Actinobacillus actinomycetemcomitans and clinical periodontal status in Finnish juvenile periodontitis patients

Microbiology of aggressive periodontitis

For decades, Aggregatibacter actinomycetemcomitans has been considered the most likely etiologic agent in aggressive periodontitis. Implementation of DNA-based microbiologic methodologies has considerably improved our understanding of the composition of subgingival biofilms, and advanced open-ended molecular techniques even allow for genome mapping of the whole bacterial spectrum in a sample and characterization of both the cultivable and not-yet-cultivable microbiota associated with periodontal health and disease. Currently, A. actinomycetemcomitans is regarded as a minor component of the resident oral microbiota and as an opportunistic pathogen in some individuals. Its specific JP2 clone, however, shows properties of a true exogenous pathogen and has an important role in the development of aggressive periodontitis in certain populations. Still, limited data exist on the impact of other microbes specifically in aggressive periodontitis. Despite a wide heterogeneity of bacteria, especially in subgingival samples collected from patients, bacteria of the red complex in particular, and those of the orange complex, are considered as potential pathogens in generalized aggressive periodontitis. These types of bacterial findings closely resemble those found for chronic periodontitis, representing a mixed polymicrobial infection without a clear association with any specific microorganism. In aggressive periodontitis, the role of novel and not-yet-cultivable bacteria has not yet been elucidated. There are geographic and ethnic differences in the carriage of periodontitis-associated microorganisms, and they need to be taken into account when comparing study reports on periodontal microbiology in different study populations. In the present review, we provide an overview on the colonization of potential periodontal pathogens in childhood and adolescence, and on specific microorganisms that have been suspected for their role in the initiation and progression of aggressive forms of periodontal disease.

Learned and unlearned concepts in periodontal diagnostics: a 50-year perspective

In the past 50 years, conceptual changes in the field of periodontal diagnostics have paralleled those associated with a better scientific understanding of the full spectrum of processes that affect periodontal health and disease. Fifty years ago, concepts regarding the diagnosis of periodontal diseases followed the classical pathology paradigm. It was believed that the two basic forms of destructive periodontal disease were chronic inflammatory periodontitis and 'periodontosis'- a degenerative condition. In the subsequent 25 years it was shown that periodontosis was an infection. By 1987, major new concepts regarding the diagnosis and pathogenesis of periodontitis included: (i) all cases of untreated gingivitis do not inevitably progress to periodontitis; (ii) progression of untreated periodontitis is often episodic; (iii) some sites with untreated periodontitis do not progress; (iv) a rather small population of specific bacteria ('periodontal pathogens') appear to be the main etiologic agents of chronic inflammatory periodontitis; and (v) tissue damage in periodontitis is primarily caused by inflammatory and immunologic host responses to infecting agents. The concepts that were in place by 1987 are still largely intact in 2012. However, in the decades to come, it is likely that new information on the human microbiome will change our current concepts concerning the prevention, diagnosis and treatment of periodontal diseases.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Characteristics of Periodontal Microflora in Acute Myocardial Infarction

BACKGROUND

Periodontitis has been linked to increased risk of cardiovascular diseases. Systemic reactions associated with cardiovascular events may depend on characteristics of the subgingival microflora in periodontitis. Our objectives were to compare the numbers of cultivable bacteria, composition of subgingival microflora and clonal distribution of Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) in two groups of patients with generalized chronic periodontitis (GCP), one with an acute myocardial infarction (AMI-GCP) and the other one without AMI (non-AMI-GCP).

METHODS

In all, 150 dentate individuals were screened for suitability to this study. Subgingival bacterial samples were collected from 11 AMI-GCP and 11 non-AMI-GCP patients who had been selected using strict inclusion criteria in an attempt to exclude confounding factors and to increase comparability of periodontal conditions by matching for periodontal probing depths and attachment levels. Culture methods were used to determine the total viable counts and occurrence and proportions of six periodontal bacterial species and yeasts. Polymerase chain reaction (PCR) technique was used to detect A. actinomycetemcomitans and Porphyromonas gingivalis (P. gingivalis). Intraspecies characterization of A. actinomycetemcomitans included serotyping and genotyping.

RESULTS

The mean proportions of P. gingivalis (P = 0.05) and Tannerella forsythensis (T. forsythensis) (P = 0.01) were significantly lower, but the numbers of Micromonas micros (M. micros) and A. actinomycetemcomitans were up to nine times higher and the mean total number of cultivable bacteria per sample higher (P <0.01) in AMI-GCP than in non-AMI-GCP.

