194 resultados para ACTINOBACILLUS-ACTINOMYCETEMCOMITANS


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BACKGROUND Loss-of-function point mutations in the cathepsin C gene are the underlying genetic event in patients with Papillon-Lefèvre syndrome (PLS). PLS neutrophils lack serine protease activity essential for cathelicidin LL-37 generation from hCAP18 precursor. AIM We hypothesized that a local deficiency of LL-37 in the infected periodontium is mainly responsible for one of the clinical hallmark of PLS: severe periodontitis already in early childhood. METHODS To confirm this effect, we compared the level of neutrophil-derived enzymes and antimicrobial peptides in gingival crevicular fluid (GCF) and saliva from PLS, aggressive and chronic periodontitis patients. RESULTS Although neutrophil numbers in GCF were present at the same level in all periodontitis groups, LL-37 was totally absent in GCF from PLS patients despite the large amounts of its precursor, hCAP18. The absence of LL-37 in PLS patients coincided with the deficiency of both cathepsin C and protease 3 activities. The presence of other neutrophilic anti-microbial peptides in GCF from PLS patients, such as alpha-defensins, were comparable to that found in chronic periodontitis. In PLS microbial analysis revealed a high prevalence of Aggregatibacter actinomycetemcomitans infection. Most strains were susceptible to killing by LL-37. CONCLUSIONS Collectively, these findings imply that the lack of protease 3 activation by dysfunctional cathepsin C in PLS patients leads to the deficit of antimicrobial and immunomodulatory functions of LL-37 in the gingiva, allowing for infection with A. actinomycetemcomitans and the development of severe periodontal disease.

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OBJECTIVES To assess the association between presence of periodontal pathogens and recurrence of disease in patients with aggressive periodontitis (AgP) after active periodontal therapy (APT) and further influencing factors. MATERIAL & METHODS Microbiological samples were taken from 73 patients with AgP 5-17 years after APT at 292 sites (deepest site per quadrant). Real-time polymerase chain reactions were used to detect the periodontal pathogens Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola. Uni- and multivariate analyses evaluated the associations between pathogens and recurrence of disease, smoking and adjunctive antibiotic therapy. RESULTS At re-examination A. actinomycetemcomitans could be detected in six patients (8.2%), P. gingivalis in 24 (32.9%), T. forsythia in 31 (42.5%) and T. denticola in 35 (48.0%). Increased levels of T. forsythia and T. denticola at re-examination were significantly associated with recurrence of disease in multivariate analyses (OR: 12.72, p < 0.001; OR 5.55, p = 0.002 respectively). Furthermore, high counts of T. denticola were found in patients with increased percentage of sites with clinical attachment levels (CAL) ≥ 6 mm compared to those with low counts (13.8% versus 3.2%, p = 0.005). CONCLUSION In patients with recurrence of disease T. forsythia and T. denticola were detected more frequently and in higher counts. Furthermore, T. denticola was found more frequently in patients with increased CAL.

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BACKGROUND Findings from animal and human studies have indicated that an oily calcium hydroxide suspension (OCHS) may improve early wound healing in the treatment of periodontitis. Calcium hydroxide as the main component is well known for its antimicrobial activity, however at present the effect of OCHS on the influence of periodontal wound healing/regeneration is still very limited. The purpose of this in vitro study was to investigate the effect of OCHS on periodontopathogenic bacteria as well as on the attachment and proliferation of osteoblasts and periodontal ligament fibroblasts. METHODS Human alveolar osteoblasts (HAO) and periodontal ligament (PDL) fibroblasts were cultured on 3 concentrations of OCHS (2.5, 5 and 7.5 mg). Adhesion and proliferation were counted up to 48 h and mineralization was assayed after 1 and 2 weeks. Furthermore potential growth inhibitory activity on microorganisms associated with periodontal disease (e.g. Porphyromonas gingivalis, Tannerella forsythia, Aggregatibacter actinomycetemcomitans) as well as the influence of periodontopathogens and OCHS on the HAO and PDL fibroblasts counts were determined. RESULTS More than a 2-fold increase in adherent HAO cells was observed at 4 h following application of OCHS when compared to the control group (p = 0.007 for 2.5 mg). Proliferation of HAO cells at 48 h was stimulated by moderate concentrations (2.5 mg; 5 mg) of OCHS (each p < 0.001), whereas a high concentration (7.5 mg) of OCHS was inhibitory (p = 0.009). Mineralization was observed only for HAO cells treated with OCHS. OCHS did not exert any positive effect on attachment or proliferation of PDL fibroblasts. Although OCHS did not have an antibacterial effect, it did positively influence attachment and proliferation of HAO cells and PDL fibroblasts in the presence of periodontopathogens. CONCLUSIONS The present data suggests that OCHS promotes osteoblast attachment, proliferation and mineralization in a concentration-dependent manner and results are maintained in the presence of periodontal pathogens.

