M P A Mayer

University of São Paulo, San Paulo, São Paulo, Brazil

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Publications (106)137.94 Total impact

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    ABSTRACT: Because ribosomal RNA (rRNA) indicates metabolic cell activity, this study aimed to evaluate the sensitivity of rRNA-based quantitative polymerase chain reaction (RT-qPCR) for the identification of active Enterococcus faecalis in root canals samples compared with a method based on ribosomal DNA (rDNA) (rRNA genes). Samples were taken from 18 teeth with persistent/secondary intraradicular infection before (S1) and after (S2) chemomechanical preparation. RNA and DNA were extracted, and complementary DNA was synthesized from RNA using RT-PCR. Complementary DNA and genomic DNA were subjected to quantitative polymerase chain reaction with primers complementary for E. faecalis 16S rRNA sequence. E. faecalis was detected in 77.8% and 72.2% of S1 samples using rRNA- and rDNA-based assays, respectively. In contrast, E. faecalis was detected in only 33.3% of S2 samples using rDNA as the template compared with 61.1% using the rRNA-based method. The median concentration of rRNA copies of E. faecalis was significantly higher than rDNA copies, indicating a higher sensitivity for the method targeting rRNA in both S1 (P < .01) and S2 samples (P < .05). After chemomechanical preparation, the number of rRNA and rDNA copies was significantly reduced (P < .05). The high ratio of rRNA to rDNA copies in S2 samples suggested that active E. faecalis persisted in root canals after chemomechanical preparation. The RT-qPCR assay provides a sensitive method for the identification of active E. faecalis from endodontic samples. Furthermore, the rRNA-based assay indicated that E. faecalis viable cells persisted in treated root canals, suggesting that it may be a useful tool for monitoring microbial load during endodontic treatment. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
    Journal of endodontics 06/2015; DOI:10.1016/j.joen.2015.04.020 · 2.79 Impact Factor
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    ABSTRACT: The objective of this study was to evaluate the effect of strict supragingival biofilm control on serum inflammatory markers and on periodontal clinical parameters in type 2 diabetes mellitus (T2DM) patients with chronic severe periodontitis. Twenty-four individuals with T2DM and periodontitis were randomly allocated to two treatment groups. The supragingival therapy group (ST, n = 12) received supragingival scaling, whereas the intensive therapy group (IT, n = 12) underwent supra- and subgingival scaling, as well as root planing. Patients from both groups received professional oral hygiene instructions every month. Data regarding visible plaque index (VPI), gingival bleeding index (GBI), bleeding on probing (BOP), probing pocket depth (PPD), clinical attachment level (CAL), serum levels of interleukin (IL)-6, IL-17A, IL-8, tumor necrosis factor α (TNF-α), monocyte chemoattractant protein (MCP)-1 enzyme-linked immunosorbent assay (ELISA), and glycated hemoglobin (HbA1c) levels were obtained at baseline and at 6 months post-therapy. Both therapies resulted in the improvement of almost all clinical periodontal parameters (p < 0.05). There were no differences in TNF-α, IL-8, IL-17A and HbA1c levels in either group (p > 0.05), between the two periods. However, MCP-1 levels were significantly reduced in both the ST (p = 0.034) and the IT (p = 0.016) groups, whereas the serum IL-6 levels were significantly reduced only in the IT group (p = 0.001). Strict control of supragingival biofilm has a limited effect on systemic inflammatory markers, and a moderate effect on periodontal clinical parameters.
    Brazilian oral research 01/2015; 29(1):1-7. DOI:10.1590/1807-3107BOR-2015.vol29.0071 · 0.77 Impact Factor
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    ABSTRACT: Periodontal disease (PD) is induced by a complex microbiota, such as Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola (together called the red complex), which triggers intense inflammatory reaction. Down syndrome (DS) individuals demonstrate a high prevalence of PD compared with those who are otherwise chromosomally normal (euploids). This pilot study aimed to evaluate the effect of non-surgical periodontal treatment in DS chronic periodontitis patients on clinical and microbiological parameters. Patients with chronic periodontitis, 23 DS and 12 euploids (control group), were submitted to non-surgical mechanical periodontal treatment, followed by maintenance for 45 days. Clinical parameters after periodontal treatment were similar in diseased and healthy sites, independent of the genetic background. Diseased sites of DS and control patients harbored similar levels of P. gingivalis and T. forsythia at baseline, but significantly higher levels of T. denticola were found in DS patients. Increased levels of P. gingivalis at healthy sites were found in DS individuals. Non-surgical periodontal therapy decreased the levels of red complex microorganisms and improved the tested clinical parameters of diseased sites in both groups. However, the levels of red complex bacteria were higher in diseased sites of DS patients after the periodontal treatment. We conclude in this pilot study that, although the mechanical periodontal treatment seemed to be effective in DS subjects over a short-term period, the red complex bacteria levels did not decrease significantly in diseased sites, as occurred in controls. Therefore, for DS patients, it seems that the conventional non-surgical periodontal therapy should be improved by utilizing adjuvants to reduce the presence of periodontopathogens.