CONCLUSION

The findings that no target subgingival species were overrepresented but the total bacterial number was higher in AMI-GCP than non-AMI-GCP patients may provide support to the hypothesis that elevated numbers of bacteria in close vicinity to sterile parenteral area present a risk for systemic health.

Clonal distribution of natural competence in Actinobacillus actinomycetemcomitans

The competence for natural transformation was investigated in 67 Actinobacillus actinomycetemcomitans strains. The transformation assays were performed with both cloned DNA fragments and chromosomal markers of A. actinomycetemcomitans. Competence was found in 12 of 18 serotype a strains, 0 of 21 serotype b strains, 0 of 14 serotype c strains, 3 of 6 serotype d strains, 3 of 4 serotype e strains, 0 of 3 serotype f strains, and 0 of 1 nonserotypeable strain. The transformation frequencies varied from 5 x 10(-3) to 4 x 10(-6) (median 1.5 x 10(-4)). The distribution pattern of natural competence is concordant with the major clonal lineages of A. actinomycetemcomitans. Serotype a strains are predominantly competent for transformation, while serotypes b and c strains are apparently non-competent.

Subgingival microflora in Turkish patients with periodontitis

BACKGROUND

No information exists on periodontitis-associated subgingival microbiota from Turkey. We determined the occurrence, interspecies relationships, and clonal characteristics for a group of periodontal bacteria in a Turkish study population.

METHODS

Subgingival microbial samples were obtained from patients with localized (LAgP, N = 18) or generalized (GAgP, N = 17) types of aggressive periodontitis, generalized chronic periodontitis (GCP, N = 14), and non-periodontitis subjects (N = 20). Culture methods were used to recover 6 periodontal bacterial species and yeasts, and a polymerase chain reaction technique was used to detect Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. Intraspecies characterization of A. actinomycetemcomitans was carried out by serotyping and genotyping.

RESULTS

All species, except for Micromonas micros (formerly Peptostreptococcus micros) occurred more frequently (P < 0.05) in periodontitis than non-periodontitis subjects. Detection frequencies for Tannerella forsythensis (formerly Bacteroides forsythus) and Campylobacter rectus differed among the periodontitis subgroups; the lowest frequency occurred in LAgP. The mean proportions of A. actinomycetemcomitans, P. gingivalis, and C. rectus were higher (P < 0.008) in GAgP than in non-periodontitis subjects. Significant positive associations were seen between 7 of the 22 possible combinations (P < 0.05). A. actinomycetemcomitans serotype c (34%) and non-serotypeable isolates (34%) were the most common antigenic types among the 305 strains analyzed. Eleven arbitrarily primed (AP)-PCR genotypes were distinguished among 273 isolates from 29 subjects. Yeasts were found in 23% of the 69 subjects.

CONCLUSIONS

The results on the Turkish study population were generally in line with earlier reports on the occurrence and interspecies relationships of certain bacteria in periodontitis. However, A. actinomycetemcomitans was not overrepresented in LAgP, and the serotype distribution resembled that reported from the East. The high frequency of non-serotypeable isolates suggests local characteristics of the species.

Clinical and microbiologic study of periodontitis associated with Kindler syndrome

BACKGROUND

Little is known about the onset and prevalence of periodontal disease in patients with the rare Kindler syndrome, a genodermatological disorder. This study investigated the level of clinical periodontal attachment in relation to age and presence of putative periodontopathogenic bacteria in individuals with Kindler syndrome.

METHODS

Eighteen individuals diagnosed with Kindler syndrome and 13 control subjects, aged 4 to 37 years, from rural Panama received a limited clinical periodontal examination. Subgingival samples were collected for identification of putative periodontal pathogens by polymerase chain reaction.

RESULTS

Mild to severe gingivitis was a common finding in all adults of the study population. Seventy-two percent (13/18) of the Kindler patients and 46% (6/13) of the control subjects showed mild to severe periodontal disease (P = 0.001, chi-square test). The onset of periodontitis was earlier and the progression occurred at a faster rate in the Kindler group. There was a strong correlation (r = 0.83) between the level of attachment loss and age in the Kindler group and a weaker correlation (r = 0.66) in the control group. The appearance of gingival tissues suggested atypical periodontitis with spontaneous bleeding and fragile, often desquamative, gingiva. In periodontitis patients, Porphyromonas gingivallis and Diallster pneumosintes tended to occur more frequently in control individuals compared to those with Kindler syndrome.

