Distribución de los genotipos de fimA en cepas de Porphyromonas gingivalis aisladas de placas subgingivales y de sangre durante bacteriemias

Introduction. Porphyromonas gingivalis is considered as a major etiological agent in the onset and progression of chronic destructive periodontitis. Porphyromonus gingivalis fimA type has been correlated to the virulence potential of the strain; therefore this gene could be involved in the ability of P. gingivalis to reach blood stream.Objective. The classifications of P. gingivalis fimA types will be compared in subgingival plaque and blood samples collected after scaling and root root planing of periodontitis patients.Materials and methods. Fifteen periodontitis patients requiring scaling and root planing were enrolled. P. gingivalis isolates were classed to genotype with fimA type-specific PCR assay. fimA gene was sequenced if the isolate was listed as unclassifiable after PCR technique.Results. Six patients showed positive P. gingivalis bacteremia. The most frequent fimA was fimA type II, followed by Ib, III and IV. In blood strains, type II was followed by IV, Ib and III.Conclusion. Type II was the most frequent genotype in blood samples and in subgingival plaque samples. However, no correlation was found between the frequency of any fimA type with SRP induced bacteremia. P. gingivalis fimA type appears to be conserved within individual patients throughout the times of sample collection. fimA gene sequence results were not in agreement with results of fimA genotyping by PCR.Introducción. Porphyromonas gingivalis es el principal agente etiológico de la periodontitis. El gen fimA ha sido relacionado con la virulencia del microorganismo, lo cual sugiere la participación de dicho gen en la capacidad del microorganismo para alcanzar el torrente sanguíneo.Objetivo. Estudiar la distribución de los tipos de fimA de P. gingivalis en muestras de placa subgingival y de sangre obtenidas durante bacteriemias después de raspaje y alisado radicular.Materiales y métodos. Se practicó un alisado radicular a 15 pacientes con periodontitis. Se obtuvieron aislamientos clínicos de P. gingivalis de la placa subgingival y durante la bacteriemia inducida por el procedimiento. Para la genotipificación se utilizó la técnica de reacción en cadena de la polimerasa (PCR) específica para fimA. En los aislamientos no clasificables por PCR se realizó secuenciación del gen fimA.Resultados. Seis pacientes fueron positivos para bacteriemia por P. gingivalis. La distribución de fimA evaluada en 30 aislamientos de placa subgingival y de sangre mostró una mayor frecuencia del fimA tipo II de P. gingivalis. En los aislamientos de placa subgingival, la detección de fimA tipo II fue seguida por Ib, III y IV; sin embargo, en los aislamientos de sangre el tipo II fue seguido por los tipos IV, Ib y III.Conclusión. En los aislamientos de sangre y de placa subgingival de pacientes con periodontitis el fimA más frecuente fue el tipo II; no fue posible correlacionar el tipo de fimA con la bacteriemia inducida por el alisado radicular. Los resultados de la secuenciación del gen fimA no concuerdan con los obtenidos por PCR

Tolerance to intraoral biofilms and their effectiveness in improving mouth dryness and modifying oral microbiota in patients with primary Sjögren’s syndrome: “Predelfi study”

IntroductionPrimary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by exocrine gland dysfunction. No therapeutic strategy is sufficient on its own for the management of dry mouth and therapeutic innovations are required.MethodsThis Predelfi study was a single-center, prospective, comparative, randomized, double-blind, cross-over controlled study with the primary objective of assessing the tolerance to and effectiveness of two adhesive biofilms (containing prebiotics and, sodium alginate, respectively) in patients with pSS and hyposialia (#NCT04206826 in ClinicalTrials.gov). Secondary objectives were to obtain initial data regarding the clinical effectiveness of such biofilms in the improvement of signs and symptoms related to dry mouth and potential changes in the oral microbiota. Ten pSS patients with pSS were included (9 females and 1 male) with a mean age of 58.1 ± 14.0 years.Results and discussionTolerance to the prebiotic and sodium alginate biofilms was assessed by the patients (visual analog scale [VAS] score 66.7 and 87.6, respectively) and the practitioner (90 and 100, respectively). The absolute changes in the VAS scores at the start and end of each treatment period highlighted an improvement in mouth dryness for the sodium alginate versus the prebiotic biofilm. The VAS scores for other parameters (mouth burning sensation; taste alteration; chewing; swallowing and speech difficulties) remained globally comparable between the two groups. Unstimulated salivary flow showed no changes regardless of the biofilm used. Regarding the oral microbiota, the sodium alginate biofilm increased the abundance of the Treponema genus, whereas the use of the prebiotic biofilm as the first treatment increased the abundance of the genera Veillonella and Prevotella. Nevertheless, the prebiotic biofilm appeared to stimulate “milder” genera with regard to periodontal infections. Furthermore, pre-treatment with the prebiotic biofilm prevented the emergence of the Treponema genus induced by subsequent treatment with the sodium alginate biofilm, suggesting a potential protective effect

Virulence de Porphyromonas gingivalis

Porphyromonas gingivalis est une bactérie anaérobie stricte responsable des maladies parodontales. La respiration et la régulation des gènes de virulence restent inconnues. Ce travail explore la chaîne respiratoire et montre l'aérotolérance de la bactérie. Les résultats affirment la capacité de transmission aéroportée et inter individus par des mécanismes activant des gènes de résistance au stress oxydatif tel que "tpx" sous la dépendance d'OsyR régulateur transcriptionnel. Après une analyse de la littérature sur les principaux gènes de virulence, hémagglutinines et gingipaïnes, les études expérimentales ont montré que l'oxygène atmosphérique n'influence pas leur expression. Par contre, la coagrégation "in vitro" avec "T.denticola", autre parodontopathogène, entraîne la surespression de "hagA", "rgpA" et "kgp" et par ce phénomène favorise le développement de la maladie parodontale.RENNES1-BU Santé (352382103) / SudocSudocFranceF

