RESUMO

The oral cavity presents a diverse microbiota in a dynamic balance with the host. Disruption of the microbial community can promote dysregulation of local immune response which could generate oral diseases. Additionally, alterations in host immune system can result in inflammatory disorders. Different microorganisms have been associated with establishment and progression of the oral diseases. Oral cavity pathogens/diseases can modulate components of the inflammatory response. Myeloid-derived suppressor cells (MDSCs) own immunoregulatory functions and have been involved in different inflammatory conditions such as infectious processes, autoimmune diseases, and cancer. The aim of this review is to provide a comprehensive overview of generation, phenotypes, and biological functions of the MDSCs in oral inflammatory diseases. Also, it is addressed the biological aspects of MDSCs in presence of major oral pathogens. MDSCs have been mainly analyzed in periodontal disease and Sjögren's syndrome and could be involved in the outcome of these diseases. Studies including the participation of MDSCs in other important oral diseases are very scarce. Major oral bacterial and fungal pathogens can modulate expansion, subpopulations, recruitment, metabolism, immunosuppressive activity and osteoclastogenic potential of MDSCs. Moreover, MDSC plasticity is exhibited in presence of oral inflammatory diseases/oral pathogens and appears to be relevant in the disease progression and potentially useful in the searching of possible treatments. Further analyses of MDSCs in oral cavity context could allow to understand the contribution of these cells in the fine-tuned balance between host immune system and microorganism of the oral biofilm, as well as their involvement in the development of oral diseases when this balance is altered.

Assuntos

Doenças Autoimunes , Células Supressoras Mieloides , Neoplasias , Síndrome de Sjogren , Humanos , Doenças Autoimunes/metabolismo , Síndrome de Sjogren/metabolismo

RESUMO

OBJECTIVES: The present study aimed to evaluate the potential of the salivary pellicle (SP) formed on titanium (Ti) surfaces to modulate the formation of a biofilm composed of Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis. MATERIALS AND METHODS: Ti substrates were incubated for 2 h with a pool of saliva samples obtained from 10 systemically and periodontally healthy subjects. Enamel substrates were included as a biological reference. Scanning electron microscopy (SEM) and Raman spectroscopy analysis were used to analyze the formation of the salivary pellicle. After the SP formation, the surfaces were incubated for 12 h with a mix of Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis. The number of bacterial cells attached to each surface was determined by the XTT assay while bacterial viability was analyzed by fluorescence microscopy using the LIVE/DEAD® BacLightTM kit. RESULTS: The SEM and Raman spectroscopy analysis confirmed the presence of a salivary pellicle formed on the tested surfaces. Regarding the biofilm formation, the presence of the SP decreases the number of the bacterial cells detected in the test surfaces, compared with the uncover substrates. Even more, the SP-covered substrates showed similar bacterial counts in both Ti and enamel surfaces, meaning that the physicochemical differences of the substrates were less determinant than the presence of the SP. While on the SP-uncover substrates, differences in the bacterial adhesion patterns were directly related to the physicochemical nature of the substrates. CONCLUSIONS: The salivary pellicle was the main modulator in the development of the biofilm consisting of representative oral bacteria on the Ti substrates. CLINICAL RELEVANCE: The results of this study provide valuable information on the modulatory effect of the salivary pellicle on biofilm formation; such information allows us to understand better the events involved in the formation of oral biofilms on Ti dental implants.

Assuntos

Biofilmes , Titânio , Humanos , Película Dentária/química , Película Dentária/microbiologia , Titânio/química , Aderência Bacteriana , Streptococcus gordonii , Fusobacterium nucleatum , Propriedades de Superfície