CONCLUSIONS

In the Kindler group, periodontitis had an onset in early teenage years and progressed more rapidly compared to non-Kindler individuals of the same geographic and ethnic group. Clinical and microbiological findings suggest atypical periodontitis in Kindler patients. We propose to include Kindler syndrome in the category of medical disorders predisposing to destructive periodontal disease.

Actinobacillus actinomycetemcomitans proportion of subgingival bacterial flora in relation to its clonal type

We investigated whether certain Actinobacillus actinomycetemcomitans clones occur in elevated proportions in subgingival flora, and if the proportions relate to other bacteria in the samples. A total of 121 A. actinomycetemcomitans strains from 121 patients with periodontitis were serotyped and 60 strains were also genotyped. The 121 strains were divided into three groups and the 60 strains into two groups according proportion of A. actinomycetemcomitans. The samples from the 60 patients with genotyped strains were cultured for five other species. Among the 121 strains, serotype b occurred significantly more frequently in the high- (n = 14, proportions > 5%, mean = 18.09, SD = 20.07%) than low- (n = 49, proportions < or = 0.1%), mean = 0.04, SD = 0.03%) or intermediate-proportion groups (n = 58, proportions > 0.5%, mean = 1.31, SD = 1.24%). Genotype 3 occurred significantly more frequently in samples with low A. actinomycetemcomitans proportions (n = 28, < or = 0.1%, mean = 0.04, SD = 0.03%) than in those with high proportions (n = 32, > 0.1%, mean = 5.70, SD = 14.60%). No differences were seen in the detection frequencies or proportions of the five bacterial species between the samples with low or high A. actinomycetemcomitans proportions. The results indicate that certain clonotypes of A. actinomycetemcomitans may preferentially occur as low proportions, suggesting their controlled growth. Conversely, some serotype b clones may have a competitive advantage in subgingival flora.

Age, dental infections, and coronary heart disease

Epidemiological and intervention studies have suggested that infections are risk factors for coronary heart disease (CHD). Dental infections have appeared as cardiovascular risk factors in cross-sectional and in follow-up studies, and the association has been independent of the "classic" coronary risk factors. This case-control study aimed at detailed assessment of the dental pathology found in various CHD categories (including elderly patients). Altogether, 85 patients with proven coronary heart disease and 53 random controls, matched for sex, age, geographic area, and socio-economic status, were compared with regard to dental status, assessed blindly with four separate scores, and to the "classic" coronary risk factors (seven of the controls had CHD, and they were not included in the analyses). The dental indices were higher among CHD patients than in the controls, but, contrary to previous studies, the differences were not significant (between the CHD patients and their matched controls or among the different CHD categories). This result could not be explained by potential confounding factors. The participants in the present study were older and had more often undergone recent dental treatment in comparison with subjects in our earlier studies. Age correlated with the severity of dental infections only in the random controls but not in the coronary patients who, although young, already had high dental scores. We believe that the higher age of the participants in the present study is the most likely reason for the results. Other possible explanations include an age-related selection bias among older CHD patients, and the fact that those participating in studies like this may have better general health and thus also less severe dental infections. Thus, the role of dental infections as a coronary risk factor varies according to the characteristics of the population studied.

Clonal infection with Actinobacillus actinomycetemcomitans following periodontal therapy

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.

Bacterial transmission in periodontal diseases: a critical review

This review paper addresses intra- and extra-familial transfer of bacteria associated with periodontal diseases. Recent advances in molecular biology provide sensitive methods to differentiate organisms within the same species, thereby facilitating tracking routes of their transmission. Evidence for the passing of microorganisms between parents and children is particularly strong. In this regard, molecular genetic techniques have demonstrated that if a child is colonized by a potentially pathogenic species, then one of the parents will usually harbor genotypically identical bacteria. The data also indicate that transfer of bacteria between spouses occur, but it appears to happen infrequently. Saliva appears to be a major vector for bacterial transmission. However, the transfer of organisms does not necessarily result in colonization or infection of the host. Furthermore, individuals who harbor putative pathogens frequently do not manifest any signs of periodontal disease. This is attributed to host defenses, bacterial antagonism, and possibly lack of pathogenicity of infecting organisms. It is concluded, based upon current evidence, that periodontal pathogens are communicable; however, they are not readily transmissible.

