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L’écosystème buccal est un environnement complexe dans lequel cohabitent plus de 700 espèces de bactéries différentes. Un déséquilibre au sein de ce biofilm est à l’origine des principales maladies de la cavité buccale : les maladies carieuses et parodontales.Pendant plusieurs années, l’étude de l’écosystème buccal s’est faite par une approche réductionniste : les microbiologistes étudiaient les espèces bactériennes individuellement. Cette stratégie a permis d’examiner et de comprendre tous les différents composants de cet écosystème, sans pour autant pouvoir appliquer les conclusions de ces études au biofilm buccal dans son ensemble. En effet, les bactéries ne se comportent pas de la même façon lorsqu’elles sont à l’état planctonique, ou lorsqu’elles sont organisées en biofilm.La flore microbienne buccale est reconnue comme étant l’une des plus complexes dans le corps humain. La multitude d’espèces en présence complique l’étude de ce biofilm. En effet, sa reproduction in vitro est rendue difficile par la complexité des relations entre chacune des espèces. De plus, son recueil, et ses décomptes qualitatif et quantitatif restent très délicats.Dans la littérature sont décrits plusieurs modèles de biofilm.Les modèles pluri-espèces dynamiques in vitro ont l’avantage de se rapprocher des conditions retrouvées in vivo, permettant un certain flux de milieu, le contrôle de paramètres tels que le pH et la température, ainsi que l’élimination des déchets produits.Cependant, ces modèles restent très onéreux et difficiles de mise en place, ce qui complique l’étude du biofilm buccal. Egalement, l’identification des bactéries mises en présence reste un sujet d’étude délicat : en effet, les méthodes traditionnelles de culture montrent des limites, et ne permettent pas une analyse quantitative des résultats, essentielle à la compréhension des phénomènes mis en jeu dans cet écosystème.Le but de notre travail ici est la mise en place de modèle de biofilm pluri-espèces dynamique, fiable et reproductible, facile à mettre en place et moins onéreux que ceux décrits dans la littérature. Ce modèle de biofilm doit permettre l’étude de l’influence de variations de conditions environnementales sur ce dernier, ainsi que celle de candidats probiotiques ayant déjà prouvé leur efficacité sur des supports in vitro statiques. Enfin, toujours dans une optique de simplification, les différentes méthodes d’identification des biofilms formés sont comparées (méthodes de culture traditionnelle, PCR conventionnelle, spectrométrie de masse MALDI-TOF, et qPCR), afin d’établir un protocole d’identification reproductible permettant une analyse qualitative et quantitative des résultats. / The oral ecosystem presents a great complexity since it can harbor more than 700 different bacterial species. Most of them are organized in a biofilm on both the dental and the mucosal surfaces. Studying this complex environment is of utmost importance because a rupture in its stability can lead to the preeminence of pathogenic microorganisms, causing dental decay, gingivitis and periodontitis.For many years, the study of the oral ecosystem was conducted throught a reductionist approach: microbiologists studies bacterial strains individually. This strategy allowed the understanding of all different components of this ecosystem, but lacked the transposition of its conclusions to the study of a whole complex oral biofilm. As a matter of fact, bacteria don’t behave the same way in a planktonic state or when they are organized in a biofilm.The oral microflora is known to be one of the most complex floras hosted by the human body. The multitude of strains hardens its study. Indeed, its in vitro reproduction is made as complex as the different interactions occurring between each strain. Moreover, harvesting and quantitative and qualitative analysis of such biofilms remain very delicate procedures.Several biofilm models have been described in the literature. In vitro dynamic multispecies models share the same asset: to closely mimic in vivo conditions. They allow a medium flow, and parametrical controls such as pH, temperature; and waste removal. However, those models are very expensive and difficult to master. Also, bacterial identification is still a tough matter : traditional culture methods have shown their limits, and don’t allow a quantitative analysis, which is essential to understand the phenomenons occurring in this ecosystem.The aim of our work was to set up a dynamic multispecies oral biofilm, both reliable and reproducible, easy to set up and less expensive than those previously described in the literature. This model shall allow the study of environmental conditions variations and the efficiency of probiotic candidates that already showed their efficacy on static supports.Lastly, we compared different biofilm identification methods, traditional culture, conventional PCR, MALDI-TOF mass spectrometry, and quantitative PCR, in order to establish a reproducible identification protocol allowing both quantitative and qualitative analysis.