    European Journal of Clinical Microbiology 11/2014; 34(3). DOI:10.1007/s10096-014-2268-7 · 2.54 Impact Factor
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    ABSTRACT: The periodontopathogen Porphyromonas gingivalis is represented by a spectrum of phenotypes ranging from commensals to pathogenic lineages. Capsule and fimbriae are considered key virulence factors in this specie, involved in colonization and host defenses evasion. Since these virulence traits may not be expressed by certain strains, we aimed to test the hypothesis that certain clusters or genotypes of P. gingivalis correlate with the production of capsule and fimbriae. Sixteen P. gingivalis isolates were evaluated. Capsule (K) was detected by optical microscopy of negatively stained cells. The presence of fimbriae (F) was determined by TEM. Genotypes were determined by NotI macrorestriction fragments analysis through Pulsed-Field Gel Electrophoresis (PFGE) and Multi-locus sequence typing (MLST) based on seven house-keeping genes. The phenotypes included F(+)K(+) (n = 4), F(-)K(+) (n = 5), F(+)K(-) (n = 5) and F(-)K(-) (n = 2). The analysis of whole genome macrorestriction fragments revealed 14 different clusters. MLST data also revealed extensive genetic diversity; however, PFGE and MLST profiles showed evident differences. There was no association between P. gingivalis clusters and encapsulated and/or fimbriated phenotypes. Genotyping methods were not able to discriminate isolates according to the production of virulence factors such as capsule and major fimbriae, indicating that recombination played a key role in the expression of capsule and fimbriae in P. gingivalis. Copyright © 2014 Elsevier Ltd. All rights reserved.
    Microbial Pathogenesis 11/2014; 77C:100-104. DOI:10.1016/j.micpath.2014.11.001 · 2.00 Impact Factor
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    ABSTRACT: Objective: to elucidate the mechanisms involved in the anti-inflammatory properties of Brazilian red propolis Method: different concentrations of ethanolic extract of Brazilian red propolis (EEBRP) were added to RAW 264.7 macrophages after activation with LPS, and NO production and cell viability determined. Production of TNF-α, IL1β, TGF-β, IL-4, IL-6, IL-10, IL-12, GM-CSF, IFN-Ɣ and expression of genes related to cytokines production and nitric oxide , PI3K-AKT and signal transduction pathway were evaluated by ELISA and RT-qPCR, respectively. Differences were determined by one-way ANOVA followed by Tukey-Kramer Result: EEBRP inhibited NO production by 69% without affecting cell viability at the concentration of 50 µg/ml when compared with control cells (treated with vehicle) (p<0.05). Levels of IL-12, GM-CSF, IFN-Ɣ, IL-1β, IL-4, IL-10 and TGF-β in cell supernatant were reduced and of TNF- α and IL-6 increased with the addition of EEBRP (p<0.05). EEBRP induced alteration in expression of 57 genes. Genes involved in Toll-like response; oxide nitric sintetase production (all types), Nf-KB and MAPK signaling pathways such as Tirap, Pdk1, Pak1, Nfkb1, Mtcp1, Gsk3b, Fos, Elk1, Il1β, Il1f9 were negatively regulated by EEBRP(fold-change rate > 5; p<0.05) Conclusion: EEBRP presents antiinflammatory properties by altering signaling pathways leading to reduction in production of pro-inflammatory factors.