Serum antibody response to Actinobacillus actinomycetemcomitans in Down's syndrome

Persons with Down's syndrome (DS) are susceptible to severe and precocious periodontal disease. Several organisms have been implicated in the etiology of periodontal disease, including Actinobacillus actinomycetemcomitans (Aa). It is unknown whether circulating antibodies correlate with the severity of periodontal disease in DS. This study determined the circulating antibody titers to Aa in sera of DS and normal patients. Eleven DS patients with periodontal disease (pocket depth > 4 mm), five DS patients with gingivitis (inflammation and pocket depth < or = 3 mm), and 10 non-DS healthy subjects had blood drawn and analyzed for antibody response to Aa. Conventional enzyme-linked immunosorbent assay (ELISA) with goat anti-human IgG was performed for Aa-reactive serum diluted 1:200 to 1:12,800. Geometric mean titer was calculated, and significant differences were noted between the control group and the DS groups (p = 0.05), with the DS periodontal group having the highest response, followed by the DS gingivitis and normal controls, respectively. The DS groups were not significantly different. DS patients may exhibit a higher Aa antibody response, due to the presence of the organism, previous exposure, or in proportion to the extent of their periodontal condition.

Distribution of biotypes and antimicrobial susceptibility of Actinobacillus actinomycetemcomitans

Eighty isolates of Actinobacillus actinomycetemcomitans from 30 Brazilian periodontitis patients were examined to determine the distribution of biotypes and in vitro antimicrobial susceptibility. Seventy-seven percent of the isolates belonged to biotype X. All A. actinomycetemcomitans isolates were susceptible to cefoxitin, imipenem and tetracycline.

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.

Bacterial-stimulated cytokine production of peripheral mononuclear cells from patients of various periodontitis categories

Periodontitis is a general term for disease categories, including juvenile periodontitis (JP), rapidly progressive periodontitis (RPP), and adult periodontitis (AP), which may or may not share a common etiology and pathogenesis. These disease categories are characterized by differences in progression of tissue destruction and differences in age group susceptibility, but not, to our knowledge, by differences in cytokine responses of inflammatory cells. The present study examined blood cell counts and interindividual variation in the ability of PBMC of patients in three different categories of periodontitis to produce cytokines after stimulation with different oral bacterial species in vitro. The AP group had a significantly lower production of IL-1ra when stimulated with Porphyromonas gingivalis (P.g.) and Actinobacillus actinomycetemcomitans (A.a.) (P < 0.05). Streptococcus sanguis (S.s.), which is associated with normal periodontal conditions, induced extremely high levels of IL-1 alpha and TNF alpha production in all groups. The RPP group had a significantly higher number of monocytes (MC) than the AP group (P < 0.05). Additionally, JP patients had a significantly higher concentration of polymorphonuclear granulocytes compared to juvenile controls (P < 0.05). In conclusion, IL-1 alpha, TNF alpha, or IL-6 production by peripheral blood MC after in vitro stimulation with oral bacterial type stains may not distinguish different categories of periodontitis. The results support the hypothesis that the cytokine IL-1ra is produced in different concentrations in the two groups: RPP and AP. Furthermore, elevated MC concentration in the RPP group compared to the AP group may be an important pathogenic feature in RPP.

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.

Microbiological and clinical monitoring of non-localized juvenile periodontitis in young adults: a report of 11 cases

It has been shown that patients with localized juvenile periodontitis (LJP) often harbor Actinobacillus actinomycetemcomitans in the subgingival area. However, little is known of the oral microflora in non-LJP juvenile periodontitis patients with less extensive disease. The purpose of this study was to describe the microflora and clinical parameters of young adults with minor to moderate periodontitis during treatment for a period of 1 year. Eleven patients 15 to 16 years of age were studied. All of them had 4 to 8 mm loss of attachment at minimally one site, but the typical clinical description of localized juvenile periodontitis was an exclusion criterion in this study. Microbiological examination of the deepest periodontal pocket and of the tongue revealed that 6 patients harbored Actinobacillus actinomycetemcomitans and 5 harbored Porphyromonas gingivalis. Almost all subjects showed relatively high proportions of Prevotella intermedia, Campylobacter rectus, motile organisms, and spirochetes. On the basis of clinical and microbiological parameters the 11 patients could be assigned to 1 of 2 groups. Six cases had moderate periodontal breakdown with loss of attachment at 7 to 44 sites. All harbored A. actinomycetemcomitans and 5 of them P. gingivalis. These 6 cases responded relatively well to initial treatment despite the continued presence of A. actinomycetemcomitans. The other group consisted of 5 cases with relatively minor periodontal breakdown; i.e, 1 or 2 sites with 4 to 6 mm loss of attachment. Neither A. actinomycetemcomitans nor P. gingivalis was detected in the deepest pocket of these patients. All 5 responded well to initial treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinobacillus actinomycetemcomitans, Capnocytophaga and Porphyromonas gingivalis in subgingival plaque of adolescents with Down's syndrome