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BACKGROUND Information on the microbiota in peri-implantitis is limited. We hypothesized that neither gender nor a history of periodontitis/smoking or the microbiota at implants differ by implant status. MATERIALS AND METHODS Baseline microbiological samples collected at one implant in each of 166 participants with peri-implantitis and from 47 individuals with a healthy implant were collected and analyzed by DNA-DNA checkerboard hybridization (78 species). Clinical and radiographic data defined implant status. RESULTS Nineteen bacterial species were found at higher counts from implants with peri-implantitis including Aggregatibacter actinomycetemcomitans, Campylobacter gracilis, Campylobacter rectus, Campylobacter showae, Helicobacter pylori, Haemophilus influenzae, Porphyromonas gingivalis, Staphylococcus aureus, Staphylococcus anaerobius, Streptococcus intermedius, Streptococcus mitis, Tannerella forsythia, Treponema denticola, and Treponema socranskii (p < .001). Receiver operating characteristic curve analysis identified T. forsythia, P. gingivalis, T. socranskii, Staph. aureus, Staph. anaerobius, Strep. intermedius, and Strep. mitis in peri-implantitis comprising 30% of the total microbiota. When adjusted for gender (not significant [NS]), smoking status (NS), older age (p = .003), periodontitis history (p < .01), and T. forsythia (likelihood ratio 3.6, 95% confidence interval 1.4, 9.1, p = .007) were associated with peri-implantitis. CONCLUSION A cluster of bacteria including T. forsythia and Staph. aureus are associated with peri-implantitis.

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The antimicrobial activity of taurolidine was compared with minocycline against microbial species associated with periodontitis (four single strains and a 12-species mixture). Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs), killing as well as activities on established and forming single-species biofilms and a 12-species biofilm were determined. The MICs of taurolidine against single species were always 0.31 mg/ml, the MBCs were 0.64 mg/ml. The used mixed microbiota was less sensitive to taurolidine, MIC and the MBC was 2.5 mg/ml. The strains and the mixture were completely killed by 2.5 mg/ml taurolidine, whereas 256 μg/ml minocycline reduced the bacterial counts of the mixture by 5 log10 colony forming units (cfu). Coating the surface with 10 mg/ml taurolidine or 256 μg/ml minocycline prevented completely biofilm formation of Porphyromonas gingivalis ATCC 33277 but not of Aggregatibacter actinomycetemcomitans Y4 and the mixture. On 4.5 d old biofilms, taurolidine acted concentration dependent with a reduction by 5 log10 cfu (P. gingivalis ATCC 33277) and 7 log10 cfu (A. actinomycetemcomitans Y4) when applying 10 mg/ml. Minocycline decreased the cfu counts by 1-2 log10 cfu independent of the used concentration. The reduction of the cfu counts in the 4.5 d old multi-species biofilms was about 3 log10 cfu after application of any minocycline concentration and after using 10 mg/ml taurolidine. Taurolidine is active against species associated with periodontitis, even within biofilms. Nevertheless a complete elimination of complex biofilms by taurolidine seems to be impossible and underlines the importance of a mechanical removal of biofilms prior to application of taurolidine.

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OBJECTIVES The aim of the present longitudinal study was to investigate bacterial colonization of the internal implant cavity and to evaluate a possible association with peri-implant bone loss. METHODS A total of 264 paper point samples were harvested from the intra-implant cavity of 66 implants in 26 patients immediately following implant insertion and after 3, 4, and 12 months. Samples were evaluated for Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Tannerella forsythia as well as total bacterial counts by real-time PCR. Bone loss was evaluated on standardized radiographs up to 25 months after implant insertion. For the statistical analysis of the data, mixed effects models were fitted. RESULTS There was an increase in the frequency of detection as well as in the mean counts of the selected bacteria over time. The evaluation of the target bacteria revealed a significant association of Pr. intermedia at 4 and 12 months with peri-implant bone loss at 25 months (4 months: P = 0.009; 12 months: P = 0.021). CONCLUSIONS The present study could demonstrate a progressive colonization by periodontopathogenic bacteria in the internal cavities of two-piece implants. The results suggest that internal colonization with Pr. intermedia was associated with peri-implant bone loss.