RESUMO

OBJECTIVE: This study aimed to standardize a quantitative polymerase chain reaction (qPCR)-based test to identify and quantify the uncultivable bacteria associated with periodontitis. METHODS: The standardization of qPCR, the curves for the quantification of Eubacterium saphenum, Eubacterium brachy, Desulfobulbus oralis, and Filifactor alocis were developed by cloning the 16 S rRNA target gene fragment, using the GEMTEasy vector. The qPCRs were validated in 55 subgingival biofilm clinical samples, from different stages of periodontitis and from periodontally healthy/gingivitis individuals, which were previously evaluated by next-generation sequencing (NGS). The results obtained by the two methods were compared by the concordance of Cohen's Kappa index, and sensitivity, specificity, receiver operating characteristic (ROC) curve, and predictive values were established. RESULTS: obtained by the two methods were compared using the concordance of Cohen's Kappa index, and sensitivity, specificity, predictive values, and ROC curves were generated. The qPCR test was standardized with efficiencies between 90% and 100% and R2: 0.997-0.999. Concordance between the qPCR and NSG was moderate to F. alocis (agreement 78.2%; kappa 0.56, p < 0.05) and fair to the other microorganisms (agreement 67.27%-72.73; kappa 0.37-0.38, p < 0.05). qPCR exhibited a high sensitivity (82.2-100%) and specificity (100%) for E. brachy, E. saphenum, and F. alocis. Sensitivity was lower to D. oralis. Conversely, qPCR demonstrated higher sensitivity to E. saphenum than NSG (100 vs. 68.1). CONCLUSIONS: The uncultivable microorganisms associated with periodontitis, D. oralis, E. brachy, E. saphenum, and F. alocis can be detected and quantified with the newly developed and validates qPCR test.

Assuntos

Gengivite , Periodontite , Humanos , Porphyromonas gingivalis/genética , Periodontite/microbiologia , Reação em Cadeia da Polimerase/métodos

RESUMO

Objective: To describe the existing knowledge about the alterations of the MBO oral microbiome and the presence of OL Oral Lesions in patients with Acute Lymphoblastic Leukemia ALL. Materials and Methods: An electronic search was carried out in the PubMed, SciELO, and academic Google databases, and descriptive, analytical, observational articles on MBO, OL, and ALL were included, following the PRISMA criteria. 642 were evaluated, duplicate articles, case reports, and those where only changes were reported during or after chemotherapy treatment were eliminated. Results: 10 articles were evaluated, published between 1997 and 2021, 4 articles agreed that the MBO of patients with ALL is in dysbiosis showing a significant increase in firmicutes 0.1%, bacillus 0.05%, and opportunistic bacteria such as Moraxella spp, Klebsiella spp 5.66%, Pseudomonas spp 3.77%, Enterobacter spp 1.88%, Acinetobacter spp 1.88% and E. coli 1.08%, the most frequent OL reported in 5 articles were spontaneous gingival bleeding 3.5%, gingivitis 25% and ulcers 9.4%. Conclusions: The oral cavity of patients with ALL is in dysbiosis and associated OL is identified. It is necessary to establish preventive strategies with a niche-ecological approach to restore the MBO, to reduce the risk of opportunistic infections and other OL during chemotherapy treatment.

RESUMO

This updated review article covers the literature between 2011 and 2021 on the antibacterial activity of EOs against the main bacteria that cause caries and periodontal diseases. The criteria to classify the in vitro antibacterial activity of EOs is updated and the most promising results are addressed.

Assuntos

Óleos Voláteis , Antibacterianos/farmacologia , Bactérias , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia

RESUMO

Cercospora brachiata is a phytopathogenic fungus. To know more about the metabolites produced by this fungus, the objective of this work was to identify, isolate and characterize substances present in extracts of the growth broth and mycelium, using gas chromatography with mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). It was also objective to evaluate the antibacterial activity of the extracts. Among the compounds identified, fatty acids, esters, and steroids can be highlighted. The main compounds identified are 9-hexadecenoic, hexadecenoic, oleic, octadecanoic, lauric, myristic, palmitic, doceno-13-enoic, stearic, linoleic, and nonadecanoic acids present in almost all extracts. For the antibacterial activity, the broth microdilution method was used. The ethyl acetate extract of the mycelium presented inhibitory concentrations (MICs) against the bacterium Actinomyces naeslundii (100 µg mL-1) and Streptococcus sanguinis (200 µg mL-1). Finally, two steroids were isolated and identified in the hexane extract of mycelium: ergosta-6,22-dien-3ß,5α,8α-triol and brassicasterol.

RESUMO

Prophylaxis with antiseptic and antibiotic therapy is common in impacted lower third molar surgeries, despite the lack of consensus among professionals and researchers in the indication for healthy patients. The aim of the present preliminary study was to verify the impact of prophylaxis therapy with antiseptic and antibiotic in healthy patients submitted to impacted lower third molar extraction, according to oral microorganism quantification. Eleven patients submitted to impacted lower third molar extraction, under prophylactic therapy with 0.12% chlorhexidine and amoxicillin in four experimental phases, were evaluated. Our results showed no significant reduction in total bacteria load, as well as in Bacteroidetes and C. albicans loads in the oral cavity, after prophylactic therapy with antiseptic and antibiotic. On the other hand, there was a significant difference between the Firmicutes levels across the follow-up, and this effect seems to be large (ηp²=0.94). Post-hoc test demonstrated that the levels of Firmicutes in T1 were higher than T0, T2, and T3, suggesting a microbiota dysbiosis, when 0.12% chlorhexidine use, which may be responsible for selection of antibiotic-resistant microorganisms. Our results alert for an overuse of antiseptic and antibiotics by dentists and for a better evaluation of the available protocols.