    2014 IADR/PER Congress; 09/2014
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    ABSTRACT: Objective: Aggregatibacter actinomycetemcomitans is associated to the etiology of aggressive periodontitis and produces the cytolethal distending toxin (AaCDT). Since CDT affects monocytic cells, we aimed to evaluate the effect of AaCDT on gene expression of pre-osteoclastic cells. Method: Monocytes obtained from murinic bone marrow (BMC) were submitted to different concentrations of recombinant AaCDT in the presence and absence of RANKL. After 6 days, viability was determined (MTT) and TRAP + cells presenting > 3 nuclei were counted. After 2-6 days, RT-qPCR was performed to evaluate expression of genes associated with osteoclastogenesis (rank, ctpk, nfatc1 and irf-8) and gapdhwas used as control. The data were analyzed by ANOVA followed by Tukey or Bonferroni tests (p < 0.05). Result: At the tested concentrations, CDT did not affect cells viability, but the number of TRAP+ multinucleated cells increased with increasing AaCDT concentrations, in the presence or absence of RANKL. The expression of rank was down regulated after 4 days of incubation in AaCDT-treated cells in the absence of RANKL. This effect was also seen in BMC added with RANKL after 2-6 days. Furthermore, after 4 and 6 days, AaCDT down regulated the expression of transcription factor nfatc1 and ctpK (encoding cathepsin K). Thus, although an increase in TRAP+ cells was observed in AaCDT treated pre-osteoclastic cells, genes involved in osteoclastogenesis were repressed by the toxin, even in presence of RANKL. Conclusion: AaCDT may affect osteoclastogenesis by inhibiting signaling in pre-osteoclastic cells, and by down regulating the expression of genes associated with mature osteoclasts.
    2014 IADR/PER Congress; 09/2014
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    ABSTRACT: Objective: recent data have shown that Brazilian red propolis presents immunemodulatory properties, which led us to elucidate the mechanisms involved in the anti-inflammatory properties of one of its components, Neovestitol Method: neovestitol was obtained from ethanolic extract of Brazilian red propolis after bio-guided fractionation coupled with GC-MS analysis. Different concentrations of Neovestitol were added to RAW 264.7 macrophages after activation with LPS. After 48 hours, NO production and cell viability were determined. Production of TNF-α, IL1β, TGF-β, IL-4, IL-6, IL-10, IL-12, GM-CSF, IFN-Ɣ and expression of genes related to cytokines production, nitric oxide , PI3K-AKT and signal transduction pathways were evaluated by ELISA and RT-qPCR, respectively. Differences were determined by one-way ANOVA followed by Tukey-Kramer Result: Neovestitol inhibited NO production by 63% without affecting cell viability at the concentration of 60 µg/ml when compared with control cells (treated with vehicle) (p<0.05). Levels of GM-CSF, IFN- Ɣ, IL-1 β, IL-4, TNF- α and IL-6 in cell supernatant were reduced and of IL-10 increased with the addition of neovestitol (p<0.05). Neovestitol induced alteration in the expression of 43 genes. Genes involved in Toll-like response; nitric oxide sintetase production (all types), Nf-KB and Il-1 signaling pathways such as Bad, Chuk, Elk1, Ifnb1, Il1b, Lif, Calm1, Capns1, Egr1, Nox1, Scd2 and Scd3 were negatively regulated by neovestitol (fold-change rate > 5; p<0.05). Furthermore, its role in inhibition of leukocyte transmigration was suggested by inhibition of expression of Nox1 and in the regulation of fatty acid associated genes such as Scd2 e Scd3 Conclusion: Neovestitol may represent a new antiinflammatory agent by inhibiting signaling pathways and consequently reducing the production of pro-inflammatory factors and by interfering in leukocyte transmigration
    2014 IADR/PER Congress; 09/2014
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    ABSTRACT: Objective: To establish an animal model to study the host immune response to Aggregatebacter actinomycetemcomitans (Aa) biofilm. Method: Titanium implant abutments were micro textured and acid-etched to facilitate biofilm formation on the surface. The abutments were inoculated in vitro with Aa D7S-1 (WT) and a double knockout mutant (DM) of omp29 and its paralogue. Sham-inoculated abutments served as negative control. Sterile titanium implants were transmucosally inserted into rat maxillary alveolar ridge with the abutments (N=15 for each of WT, DM and sham-inoculated groups). The animals were evaluated clinically up to 6 weeks. Micro-CT imaging was performed at 3 and 6 weeks. The levels of Aa on the abutments were determined by quantitative PCR. Result: Presurgically, the amount of biofilm was on average 9.9×106± 4.9×106 of WT cells/abutment and 2.2×107±8.4×106 DM cells/abutment. After the surgery, bleeding, ulceration, hyperplasia, and necrosis were observed around biofilm-inoculated titanium abutments. By 3 weeks 8/15, 6/15 and 6/15 implants remained stable in WT, DM and sham-inoculated implants, respectively. By 6 weeks 3/15, 5/15 and 5/15 implants remained stable in WT, DM and sham-inoculated implants, respectively. After 6 weeks, the persistence of Aa on the abutment was as followed: 22% of WT and <1% DM. Bone loss was noted in bone surrounding implants inoculated with bacteria but not in shame-inoculated implants. Conclusion: A novel animal model where Aa biofilm was established in vitro on titanium implant abutments prior to installation in rat oral cavity, leading to an inflammatory response, osteolysis, and tissue destruction. This model could be used to investigate host responses to biofilm and anti-biofilm treatment strategies.
