Aggregatibacter actinomycetemcomitans is an oral bacterium that is mainly associated with aggressive forms of periodontitis, which most often starts at an early age. Amongst the virulence factors of A. actinomycetemcomitans, two exotoxins, the leukotoxin (LtxA) and the cytolethal distending toxin (Cdt), are suggested to play an important role in the pathogenicity of aggressive periodontitis. There is also a genetic diversity of the different strains of A. actinomycetemcomitans, and a variation in the ability of different strains to express and release exotoxins has been suggested. Of the different genotypes of A. actinomycetemcomitans, the highly leukotoxic JP2 genotype, which is prevalent in individuals of African origin, seems to be the genotype that is most strongly associated with localized aggressive periodontitis. This thesis is built upon studies of a West African adolescent population. The aim was to study the virulence characteristics of A. actinomycetemcomitans genotypes with a specific focus on the LtxA and the Cdt in relation to the progression of attachment loss (AL). The specific aim was first, to investigate cross-sectionally the presence of the JP2 and non-JP2 genotypes of A. actinomycetemcomitans in relation to the prevalence of AL and then prospectively to assess the progression of AL in a Ghanaian adolescent population. Second, in clinical isolates of A. actinomycetemcomitans obtained from the participants of the study, the serotypes and the virulence characteristics related to the two exotoxins were studied and associated with the progression of AL at the individual level. In Paper I, based on the study population consisting of 500 adolescents (mean age 13.2 years; SD ±1.5), it was shown that the overall carrier rate of A. actinomycetemcomitans was high (54.4%) and that the presence of this bacterium was associated with AL ≥ 3 mm. The JP2 genotype was prevalent (8.8%) in this population. In Paper II, 397 (79.4%) of the study participants were periodontally examined again at a 2-year follow-up. The presence of the JP2 genotype of A. actinomycetemcomitans in subgingival plaque was strongly associated with the progression of AL. This study also provided support for an enhanced estimated risk (odds ratio, OR=3.4), though less pronounced, for the progression of AL in individuals positive for the non-JP2 genotypes of A. actinomycetemcomitans. In Paper III, all three cdt genes (a, b and c) were detected in 79% of the examined A. actinomycetemcomitans isolates, all of which expressed an active toxin. The distribution of the cdt genes showed a serotype-dependent pattern. In particular, the presence of the b serotypes (both JP2 and non-JP2 genotypes) was associated with the disease progression, whereas the expression of Cdt was not particularly related to the disease progression.  In Paper IV, it was shown that the presence of of A. actinomycetemcomitans isolates with high leukotoxicity, also those of the non-JP2 genotypes of A. actinomycetemcomitans, were associated with an increased risk of the progression of AL in relation to the reference group. The main proportion of the serotype b isolates was distributed in the category of highly leukotoxic isolates. The analyses of the non-JP2 genotypes of serotype b indicated a diversity linked to the level of leukotoxicity. In conclusion, A. actinomycetemcomitans in general was associated with the progression of AL. Individuals with an increased risk of developing progression of AL mainly harboured isolates of A. actinomycetemcomitans with a high leukotoxicity, which suggests that the LtxA is an important virulence factor. Of the two exotoxins, the pathogenic potential was mainly associated with the LtxA, while the role of the Cdt is unclear.

Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [67]-81).