Assuntos

Clorexidina , Dente Serotino , Antibacterianos/uso terapêutico , Antibioticoprofilaxia , Disbiose/tratamento farmacológico , Firmicutes , Humanos , Dente Serotino/cirurgia

RESUMO

Immune responses at the boundary between the host and the world beyond are complex and mucosal tissue homeostasis relies on them. Obstructive sleep apnea (OSA) is a syndrome suffered by children with hypertrophied tonsils. We have previously demonstrated that these tonsils present a defective regulatory B cell (Breg) compartment. Here, we extend those findings by uncovering the crucial role of resident pro-inflammatory B and T cells in sustaining tonsillar hypertrophy and hyperplasia by producing TNFα and IL17, respectively, in ex vivo cultures. Additionally, we detected prominent levels of expression of CD1d by tonsillar stratified as well as reticular epithelium, which have not previously been reported. Furthermore, we evidenced the hypertrophy of germinal centers (GC) and the general hyperplasia of B lymphocytes within the tissue and the lumen of the crypts. Of note, such B cells resulted mainly (IgG/IgM)+ cells, with some IgA+ cells located marginally in the follicles. Finally, by combining bacterial culture from the tonsillar core and subsequent identification of the respective isolates, we determined the most prevalent species within the cohort of OSA patients. Although the isolated species are considered normal oropharyngeal commensals in children, we confirmed their capacity to breach the epithelial barrier. Our work sheds light on the pathological mechanism underlying OSA, highlighting the relevance taken by the host immune system when defining infection versus colonization, and opening alternatives of treatment.

Assuntos

Bactérias/imunologia , Infecções Bacterianas/imunologia , Mucosa Bucal/imunologia , Mucosa Bucal/microbiologia , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/imunologia , Tonsilite/complicações , Tonsilite/imunologia , Adolescente , Linfócitos B/imunologia , Bactérias/isolamento & purificação , Infecções Bacterianas/microbiologia , Células Cultivadas , Criança , Pré-Escolar , Doença Crônica , Estudos de Coortes , Citocinas/metabolismo , Feminino , Centro Germinativo/imunologia , Humanos , Hipertrofia/imunologia , Hipertrofia/metabolismo , Inflamação/imunologia , Inflamação/metabolismo , Masculino , Tonsila Palatina/imunologia , Linfócitos T/imunologia , Tonsilectomia , Tonsilite/microbiologia , Tonsilite/cirurgia

RESUMO

A doença periodontal é uma doença infecciosa que atinge os tecidos de sustentação e proteção do dente e tem como principal determinante o biofilme dental. Recentemente foram feitas pesquisas que indicam a doença periodontal como um provável fator de risco para doenças cardiovasculares, incluindo aterosclerose, infarto do miocárdio, acidente vascular cerebral, diabetes, partos prematuros e distúrbios respiratórios. O presente trabalho tem como objetivo revisar na literatura a partir das influências da doença periodontal no desenvolvimento e potencialização de patologias pulmonares, compreendendo o processo infeccioso no trato respiratório ocasionado por bactérias bucais. Para tanto, foi realizada uma busca eletrônica de artigos científicos indexados em bases de dados, como: Pubmed, Scielo e Lilacs. Os critérios de inclusão adotados, foram: a) Idioma: Línguas Portuguesa e Inglesa; b) Período: De 2007 a 2018; c) Método de pesquisa: Estudos observacionais e ensaios clínicos. Os estudos que buscam investigar o vínculo existente entre as doenças periodontais e patologias pulmonares, bem como os fatores facilitadores e predisponentes são fundamentais à elaboração de estratégias no que concerne aos setores da saúde, em virtude de estarem relacionados a altos índices de morbidade e mortalidade. Os achados da literatura acima apresentadas neste trabalho, demonstram que a higienização bucal é o mecanismo mais eficaz à prevenção de origem e exacerbação de patologias respiratórias, provenientes do contato com agentes patógenos oriundos do biofilme oral.(AU)