Indiana University-Purdue University Indianapolis (IUPUI) / Biofilm-related infections account for more than 75% of all microbial infections in humans. Several studies argued that the biofilm-dispersal process initiates systemic infections by causing bacteria to be released into the host. Although our knowledge of the characteristics of dispersed bacteria is still limited, it is recognized that these bacteria have different characteristics, such as higher virulence and adhesion factors, in contrast to their planktonic and sessile counterparts. Streptococcus mutans (S. mutans), which is the major pathogen in the formation of dental caries has also been detected in atherosclerotic plaques, and heart valve specimens from patients with cardiovascular diseases. In oral isolates, the frequency of S. mutans strains positive for the collagen binding protein (CBP) cnm+ gene has been estimated to be 10-20%. Tobacco use is considered to be an independent risk factor for both atherosclerosis and dental caries. Knowledge about S. mutans biofilm dispersal is lacking. Thus, studying the characteristics of dispersed bacteria is crucial to fill that gap of knowledge. We began our investigation by conducting a review of the literature on current findings about biofilm formation and dispersion of several oral and extraoral pathogens, in addition to methodologies for analyzing the dispersion phase. For this study, we identified and chose three dispersion-inducing compounds: adenosine triphosphate (ATP), cis-2-deconoic acid (CDA), and nicotine (NIC). Subsequently, the dispersion, adhesion to collagen type IV, and invasion of bovine aortic endothelial cells (BAEC) were studied using two S. mutans strains, UA159 (Cnm-) and TLJ60a (Cnm+). Both strains showed increased dispersion, adherence rates to collagen type IV, and invasion percentages of BAEC when treated with dispersion inducers compared to their control. In the ATP and NIC groups, TLJ60a (Cnm+) demonstrated greater dispersion and adherence to collagen type IV than UA159 (Cnm-). Harboring the cnm encoding gene appears to enhance S. mutans invasion of BAEC in both biofilm and dispersed cells. In the Cnm+ strain, ATP-induced dispersed cells demonstrated a consistent increase in type IV collagen adhesion and BAEC invasion rates. Therefore, it is imperative to investigate the impact of ATP secretion by damaged endothelial cells in determining S. mutans role in atherogenesis. / 2023-12-28

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-06-08T20:01:21Z No. of bitstreams: 1 Dissertação - Julie Marie Martins Monteiro.pdf: 996366 bytes, checksum: 7736bdc6fce423bd155ddb42d5bb7df9 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-06-08T20:01:34Z (GMT) No. of bitstreams: 1 Dissertação - Julie Marie Martins Monteiro.pdf: 996366 bytes, checksum: 7736bdc6fce423bd155ddb42d5bb7df9 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-06-08T20:03:17Z (GMT) No. of bitstreams: 1 Dissertação - Julie Marie Martins Monteiro.pdf: 996366 bytes, checksum: 7736bdc6fce423bd155ddb42d5bb7df9 (MD5) / Made available in DSpace on 2016-06-08T20:03:17Z (GMT). No. of bitstreams: 1 Dissertação - Julie Marie Martins Monteiro.pdf: 996366 bytes, checksum: 7736bdc6fce423bd155ddb42d5bb7df9 (MD5) Previous issue date: 2015-05-29 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / Phytochemical investigations led to the isolation and characterization of biflorin that among the compounds already isolated from Capraria biflora, showed promise with a powerful antimicrobial and antitumor activity. Therefore, the aim of this study was to evaluate the antimicrobial activity of biflorin on the oral cavity microorganisms and cytotoxic activity on cancer cell lineage of the oral cavity. The screening of antimicrobial activity biflorin was performed by diffusion technique in agar with the microorganisms Streptococcus mutans ATCC25175, Streptococcus