribution of IgG subclass antibodies to A. actinomycetemcomitans in periodontal disease. The results demonstrated that the primary responses of patients with periodontitis to A. actinomycetemcomitans were of the IgG1 and IgG3 subclasses, which is consistent with elicited responses to protein antigens. In contrast, the primary subclass response in normal subjects was limited to the IgG2 subclass and may represent broader cross-reactivity to polysaccharide antigens-lipopolysaccharide from the bacteria.

The role of Actinobacillus actinomycetemcomitans in periodontal disease

The different forms of periodontitis are all associated with a distinct bacterial flora. However, a clear relationship is described between localized juvenile periodontitis (LJP) and Actinobacillus actinomycetemcomitans. Eleven LJP patients all harboured A. actinomycetemcomitans. The arrest of LJP is often impossible, due to the inability to eliminate A. actinomycetemcomitans. Therefore, antibiotic treatment was introduced in combination with the initial treatment. We studied the effect of periodontal treatment on the microflora and clinical status of periodontal disease patients using different therapies. Group 3 attained the best results (initial treatment and a combination metronidazole and amoxicillin), the group to eliminate A. actinomycetemcomitans effectively.

Black-pigmented Bacteroides species and Actinobacillus actinomycetemcomitans in subgingival plaque of adult Kenyans

A microbiological study was performed of the subgingival plaque on 2 sites in each of 20 adults originating from a rural area 40 km outside Nairobi, Kenya. The recovery rate of B. gingivalis was 70%, of B. intermedius 100% and of A. actinomycetemcomitans 40% of the subjects, and 50%, 90% and 28%, respectively, of the sites. The isolated strains exhibited similar biochemical characteristics and antibiotic susceptibility pattern as type strains of these species. The high recovery rate of these 3 bacterial species in adult Kenyans was a rather surprising finding, since pathological pocketing was found only sporadically. Furthermore, the results of 2 methodological approaches tested demonstrated that such microbiological studies can be carried out in countries with limited laboratory facilities.

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.

Human serum antibody responses to oral microorganisms. IV. Correlation with homologous infection

Recent microbiological studies of periodontal disease in humans have supported the concept of a specific bacterial etiology. While individual agents have not been unequivocally identified, numerous Gram-negative members of the subgingival microflora have been implicated. In addition, elevations in systemic antibody responses have been consistent with certain oral microorganisms being involved in an infectious process associated with the disease. This report delineates the relationship between elevated systemic antibody levels and oral colonization with the homologous microorganism at active disease sites. Thirty-four patients with various types of periodontal disease were examined. Using ELISA, each patient was shown to have an elevated antibody response to at least one organism from a battery of 18 oral microorganisms that were tested. Subsequently, subgingival plaque was cultured from disease-active and -inactive sites of each subject. The results demonstrated that the same microorganism to which the individual exhibited elevated serum antibody responses was detected in nearly 55% of the disease-active sites, while only 18% of the inactive sites showed the microorganism. Certain microorganisms including Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, Eikenella corrodens and Wolinella recta were primarily or exclusively correlated with active disease lesions. These findings support the hypothesis that elevated systemic antibodies to periodontopathic bacteria are reflective of subgingival colonization and exist as a response to a bacterial infection at disease-active sites.

Purification and biochemical properties of a bacteriocin from Actinobacillus actinomycetemcomitans

Extracts of certain strains of Actinobacillus actinomycetemcomitans are inhibitory to strains of Streptococcus sanguis such as S. sanguis ATCC 10556. The isolation of a protein from an A. actinomycetemcomitans sonic extract which copurified with the inhibitory activity was accomplished by preparative isoelectric focusing, Sephadex G-100 gel filtration chromatography, and preparative polyacrylamide gel electrophoresis (PAGE). The resulting isolated protein, which focused at a pH of 6.1 to 6.3, appeared as a single band in anionic nondissociating PAGE analysis. This protein could be dissociated into two subunits with molecular weights of 50,000 and 70,000, which were resolvable by PAGE analysis. A 1,758-fold increase in specific activity was seen in the purified inhibitory protein compared with the crude sonic extract starting material. The properties of the inhibitory activity in the A. actinomycetemcomitans extract are characteristic of a bacteriocin. Accordingly, we propose the name actinobacillicin for the inhibitory protein.

Treatment of localized juvenile periodontitis (periodontosis). A review

Localized juvenile periodontitis is a disease of the adolescent periodontium characterized by rapid alveolar destruction around molar and incisor teeth of the permanent dentition. Early treatment methods were variable and often empirical due to lack of knowledge concerning etiology. Elucidation of factors associated with the disease has led to different therapeutic approaches. A comprehensive review of these modalities is presented.

The non-specific theory in microbial etiology of inflammatory periodontal diseases

In the absence of toothbrushing, the gingival crevice is colonized by a complex indigenous microflora causing gingivitis, a non-specific inflammation. Subgingival plaque may develop by downgrowth into the inflamed pocket of those micro-organisms from supragingival plaque which can multiply there. By direct microscopy, increased proportions of motile rods and spirochetes have been found in diseased pockets. Cultures on selective media have demonstrated increased prevalence of various gram-negative rods. Cultures on non-selective media have revealed the complexity and variability of the subgingival microflora, comprising more than 200 species. Destructive periodontitis is the result of subgingival colonization, which is favored by such ecological changes as plaque accumulation, gingivitis, and gingival exudate. These changes increase the numbers of micro-organisms and alter their proportions, but no single species appears in active sites which is not also commonly present in inactive sites. The subgingival micro-organisms have several virulence factors which promote colonization of the pockets, destroy host defense mechanisms, and provoke inflammation. It appears that different combinations of indigenous bacteria, rather than just a single species, can produce the pathogenic potential necessary to cause progression from gingivitis to destructive periodontitis.