    2014 IADR/PER Congress; 09/2014
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    ABSTRACT: Given the spread of antibiotic resistance in bacterial pathogens, antimicrobial peptides that can also modulate the immune response may be a novel approach for effectively controlling periodontal infections. In the present study, we used a three-dimensional (3D) co-culture model of gingival epithelial cells and fibroblasts stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS) to investigate the anti-inflammatory properties of human beta-defensin-3 (hBD-3) and cathelicidin (LL-37) and to determine whether these antimicrobial peptides can act in synergy. The 3D co-culture model composed of gingival fibroblasts embedded in a collagen matrix overlaid with gingival epithelial cells had a synergistic effect with respect to the secretion of IL-6 and IL-8 in response to LPS stimulation compared to fibroblasts and epithelial cells alone. The 3D co-culture model was stimulated with non-cytotoxic concentrations of hBD-3 (10 and 20 µM) and LL-37 (0.1 and 0.2 µM) individually and in combination in the presence of A. actinomycetemcomitans LPS. A multiplex ELISA assay was used to quantify the secretion of 41 different cytokines. hBD-3 and LL-37 acted in synergy to reduce the secretion of GRO-alpha, G-CSF, IP-10, IL-6, and MCP-1, but only had an additive effect on reducing the secretion of IL-8 in response to A. actinomycetemcomitans LPS stimulation. The present study showed that hBD-3 acted in synergy with LL-37 to reduce the secretion of cytokines by an LPS-stimulated 3D model of gingival mucosa. This combination of antimicrobial peptides thus shows promising potential as an adjunctive therapy for treating inflammatory periodontitis.
    PLoS ONE 09/2014; 9(9):e106766. DOI:10.1371/journal.pone.0106766 · 3.53 Impact Factor
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    ABSTRACT: AimsTo evaluate the association among serum immunoglobulin G (IgG) responses to Aggregatibacter actinomycetemcomitans (Aa) serotypes a, b and c, Porphyromonas gingivalis (Pg) Tannerella forsythia (Tf) and clinical parameters in Aggressive Periodontitis (AP) subjects. Associations between periodontal pathogens and clinical and immunological parameters were also evaluated.Methods38 subjects diagnosed with generalized AP (GAP) and localized AP (LAP) were included. Ten healthy controls were also evaluated. Clinical parameters were assessed and percentages of subgingival levels of Aa, Pg and Tf, (beyond bacterial load), were determined by quantitative real-time polymerase chain reaction. Serum IgG antibody levels against Aa, Pg and Tf were evaluated by enzyme-linked immunosorbent assay.ResultsPercentages of Aa, Pg and Tf were significantly higher in AP than in controls. The response to Aa serotype c was higher in LAP subjects than in controls. There were no differences in microbial composition or antibodies responses between GAP and LAP, except for IgG response to Tf. Pg levels were correlated with PD, BoP and CAL in GAP but not in LAP subjects. Tf levels correlated to PD and CAL in GAP subjects. In GAP, the infection levels of Aa and Pg correlated with the corresponding IgG levels to Aa serotype c and Pg.Conclusion Given the evidences that IgG response in AP patients correlated with bacterial infection level in GAP, but not in LAP, and that LAP patients lack a response to Tf, despite harboring this species, our data suggests a difference in host immune defense between these two forms of aggressive periodontitis.This article is protected by copyright. All rights reserved.