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Background: Studies of oyster microbiomes have revealed that a limited number of microbes, including pathogens, can dominate microbial communities in host tissues such as gills and gut. Much of the bacterial diversity however remains underexplored and unexplained, although environmental conditions and host genetics have been implicated. We used 454 next generation 16S rRNA amplicon sequencing of individually tagged PCR reactions to explore the diversity of bacterial communities in gill tissue of the invasive Pacific oyster Crassostrea gigas stemming from genetically differentiated beds under ambient outdoor conditions and after a multifaceted disturbance treatment imposing stress on the host. Results: While the gill associated microbial communities in oysters were dominated by few abundant taxa (i.e. Sphingomonas, Mycoplasma) the distribution of rare bacterial groups correlated to relatedness between the hosts under ambient conditions. Exposing the host to disturbance broke apart this relationship by removing rare phylotypes thereby reducing overall microbial diversity. Shifts in the microbiome composition in response to stress did not result in a net increase in genera known to contain potentially pathogenic strains. Conclusion: The decrease in microbial diversity and the disassociation between population genetic structure of the hosts and their associated microbiome suggest that disturbance (i.e. stress) may play a significant role for the assembly of the natural microbiome. Such community shifts may in turn also feed back on the course of disease and the occurrence of mass mortality events in oyster populations.

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A alveolite seca (AS) é uma das complicações pós-operatórias mais comuns e sintomáticas na odontologia, porém, até o momento não há um protocolo de tratamento definido. O composto fenólico guaiacol (Gu) é um dos materiais utilizados para revestimento intra-alveolar devido às suas propriedades analgésicas, antioxidantes e antimicrobianas. Contudo, sua desvantagem é a dificuldade de manipulação decorrente da sua baixa estabilidade, alta volatilidade e sensibilidade à oxidação. Para melhorar suas propriedades e aumentar sua aplicabilidade clínica, um complexo de inclusão de Gu com ß-ciclodextrina (ßcd) foi desenvolvido. A formação do complexo supramolecular de Gu:ßcd foi caracterizada mediante a ressonância magnética nuclear (RMN), nos experimentos de 1H e 2D ROESY. A atividade antibacteriana do Gu e Gu:ßcd frente a Escherichia coli, Staphylococcus aureus, Streptococcus mitis, Streptococcus mutans, Streptococcus sanguis e Aggregatibacter actinomycetemcomitans foi analisada pelo método da microdiluição e sua citotoxicidade em osteoblastos de calvária de rato, foi estudado com o ensaio do MTT. O processo de reparo alveolar induzido pelo Gu:ßcd foi avaliado histologicamente após tratamento de alveolite seca em molares inferiores de ratos. A RMN mostrou correlações espaciais entre os hidrogênios internos (H3 e H5) da ßcd e os hidrogênios aromáticos, H(a) e H(b) do Gu, confirmando a formação do complexo. A complexação do Gu na ßcd potencializou seu efeito antibacteriano e reduziu sua citotoxicidade em osteoblastos. O estudo in vivo evidenciou a ocorrência de ossificação no ápice alveolar dos ratos tratados com Gu:ßcd, no 7o dia. No 14o dia, as trabéculas ósseas ocuparam também o terço médio do alvéolo e no 21o dia, todo o alvéolo se encontrava preenchido por osso neoformado. Estes resultados foram similares ao controle negativo e superiores ao controle positivo (Alvogyl®). Os benefícios obtidos pela inclusão do Gu na ßcd foram demonstrados pela melhora das propriedades biológicas do Gu in vitro e o adequado reparo alveolar in vivo.

