Self-ligating versus conventional metallic brackets on Streptococcus mutans retention:A systematic review

ABSTRACT Objective: The present study aimed to review the literature systematically and assess comparatively whether self-ligating metallic brackets accumulate less Streptococcus mutans biofilm than conventional metallic brackets. Material and methods: The systematic search was performed following PRISMA guidelines and registration in PROSPERO. Seven electronic databases (Google Scholar, LILACS, Open Grey, PubMed, SciELO, ScienceDirect, and Scopus) were consulted until April 2016, with no restriction of language and time of publication. Only randomized clinical studies verifying S. mutans colonization in metallic brackets (self-ligating and conventional) were included. All steps were performed independently by two operators. Results: The search resulted in 546 records obtained from the electronic databases. Additionally, 216 references obtained from the manual search of eligible articles were assessed. Finally, a total of 5 studies were included in the qualitative synthesis. In 1 study, the total bacterial count was not different among self-ligating and conventional brackets, whereas in 2 studies the amount was lower for self-ligating brackets. Regarding the specific count of S. mutans, 2 studies showed less accumulation in self-ligating than in conventional brackets. Conclusion: Based on the limited evidence, self-ligating metallic brackets accumulate less S. mutans than conventional ones. However, these findings must be interpreted in conjunction with particularities individual for each patient – such as hygiene and dietary habits, which are components of the multifactorial environment that enables S. Mutans to proliferate and keep retained in the oral cavity.</jats:p

Heterologous expression of Streptococcus mutans cnm in Lactococcus lactis promotes intracellular invasion, adhesion to human cardiac tissues and virulence

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOIn S. mutans, the expression of the surface glycoprotein Cnm mediates binding to extracellular matrix proteins, endothelial cell invasion and virulence in the Galleria mellonella invertebrate model. To further characterize Cnm as a virulence factor, the cnm gene from S. mutans strain OMZ175 was expressed in the non-pathogenic Lactococcus lactis NZ9800 using a nisin-inducible system. Despite the absence of the machinery necessary for Cnm glycosylation, Western blot and immunofluorescence microscopy analyses demonstrated that Cnm was effectively expressed and translocated to the cell wall of L. lactis. Similar to S. mutans, expression of Cnm in L. lactis enabled robust binding to collagen and laminin, invasion of human coronary artery endothelial cells and increased virulence in G. mellonella. Using an ex vivo human heart tissue colonization model, we showed that Cnm-positive strains of either S. mutans or L. lactis outcompete their Cnm-negative counterparts for tissue colonization. Finally, Cnm expression facilitated L. lactis adhesion and colonization in a rabbit model of infective endocarditis. Collectively, our results provide unequivocal evidence that binding to extracellular matrices mediated by Cnm is an important virulence attribute of S. mutans and confirm the usefulness of the L. lactis heterologous system for further characterization of bacterial virulence factors.In S. mutans, the expression of the surface glycoprotein Cnm mediates binding to extracellular matrix proteins, endothelial cell invasion and virulence in the Galleria mellonella invertebrate model. To further characterize Cnm as a virulence factor, the cnm gene from S. mutans strain OMZ175 was expressed in the non-pathogenic Lactococcus lactis NZ9800 using a nisin-inducible system. Despite the absence of the machinery necessary for Cnm glycosylation, Western blot and immunofluorescence microscopy analyses demonstrated that Cnm was effectively expressed and translocated to the cell wall of L. lactis. Similar to S. mutans, expression of Cnm in L. lactis enabled robust binding to collagen and laminin, invasion of human coronary artery endothelial cells and increased virulence in G. mellonella. Using an ex vivo human heart tissue colonization model, we showed that Cnm-positive strains of either S. mutans or L. lactis outcompete their Cnm-negative counterparts for tissue colonization. Finally, Cnm expression facilitated L. lactis adhesion and colonization in a rabbit model of infective endocarditis. Collectively, our results provide unequivocal evidence that binding to extracellular matrices mediated by Cnm is an important virulence attribute of S. mutans and confirm the usefulness of the L. lactis heterologous system for further characterization of bacterial virulence factors811829FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2014/07231-0; 2013/25080-7308644/2011-

Transcriptional and phenotypic characterization of novel Spx-regulated genes in Streptococcus mutans

CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOIn oral biofilms, two of the major environmental challenges encountered by the dental pathogen Streptococcus mutans are acid and oxidative stresses. Previously, we showed that the S. mutans transcriptional regulators SpxA1 and SpxA2 (formerly SpxA and SpxB, respectively) are involved in stress survival by activating the expression of classic oxidative stress genes such as dpr, nox, sodA and tpx. We reasoned that some of the uncharacterized genes under SpxA1/A2 control are potentially involved in oxidative stress management. Therefore, the goal of this study was to use Spx-regulated genes as a tool to identify novel oxidative stress genes in S. mutans. Quantitative real-time PCR was used to evaluate the responses of ten Spx-regulated genes during H2O2 stress in the parent and Delta spx strains. Transcription activation of the H2O2-induced genes (8 out of 10) was strongly dependent on SpxA1 and, to a lesser extent, SpxA2. In vitro transcription assays revealed that one or both Spx proteins directly regulate three of these genes. The gene encoding the FeoB ferrous permease was slightly repressed by H2O2 but constitutively induced in strains lacking SpxA1. Nine genes were selected for downstream mutational analysis but inactivation of smu127, encoding a subunit of the acetoin dehydrogenase was apparently lethal. In vitro and in vivo characterization of the viable mutants indicated that, in addition to the transcriptional activation of reducing and antioxidant pathways, Spx performs an important role in iron homeostasis by regulating the intracellular availability of free iron. In particular, inactivation of the genes encoding the Fe-S biogenesis SUF system and the previously characterized iron-binding protein Dpr resulted in impaired growth under different oxidative stress conditions, increased sensitivity to iron and lower infectivity in rats. These results serve as an entryway into the characterization of novel genes and pathways that allow S. mutans to cope with oxidative stress.In oral biofilms, two of the major environmental challenges encountered by the dental pathogen Streptococcus mutans are acid and oxidative stresses. Previously, we showed that the S. mutans transcriptional regulators SpxA1 and SpxA2 (formerly SpxA and SpxB, respectively) are involved in stress survival by activating the expression of classic oxidative stress genes such as dpr, nox, sodA and tpx. We reasoned that some of the uncharacterized genes under SpxA1/A2 control are potentially involved in oxidative stress management. Therefore, the goal of this study was to use Spx-regulated genes as a tool to identify novel oxidative stress genes in S. mutans. Quantitative real-time PCR was used to evaluate the responses of ten Spx-regulated genes during H2O2 stress in the parent and Delta spx strains. Transcription activation of the H2O2-induced genes (8 out of 10) was strongly dependent on SpxA1 and, to a lesser extent, SpxA2. In vitro transcription assays revealed that one or both Spx proteins directly regulate three of these genes. The gene encoding the FeoB ferrous permease was slightly repressed by H2O2 but constitutively induced in strains lacking SpxA1. Nine genes were selected for downstream mutational analysis but inactivation of smu127, encoding a subunit of the acetoin dehydrogenase was apparently lethal. In vitro and in vivo characterization of the viable mutants indicated that, in addition to the transcriptional activation of reducing and antioxidant pathways, Spx performs an important role in iron homeostasis by regulating the intracellular availability of free iron. In particular, inactivation of the genes encoding the Fe-S biogenesis SUF system and the previously characterized iron-binding protein Dpr resulted in impaired growth under different oxidative stress conditions, increased sensitivity to iron and lower infectivity in rats. These results serve as an entryway into the characterization of novel genes and pathways that allow S. mutans to cope with oxidative stress104CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES [6849-12-1]FAPESP [2012/032278-3, 2014/03816-4]6849-12-12012/032278-3; 2014/03816-

Bioactive molecule optimized for biofilm reduction related to childhood caries

To evaluate antimicrobial activity of a new nitrochalcone (NC-E08) against Candida albicans and Streptococcus mutans, and its toxicity. Materials & methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration/minimum fungicidal concentration (MFC) were determined against C. albicans and S. mutans, as well as antibiofilm potential and toxicity (human gingival fibroblast and Galleria mellonella). Infection and treatment were performed in G. mellonella. Results & conclusion: NC-E08 showed antimicrobial activity in C. albicans (MIC: 0.054 mM) and S. mutans (MIC: 0.013 mM); 10xMIC treatment reduced 4.0 log10 biofilms for both strains and there was a reduction in survival of mixed biofilms of C. albicans and S. mutans (6.0 and 4.0 log10, respectively). NC-E08 showed no cytotoxicity in human gingival fibroblast cells and G. mellonella. NC-E08 after larval infection protected them 90% (p<0.05). Thus, is a promising one for the prevention and treatment of S. mutans and C. albicans infections.141412071220CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES474335/2013; 474335/2013-5Sem informaçã

