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

Occurrence of Periodontopathic and Superinfecting Bacteria in Chronic and Aggressive Periodontitis Subjects in a Colombian Population

BACKGROUND

Differences in the composition of subgingival microbiota in periodontitis have been observed in different geographic locations. Some of these microbial differences could have clinical significance. This study describes clinical parameters and the composition of the subgingival microbiota in chronic periodontitis (CP) and aggressive periodontitis (AgP) patients in a Colombian population.

METHODS

Clinical parameters (probing depth, clinical attachment level, bleeding on probing, and plaque index) and plaque samples from 68 CP, 12 AgP, and 30 periodontally healthy subjects were analyzed. Subgingival samples were processed using culture, biochemical tests, and polymerase chain reaction for the detection of periodontal and superinfecting pathogens. The analysis of variance, chi(2), and Kruskal-Wallis tests were used to evaluate differences between groups for clinical parameters and microbiologic composition (P <or=0.05).

RESULTS

Clinical parameters were significantly increased in CP and AgP patients compared to healthy subjects (P <0.001), but no differences were found between periodontitis groups. Porphyromonas gingivalis, Tannerella forsythensis, and Eikenella corrodens showed higher frequencies in AgP compared to CP and healthy subjects (P <0.05). Extension (localized and generalized) of the periodontal destruction had no effect on the composition of the subgingival microbiota. Gram-negative enteric rods were more frequent in AgP patients (P <0.01).

CONCLUSIONS

This study demonstrated a high prevalence of P. gingivalis, T. forsythensis, and E. corrodens in AgP patients. Gram-negative enteric rods were frequent in AgP and CP patients. Differences in the composition of subgingival microbiota in periodontitis patients need to be taken into account when considering the best therapeutic approach for each individual, including the use of antibiotics.

Microbiological profile of early onset/aggressive periodontitis patients

OBJECTIVES

The objectives of this study were to characterize the bacterial profile and to seek possible bacterial associations in the subgingival microbiota of early onset periodontitis/aggressive periodontitis patients by using two different techniques, culture and immunofluorescence.

MATERIAL AND METHODS

The study group consisted of 66 systemically healthy individuals with evidence of early onset periodontitis - 41 females and 25 males aged 23-35 years (mean 31.1 +/- 3.1 years). Bacterial samples were collected from the deepest site in each quadrant, resulting in a total of 264 sites with a mean probing pocket depth of 6.6 +/- 1.5 mm. Samples were cultured anaerobically and in 10% CO(2) using selective and nonselective media, and isolates were characterized to species level. Indirect immunofluorescence using monoclonal antibodies was applied to detect Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia (Bacteroides forsythus, Tannerella forsythensis), Prevotella intermedia/Prevotella nigrescens, Campylobacter rectus, Peptostreptococcus micros and Actinomyces israelii.

RESULTS

93.6% of sampled sites showed bleeding on probing and 23.5% were positive for suppuration. P. intermedia/P. nigrescens, P. gingivalis, and C. rectus were detected in 77.3-85.9% of samples using culture methods and in 85.6-91.3% using immunofluorescence. P. micros and A. actinomycetemcomitans were found, respectively, in 63.3% and 25.0% of all sites using culturing and in 58.7% and 27.7% sites using immunofluorescence. Significantly strong positive associations were observed between T. forsythia and C. rectus (odds ratio 109.46), and T. forsythia and P. gingivalis (odd ratio 90.26), whereas a negative association was seen between P. intermedia/P. nigrescens and A. actinomycetemcomitans (odds ratio 0.42). Coinfection by P. gingivalis, T. forsythia, P. intermedia/P. nigrescens and C. rectus was observed in 62.1% of the test sites, and in 89.4% of the studied subjects. The sensitivity of immunofluorescence for T. forsythia, C. rectus, P. intermedia/P. nigrescens and P. gingivalis was found to be very high (0.99-0.94) using culture as the reference detection method. The agreement between culture and immunofluorescence in detecting the presence or absence of the investigated species was 85.2-88.1% for P. gingivalis, P. intermedia/P. nigrescens, C. rectus, and T. forsythia, 75.9% for A. actinomycetemcomitans and 70.4% for P. micros.