Pathogénèse des maladies parodontales et la réponse de l'hôte (Étude des polymorphismes génétiques dans les parodontites)

Les parodontites sont considérées comme des maladies complexes. Nous avons procédé à une revue de la littérature sur l'association entre les polymorphismes des gènes et la susceptibilité aux parodontites. Nous avons constaté qu'il est difficile de tirer des conclusions pour l'ensemble de la population mondiale en ce qui concerne les polymorphismes des gènes de l'IL-1, l'IL-2, l'IL-4, l'IL-6, l'IL-10, du TNF-a, du TGF-b, des MMP, du récepteur du Fc, de la vitamine D et le CD14 et leur association ou non avec les parodontites. Toutefois, les résultats varient considérablement entre les études; en effet, la taille des échantillons, le choix des ethnies (...) semblent influencer ces résultats. Un plus grand nombre de cas par étude, des phénotypes bien définis, le contrôle des autres facteurs de risque et l'analyse de multiples gènes et des polymorphismes sont nécessaires pour comprendre la contribution des polymorphismes génétiques dans les parodontites.RENNES1-BU Santé (352382103) / SudocSudocFranceF

Etude de la recolonisation bactérienne de la poche parodontale après traitement à la prexidine®

rLe traitement initial de la maladie parodontale s'effectue grâce à un débridement parodontal qui dans la plupart des cas associé à une hygiène bucco-dentaire stricte suffit à engendrer une cicatrisation parodontale satisfaisante.Afin d'obtenir une aide supplémentaire, l'utilisation d'un adjuvant pendant le débridement parodontal mais également en inter-séance est la plupart du temps prescrit par les chirurgiens dentistes.Nous avons choisi d'étudier l'efficacité de la prexidine® prescrite en inter-séance de débridement parodontal sur la recolonisation bactérienne des poches parodontales et plus particuliérement sur porphyromomas gingivalis (Pg).RENNES1-BU Santé (352382103) / SudocSudocFranceF

Hémochromatose et parodontites (un projet de recherche clinique)

RENNES1-BU Santé (352382103) / SudocSudocFranceF

Elimination du biofilm et du tartre radiculaire (analyse comparative de deux instruments ultrasonores)

RENNES1-BU Santé (352382103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Peptidylarginine désiminases du microbiote buccal et polyarthrite rhumatoïde

National audienceIn the last decade, the association between the periodontitis and rheumatoid arthritis (RA) has been established, suggesting that oral microbiome plays a causal role by initiating this chronic autoimmune inflammatory disease of articulation. Both pathogenesis are similar in term of chronic inflammation, tissue breakdown and bone resorption. Molecular aspects have also revealed that citrullination, a post-translational modification catalyzed by peptidyl-arginine deiminases (PADs), is involved in both diseases. For RA, citrullinated proteins production leads to the synthesis the of anti-citrullinated protein antibodies triggering the loss of immune tolerance. In humans, five PADs have been identified. Recently, studies have found that only Porphyromonas species possess PAD. Thus, a major periodontal pathogen, Porphyromonas gingivalis, is able to generate citrullinated epitopes, and could consequently induce anti-citrullinated protein antibodies. In this review, citrullination process, periodontitis and RA are described to put them in relation with molecular, clinical and epidemiological studies establishing the association between periodontitis and RA

Microbiota in Periodontitis: Advances in the Omic Era

International audienceThe complexity of the oral microbiome continues to astound researchers even with the advancement of multi-disciplinary strategies being used to study these microorganisms in relation to the human body. There is extensive literature available that explains how oral bacterial communities exist within the biofilm and maintains a balance with the host immune system, but when this balance is tipped disease can occur. The purpose of this review is to highlight the subgingival microbial compositions during health and periodontal disease using next generation sequencing techniques, as well as determining the types of functional activities that partake during these states. The subgingival microbiota is a fluid structure that can adapt accordingly to the environment and the identification of signature biomarkers may aid in the assessment of risk and disease severity in an individual to complement clinical diagnosis in the future

Medication-Related Osteonecrosis of the Jaw: evaluation of a therapeutic strategy in oral surgery

International audienceBackground: Medication-related osteonecrosis of the jaw (MRONJ) is a severe adverse illness linked to antiresorptive therapies (ART), for which there is no therapeutic gold standard. Many factors can influence MRONJ evolution such as cancer type, treatment, comorbidities, and accumulated dose of ART. The aim of this study was to determine the influencing factors of MRONJ treatments success.Methods: This retrospective study focused on patients treated for MRONJ in a French tertiary centre. Non-operative therapy was always applied, ART were suspended if appropriate, and surgery (MRONJ removal and musculo-mucosal flap reconstruction) was performed in the absence of contraindication. The evaluation criteria were bone and mucosal healing 3 months after surgery.Results: 81 MRONJ were included; medical treatment alone was administered to 26% while the remaining 74% received additional surgery. Therapeutic success reached 86.7% (52/60) for surgery compared to 42.9% (9/21) for medical treatment alone (p<0.001). Age (OR=1.08, p=0.014) and the absence of infection (OR=5.32, p=0.042) were in favour of success, while medical treatment alone (OR=0.03, p<0.001) was highly unfavourable.Conclusion: MRONJ healing is influenced by age, non-infectious stages, and surgery. Additional surgery in MRONJ treatment should be advised if the health of the patient permits