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Se observa en la literatura una gran controversia alrededor de la capacidad del láser para aportar mejorías al tratamiento periodontal no quirúrgico. El objetivo de este estudio es valorar si, en el tratamiento periodontal básico, el láser es más eficaz que el raspado y alisado radicular en cuanto a la mejoría de parámetros tanto clínicos (profundidad de sondaje, sangrado al sondaje y nivel de inserción) como microbiológicos (presencia o ausencia de A. actinomycetemcomitans, P. gingivalis, T. forsythia). 10.3. MATERIALES Y MÉTODOS Se seleccionan 36 pacientes con enfermedad periodontal crónica generalizada de grado moderado-severo y se reparten en dos grupos: 18 pacientes para el grupo control, en el que se realiza el tratamiento periodontal convencional con instrumentación manual, y 18 pacientes para el grupo experimental, en el que se realiza el tratamiento con el láser Er,Cr:YSGG. Los datos clínicos analizados son: el índice de placa, el índice gingival, la recesión gingival, el nivel de inserción y la profundidad de sondaje. En el laboratorio se analiza, por medio de la PCR, la muestra microbiológica del surco gingival. Los participantes también rellenan un cuestionario sobre la hipersensibilidad dental y las molestias en general percibidas durante el tratamiento. Todos los datos se toman al principio del estudio y a las seis semanas de haber finalizado el tratamiento. Se utiliza el método UNIANOVA para el análisis estadístico entre los dos grupos...

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Arachidonic acid (AA) a precursor in the formation of eicosanoids which are lipid mediators with a number of functions in human physiology and pathology. The most of the eicosanoids act as proinflammatory mediators and contribute to the development and proliferation of tumors. In this thesis we evaluated two mediators: 15-deoxy-Δ12,14-PGJ2 (15d- PGJ2) and epoxieicosatrienoic acids (EETs) both act with an opposite activity of most eicosanoids, with an anti-inflammatory and and anti-tumoral action these two distinct mediators from AA pathway were used in this thesis in two different projects. First: 15d- PGJ2, was described that to have an antiproliferative activity and to induce apoptosis in several types of tumor cells however, the effect of 15d- PGJ2 in thyroid cancer cells was unknown in this sense, we tested in vitro cultured thyroid tumor cells, here in TPC1 cells, and treated with different concentrations of 15d- PGJ2 (0 to 20 uM) the treated cells showed a decrease in proliferation and an increase in apoptosis and a decrease in IL-6 release and relative expression. These key results together demonstrate that 15d- PGJ2 can be used as a new therapy for thyroid cancer. Second: The EETs are converted to their diols by soluble epoxy hydrolase (sEH) to maintain the stability of EETs and their anti-inflammatory activity, an inhibitor (TPPU) against was used to sEH in a periodontitis model induced with Aggregatibacter actinomycetemcomitans. The oral treatment in mice with TPPU and sEH Knockout animals showed bone loss reduction accompanied by a decrease in the osteoclastogenic molecules, like RANK, RANKL and OPG, demonstrating that pharmacological inhibition of sEH may have therapeutic value in periodontitis and inflammatory diseases that involve bone resorption.

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A doença periodontal é caracterizada como um conjunto de condições inflamatórias, de carater crônico ou agudo, e de origem bacteriana, que começa por afetar o tecido gengival e pode levar, com o tempo, à perda dos tecidos de suporte dos dentes. As reações inflamatórias e imunológicas à placa bacteriana representam as características predominantes da gengivite e da periodontite. A reação inflamatória é visível, microscópica e clinicamente, no periodonto afetado e representa a reação do hospedeiro à microbiota da placa e seus produtos. O processo de infecção no sulco periodontal leva, inicialmente, a formação de uma mucosite periodontal, que pode ser definida como uma inflamação dos tecidos moles periodontáis, sem ocasionar perda óssea, sendo reversível, se o seu diagnóstico for atempado. Os processos inflamatórios e imunológicos atuam nos tecidos gengivais para proteger contra o agressãoes microbianas, impedindo os microrganismos de se disseminarem ou invadirem os tecidos. Em alguns casos, essas reações de defesa do hospedeiro podem ser prejudiciais porque também são passíveis de danificar as células e estruturas vizinhas do tecido conjuntivo. Além disso, as reações inflamatórias e imunológicas cuja extensão alcança níveis mais profundos do tecido conjuntivo, além da base do sulco, podem envolver o osso alveolar nesse processo destrutivo. Assim, tais processos defensivos podem, paradoxalmente, ser os responsáveis pela maior parte da lesão tecidual observada na gengivite e na periodontite. O objectivo desse trabalho é fazer uma revisão de literatura específica sobre a etiologia da doença periodontal respectivamente. Serão descritos os principais agentes microbianos que estão relacionados com a doença periodontal e a forma como influenciam o desenvolvimento da doença, procurando desta forma contribuir para a procura de tratamentos mais eficientes.