CONCLUSIONS

The microbial profile of the early onset/aggressive periodontitis population was complex. The agreement between the two detection methods was very high.

Herpesviral-bacterial interactions in aggressive periodontitis

BACKGROUND

Human cytomegalovirus, Epstein-Barr virus and herpesvirus co-infections occur with significantly higher frequency in actively progressing than in stable periodontitis sites of adolescents and young adults. Also, periodontal presence of cytomegalovirus and Epstein-Barr virus is associated with increased occurrence of subgingival Porphyromonas gingivalis, Bacteroides forsythus, Dialister pneumosintes, Prevotella intermedia, Prevotella nigrescens, Treponema denticola and Actinobacillus actinomycetemcomitans.

AIM

This article reviews the evidence linking herpesviruses to the development of aggressive periodontitis and suggests a potential mechanism for herpesviral acceleration of the periodontal disease process.

CONCLUSIONS

It seems to be a reasonable supposition that the etiopathogenesis of various types of aggressive periodontitis includes the combined action of herpesviruses and specific bacterial species. New vaccines and vaccination technologies that are being developed against herpesviruses warrant testing for their ability to induce a protective immune response against destructive periodontal disease. Clearly, the importance of combined herpesviral-bacterial infections and associated host responses in the development of periodontitis needs to be studied further.

Three case reports of aggressive periodontitis associated with Porphyromonas gingivalis in younger patients

The terms 'early onset periodontitis' (EOP) and 'juvenile periodontitis' (JP) were replaced by that of 'aggressive periodontitis' in a recent international workshop for the classification of periodontal diseases and conditions. The chief etiologic agent for aggressive periodontitis is considered to be Actinobacillus actinomycetemcomitans in localized juvenile periodontitis. Porphyromonas gingivalis is also mentioned as the etiologic agent of the aggressive periodontitis, although to date its role remains questionable. This communication describes three cases of aggressive periodontitis found to be associated with P. gingivalis but not A. actinomycetemcomitans by polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Our findings clarify the role of P. gingivalis as an etiologic agent in this type of periodontitis and confirm its inclusion in the current definition of aggressive periodontitis.

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.

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.

Oral ecology and person-to-person transmission of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis

The ecological characteristics of the oral cavity are dissimilar for A. actinomycetemcomitans and for P. gingivalis, as judged by differences in their colonization preferences and patterns, associations with periodontal disease parameters, relationships with the subgingival microbiota and the type of periodontitis and their clonal persistence in the oral cavity. These features also suggest that as a periodontal pathogen, A. actinomycetemcomitans is different from P. gingivalis. Probably in most infected individuals, low levels of A. actinomycetemcomitans can persist for years in equilibrium with the host and the resident oral microbiota. However, it is well established that A. actinomycetemcomitans can cause disease in some individuals or in some circumstances when the regulatory mechanisms are unable to maintain homeostasis in the ecosystem. Elevated A. actinomycetemcomitans proportions of the biota can be regarded as a sign of ecological imbalance, leading to increased risk of periodontal destruction. There is also evidence showing elevated pathogenic potential of certain A. actinomycetemcomitans clones. Although A. actinomycetemcomitans seems to be relatively rarely transmitted between cohabiting adults, transmission can occur to periodontally healthy children of A. actinomycetemcomitans-positive parents. Parents and children may share factors that promote successful oral colonization of A. actinomycetemcomitans, or the window of opportunity is in childhood. Therefore, to prevent parent-child transmission of A. actinomycetemcomitans, bacterium-positive parents of young children are optimal targets for enhanced information and treatment. In selected populations, screening for specific clones of A. actinomycetemcomitans has been employed in prevention of peridontitis. Future research aiming at finding the reasons which cause the changes in the oral homeostasis to allow the growth of A. actinomycetemcomitans may give insight into novel prevention strategies for A. actinomycetemcomitans-associated periodontitis. Compared with A. actinomycetemcomitans, P. gingivalis shows a different pattern of coexistence with the host. In periodontal health or in children, P. gingivalis is absent or only rarely detected. When present, P. gingivalis is commonly recovered in high numbers from dentitions exhibiting inflamed periodontitis and poor oral hygiene. Contrary to A. actinomycetemcomitans, the data on the vertical transmission of P. gingivalis are limited. The major infection route of P. gingivalis seems to be between adults, indicating that P. gingivalis commonly colonizes in an established oral microbiota. These characteristics suggest that the degree of tolerance between P. gingivalis and the host is inferior to that between A. actinomycetemcomitans and the host. It appears that the association of P. gingivalis with disease is a rule rather than an accidental incident. On these grounds, it seems that the host-P. gingivalis relationship approaches antibiosis. Since P. gingivalis infection is related to a typical periodontal eco-pathology, the susceptibility to person-to-person transmission of this pathogen may be controlled by periodontal treatment and emphasizing the significance of high standard oral hygiene.