salivarius ATCC7073, Streptococcus oralis ATCC10557 and Lactobacillus paracasei ATCC335. The quantification of the antimicrobial activity was performed by broth microdilution technique to determine the minimum inhibitory concentration (MIC). To evaluate the cytotoxicity of cancer lineage of the oral cavity was used cell line CAL-27 and the Alamar blue assay. In the agar diffusion test, biflorin presented antimicrobial activity against all evaluated microorganisms. The greatest antimicrobial activity was observed in trials with Lactobacillus paracasei and lower in trials with Streptococcus salivarius. Whereas biflorin was active against all tested micro-organisms, it determined the minimum inhibitory concentration. In the microdilution test biflorin showed lower MIC against Streptococcus mutans (MIC = 0,70μg/mL) and Streptococcus salivarius (MIC 3,125 μg/mL). While the 2% chlorhexidine was effective in its lower dilution (0,015%) of all tested bacteria. In Alamar blue cytotoxicity assay, the IC50 value of biflorin on the CAL 27 in 72 hours was 3.69 (3.17 to 4.30μM/mL) and Doxorubicin (control) was 0.039 (0.036- 0.088 μM/mL).The results suggest that biflorin can be incorporated in dental applications and products for the treatment of cancers of the oral cavity, but it is necessary to continue the research in this area with this substance / Investigações fitoquímicas levaram ao isolamento e caracterização da Biflorina que dentre os compostos já isolados da Capraria biflora, mostrou-se promissora com uma potente atividade antimicrobiana e antitumoral. Portanto, o objetivo deste estudo foi avaliar a atividade antimicrobiana da biflorina sobre micro-organismos da cavidade bucal e atividade citotóxica sobre linhagem de célula cancerígena da cavidade bucal. A triagem da atividade antimicrobiana da biflorina foi realizada através da técnica de difusão em ágar com os microorganismos Streptococcus mutans ATCC25175, Streptococcus salivarius ATCC7073, Streptococcus oralis ATCC10557 e Lactobacillus paracasei ATCC335. A quantificação desta atividade antimicrobiana foi realizada pela técnica de microdiluição em caldo para determinação da concentração inibitória mínima (CIM). Para avaliação da citotoxicidade sobre linhagem cancerígena da cavidade bucal foi utilizada a linhagem celular CAL-27 e o ensaio de Alamar blue. No teste de difusão em ágar, a biflorina apresentou atividade antimicrobiana frente atodos os micro-organismos avaliados. A maior atividade antimicrobiana foi observada nos ensaios com o Lactobacillus paracasei e a menor nos ensaios com Streptococcus salivarius. Considerando que a biflorina foi ativa frente a todos os micro-organismos testados, determinou-se a concentração inibitória mínima. No teste de microdiluição a biflorina apresentou menor CIM frente ao Streptococcus mutans (MIC=0,70 μg/mL) e Streptococcus salivarius (MIC 3,125 μg/mL). Enquanto a clorexidina a 2% foi eficaz em sua menor diluição (0,015%) sobre todas as bactérias testadas. No teste de citotoxicidade do Alamar blue, o valor da IC50 da Biflorina sobre a CAL-27 em 72 horas foi de 3.69 (3.17 – 4.30μM/mL) e a Doxorrubicina (controle) foi 0.039 (0.036-0.088μg/mL). Os resultados sugerem que a biflorina pode ser incorporada a produtos de uso odontológico e para o tratamento de neoplasias da cavidade oral, porém é necessário dar continuidade aos estudos com esta substância nesta área