Levels of Actinobacillus actinomycetemcomitans, Capnocytophaga and Porphyromonas gingivalis were determined in subgingival plaque samples from 37 adolescents with Down's syndrome and 37 healthy controls matched with respect to age and sex. Gingival inflammation, supra- and subgingival calculus, periodontal pockets ( > 4 mm) and alveolar bone loss were registered. Alveolar bone loss was more frequent in Down's syndrome subjects (32%) than in the controls (3%). A. actinomycetemcomitans was detected in the subgingival plaque in 35% of the Down's syndrome adolescents and in 5% of the controls. On site level, A. actinomycetemcomitans and Capnocytophaga were more frequent in the subgingival plaque samples of Down's syndrome children than in those of controls. Comparing Down's syndrome subjects positive or negative for A. actinomycetemcomitans and Capnocytophaga, no significant differences were found in terms of gingival inflammation, periodontal pockets ( > 4 mm) or number of sites with alveolar bone loss. The results indicate an altered microbial composition of the subgingival plaque of Down's syndrome subjects compared with healthy controls, with higher frequency of A. actinomycetemcomitans.

A follow-up case report of Actinobacillus actinomycetemcomitans in human periodontal disease

The purpose of this investigation was to compare clinical and microbial parameters in a follow-up case report of adult subjects harboring Actinobacillus actinomycetemcomitans (Aa) with clinically matched subjects who did not have detectable Aa. 16 subjects with Aa and 16 subjects without Aa at the baseline examination were re-examined at an average of 46 months following collection of baseline data. Clinical measurements were recorded and subgingival plaque sampled and evaluated for microbial flora from each maxillary first molar. In 16 subjects with Aa at baseline, 4 sites in 3 subjects had detectable actinobacilli at the follow-up appointment. 26 sites in 13 individuals with Aa at baseline had a significantly increased gingival index at the follow-up visit (p less than or equal to 0.05), but there was no significant increase in probing depth or attachment loss. 32 sites in the 16 subjects without Aa at baseline still did not have detectable levels of this microorganism at the follow-up examination nor was there any significant difference between baseline and the follow-up appointment for the gingival index, probing depth and attachment level measurements. In subjects with Aa at baseline, 1 of 12 teeth without Aa and 5 of 20 teeth with Aa had been extracted prior to the follow-up visit. In this population group, having sites where Aa was detected, 6 of 9 teeth which had a probing depth greater than or equal to 5 mm were lost before the follow-up data collection appointment. In the control group, which did not have detectable Aa at baseline, 9 teeth with probing depths greater than or equal to 5 mm were not lost. These observations, although not proving, suggest in this population group, that deeper probing depths taken together with the presence of Aa may have placed an individual at greater risk of tooth loss.

Proximal attachment loss in Swedish adolescents

The present study describes periodontal conditions in 22 adolescents with proximal attachment loss greater than or equal to 2 mm (AL) and 22 matched referents without AL, all identified in a cross-sectional study of 570 16- and 18-year-old. The cases were followed for 3 years and the referents for 1 year while they were in the care of an organized dental health system. With the exception of 1 case with Morbus Hodgkin, the case and referent groups had a similar background with respect to general health and participation in the dental health program. Bleeding on probing was found at AL sites in 12 of the cases and at corresponding sites in 4 referents. 2 cases had a history of eruption disorders at the AL sites, 1 case had experienced a defective filling and 1 had a root fissure at the AL sites. At re-examinations after 1 and 3 years, 10 out of 21 earlier identified AL cases did not meet the criterion of 1 or more sites with AL greater than or equal to 2 mm. None of the cases showed progression greater than or equal to 2 mm of the lesions. In 1 case, the number of AL sites increased during the period. 4 of the cases harboured Actinobacillus actinomycetemcomitans (A.a.) at AL sites in year 1 and 3 in year 3. 8 of the cases and 4 referents had antibodies specific for A.a.-leukotoxin. The 2 most severe cases, in terms of number of sites with AL, showed bleeding at 1 or more of the AL sites, harboured A.a. at these sites and had serum titers against A.a.-leukotoxin.