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.

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)

Actinobacillus actinomycetemcomitans in adult periodontitis. I. Topographic distribution before and after treatment

The aim of this investigation was to study the topographic distribution of Actinobacillus actinomycetemcomitans in patients with adult periodontitis before and after mechanical periodontal treatment (repeated oral hygiene instructions, systematic deep scaling, and root planing). In 10 A. actinomycetemcomitans-positive patients, subgingival microbial samples were obtained from the mesial and distal aspect of every tooth (38 to 56 sites per patient, 479 sites in total) before and one month after treatment. The samples were cultured on TSBV agar. A. actinomycetemcomitans was identified based on phenotypical and serological criteria. A. actinomycetemcomitans was present in 40% of the samples taken before and in 23% of the samples taken after treatment. Before treatment, the frequency of A. actinomycetemcomitans-positive samples per patient was wide spread and ranged from 7 to 90%. After treatment, two patterns of A. actinomycetemcomitans distribution could be recognized: the majority of the patients showed only a limited percentage of positive samples and yielded less than 10(5) A. actinomycetemcomitans. In three subjects, however, relatively high numbers of positive sites were still present, and many of these positive sites showed high A. actinomycetemcomitans counts. Logistic multiple regression showed the presence of A. actinomycetemcomitans before treatment depended strongly on the individual and was significantly associated with probing depth (P < 0.001) and bleeding upon sampling (P = 0.07). The highest chance of detecting A. actinomycetemcomitans existed in deep pockets which bled upon sampling. After treatment, there was a strong individual influence and an influence of probing depth (P < 0.001). The highest chance of detecting A. actinomycetemcomitans existed in residual pockets in the range of 5 mm.

In vitro phagocytosis by crevicular phagocytes in various forms of periodontitis

Phagocytes from the gingival crevice fluid (CF-cells) of 11 patients with localized juvenile and post-juvenile periodontitis (LJP/PJP), 14 with rapidly progressive periodontitis (RPP), 11 with adult periodontitis (AP), and 14 controls without periodontal disease were examined. Phagocytic activity in vitro was assessed. Crevicular washings were obtained from healthy sites of controls and diseased sites of patients after completion of the oral hygiene phase (professional and home care). The cells were carefully processed to avoid mechanical damage. The in vitro phagocytosis by uptake of opsonized C. albicans was performed in a moist chamber (30 minutes, 37 degrees C) and examined by light microscopy. CF-cells were differentiated on the basis of their morphological appearance. The majority of cells in crevicular washings were PMNs, some macrophages, and few lymphocytes. Phagocytic activity in patients with LJP/PJP and RPP was significantly decreased in comparison with that from AP and the control group. The decreased percentage of cells phagocytosing opsonized C. albicans was associated with the enhanced adherence of opsonized C. albicans. Moreover cell viability of CF-cells from LJP/PJP sites was significantly reduced. The data from the present study suggest that the in vitro phagocytosis of crevicular phagocytes in juvenile and rapidly progressive periodontitis lesions is diminished.