Orientador: Carlos Rossa Junior / Banca: Shannon Margaret Wallet / Banca: Karina Gonzales Silvério Ruiz / Banca: Alexandra Ivo de Medeiros / Banca: Paulo Sérgio Cerri / Resumo: Inflammasomes are multi-protein complexes that can amplify the inflammatory signal in situations involving host-microbial interactions and host tissue destruction, such as chronic periodontal disease. There is a relative scarcity of information on the role of NLRC4 and NLRP3 inflammasomes in periodontal disease. In this study, we used a model of bacteria-initiated periodontal disease in WT, Ipaf-knockout (Ipaf-KO), Caspase 1-knockout (Casp1-KO) and NLRP3-knockout (NLRP3-KO) mice to describe the effect of those inflammasomes on inflammation and alveolar bone resorption. Heat-killed Aggregatibacter actinomycetemcomitans (Aa) were injected in the gingival tissues on the palatal aspect adjacent to first molars of wild-type (WT), Ipaf-KO, Casp1-KO and NLRP3-KO mice, and control animals received the suspension vehicle (PBS). Severity of bone resorption was quantitated by μCT analysis. Inflammation was assessed by immunofluorescence, verifying the presence and intensity of a pan-leukocyte (CD45) and a neutrophil (Ly6G) markers. Osteoclast number was determined by TRAP and gene expression of RANKL, MMP-13, TNF-a, IL-6 and IL-10 in the gingival tissues was evaluated by RT-qPCR. In the first publication, μCT analysis showed a significantly greater inflammatory bone resorption in Ipaf-KO mice; however there was no difference between WT and Ipaf-KO on osteoclast numbers of inflammatory infiltrate. Expression of candidate genes was also similarly increased by the induction of experimental... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Inflamassomos são complexos multi protéicos capazes de amplificar o sinal inflamatório em condições de interações microbiota-hospedeiro e destruição tecidual, como a doença periodontal crônica. Devido à escassez de informações sobre o papel dos inflamassomos NLRC4 e NLRP3 na doença periodontal, utilizamos neste estudo um modelo de doença periodontal induzida por bactérias em camundongos WT, Ipafknockout (Ipaf-KO), Caspase 1-knockout (Casp1-KO) e NLRP3-knockout (NLRP3-KO) para descrever o efeito destes na inflamação e reabsorção óssea alveolar. Aggregatibacter actinomycetemcomitans (Aa) inativadas pelo calor foram injetadas nos tecidos gengivais palatais adjacentes aos primeiros molares dos camundongos normais e knockout, e os grupos controle receberam o mesmo volume do veículo de suspensão (PBS). A severidade da reabsorção óssea foi quantificada por análise de μCT. A inflamação foi avaliada por imunofluorescência, verificando-se presença e intensidade da coloração por marcadores de leucócitos (CD45) e neutrófilos (Ly6G). O número de osteoclastos foi determinado por TRAP e a expressão gênica de RANKL, MMP-13, TNF-a, IL-6 e IL-10 nos tecidos gengivais avaliada por RT-qPCR. A publicação 1 mostra uma reabsorção óssea inflamatória significativamente maior nos camundongos Ipaf-KO, sem diferenças, porém, no número de osteoclastos entre WT e Ipaf-KO. A expressão dos genes-alvo aumentou com a indução da doença periodontal, exceto de TNFa e IL-10, que foram altas n... (Complete abstract click electronic access below) / Doutor

Aggregatibacter actinomycetemcomitans is a gram-negative, facultative anaerobic coccobacillus bacterium that colonizes the human oral cavity. Regarding the bacterial consortium found into biofilms, previous studies have suggested that the occurrence of particular serotypes of A. actinomycetemcomitans may be related to other oral microorganisms. Interestingly, the relations among these bacterial species seem to be under influence of geographic and ethnical aspects. Objective: This study aimed to evaluate the frequency of A. actinomycetemcomitans serotype-specific antigens and its association with Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Campilobacter rectus in Brazilian subjects. Method: A wide group of subjects (n=1320) had their periodontal status determined and were screened for the subgingival presence of A. actinomycetemcomitans serotypes. Then, a total of 263 individuals A. actinomycetemcomitans positive for serotypes A, B, C and E were considered in this survey. Subsequently, in this same group of positive subjects, the presence of P. gingivalis, P. intermedia, T. forsythia and C. rectus from periodontal pockets were also evaluated by PCR. Result: Out of 263 subjects investigated, A. actinomycetemcomitans serotype A was detected in 28.5% subjects; serotype B in 15.97%; serotype C in 51.71% and serotype E in 3.80% subjects. The frequency of serotype A of A. actinomycetemcomitans was significantly higher in C. rectus positive subjects than in P. gingivalis, P. intermedia or T. forsythia positive subjects. Additionally, the frequency of serotypes B and C were significantly higher in both C. rectus and T. forsythia positive subjects in comparison to P. gingivalis and P. intermedia positive subjects. Meanwhile, the frequency of serotype