    Journal Of Clinical Periodontology 07/2014; 41(10). DOI:10.1111/jcpe.12296 · 3.61 Impact Factor
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    ABSTRACT: Objectives: the role of periodontitis in systemic inflammation in type 2 diabetes mellitus (T2DM) is still not fully elucidated. This study aimed to evaluate serum levels of a cytokines panel in patients with T2DM and moderate to severe chronic periodontitis and to compare with their controls. Methods: 50 patients older than 40 years and with BMI < 40 were enrolled in this study. Periodontal condition and glycated haemoglobin levels (HbA1c) were evaluated. Five groups were analyzed: DMI+P: periodontitis, poor controlled T2DM (HbA1c ≥ 8.0%); DMA+P: periodontitis, well controlled T2DM (HbA1c < 8.0%), P: non-diabetic with periodontitis, D group: diabetic without periodontitis and H group: non-diabetic without periodontitis. Cytokines sera levels were determined with the Bio Plex Pro Human Cytokine GrpI Panel 17. Periodontal clinical data were analyzed by statistical software (SPSS Inc., USA) and cytokines data were analyzed by non-parametric statistical methods Kruskall-Wallis and Dunns. Results were considered statistically significant at p < 0.05. Results: Mean ± standard deviation of HbA1c (%) of each group was: H: 5.22±0.48; P: 5.47±0.57; D: 7.43±0.82; DMA+P: 6.74±0.74 and DMI+P: 10.55±2.28. IL-2, IL-4, IL-17 and IFN-δ were not detected in most sera samples. There were no statistical differences among groups for IL-8, IL-12, IL-13 and MIP-1β. H group presented lower levels of IL-1β, IL-5, IL-10, MCP-1 and higher GM-CSF levels than the others groups. TNF-α was elevated in all periodontitis groups (DMI+P, DMA+P and P) independently on the presence of diabetes (D and H), whereas IL-6 and G-CSF were significantly higher only in DMI+P when compared to H. D group was characterized by higher values of IL-7 when compared to H group. Conclusion: The data indicates that periodontitis increases systemic inflammatory markers in no diabetes and diabetic patients. However the latter, particularly those with poor-glycemic control there is a more pronounced inflammatory response.
    IADR General Session and Exhibition 2014; 06/2014
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    ABSTRACT: Diabetes has been associated with periodontitis, but the mechanisms through which periodontal diseases affect the metabolic control remain unclear. Objective: This study aimed to evaluate serum leveis of inflammatory markers, IL-8, IL-6 and monocyte chemoattractant protein 1 (MCP-1), in type 2 diabetic patients in the presence of chronic periodontitis. Material and Methods: Forty two individuals were enrolled in this study and assigned to one of five groups: diabetes mellitus with inadequate glycemic control and periodontitis (DMI+P, n = 10), diabetes mellitus with adequate glycemic control and periodontitis (DMA+P, n = 10), diabetes mellitus without periodontitis (DM, n = 10), periodontitis without diabetes (P, n=6), and neither diabetes nor periodontitis (H, n = 6). Periodontal clinical examination included visible plaque index (PL), gingival bleeding index (GB), probing depth (PD), attachment level (AL) and bleeding on probing (BP). Glycemic control was evaluated by serum concentration of glycated hemoglobin (HbAlc). Inflammatory serum markers IL-8, IL-6 and (MCP-1) were measured by ELISA. Results: DMI+P and DMA+P groups presented higher PD (p=0.025) and AL (p=0.003) values when compared to the P group. There were no significant differences among groups for IL-6, IL-8 and MCP-1 serum levels. Conclusions: Although periodontitis was more severe in diabetic patients, the serum levels of the investigated inflammatory markers did not differ among the groups.