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The periodontal disease isaninfectious disease that reaches the tissues of support and protection of the tooth, its main determinant is the dental biofilm. Research has recently be end one that indicate periodontal disease as a likely risk factor for cardiovascular disease, including at herosclerosis, myocardial linfarction, stroke, diabetes, preterm delivery, and respiratory disorders. The present work aim store view in the literature from the influences of periodontal disease on the development and potentiation of pulmonary pathologies, including the infectious process in the respiratory tractcaused by oral bacteria. To do so an electronic search of scientific articles indexed in data bases was performed, such as Pubmed, Scielo and Lilacs. The inclusion criteria adopted were: a) Language: Portuguese and English; b) Period: From 2007 to 2018; c) Research method: Observational studies and clinical trials. Studies that seek to investigate the link between periodontal diseases and pulmonary pathologies, as well as the facilitating and predisposing factors are fundamental to the development of strategies in the health sectors, because they are related to high morbidit yandmortality rates. The literature findings presented in this study, demonstrated that oral hygiene is the most effective mechanism for the prevention of origin and exacerbation of respiratory pathologies, arising from contact with pathogenic agents originating from oral biofilm (AU)

Assuntos

Doenças Periodontais , Periodontite , Bactérias , Pneumopatias

RESUMO

The biotransformation of the lignan (-)-cubebin by filamentous fungi Aspergillus terreus and Aspergillus niger is an efficient bioprocess for obtaining (-)-hinokinin and (-)-parabenzlactone. The relevance of getting (-)-hinokinin is due to its promising effect against oral pathogens, especially S. sanguinis (both MIC and MBC 12.5 µg/mL), and other previous reported effects against Chagas disease and as anti-inflammatory. The advantage of using fungal transformation is the use of non-toxic and/or non-pollutant reagents and/or solvents in comparison with semi-synthesis. Microbial transformation of (-)-cubebin is also important to evaluate its human metabolism, since Aspergillus species are capable of mimicking P450 reactions, providing possible products of the metabolism, which is important in the assessment of its efficacy and safety. Furthermore, the present study describes a reliable RP-HPLC method to perform quantification of (-)-hinokinin in fungal extracts. It is simple, fast, selective, linear, precise, accurate and robust according to validation guidelines.

Assuntos

4-Butirolactona/análogos & derivados , Aspergillus/metabolismo , Bactérias/efeitos dos fármacos , Benzodioxóis/metabolismo , Compostos de Benzil/metabolismo , Biotransformação , Lactonas/metabolismo , Lignanas/metabolismo , 4-Butirolactona/análise , 4-Butirolactona/metabolismo , 4-Butirolactona/farmacologia , Benzodioxóis/análise , Benzodioxóis/farmacologia , Compostos de Benzil/farmacologia , Fungos , Humanos , Lactonas/farmacologia , Lignanas/análise , Lignanas/farmacologia

RESUMO

We present an overview of how members of the oral microbiota respond to their environment by regulating gene expression through two-component signal transduction systems (TCSs) to support conditions compatible with homeostasis in oral biofilms or drive the equilibrium toward dysbiosis in response to environmental changes. Using studies on the sub-gingival Gram-negative anaerobe Porphyromonas gingivalis and Gram-positive streptococci as examples, we focus on the molecular mechanisms involved in activation of TCS and species specificities of TCS regulons.

RESUMO

This study aimed to assess differences in selected oral bacteria in children according to the severity of dental caries. One hundred and thirty-six children, 36-60 months old were divided into three groups according to caries status: caries-free (CF) (n=47), early childhood caries (ECC) (n=40) and severe-early childhood caries (S-ECC) (n=49). Saliva was collected for detection and quantification of selected oral streptococci, Actinomyces naeslundii, Lactobacillus spp., Bifidobacterium spp., and Scardovia wiggsiae by quantitative-polymerase chain reaction. The results showed that the detection and quantitative levels of S. mutans, S. sobrinus, Bifidobacterium spp. and S. wiggsiae were significantly higher in S-ECC children compared to CF and ECC children, while for S. salivarius were significantly higher in CF compared to ECC and S-ECC children. There was no statistical difference among the clinical groups for S. mitis, S. oralis, A. naeslundii and Lactobacillus spp. levels and detection. S-ECC children had a lower monthly family income, started tooth brushing later and were breastfeed for a longer duration compared to CF children. S. mutans levels were positively correlated with S. wiggsiae and Bifidobacterium spp. levels, lower mother's education and child bottle-feeding before sleeping and negatively correlated with S. salivarius. It was concluded that in addition to S. mutans, other bacterial species, including bifidobacteria, Scardovia wiggsiae and S. sobrinus, are associated with severity of early childhood caries, although their role in the progress of dental caries remains unclear.