Prevalence of juvenile periodontitis in Chile

The aim of this survey was to study the prevalence of juvenile periodontitis in schoolchildren aged 15-19 years in Santiago, Chile. A random sample of 2500 schoolchildren (1318 male, 1182 female) that represented the full range of different socio-economic strata and ethnic groups seen in the population of Santiago, was used. Initially, the children were screened clinically at school by assessment of probing depths around the incisors and first molars with a WHO 621 pattern probe. Children with 2 or more teeth with 5.5 mm or deeper pockets were invited for a radiographic examination comprising bitewing radiographs of molars, and periapical radiographs of incisors. Any subject with 2 mm or more alveolar bone loss was invited for a full clinical and radiographic examination. After screening, 27 subjects had a tentative diagnosis of juvenile periodontitis. 4 of these refused radiographic examination and only accepted a thorough clinical examination. 23 subjects presented themselves for the radiographic and complete clinical examination. Of the 27 subjects selected for detailed examination, 8 subjects (7 female, and 1 male) were diagnosed as having juvenile periodontitis. There was an overall prevalence of juvenile periodontitis of 0.32% with 95% confidence, which gives a range of +/- 0.10%. When prevalence was assessed by socio-economic status, juvenile periodontitis was found more commonly in low socio-economic group. The results of the current study suggest that in Chile, there might be a relationship between socio-economic status and prevalence of juvenile periodontitis, and that this disease is more frequent in women.

Dental bacterial plaques. Nature and role in periodontal disease

Antony van Leeuwenhoek first described oral bacteria. However, not until almost 200 years later was the famous Koch postulate introduced. Since then, research has extensively been performed regarding the development and microbiology of dental plaques. In spite of the complexity of the developing flora of supragingival plaque, culture studies have shown a remarkably orderly succession of organisms. Lately, the concept of microbial specificity in the etiology of periodontal diseases has been widely suggested, i.e., that different forms of periodontal disease are associated with qualitatively distinct dental plaques. Cross-sectional and longitudinal studies of the predominant cultivable microflora reveal that only a small number of the over 300 species found in human subgingival plaques are associated with periodontal disease. Among the commonly mentioned are: Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, Bacteroides intermedius, Capnocytophaga sp., Eikenella corrodens, Fusobacterium nucleatum, and Wolinella recta, as well as certain gram-positive bacteria such as Eubacterium species. Anti-infective therapy for many systemic infections equals the use of antimicrobial drugs. However, for localized infections like periodontal diseases, treatment may consist of a combination of mechanical wound debridement and the application of an antimicrobial agent. The general effectiveness of mechanical anti-infective therapy and successful oral hygiene in the management of periodontal disease is well established in the literature and has met the test of success in clinical practice for most cases of periodontitis in adults. The definition of periodontal pathogens as either opportunistic pathogens, or as exogenous pathogens carries with it significant implications.(ABSTRACT TRUNCATED AT 250 WORDS)

Recovery of A. actinomycetemcomitans from teeth, tongue, and saliva

The recovery of actinobacillus actinomycetemcomitans simultaneously from subgingival sites around teeth and dorsum of the tongue and/or saliva was examined in 293 subjects at 444 visits; 295 paired samples were available from subgingival sites and tongue, 171 paired samples from subgingival sites and stimulated saliva, and 137 paired samples from subgingival sites and unstimulated saliva. Sixty-one subjects were periodontally healthy (mean age 20.3 years); 55 exhibited localized juvenile periodontitis (mean age 21.8 years); 176 adult periodontitis (mean age 46.7 years); and 1 prepubertal periodontitis (age 10 years). When A. actinomycetemcomitans was recovered from subgingival sites, it was also found in 56.3%, 69.9%, and 35.9% of the paired samples from tongue, and stimulated and unstimulated saliva, respectively. No difference in the detection rate of A. actinomycetemcomitans from tongue or stimulated saliva was seen between the subjects with healthy or diseased periodontium. When A. actinomycetemcomitans was not recovered from subgingival sites, it was cultured in 6.8%, 2.0%, and 1.4% of the paired samples from tongue, and stimulated and unstimulated saliva, respectively. In search for noninvasive, inexpensive, and easily run sampling methods for the recovery of oral A. actinomycetemcomitans samples from stimulated saliva and tongue may prove useful in clinical periodontology.

Salivary defense mechanisms in juvenile periodontitis

The local, saliva-associated defense mechanisms of 28 juvenile periodontitis (JP) patients and their age- and sex-matched controls were studied. Lysozyme, lactoferrin, salivary peroxidase, myeloperoxidase, and thiocyanate concentrations were determined from both whole saliva and parotid saliva. The total concentrations of salivary IgA, IgG, and IgM were assayed. The periodontal condition and the salivary flow rates were registered. Among the JP patients, a significantly elevated concentration of IgG was found in parotid saliva but not in whole saliva. Salivary peroxidase activities were significantly low both in the whole and in the parotid saliva samples of the JP patients, and leukocyte-derived myeloperoxidase was present in significantly low amounts in whole saliva of these patients. Because both glandular (salivary peroxidase) and polymorphonuclear-cell-derived (myeloperoxidase) enzyme activities were low among the JP patients, suppressed peroxidase-mediated host defense mechanisms could be characteristic of JP.