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.

IgG antibody response of localized juvenile periodontitis patients to the 29 kilodalton outer membrane protein of Actinobacillus actinomycetemcomitans

Levels of serum IgG antibody to the 29 kilodalton outer membrane protein of A. actinomycetemcomitans Y4 in sera of periodontally healthy subjects and localized juvenile periodontitis patients were determined using an enzyme-linked immunosorbent assay (ELISA). The 29 kDa protein was isolated by solubilization of an octylglucoside-NaCl insoluble fraction by incubation at ambient temperature in 20 mM sodium phosphate, pH 7.5, containing 1% sodium dodecyl sulfate. The isolated protein migrated on SDS-polyacrylamide gels with an apparent molecular mass of 29 kDa following incubation in sample buffer at ambient temperature. However, the protein migrated with an apparent molecular mass of 34 kDa following incubation in sample buffer at 100 degrees C for 10 minutes. Geometric mean IgG antibody titers to the 29 kDa protein were significantly higher in sera from LJP subjects than in sera obtained from periodontally healthy subjects. Twenty-two of 35 LJP sera (63%) had antibody titers greater than 2 standard deviations from the mean titer of the periodontally healthy group. Among LJP subjects, elevated antibody titers to the 29 kDa protein were found primarily in subjects greater than or equal to 18 years of age, with the highest titers seen in patients 18 to 21 years of age. The results of this study indicate that the humoral response of LJP subjects to A. actinomycetemcomitans includes the production of IgG antibodies which recognize the major outer membrane proteins of this organism.

Generalized juvenile periodontitis: report of a familial case followed for 5 years

The case of a family, followed for 5 years and showing an exceptionally high prevalence of Generalized Juvenile Periodontitis (GJP), is presented. Two siblings were affected by a severe form of GJP meanwhile the dycorial twin of one was periodontally healthy. Both the affected siblings showed infection by Actinobacillus actinomycetemcomitans (Aa), but only one presented a reduced chemotaxis of the peripheral PMNs. The dycorial twin consistently displayed a freedom from Aa and a reduction in the peripheral PMNs chemotaxis. The extraction of the compromised teeth in the two affected siblings has been followed by colonization of new sites by Aa; only repeated administration of systemic tetracyclines seems to protect the subjects from colonization of other sites. These findings may contribute to the understanding of the etiology, pathogenesis, and therapy of juvenile periodontitis.

Microscopic characterization of root surface-associated microbial plaque in localized juvenile periodontitis

The purpose of this investigation was to characterize by scanning electron microscopy, the microbial morphotypes associated with the roots of teeth from patients exhibiting localized juvenile periodontitis (LJP). Eighteen teeth were examined from 10 adolescent patients who satisfied the standard clinical diagnostic criteria for LJP. The microscopic evaluation was facilitated by dividing that portion of the root exposed to the periodontal pocket into coronal, middle, and apical one-thirds. Controls consisted of an equal number of teeth matched as to pocket depth and anatomical type obtained from patients exhibiting adult periodontitis (AP). All specimens were coded and examiners were unaware of their origins. Results of the SEM evaluation revealed little difference in microbial morphotypes comprising the root associated plaque in the coronal one-third of LJP specimens when compared to the AP controls. The dominant microbial morphotypes were cocci, short and long rods, filamentous microorganisms, and spirochetes. However, microbial plaque located in the middle and apical one-third root zones of LJP specimens was distinctly different than that of AP specimens. In the deeper pocket zones the dominant microbial morphotypes in LJP specimens were limited to cocci, short rods, coccobacilli, and various sized spirochetes. In contrast, AP specimens exhibited a collection of microbial morphotypes consisting of cocci, short rods, long rods, filamentous organisms and spirochetes. Calculus was found on the root surfaces of all specimens regardless of disease category although, as a group, the LJP specimens featured lesser amounts. Although areas of root resorption were common in both LJP and AP groups, they were more frequently observed in LJP specimens, likely associated with the generally less confluent deposits of calculus and plaque.

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.