Assuntos

Cárie Dentária/microbiologia , Cárie Dentária/patologia , Saliva/microbiologia , Actinobacteria/isolamento & purificação , Bifidobacterium/isolamento & purificação , Pré-Escolar , Feminino , Humanos , Renda/estatística & dados numéricos , Lactobacillus/isolamento & purificação , Masculino , Reação em Cadeia da Polimerase , Índice de Gravidade de Doença , Streptococcus/isolamento & purificação

RESUMO

OBJECTIVE: to investigate the associations of oral microbiota, leucocytes count, neutrophil count, platelet counts and hemoglobin level, and the severity of oral mucositis in pediatric patients with acute lymphoblastic leukemia (ALL) receiving chemotherapy. MATERIALS AND METHODS: 71 prospective patients were included. Analyses of oral microbiota and blood sample were conducted on days 14 (D14) and 56 (D56) of the Brazilian GBTLI-99 treatment protocol. Herpes simplex virus (HSV) identification was performed by PCR followed by DNA sequencing analysis. Bacteria and fungi identification was obtained by standard microbiological culture tests. RESULTS: 103 episodes of mucositis occurred, being 65 at D14 and 38 at D56. Most cases positive for herpes viral DNA sequences were identified as HSV-1. At D14, we found a significant association between the severity of mucositis and presence of HSV-1 (p = 0.0347), Candida spp. (p = 0.0078), and low platelet count (p = 0.0064). At D56, we found a significant association between the severity of mucositis and the presence of HSV-1 (p = 0.0317), previous HSV-1 presence on D14 (p < 0.0001) and neutrophil count (p = 0.0211). CLINICAL RELEVANCE: the identification of risk factors for mucositis in children and adolescents may contribute to the development of new strategies for prevention and/or treatment, reducing the complications associated with this condition. CONCLUSIONS: the presence of HSV, platelet count, and Candida spp. presence at D14 of ALL induction treatment is associated with increased severity of mucositis in children and adolescents. At D56 of ALL treatment, mucositis severity was associated with neutrophil count, HSV presence, and previous presence of HSV (at D14).

Assuntos

Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Candida , Candidíase/epidemiologia , Herpes Simples/epidemiologia , Herpesvirus Humano 1 , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Estomatite/epidemiologia , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Brasil/epidemiologia , Candidíase/induzido quimicamente , Criança , Pré-Escolar , Feminino , Herpes Simples/induzido quimicamente , Humanos , Lactente , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Estudos Prospectivos , Estomatite/induzido quimicamente

RESUMO

OBJECTIVES: This study reports on the synthesis, materials characterization, antimicrobial capacity, and cytocompatibility of novel ZnO-loaded membranes for guided tissue/bone regeneration (GTR/GBR). METHODS: Poly(ɛ-caprolactone) (PCL) and PCL/gelatin (PCL/GEL) were dissolved in hexafluoropropanol and loaded with ZnO at distinct concentrations: 0 (control), 5, 15, and 30wt.%. Electrospinning was performed using optimized parameters and the fibers were characterized via scanning and transmission electron microscopies (SEM/TEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), contact angle (CA), mechanical testing, antimicrobial activity against periodontopathogens, and cytotoxicity test using human dental pulp stem cells (hDPSCs). Data were analyzed using ANOVA and Tukey (α=5%). RESULTS: ZnO nanoparticles were successfully incorporated into the overall submicron fibers, which showed fairly good morphology and microstructure. Upon ZnO nanoparticles' incorporation, the PCL and PCL/GEL fibers became thicker and thinner, respectively. All GEL-containing membranes showed lower CA than the PCL-based membranes, which were highly hydrophobic. Overall, the mechanical properties of the membranes were reduced upon ZnO incorporation, except for PCL-based membranes containing ZnO at the 30wt.% concentration. The presence of GEL enhanced the stretching ability of membranes under wet conditions. All ZnO-containing membranes displayed antibacterial activity against the bacteria tested, which was generally more pronounced with increased ZnO content. All membranes synthesized in this study demonstrated satisfactory cytocompatibility, although the presence of 30wt.% ZnO led to decreased viability. SIGNIFICANCE: Collectively, this study suggests that PCL- and PCL/GEL-based membranes containing a low content of ZnO nanoparticles can potentially function as a biologically safe antimicrobial GTR/GBR membrane.