Associations between six DNA probe-detected periodontal bacteria and alveolar bone loss and other clinical signs of periodontitis

The purpose of the present study was to assess the associations between the presence and amounts of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, B. intermedius, Eikenella corrodens, Wolinella recta, and Fusobacterium nucleatum in the periodontal pocket and the degree of alveolar bone loss and other clinical signs of periodonitis, such as probing pocket depth, attachment level, and presence of bleeding on probing at the same site. The study material comprised 16 subjects with or without approximal sites showing longitudinal alveolar bone loss who were selected from a group of 142 subjects monitored radiographically over the past 4 years. In this group 105 sites were examined, of which 58 showed recent alveolar bone loss greater than or equal to 1 mm. Subgingival plaque was collected with absorbent paper points and hybridized with 32P-labeled DNA probes specific for the above-mentioned bacteria. The amount of each bacterial species was correlated with the degree of bone loss over time and the three clinical measurements by means of Spearman rank correlation. A. actinomycetemcomitans showed poor correlations with all three clinical signs of periodontal inflammation, whereas B. gingivalis and W. recta demonstrated significant positive correlations with the three clinical measurements and with attachment level and pocket depth, respectively. In addition, the amount of A. actinomycetemcomitans, B. gingivalis and W. recta showed significant positive correlation with the extent of alveolar bone loss at the site. In contrast, the amounts of B. intermedius, E. corrodens, and F. nucleatum showed negative correlations with all four measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of periodontal breakdown in adolescents and presence of Actinobacillus actinomycetemcomitans in subjects with attachment loss

The present investigation was carried out to study the prevalence and clinical appearance of destructive periodontal disease in a school population of 15- to 16-year old adolescents in Amsterdam. In addition the prevalence of Actinobacillus actinomycetemcomitans was studied in those subjects showing attachment loss. Attachment loss was diagnosed in 230 of the 4565 subjects participating which is about 5% of the population studied. Within this population males were more frequently affected than females (P = 0.008). Extensive periodontal destruction was found in 16 subjects (0.3%). In this group a female/male ratio was found of 1.3:1. As a result of the epidemiological survey, 105 subjects with attachment loss volunteered for further investigation. The results showed that presence of plaque, redness and swelling of the gingiva, and bleeding on probing were general phenomena. In addition, the bleeding/plaque ratio, as determined for each subject at sites without attachment loss, increased with the severity of periodontal disease as expressed by the number of sites with attachment loss (P = 0.0038) as well as by the amount of destruction at these sites (P = 0.002). A. actinomycetemcomitans could be identified in 18 of the 105 subjects with attachment loss. Analysis showed that A. actinomycetemcomitans was more frequently isolated in subjects with moderate to severe periodontal breakdown than in subjects with mild breakdown (P less than 0.02). When estimating the percentage of juvenile periodontitis patients on the basis of the classically accepted criteria, it seems likely that between 0.1% to 0.2% of the population in Amsterdam is suffering from this disease entity.

Actinobacillus actinomycetemcomitans serotypes and leukotoxicity in Korean localized juvenile periodontitis

Actinobacillus actinomycetemcomitans is though to play an important role in the pathogenesis of localized juvenile periodontitis (LJP). Preliminary data suggested that the serotype distribution of A. actinomycetemcomitans in Korea and the United States differ. This study evaluated A. actinomycetemcomitans prevalence, serotype distribution, and leukotoxicity in Korean LJP patients by culture, enzyme-linked immunosorbent assay, indirect immunofluorescence, and lactate dehydrogenase release from polymorphonuclear leukocytes exposed to A. actinomycetemcomitans. A. actinomycetemcomitans occurred in 75% of LJP lesions and 6% of normal sites with approximately equal distribution of serotype a, b, and c. Single serotypes were isolated from nine patients while three patients harbored two serotypes either in the same or different disease sites. A. actinomycetemcomitans leukotoxicity occurred in 22% isolates with a 69% prevalence. Individual sites harbored both leukotoxic and non-leukotoxic strains with no serotype association. The distribution of serotypes and leukotoxic strains of A. actinomycetemcomitans in Korean LJP patients differed from those reported in the United States. This suggests that serotype b may not be more important in the pathogenesis of LJP.