    Journal of applied oral science: revista FOB 04/2014; 22(2):103-8. DOI:10.1590/1678-775720130540 · 0.80 Impact Factor
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    ABSTRACT: Aggregatibacter actinomycetemcomitans is an important periodontal pathogen that can participate in periodontitis and other non-oral infections. The cytolethal distending toxin (Cdt) is among the virulence factors produced by this bacterium. The Cdt is also secreted by several mucosa-associated Gram-negative pathogens and may play a role in perpetuating the infection by modulating the immune response. Although the toxin targets a wide range of eukaryotic cell types little is known about its activity on macrophages which play a key part in alerting the rest of the immune system to the presence of pathogens and their virulence factors. In view of this, we tested the hypothesis that the A. actinomycetemcomitans Cdt (AaCdt) disrupts macrophage function by inhibiting phagocytic activity as well as affecting the production of cytokines. Murine macrophages were co-cultured with either wild-type A. actinomycetemcomitans or a Cdt− mutant. Viable counts and qPCR showed that phagocytosis of the wild-type strain was significantly reduced relative to that of the Cdt− mutant. Addition of recombinant Aa(r)Cdt to co-cultures along with the Cdt− mutant diminished the phagocytic activity similar to that observed with the wild type strain. High concentrations of Aa(r)Cdt resulted in decreased phagocytosis of fluorescent bioparticles. Nitric oxide production was modulated by the presence of Cdt and the levels of IL-1β, IL-12 and IL-10 were increased. Production of TNF-α did not differ in the co-culture assays but was increased by the presence of Aa(r)Cdt. These data suggest that the Cdt may modulate macrophage function in A. actinomycetemcomitans infected sites by impairing phagocytosis and modifying the pro-inflammatory/anti-inflammatory cytokine balance.
    Cytokine 03/2014; 66(1):46–53. DOI:10.1016/j.cyto.2013.12.014 · 2.87 Impact Factor
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    ABSTRACT: The association between periodontitis and some of the problems with pregnancy such as premature delivery, low weight at birth, and preeclampsia (PE) has been suggested. Nevertheless, epidemiological data have shown contradictory data, mainly due to differences in clinical parameters of periodontitis assessment. Furthermore, differences in microbial composition and immune response between aggressive and chronic periodontitis are not addressed by these epidemiological studies. We aimed to review the current data on the association between some of these problems with pregnancy and periodontitis, and the mechanisms underlying this association. Shifts in the microbial composition of the subgingival biofilm may occur during pregnancy, leading to a potentially more hazardous microbial community. Pregnancy is characterized by physiological immune tolerance. However, the infection leads to a shift in maternal immune response to a pathogenic pro-inflammatory response, with production of inflammatory cytokines and toxic products. In women with periodontitis, the infected periodontal tissues may act as reservoirs of bacteria and their products that can disseminate to the fetus-placenta unit. In severe periodontitis patients, the infection agents and their products are able to activate inflammatory signaling pathways locally and in extra-oral sites, including the placenta-fetal unit, which may not only induce preterm labor but also lead to PE and restrict intrauterine growth. Despite these evidences, the effectiveness of periodontal treatment in preventing gestational complications was still not established since it may be influenced by several factors such as severity of disease, composition of microbial community, treatment strategy, and period of treatment throughout pregnancy. This lack of scientific evidence does not exclude the need to control infection and inflammation in periodontitis patients during pregnancy, and treatment protocols should be validated.
    Frontiers in Public Health 01/2014; 2:290. DOI:10.3389/fpubh.2014.00290
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    ABSTRACT: Aggregatibacter actinomycetemcomitans serotypes are clearly associated with periodontitis or health, which suggests distinct strategies for survival within the host. We investigated the transcription profile of virulence-associated genes in A. actinomycetemcomitans serotype b (JP2 and SUNY 465) strains associated with disease and serotype a (ATCC 29523) strain associated with health. Bacteria were co-cultured with immortalized gingival epithelial cells (OBA-9). The adhesion efficiency after 2 hours and the relative transcription of 13 genes were evaluated after 2 and 24 hours of interaction. All strains were able to adhere to OBA-9, and this contact induced transcription of pgA for polysaccharide biosynthesis in all tested strains. Genes encoding virulence factors as Omp29, Omp100, leukotoxin, and CagE (apoptotic protein) were more transcribed by serotype b strains than by serotype a. ltxA and omp29, encoding the leukotoxin and the highly antigenic Omp29, were induced in serotype b by interaction with epithelial cells. Factors related to colonization (aae, flp, apaH, and pgA) and cdtB were upregulated in serotype a strain after prolonged interaction with OBA-9. Genes relevant for surface colonization and interaction with the immune system are regulated differently among the strains, which may help explaining their differences in association with disease.