Abstract Purpose: The oral microbiome has been related to numerous extra oral diseases. Recent studies detected a high abundance of oral bacteria in inflamed appendices in pediatric patients. To elucidate the role of oral bacteria in acute pediatric appendicitis, we studied the oral and appendiceal microbiome of affected children compared to healthy controls. Methods: Between 1-6/2015, 21 children undergoing appendectomy for acute appendicitis and 28 healthy controls were prospectively enrolled in the study. All individuals underwent thorough dental examination as well as laboratory for CRP, neutrophil and leukocyte count. Samples of inflamed appendices and the gingival sulcus were taken for 16S rDNA sequencing. Additionally, RT-qPCR of Fusobacterium nucleatum, Peptostreptococcus stomatis and Eikenella corrodens was performed and their viability was tested under acidic conditions to mimic gastric transfer. Results: In appendices, Bacteriodetes and Porphyromonas were discovered as dominant phylum and genus. In sulcus samples, Firmicutes and Streptococcus were detected predominantly. Peptostreptococcus stomatis, Eikenella corrodens and Fusobacterium nucleatum were identified in each sample group. In contrast to controls, viable amounts of Peptostreptococcus stomatis were increased in appendices and correlated with leukocyte count and CRP levels. Postprandial viability could be demonstrated for all tested bacteria. Conclusion: In children with acute appendicitis, we identified several oral bacterial pathogens. Based on postprandial viability of selected species, a viable migration from the oral cavity through the stomach to the appendix seems possible. Thus, the oral cavity could be a relevant reservoir for acute appendicitis.

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Einleitung Die ständige Suche nach effektiveren und/oder weiteren botanischen Antibiotika im weiten Feld der geographischen Artenvielfalt macht den Stand der Forschung sehr unübersichtlich. Ziel dieser Arbeit ist es, durch Literaturrecherche eine Übersicht antimikrobiell wirksamer Pflanzen, Zubereitungen und Extrakte auf ausgewählte Bakterien der Mundhöhle aufzuzeigen. Material und Methoden Die Literaturrecherche erfolgte weltweit durch englische Schlüsselwörter in den elektronischen Datenbanken Cochrane Library, Pubmed / Medline, Embase und Google scholar für den Zeitraum bis einschließlich Dezember 2012. Ergebnisse Es wurden Veröffentlichungen über 735 Pflanzen gefunden, die auf ihre antimikrobielle Wirkung gegen folgende Mikroorganismen getestet wurden: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, Streptococcus mutans, Streptococcus mitis, Streptococcus oralis, Streptococcus sanguinis, Streptococcus gordonii. Gute antimikrobielle Wirkung zeigten Extrakte von 149 Pflanzen. In 87 klinischen Studien wurden Extrakte und Mixturen von ingesamt 61 Pflanzen untersucht, wovon nur 4 Studien keinen Effekt auf die klinischen Parameter hatten. Schlussfolgerung für die Klinik Pflanzenextrakte als neue potenzielle antimikrobielle Wirkstoffe in Prävention und Therapie von oralen Erkrankungen erforden noch weitere kontrollierte Studien in definierten Verfahren. / Introduction The constant search for more effective and / or other botanical antibiotics in the vast field of geographic diversity makes the state of research very confusing. The aim of this work is to show an overview of antimicrobial plants, preparations and extracts on selected bacteria of the oral cavity through literature. Material and Methods The literature search was carried worldwide by English keywords in the electronic databases Cochrane Library, PubMed / Medline, Embase and Google scholar for the period up to and including December 2012. Results Publications were found about 735 plants. They were tested for antimicrobial activity against the following microorganisms: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, Streptococcus mutans, Streptococcus mitis, Streptococcus oralis, Streptococcus sanguinis, Streptococcus gordonii. Extracts of 149 plants showed good antimicrobial effect. In 87 clinical studies, extracts and mixtures of a total of 61 plants were examined, of which only 4 studies had no effect on clinical parameters Conclusion for the clinic Require new potential plant extracts as antimicrobial agents in the prevention and treatment of oral diseases, further controlled studies in defined procedures