E was not associated with the presence of the other periodontal pathogens investigated. Conclusion: We observed a positive association between A. actinomycetemcomitans serotypes A with C. rectus and between B and C serotypes with C. rectus and T. forsythia. / Aggregatibacter actinomycetemcomitans é uma bactéria do tipo cocobacilo anaeróbia facultativa gram-negativa que coloniza a cavidade oral humana. Levando em consideração as associações bacterianas encontradas no biofilme dentário, estudos prévios têm sugerido que a ocorrência de sorotipos específicos de A. actinomycetemcomitans pode estar relacionada à ocorrência de outros micro-organismos orais. Curiosamente, as relações entre essas espécies de bactérias parecem sofrer influência de aspectos geográficos e étnicos. Objetivo: Este estudo tem como objetivo avaliar a frequência de sorotipo-específicos de A. Actinomycetemcomitans e suas associações com Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia e Campilobacter rectus em indivíduos brasileiros. Materiais e Métodos: Um extenso grupo de indivíduos (n=1320) teve sua condição periodontal determinada e foram selecionados pela presença subgengival de algum sorotipo de A. actinomycetemcomitans. Sendo assim, um total de 263 indivíduos positivos para os sorotipos A, B, C e E foram considerados nessa pesquisa. Posteriormente, nesse mesmo grupo de indivíduos positivos, foram avaliadas, por PCR, a presença de P. gingivalis, P. intermedia, T. forsythia e C. rectus nas bolsas periodontais. Resultados: Dos 263 indivíduos investigados, o sorotipo A de A. actinomycetemcomitans foi detectado em 28,5% dos casos, o sorotipo B em 15,97%, o sorotipo C em 51,71% e o sorotipo E em 3,80% dos indivíduos. A frequência do sorotipo A de A. actinomycetencomitans foi significativamente maior em indivíduos positivos para C. rectus do que em indivíduos positivos para P. gingivalis, P. intermedia ou T. forsythia. Além disso, a frequência de sorotipos B e C foi significativamente maior tanto em indivíduos positivos para C. rectus quanto em T. forsythia quando comparados a indivíduos positivos para P. gingivalis e P. intermedia. Entretanto, a frequência do sorotipo E não foi associada com a presença de nenhum dos periodontopatógenos investigados. Conclusão: Observamos uma associação positiva entre o sorotipo A de A. actinomycetemcomitans com C. rectus e entre o sorotipo B e C com C. rectus e T. forsythia.

Made available in DSpace on 2014-06-12T23:02:15Z (GMT). No. of bitstreams: 2 arquivo969_1.pdf: 1672515 bytes, checksum: 57a925ef24be8c7dd06dd31514a160d4 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O presente trabalho teve por objetivo avaliar a presença dos periodontopatógenos que formam o complexo vermelho (Tannerella forsythia (Tf), Porphyromonas gingivalis (Pg) e Treponema denticola (Td)) e o Aggregatibacter actinomycetemcomitans (Aa) em pacientes portadores de periodontite crônica. A amostra foi constituída de 29 pacientes com diagnóstico clínico e radiográfico de periodontite crônica de acordo com os critérios da AAP (2000). Todos os dentes foram sondados em seis sítios para registro de profundidade, perda de inserção clínica e sangramento após sondagem. As amostras para análise microbiológica foram coletadas dos 4 sítios com maior profundidade de sondagem para cada paciente, totalizando 116 amostras. Estas amostras foram processadas através da técnica de PCR convencional e foram observados os seguintes resultados: 46,6% apresentaram resultado positivo para a bactéria Pg; 41,4% para Tf; 33,6% para Td e 27,6% para Aa. Não se verificou associação significante entre a presença dos periodontopatógenos e as variáveis faixa etária, sexo e sangramento à sondagem. Para a bactéria Pg verificou-se associação significante (p<0,05) com a variável placa visível, e a presença das bactérias Pg e Tf foi mais prevalente (p < 0,05) em bolsas periodontais &#8805; 8 mm. Nos sítios com profundidade &#61619; 8 mm foram observadas com maior freqüência as combinações Pg + Tf (23,2%) e Pg + Tf + Td (20,0%). Foram estatisticamente significantes (p < 0,05) as associações entre a presença simultânea das bactérias Aa + Pg, Aa+ Tf, Pg + Tf e entre Tf + Td. Concluiu-se que as bactérias analisadas, principalmente as do complexo vermelho, estiveram fortemente relacionadas com a periodontite crônica, e que as bactérias Pg e Tf foram mais frequentes em bolsas periodontais profundas