Assuntos

Células-Tronco Adultas/fisiologia , Perda do Osso Alveolar/terapia , Anti-Infecciosos/química , Polpa Dentária/fisiologia , Regeneração Tecidual Guiada , Bicamadas Lipídicas/química , Nanopartículas Metálicas/química , Regeneração Óssea , Células Cultivadas , Gelatina/química , Humanos , Membranas Artificiais , Poliésteres/química , Espectroscopia de Infravermelho com Transformada de Fourier , Óxido de Zinco/química

RESUMO

The oral cavity may act as a reservoir for several pathogens related to systemic infections. Therefore, the purpose of this study was to determine the prevalence and levels of pathogenic bacteria in the subgingival biofilm of chronic periodontitis lesions and healthy periodontal sites using the checkerboard DNA-DNA hybridization technique. 200 samples of subgingival biofilm from sites with periodontitis (probing pocket depth > 4 mm and /or clinical attachment level > 4 mm) and 200 samples from healthy sites of 14 patients with chronic periodontitis, as well as 200 samples from 3 periodontally healthy patients were obtained. The presence and levels of 11 pathogenic bacteria were determined using whole genomic DNA probes and the checkerboard method, computed for each site and then across sites within each subject group. Significance of differences in clinical and microbiological parameters among groups were examinated using the Mann-Whitney and Wilcoxon sign tests. The predominant species in all 600 samples included Corynebacterium diphtheriae, Enterococcus faecalis, Staphylococcus aureus,Acinetobacter baumannii and Escherichia coli. In general, most of the species were detected in greater prevalence and levels in sites with and without disease from patients with periodontitis in comparison to the periodontally healthy group. In particular, C. diphtheriae, E. coli, E. faecalis, P. aeruginosa and S. aureus were significantly more prevalent and detected in higher counts in diseased sites of patients with periodontal disease compared to healthy subjects (p 0.05). Clinical signs of disease presented a positive correlation with the species A. baumannii, Streptococcus pyogenes, E. coli, S. aureus and P. aeruginosa. In conclusion, "non-oral" pathogenic bacteria are detected in high prevalence and levels in periodontal sites of chronic periodontitis patients.

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Apesar da extensa literatura sobre a associação de bactérias orais e doenças sistêmicas, tem se dado pouca atenção à cavidade oral como um reservatório de bactérias patogênicas "não-orais". A microbiota oral é constituída de mais de 300 espécies bacterianas já caracterizadas, além de organismos não cultiváveis que vêm sendo descobertos através de técnicas moleculares. O objetivo do presente estudo foi determinar a prevalência e os níveis de 11 bactérias patogênicas "não-orais" em sítios periodontais de pacientes com periodontite e de pacientes saudáveis, utilizando a técnica do "Checkerboard DNA-DNA hybridization". 200 amostras de biofilme subgengival de sítios doentes (PBS > 4mm e/ou NCI > 4mm), 200 amostras de sítios saudáveis de 14 pacientes com periodontite e 200 amostras de sítios de 3 pacientes saudáveis foram selecionadas. A prevalência (% de sítios colonizados) e os níveis de cada espécie bacteriana foram computados para cada sítio e dentro de cada grupo. Diferenças clínicas e microbiológicas entre os grupos foram avaliadas através dos testes de Mann-Whitney e Wilcoxon. As espécies que predominaram nas 600 amostras analisadas incluíram Corynebacterium diphtheriae, Enterococcus faecalis, Staphylococcus aureus, Acinetobacter baumannii e Escherichia coli. Em geral, a maioria das espécies estudadas foi detectada com maior freqüência e em níveis elevados nos sítios com e sem doença nos pacientes com periodontite em relação ao grupo com saúde periodontal. Em particular, C. diphtheriae, E. coli, E. faecalis, Pseudomonas. aeruginosa e S. aureus foram significantemente mais prevalentes e detectadas em maior número nos sítios doentes de pacientes com periodontite em relação aos sítios de indivíduos com saúde periodontal (p 0,05). Sinais clínicos de doença periodontal apresentaram uma correlação positiva com as espécies A. baumannii, Streptococcus pyogenes, E. coli, S. aureus e P. aeruginosa. Além disso, as espécies S. pyogenes e A. baumannii, C. diphteriae e E. faecalis,C. diphteriae e S. pyogenes, S. aureus e P. aeruginosa também demonstraram uma forte correlação positiva entre si. Bactérias patogênicas "não-orais" são detectadas em grande prevalência e altos níveis em sítios de pacientes com periodontite crônica.