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The 15-deoxy-(Delta 12,14)-PG J(2) (15d-PGJ(2)) has demonstrated excellent anti-inflammatory results in different experimental models. It can be used with a polymeric nanostructure system for modified drug release, which can change the therapeutic properties of the active principle, leading to increased stability and slower/prolonged release. The aim of the current study was to test a nano-technological formulation as a carrier for 15d-PGJ(2), and to investigate the immunomodulatory effects of this formulation in a mouse periodontitis model. Poly (D, L-lactide-coglycolide) nanocapsules (NC) were used to encapsulate 15d-PGJ(2). BALB/c mice were infected on days 0, 2, and 4 with Aggregatibacter actinomycetemcomitans and divided into groups (n = 5) that were treated daily during 15 d with 1, 3, or 10 mu g/kg 15d-PGJ(2)-NC. The animals were sacrificed, the submandibular lymph nodes were removed for FACS analysis, and the jaws were analyzed for bone resorption by morphometry. Immunoinflammatory markers in the gingival tissue were analyzed by reverse transcriptase-quantitative PCR, Western blotting, or ELISA. Infected animals treated with the 15d-PGJ(2)-NC presented lower bone resorption than infected animals without treatment (p < 0.05). Furthermore, infected animals treated with 10 mu g/kg 15d-PGJ(2)-NC had a reduction of CD4(+)CD25(+)FOXP3(+) cells and CD4/CD8 ratio in the submandibular lymph node (p < 0.05). Moreover, CD55 was upregulated, whereas RANKL was downregulated in the gingival tissue of the 10 mu g/kg treated group (p < 0.05). Several proinflammatory cytokines were decreased in the group treated with 10 mu g/kg 15d-PGJ(2)-NC, and high amounts of 15d-PGJ(2) were observed in the gingiva. In conclusion, the 15d-PGJ(2)-NC formulation presented immunomodulatory effects, decreasing bone resorption and inflammatory responses in a periodontitis mouse model. The Journal of Immunology, 2012, 189: 1043-1052.

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La periodontitis puede afectar el curso y patogenia de enfermedades respiratorias crónico-degenerativas como la enfermedad pulmonar obstructiva crónica. Dichas enfermedades tienen alta prevalencia, siendo ésta del 67% en la población mexicana para la periodontitis y del 10% en la población adulta a nivel mundial para la EPOC. El propósito de esta investigación fue buscar una asociación microbiológica entre las condiciones antes mencionadas. Se encontró evidencia de que la placa dentobacteriana puede resguardar patógenos como P. gingivalis, A. actinomycetemcomitans, F. nucleatum y S. aureus, responsables de exacerbaciones en pacientes con EPOC. La mala higiene periodontal y la pérdida de inserción gingival y de hueso alveolar pueden incrementar el riesgo de desarrollar EPOC. Existe una asociación epidemiológica entre la periodontitis y la EPOC. Sin embargo, los resultados de los estudios que han tratado de explicar la influencia de la enfermedad periodontal en la severidad y el curso de la EPOC no son concluyentes y se ve la necesidad de realizar estudios epidemiológicos prospectivos a gran escala.

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Introduction: Porphyromonas gingivalis is associated with periodontitis and exhibit a wide array of virulence factors, including fimbriae which is encoded by the FimA gene representing six known genotypes. Objetive: To identify FimA genotypes of P. gingivalis in subjects from Cali-Colombia, including the co-infection with Aggregatibacter actinomycetemcomitans , Treponema denticola , and Tannerella forsythia . Methods: Subgingival samples were collected from 151 people exhibiting diverse periodontal condition. The occurrence of P. gingivalis, FimA genotypes and other bacteria was determined by PCR. Results: Porphyromonas gingivalis was positive in 85 patients. Genotype FimA II was more prevalent without reach significant differences among study groups (54.3%), FimA IV was also prevalent in gingivitis (13.0%). A high correlation (p= 0.000) was found among P. gingivalis, T. denticola, and T. forsythia co-infection. The FimA II genotype correlated with concomitant detection of T. denticola and T. forsythia. Conclusions: Porphyromonas gingivalis was high even in the healthy group at the study population. A trend toward a greater frequency of FimA II genotype in patients with moderate and severe periodontitis was determined. The FimA II genotype was also associated with increased pocket depth, greater loss of attachment level, and patients co-infected with T. denticola and T. forsythia.