Das parodontopathogene Bakterium Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) exprimiert zahlreiche Virulenzfaktoren. In dieser Studie wurden die Gene für die Virulenzfaktoren Leukotoxin (LtxA), Cytolethal Distending Toxin (CDT) und Fimbriae-assoziiertes Protein (Flp1) in 99 A. actinomycetemcomitans-Isolaten aus der Plaque von Parodontitispatienten aus vier deutschen Universitätskliniken untersucht. Die Proben wurden serotypisiert. Die Entnahme erfolgte mit sterilen Papierspitzen aus der jeweils tiefsten Tasche jedes Quadranten. Es wurden von den Patienten Sondierungstiefe (PD) und Attachmentlevel (AL) an sechs Stellen pro Zahn gemessen und ebenfalls die Tiefen an den vier Entnahmestellen notiert. Außerdem wurden ethnische Herkunft der Eltern, Geschlecht und Raucherstatus erfragt. Lediglich zwei A. actinomycetemcomitans-Isolate aus Frankfurt/Main wiesen das ltx-Gen mit Deletion auf. Diese zeigten signifikant höhere PD an den vier Entnahmestellen. Die übrigen 97 Proben hatten das ltx-Gen ohne Deletion in der DNA-Promotorregion ihrer A. actinomycetemcomitans-Stämme. Probanden mit Genlokus für das cdtB-Gen, mit drei cdt-Genen oder insgesamt fünf Genen für Virulenzfaktoren litten signifikant häufiger an aggressiver Parodontitis. A. actinomycetemcomitans-Isolate mit cdtA-Gen, cdtB-Gen, cdtCGen, drei cdt-Gene oder flp-1-Gen wiesen signifikant häufiger Serotyp b oder c auf. Probanden ohne cdtC-Gen oder flp-1-Gen in der DNA ihrer isolierten A. actinomycetemcomitans-Stämme zeigten am häufigsten Serotyp e. Probanden mit Genlokus für das cdtB-Gen oder drei cdt-Gene in den isolierten A. actinomycetemcomitans-Proben oder mit aggressiver Parodontitis stammten signifikant häufiger aus dem Ausland. Es wurde kein signifikanter Zusammenhang zwischen Vorkommen der Gene für Virulenzfaktoren und PD bzw. AL im gesamten Gebiss gefunden.

Objectives: Microbial infection and the host response to the infection play a significant role in the etiology of periodontal diseases. Previous studies reported a relatively high prevalence of periodontitis among adolescents in Morocco. The importance of the composition of subgingival plaque and the presence and proportion of Aggregatibacter actinomycetemcomitans to the total plaque bacteria in the pathogenesis of periodontitis is not well understood. The purpose of this study is to compare the relative abundance of A. actinomycetemcomitans in subgingival dental plaque from young Moroccans with aggressive periodontitis, chronic periodontitis, and those without periodontitis, and to construct a multivariable model to investigate the effect of demographic attributes of age, gender and relative ratio of A. actinomycetemcomitans in dental plaque with periodontal disease status. Methods: Sample population includes 984 subjects, aging from 12-20 years old, who were surveyed and examined for periodontal disease status. 82 subjects were selected consisting of 26% aggressive periodontitis, 12% chronic periodontitis, and 62% without periodontitis. Subgingival plaque was collected from these 82 subjects. Whole DNA was extracted and purified, and real-time PCR was used employing a primer for eubacteria, and specific primer for A. actinomycetemcomitans. PCR assays confirmed the amplification and quantification of DNA of total bacterial and A. actinomycetemcomitans. Results: 73% of the subjects harbored A. actinomycetemcomitans: 63% in aggressive periodontitis, 90% in chronic periodontitis, and 73% in controls. The percentage A. actinomycetemcomitans to total bacterial load increased with age, was similar among males and females, and was somewhat higher in persons with periodontitis than the controls. Using a logistic regression analysis that included age, gender and A. actinomycetemcomitans ratio showed that only age is significantly correlated with the diagnosis of periodontitis in this population. Conclusions: A. actinomycetemcomitans is prevalent among this young Moroccan group and is somewhat more prevalent in subjects with periodontitis than the controls. However, the presence and ratio of this species to the total bacteria in subgingival plaque explained only a small proportion of the variance in periodontitis in this group. / Oral Biology

The Gram-negative bacterium Aggregatibacter actinomycetemcomitans is primarily associatedwith aggressive forms of periodontal disease. Additionally, it has occasionally been found to causemetastatic infections in non-oral sites. This requires the ability to evade the bactericidal activity ofthe complement system of the humoral immune system. Outer membrane proteins, namely,Omp100 and OmpA have been connected to normal human serum resistance for several bacteriaspecies. The objective of this study was to investigate if serum-resistant ompA mutants can beobtained, and to detect changes in OMP expression. We used A. actinomycetemcomitansserotype a strain D7SS and D7SS ompA knockouts. The strains were incubated in 50 % NHS.This resulted in a substantial decrease of survival among D7SS ompA knockouts. D7SS ompAknockouts were exposed to 50 % NHS once more to confirm stable serum resistance. 13 out of14 tested clones showed growth, indicating that serum resistant ompA mutants could begenerated. SDS-PAGE gel of extracted outer membrane vesicles revealed an additional proteinband of approximately 34 kDa in at least 4 of 5 tested serum resistant ompA mutants. This proteinband has been analyzed in the laboratory, and according to LC-MS/MS it contains an OmpAhomologue, which has been named OmpA2. We conclude that OmpA2 expression might be amajor mechanism for serum survival in A. actinomycetemcomitans serotype a strain D7SS ompAknockouts.