    Journal of Oral Microbiology 10/2013; 5. DOI:10.3402/jom.v5i0.21473
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    ABSTRACT: The aim of this study was to investigate the effect of non-surgical treatment of periodontitis on the levels of periodontopathogens and clinical parameters in patients with different genetic backgrounds given by the polymorphisms in the IL8 gene. Thirty patients grouped according to IL8 ATC/TTC or AGT/TTC haplotypes were submitted to non-surgical periodontal treatment. Levels of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were determined in 240 subgingival plaques samples by qPCR. The association between IL8 haplotypes and the levels of periodontopathogens and clinical parameters was investigated with multilevel analysis accounting for the clustering of diseased sites analyzed within patients. It was observed that neither levels of periodontopathogens nor non-surgical treatment were associated with IL8 haplotype. For diseased and healthy sites, clinical parameters after periodontal treatment were similar, independently of the IL8 haplotype. Nonetheless, at the same period, diseased sites of AGT/TTC patients harbored higher levels of P.gingivalis, T.denticola, T.forsythia, and red complex than those of ATC/TTC. However, the non-surgical periodontal therapy resulted in decreased levels of these periodontopathogens and of the tested clinical parameters of diseased sites for both groups. Non-surgical therapy is equally effective in improving clinical parameters and decreasing the levels of periodontopathogens, independent from the genotype groups given by the IL8 haplotype. This article is protected by copyright. All rights reserved.
    Pathogens and Disease 07/2013; DOI:10.1111/2049-632X.12062 · 2.55 Impact Factor
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    ABSTRACT: Enterococcus faecalis is a member of the mammalian gastrointestinal microbiota but has been considered a leading cause of hospital-acquired infections. In the oral cavity, it is commonly detected from root canals of teeth with failed endodontic treatment. However, little is known about the virulence and genetic relatedness among E. faecalis isolates from different clinical sources. This study compared the presence of enterococcal virulence factors among root canal strains and clinical isolates from hospitalized patients to identify virulent clusters of E. faecalis. Multilocus sequence typing analysis was used to determine genetic lineages of 40 E. faecalis clinical isolates from different sources. Virulence clusters were determined by evaluating capsule (cps) locus polymorphisms, pathogenicity island gene content, and antibiotic resistance genes by polymerase chain reaction. The clinical isolates from hospitalized patients formed a phylogenetically separate group and were mostly grouped in the clonal complex 2, which is a known virulent cluster of E. faecalis that has caused infection outbreaks globally. The clonal complex 2 group comprised capsule-producing strains harboring multiple antibiotic resistance and pathogenicity island genes. On the other hand, the endodontic isolates were more diverse and harbored few virulence and antibiotic resistance genes. In particular, although more closely related to isolates from hospitalized patients, capsule-producing E. faecalis strains from root canals did not carry more virulence/antibiotic genes than other endodontic isolates. E. faecalis isolates from endodontic infections have a genetic and virulence profile different from pathogenic clusters of hospitalized patients' isolates, which is most likely due to niche specialization conferred mainly by variable regions in the genome.
    Journal of endodontics 07/2013; 39(7):858-64. DOI:10.1016/j.joen.2013.01.009 · 2.79 Impact Factor
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    ABSTRACT: Periodontitis is an inflammatory disease that results from an interaction between dental biofilm agents and the host immune-inflammatory response. Periodontopathogenic organisms, such as Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, as well as the host's susceptibility, represented by the host's genetic makeup, are the key factors that influence this complex disease. Recently, we identified haplotypes in the IL4 gene that were associated with chronic periodontitis (CP). This study aimed to evaluate whether subjects with different IL4 haplotypes (TCI/CCI and TTD/CTI) would be differentially colonized by periodontopathogens and whether they would respond differently to non-surgical periodontal therapy. Thirty-nine patients carrying the IL4 haplotype of genetic susceptibility to CP (IL4+) or protection against CP (IL4-) were evaluated. Those groups were further subdivided into individuals with CP (CP IL4+ or CP IL4-) and those that were periodontally healthy (H) (H IL4+ or H IL4-). CP patients were submitted to non-surgical periodontal therapy. Clinical and microbiological analyses were performed considering the data at baseline and 45 and 90 days after periodontal therapy. Periodontopathogens levels were evaluated by absolute quantitative polymerase chain reaction (qPCR). The baseline data revealed that the total levels of periodontopathogens were higher in the CP IL4+ than in the CP IL4- groups. Clinical analyses revealed that the periodontal therapy was equally effective, independent of the subject's IL4 genetic load. The TCI/CCI IL4 haplotype, previously associated with genetic susceptibility to CP, was also associated with increased levels of periodontopathogenic bacteria, but this genetic background did not influence the response to non-surgical periodontal treatment.
