Resumo O peridontopatógeno Aggregatibacter actinomycetemcomitans coloniza a cavidade oral aderindo e invadindo as células epiteliais e participando da formação de biofilme em superfícies duras. Aae, uma proteína autotransportadora está relacionada com a adesão bacteriana às células epiteliais. Devido às múltiplas funções desempenhadas por proteínas bacterianas autotransportadoras, este estudo teve como objetivo avaliar o papel de aae de A. actinomycetemcomitans tanto na capacidade de aderir à hidroxiapatita recoberta por saliva (SHA), quanto a de formar biofilme. Um mutante nulo aae foi construído. Suas propriedades hidrofóbicas, bem como a sia capacidade para aderir às células epiteliais, à SHA e para formar biofilme foram avaliadas e comparadas com a cepa -mãe, A. Actinomycetemcomitans VT1169. O mutante nulo aae apresentou redução de hidrofobicidade, assim como diminuição da adesão à SHA e na formação de biofilme, quando comparado à cepa parental. Estes dados sugerem que aae media a adesão de A. Actinomycetemcomitans às células epiteliais e pode também estar envolvida na formação de biofilme e na interação com proteínas salivares adsorvidas.

Abstract The periodontopathogen Aggregatibacter actinomycetemcomitans colonizes oral cavity by binding to and invading epithelial cells as well as by participating in biofilms formed on hard surfaces. Aae, an autotransporter protein, is implicated in bacterial adhesion to epithelial cells. Due to the multiple functions of bacterial autotransporter proteins, this study aimed to evaluate the role of aae in A. actinomycetemcomitans ability to adhere to both saliva-coated hydroxyapatite (SHA) and biofilm. An aae null mutant was constructed. Its hydrophobic properties as well as its ability to adhere to epithelial cells, SHA and to form biofilm were evaluated and compared with the parental strain, A. actinomycetemcomitans VT1169. The aae null mutant showed reduced hydrophobicity, as well as decreased binding to SHA and biofilm formation compared to the parental strain. These data suggest that aae mediates A. actinomycetemcomitans adhesion to epithelial cells and may be involved in biofilm formation and interaction with adsorbed salivary proteins.

RESUMO: Origanum vulgare (orégano) tem sido reconhecido como uma espécie vegetal que possui várias propriedades terapêuticas, de modo que atualmente seu potencial antimicrobiano vem recebendo um grande interesse científico. Este estudo objetivou avaliar a ação antimicrobiana (bactericida e bacteriostática) do óleo essencial comercial de O. vulgare sobre cepas de Escherichia coli e Staphylococcus aureus , bactérias envolvidas em toxinfecções alimentares. Foram utilizadas cepas padrão (American Type Culture Collection - ATCC) e clínicas e estas foram submetidas à ação do óleo essencial em diferentes concentrações, por meio das técnicas de microdiluição (para determinação da concentração inibitória mínima - CIM) e de macrodiluição (para determinação da concentração bactericida mínima - CBM). Foi possível observar que houve variação do potencial antimicrobiano do óleo essencial entre as cepas utilizadas. Para E. coli ATCC 25922, a CIM foi de 6,25 µL/ mL e a CBM de 12,5 µL/mL, enquanto para a amostra clínica os valores foram 12,5 e 25 µL/mL, respectivamente. Já para S. aureus ATCC 25923, a CIM e a CBM foram de 12,5 µL/ mL, enquanto para a amostra clínica os valores foram 6,25 e 25 µL/mL, respectivamente. Portanto, esse óleo essencial de O. vulgare mostrou poder de inibição do crescimento e viabilidade das cepas ensaiadas. No entanto, novos estudos são necessários para que sejam determinadas as concentrações ideais do orégano como antimicrobiano natural, levando em consideração os fatores que influenciam sua composição e a quantidade e qualidade dos compostos ativos.

ABSTRACT: Origanum vulgare (oregano) was recognized as a species with several therapeutic properties. Nowadays, its antimicrobial potential has been receiving a large scientific interest. This study aimed at evaluating the antimicrobial activity (bactericidal and bacteriostatic) of an O. vulgare commercial essential oil against strains of Escherichia coli and Staphylococcus aureus bacteria related to food intoxication and infection. Standard (American Type Culture Collection - ATCC) and clinical strains were submitted to the action of an essential oil in different concentrations through microdilution (for determination of minimum inhibitory concentration - MIC) and macrodilution (for determination of the minimum bactericidal concentration - MBC) techniques. Variation in the antimicrobial potential of an essential oil among the tested strains was observed. For E. coli ATCC 25922, the MIC was 6.25 µL/mL and MBC 12.5 µL/ mL, while for the clinical sample, values varied respectively between 12.5 and 25 µL/mL. For S. aureus ATCC 25923, values of MIC and MBC were 12.5 µL/mL, while for the clinical sample they respectively were 6.25 and 25 µL/mL. Thus, the essential oil of O. vulgare showed inhibition power of growth and viability in the tested strains. However, further studies are necessary to determine the optimal concentrations of oregano to act as a natural antimicrobial, considering the factors that influence their composition, and the quantity and quality of active compounds.

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.

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.