Aggregatibacter actinomycetemcomitans is a Gram negative bacterium found exclusively in the mammalian oral cavity where it resides in the gingival crevice, the space between the tooth and gum tissue. Though it has historically been considered a common commensal organism, it is now appreciated that A. actinomycetemcomitans is an opportunistic pathogen associated with the diseases periodontitis and endocarditis. To cause infection, A. actinomycetemcomitans must interact and compete with neighboring bacteria for space and nutrients, though little is known about the physiology it employs within the gingival crevice. Using A. actinomycetemcomitans grown in a chemically defined medium containing carbon sources found in vivo, I use transcriptome analyses and growth studies to show that A. actinomycetemcomitans preferentially utilizes lactate over the phosphotransferase system (PTS) sugars glucose and fructose. Additionally, the presence of lactate or pyruvate inhibits the transport and metabolism of these sugars in a post-transcriptionally controlled process I have termed PTS substrate exclusion. Since lactate is an energetically inferior carbon source, PTS substrate exclusion appears to be a carbon resource partitioning mechanism that allows A. actinomycetemcomitans to avoid competition for energetically favorable sugars with other species, and I propose a model to describe this phenomenon. To begin to understand the mechanism of PTS substrate exclusion, I examine the first step of the proposed model by purifying and characterizing the L-lactate dehydrogenase (LctD) from A. actinomycetemcomitans. I demonstrate that, unlike other studied lactate dehydrogenases, the LctD from A. actinomycetemcomitans does not exhibit feedback inhibition in the presence of physiologically relevant concentrations of pyruvate, which supports my hypothesis that elevated intracellular pyruvate levels inhibit the PTS. The results of my studies provide insight into a new regulatory mechanism governing carbon utilization in this bacterium. / text

Dentro do contexto do novo paradigma da doença periodontal, alguns estudos têm sugerido que a doença periodontal poderia influenciar o desenvolvimento de doenças sistêmicas, incluindo os acidentes vasculares cerebrais. O objetivo deste estudo foi avaliar as condições periodontais de pacientes com acidente vascular cerebral (AVC), comparativamente à amostra populacional sem AVC, bem como identificar e quantificar o nível de bactérias periodontopatogênicas presentes nas áreas de bolsa periodontal com a finalidade de investigar a correlação da doença periodontal com acidente vascular cerebral. Para tanto, foram selecionados 80 pacientes de ambos os sexos, com idade entre 30-80 anos. O grupo experimental foi constituído por 20 pacientes internados em ambiente hospitalar devido à ocorrência de AVC. O grupo controle foi constituído de 60 pacientes provenientes da amostra populacional da cidade de Bauru que não apresentavam sinais e sintomas clínicos ou história familiar de AVC. Um questionário de saúde investigando as possíveis causas do AVC e outras condições sistêmicas foi aplicado a todos os pacientes. Os dois grupos foram avaliados periodontalmente quanto às medidas de profundidade de sondagem, nível de inserção, sangramento à sondagem e índice de placa. Para identificar e quantificar as bactérias periodontopatogênicas, Porphyromonas gingivalis e Aggregatibacter (Actinobacillus) actinomycetemcomitans, em ambos os grupos, foi coletada amostra de placa dentomicrobiana subgengival dos dois sítios com maior profundidade de sondagem de todos os pacientes, por meio da introdução de tira de papel esterilizada (PerioPaper) no sulco gengival. A análise qualitativa e quantitativa dessas bactérias foi realizada por meio de PCR convencional e em tempo real. Os dados obtidos foram analisados por meio de análise de variância (ANOVA) complementado pelo método de Tukey, teste de correlação de Spearman, teste \"t\" de Student, Mann-Whitney, Qui-Quadrado e \"Odds Ratio\" para avaliar a correlação entre os diferentes parâmetros clínicos periodontais com o AVC e os resultados obtidos pelo PCR convencional e PCR em tempo-real, com nível de confiança de 95%. Os resultados obtidos mostraram maior prevalência da doença periodontal no grupo teste (95%) do que no controle (28,3%). O nível de inserção à sondagem, índice de placa e índice gengival estavam significativamente aumentados nos pacientes com AVC (p<0,001). Entretanto, as