    European Journal of Clinical Microbiology 06/2013; 32(12). DOI:10.1007/s10096-013-1903-z · 2.54 Impact Factor
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    ABSTRACT: Chronic periodontitis (CP) is considered to be a multifactorial disease influenced by microbial and genetic factors. The aim of the present study was to investigate whether the genetic susceptibility to CP in individuals with the IL8 ATC/TTC haplotype is associated with subgingival levels of periodontopathogens. Sixty-five individuals, grouped according to the presence (n = 28) or absence (n = 37) of the IL8 haplotype, were evaluated. After clinical periodontal evaluation, each group was subdivided according to the presence (CP) or absence (H) of periodontitis. Four subgingival samples were obtained from CP and two samples per subject from H patients. The levels and proportions of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were analyzed using quantitative real-time polymerase chain reaction (q-PCR). No differences were found in the proportion of periodontopathogenic bacteria between groups with the presence or absence of the IL8 haplotype. However, in the CP groups, the levels of periodontopathogens were significantly higher in the individuals without the IL8 haplotype than in the individuals with the IL8 haplotype. These results suggest that periodontal destruction may occur in patients who are considered to be genetically susceptible to CP with a lower microbial challenge because of the presence of the IL8 ATC/TTC haplotype than in patients without this haplotype.
    European Journal of Clinical Microbiology 05/2013; DOI:10.1007/s10096-013-1884-y · 2.54 Impact Factor
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    ABSTRACT: Background and Objective Periodontopathogens experience several challenges in the oral cavity that may influence their transcription profile and resulting phenotype. This study evaluated the effect of environmental changes on phenotype and gene expression in a serotype b Aggregatibacter actinomycetemcomitans isolate. Material and Methods Cultures in early exponential phase and at the start of stationary growth phase in microaerophilic and anaerobic atmospheres were evaluated. Cell hydrophobic properties were measured by adherence to n-hexadecane; in addition, adhesion to, and the ability to invade, KB cells was evaluated. Relative transcription of 12 virulence-associated genes was determined by real-time reverse transcritption quantitative PCR. ResultsThe culture conditions tested in this study were found to influence the phenotypic and genotypic traits of A.actinomycetemcomitans. Cells cultured in microaerophilic conditions were the most hydrophobic, reached the highest adhesion efficiency and showed up-regulation of omp100 (which encodes an adhesion) and pga (related to polysaccharide synthesis). Cells grown anaerobically were more invasive to epithelial cells and showed up-regulation of genes involved in host-cell invasion or apoptosis induction (such as apaH, omp29, cagE and cdtB) and in adhesion to extracellular matrix protein (emaA). Conclusion Environmental conditions of different oral habitats may influence the expression of factors involved in the binding of A.actinomycetemcomitans to host tissues and the damage resulting thereby, and thus should be considered in in-vitro studies assessing its pathogenic potential.
    Journal of Periodontal Research 04/2013; 48(6). DOI:10.1111/jre.12067 · 2.22 Impact Factor

Publication Stats

972 Citations
137.94 Total Impact Points

Institutions

  • 1998–2015
    • University of São Paulo
      • • Department of Stomatology (Baurú)
      • • Instituto de Ciências Biomédicas (ICB)
      • • Department of Immunology (ICB)
      • • Faculdade de Odontologia (FO) (São Paulo)
      San Paulo, São Paulo, Brazil
  • 2012
    • Universidade Cidade de São Paulo
      San Paulo, São Paulo, Brazil
  • 2011
    • Universidade Guarulhos
      Guarulhos, São Paulo, Brazil
  • 2010
    • Instituto de Pesquisas Energéticas e Nucleares
      • Center for Laser and Applications (CLA)
      San Paulo, São Paulo, Brazil
  • 2001
    • The Forsyth Institute
      Cambridge, Massachusetts, United States
  • 1999
    • Universidade Federal de São Paulo
      • School of Medicine
      San Paulo, São Paulo, Brazil