Anti-inflammatory and anti-biofilm properties of ent-nemorosone from brazilian geopropolis

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOent-Nemorosone is a benzophenone isolated from geopropolis from Melipona scutellaris whose biological properties remain unexplored. Herein, we evaluated the anti-inflammatory activity of ent-nemorosone by in vivo neutrophil migration and TNF-alpha quantification, as well as by in vitro TNF-alpha quantification, ERK 1/2 phosphorylation, NF-kB activation and nuclear translocation of p65 in stimulated macrophages. ent-Nemorosone was also tested for its antimicrobial effects against Streptococcus mutans biofilm adhesion, polysaccharide production, and viability ent-Nemorosone reduced the influx of neutrophils and TNF-alpha release into the peritoneal cavity of mice, as well as the in vitro TNF-alpha levels, ERK 1/2 phosphorylation, NF-kB activation and nuclear p65 translocation. Furthermore, this compound inhibited biofilm adhesion and reduced the amount of extra- and intracellular polysaccharides synthesized by S. mutans. Thus, ent-nemorosone showed promising anti-inflammatory activity by acting on TNF-alpha release in macrophages, as well as anti-biofilm properties by reducing S. mutans polysaccharide production. (C) 2016 Elsevier Ltd. All rights reserved.ent-Nemorosone is a benzophenone isolated from geopropolis from Melipona scutellaris whose biological properties remain unexplored. Herein, we evaluated the anti-inflammatory activity of ent-nemorosone by in vivo neutrophil migration and TNF-alpha quantification, as well as by in vitro TNF-alpha quantification, ERK 1/2 phosphorylation, NF-kB activation and nuclear translocation of p65 in stimulated macrophages. ent-Nemorosone was also tested for its antimicrobial effects against Streptococcus mutans biofilm adhesion, polysaccharide production, and viability ent-Nemorosone reduced the influx of neutrophils and TNF-alpha release into the peritoneal cavity of mice, as well as the in vitro TNF-alpha levels, ERK 1/2 phosphorylation, NF-kB activation and nuclear p65 translocation. Furthermore, this compound inhibited biofilm adhesion and reduced the amount of extra- and intracellular polysaccharides synthesized by S. mutans. Thus, ent-nemorosone showed promising anti-inflammatory activity by acting on TNF-alpha release in macrophages, as well as anti-biofilm properties by reducing S. mutans polysaccharide production262735FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2011/16501-3; 2011/23635-6; 2012/22378-2; 2012/22002-

Growth competition on solid media between the peroxigenic <i>S</i>. <i>gordonii</i> and <i>S</i>. <i>mutans</i> UA159 and its derivatives.

<p>Competition assay reveals that <i>S</i>. <i>mutans</i> Δ<i>dpr</i> is sensitive to the H_<b>2</b>O_<b>2</b> produced by <i>S</i>. <i>gordonii</i> (center spot). Under the conditions tested, growth of UA159, Δ<i>feo</i> and Δ<i>suf</i> strains (shown) as well as Δ<i>smu143</i>, Δ<i>smu144</i>, Δ<i>smu929</i>, Δ<i>smu1296</i> and Δ<i>smu1645</i> (not shown) was not inhibited by <i>S</i>. <i>gordonii</i>. The assay was repeated with catalase overlaid onto the <i>S</i>. <i>gordonii</i> spot to inactivate the H_<b>2</b>O_<b>2</b>, resulting in complete loss of sensitivity for the Δ<i>dpr</i> strain.</p

Phenotype enhancement screen of Spx-regulated genes.

<p>Growth of single mutants (Δ<i>smu143</i>, Δ<i>smu144</i>, Δ<i>smu929</i>, Δ<i>smu1296</i> and Δ<i>smu1645</i>, open black bars) and double (Δ<i>smu/</i>Δ<i>spxA1</i>, open red bar) in relation to wild-type UA159 and Δ<i>spxA1</i> single mutant. Solid bars represent normalized growth of Δ<i>spxA1</i> strains (grey bar, set to -1) in relation to UA159 (black bar, set to 1). (*) <i>p</i> ≤ 0.05.</p