medidas de profundidade de sondagem não mostraram diferenças significantes entre os grupos (p=0,051), embora estivessem aumentadas para o grupo teste. A presença e quantidade da P.gingivalis foi estatisticamente maior no grupo teste do que no controle (p<0,05). Não foi encontrado A.actinomycetemcomitans em nenhum dos grupos estudados. Do total de pacientes com AVC, 65% desenvolveram AVC-I e 35% AVC-H. Pacientes com AVC-H abrigavam maiores níveis de P.gingivalis do que pacientes com AVC-I. Entretanto, nesse grupo, houve correlação positiva entre bolsas mais profundas e contagem de bactérias (p<0,05), o que não foi observado para AVC-H. A análise de risco por \"odds ratio\" identificou que pacientes com doença periodontal apresentam risco elevado de desenvolvimento de AVC (OR=48,06, IC=95%). Esses achados indicam que a doença periodontal é mais prevalente e severa em pacientes com AVC-I ou AVC-H, com grande quantidade de bactérias, especialmente P. gingivalis, presente em bolsas periodontais mais profundas, sugerindo que a doença periodontal poderia atuar como fator de risco ao desenvolvimento de acidentes vasculares cerebrais. / Inside of the context of the new paradigm of the periodontal disease, some studies have suggested that the periodontal disease could influence the development of systemics diseases, including vascular cerebral accident. The aim of this study was to evaluate the periodontal conditions of patients with vascular cerebral accidents (VCAs), comparatively to the population sample without VCA, as well as identifying and quantifying the level of periodontopathic bacteria presents in the areas of periodontal pocket in order to investigate the correlation of the periodontal disease with vascular cerebral accident. For this study, it had been selected 80 patients of both genders, with age between 30-80 years. The experimental group consisted of 20 hospitalized patients presenting VCA. The control group was consisted of 60 patients proceeding from the population sample of Bauru who did not present clinical signs and symptoms or family history of VCA. A health questionnaire investigating the possible causes of the VCA and others systemics conditions was applied to all patients. The both groups were periodontally evaluated according to probing depth measures; bleed on probing and plaque index. In other to identify and quantify the periodontopathic bacteria Porphyromonas gingivalis and Aggregatibacter (Actinobacillus) actinomycetemcomitans, in both groups, a sample of subgengival plaque was collected from the two deepest sites of all patients by the introduction of sterilized paper strip (PerioPaper). The qualitative and quantitative analysis of these bacteria was performed by conventional PCR and Real Time PCR. Data were analyzed by variance analysis test (ANOVA) complemented by the Tukey test, Pearson correlation test, Student \"t\" test, Mann-Whitney test, Qui-Square test and Odds Ratio to evaluate the different correlations between the different periodontal clinical parameters VCA, and the results obtained from the Real Time PCR, with a 95% confidence level. The analysis of the results showed significantly bigger prevalence of the periodontal disease in the test group (95%) than the control group (28,3%). The level of insertion, plaque index and bleeding on probing were significantly increased in the patients with VCA (p<0,001). However, the probing depth measures had not shown significant differences between the groups (p=0,051), even so were increased for the test group. The presence and amount of the P.gingivalis were statistically bigger in the test group than the control group (p<0,05). A.actinomycetemcomitans was not found in any of the studied groups. Considering all patients with VCA, 65% developed VCA-I and 35% VCA-H. Patients with VCA-H showed greater levels of P.gingivalis than patient with VCA-I. However, in this group, it had positive correlation between deeper pockets and number of bacteria (p<0,05), what it was not observed for VCA-H. The analysis of risk for \"odds ratio\" identified that patient with periodontal disease present high risk of VCA development (OR=48,06, IC=95%). These findings show that the periodontal disease is more prevalent and severe in patients with VCA-I or VCA-H, with great amount of bacteria, especially P. gingivalis, present in deeper periodontal pockets, suggesting that the periodontal disease could play as risk factor on the development of vascular cerebral accident.