Detection and distribution of Actinobacillus actinomycetemcomitans in the primary dentition

The occurrence of actinobacillus actinomycetemcomitans (A.a.) in plaque samples from the primary dentition was studied in 55 healthy Finnish children from four to seven years of age. A.a. was isolated in seven (13%) children, four boys and three girls. A further examination of the distribution and infection level of A.a. in the oral cavity of five of the A.a.-positive children revealed that A.a. was found in 26 of 45 plaque samples (7-10 samples from each child) and in all samples obtained from the dorsum of the tongue. The individual detection rates of A.a. were 3/7, 5/10, 6/10, 6/10 and 6/8 of the dental sites examined. A.a. occurred in 9/10 of the second primary molars, 8/10 of the first primary molars, 5/10 of the cuspids, 4/8 of the upper incisors and in none of the lower incisors examined. The proportions of A.a. within the dentition had a wide range. In 58% of the A.a.-positive samples, the proportions were less than 1%, and none exceeded 10% of the flora. Gingival bleeding after sampling with floss occurred more than twice as frequently in the A.a.-positive as in the A.a.-negative sites (16%/42%). The results indicate that A.a. was a rather frequent member of the oral flora in the children with primary teeth. The primary molars and the dorsum of the tongue seemed to be preferred sites for A.a. More than one site should be sampled to determine the infection level of A.a. within the dentition.

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.

Certain bacterial species and morphotypes in localized juvenile periodontitis and in matched controls

Subgingival microflora in localized juvenile periodontitis (LJP) was examined by culture of certain bacterial species and by direct dark-field microscopy in affected and unaffected periodontal pockets of 11 patients and in their age- and sex-matched controls. Only Actinobacillus actinomycetemcomitans (A.a.) correlated to periodontal destruction and occurred most frequently at the affected LJP sites. A.a., Bacteroides intermedius and Fusobacterium nucleatum were isolated in proportions greater than 5% of the flora at the affected LJP sites, but various Actinomyces spp. at the unaffected and control sites. The proportions of straight rods, fusiforms and small spirochetes correlated to gingival bleeding tendency and were higher at the affected LJP sites than at the control sites. Certain nonpigmented Bacteroides spp. and Eikenella corrodens were never isolated when only cocci were seen at dark-field microscopy. The more complex the flora, the more frequently B. intermedius occurred. The results support a significant role for A.a. in LJP and indicate that certain bacterial species appear to prefer occurring in the complex composition of subgingival microflora.

Occurrence of Actinobacillus actinomycetemcomitans and spirochetes in relation to age in localized juvenile periodontitis

Occurrence of Actinobacillus actinomycetemcomitans (A.a.) and spirochetes was examined in relation to the age of patients suffering from localized juvenile periodontitis (LJP). Twenty LJP patients were divided into three age groups: 14-16, 17-19, and 20-25 years of age. Two sites with radiographic alveolar bone loss and two sites without bone loss were examined in each patient. Probing depth, gingival bleeding after probing, and orthopantomographic alveolar bone loss were recorded. Subgingival bacterial samples were taken from the same four sites for cultivation of A.a., and for dark-field microscopic assessment of spirochetes. A.a. was isolated in the youngest group more frequently than in the two older ones. Spirochetes were detected in the youngest group as well, but were not related to the age of the patients. A.a. occurred as frequently with as without spirochetes, both in pockets exhibiting and not exhibiting bone loss. There was no difference in the spirochete proportions between the A.a.-positive and -negative sites. The occurrence of A.a. was not related to the absence, presence, or proportions of the spirochetes, but, unlike the situation with spirochetes, was related to the age of the LJP patients. Thus the occurrence of A.a. is possibly associated with the activity of the disease.

Subgingival microflora and periodontal conditions in healthy teenagers

The composition of subgingival flora was correlated with clinical periodontal conditions in 100 teenagers aged 12 to 17 years. The Community Periodontal Index of Treatment Needs (CPITN) was used for the clinical examination. Subgingival bacterial samples were taken from the mesial surface of each first molar, two samples for dark-field microscopy and two samples for Actinobacillus actinomycetemcomitans (A.a.) cultivation. Fifty-nine subjects had at least three healthy sextants. Score 1 was the highest CPITN recording in 61 subjects and Score 2 in 30 subjects. None had scores 3 or 4. In dark-field microscopy, cocci predominated in most samples. Straight rods, fusiforms and motile rods correlated negatively to the number of healthy sextants per subject. Straight rods and fusiforms showed a positive correlation to gingival bleeding tendency at the sampled site. A.a. was isolated in four subjects. Motile microorganisms and A.a. were detected rarely in subjects with good periodontal conditions.