Assessment of seven culture media for the growth and isolation of Capnocytophaga spp.

International audienc

Isolation and characterization of mesotrione-degrading Bacillus sp. from soil

International audienceDissipation kinetics of mesotrione, a new triketone herbicide, sprayed on soil from Limagne (Puy-de-Dôme, France) showed that the soil microflora were able to biotransform it. Bacteria from this soil were cultured in mineral salt solution supplemented with mesotrione as sole source of carbon for the isolation of mesotrione-degrading bacteria. The bacterial community structure of the enrichment cultures was analyzed by temporal temperature gradient gel electrophoresis (TTGE). The TTGE fingerprints revealed that mesotrione had an impact on bacterial community structure only at its highest concentrations and showed mesotrione-sensitive and mesotrione-adapted strains. Two adapted strains, identified as Bacillus sp. and Arthrobacter sp., were isolated by colony hybridization methods. Biodegradation assays showed that only the Bacillus sp. strain was able to completely and rapidly biotransform mesotrione. Among several metabolites formed, 2-amino-4-methylsulfonylbenzoic acid (AMBA) accumulated in the medium. Although sulcotrione has a chemical structure closely resembling that of mesotrione, the isolates were unable to degrade i

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

Real-Time Assessment of Health-Care Requirements During the Zika Virus Epidemic in Martinique.

The spread of Zika virus in the Americas has been associated with a surge in Guillain-Barré syndrome (GBS) cases. Given the severity of GBS, territories affected by Zika virus need to plan health-care resources to manage GBS patients. To inform such planning in Martinique, we analyzed Zika virus surveillance and GBS data from Martinique in real time with a modeling framework that captured dynamics of the Zika virus epidemic, the risk of GBS in Zika virus-infected persons, and the clinical management of GBS cases. We compared our estimates with those from the 2013-2014 Zika virus epidemic in French Polynesia. We were able to predict just a few weeks into the epidemic that, due to lower transmission potential and lower probability of developing GBS following infection in Martinique, the total number of GBS cases in Martinique would be substantially lower than suggested by simple extrapolations from French Polynesia. We correctly predicted that 8 intensive-care beds and 7 ventilators would be sufficient to treat GBS cases. This study showcased the contribution of modeling to inform local health-care planning during an outbreak. Timely studies that estimate the proportion of infected persons that seek care are needed to improve the predictive power of such approaches

Prevalence of oropharyngeal beta-lactamase-producing Capnocytophaga spp. in pediatric oncology patients over a ten-year period

BACKGROUND: The aim of this study was to evaluate the prevalence of beta-lactamase-producing Capnocytophaga isolates in young children hospitalized in the Pediatric Oncology Department of Hôpital Sud (Rennes, France) over a ten-year period (1993–2002). METHODS: In neutropenic children, a periodic survey of the oral cavity allows a predictive evaluation of the risk of systemic infections by Capnocytophaga spp. In 449 children with cancer, 3,053 samples were collected by oral swabbing and plated on TBBP agar. The susceptibility of Capnocytophaga isolates to five beta-lactams was determined. RESULTS: A total of 440 strains of Capnocytophaga spp. were isolated, 309 (70%) of which were beta-lactamase producers. The beta-lactamase-producing strains were all resistant to cefazolin, 86% to amoxicillin, and 63% to ceftazidime. The proportion of strains resistant to third-generation cephalosporins remained high throughout the ten-year study, while susceptibility to imipenem and amoxicillin combined with clavulanic acid was always conserved. CONCLUSION: These results highlight the risk of antibiotic failure in Capnocytophaga infections and the importance of monitoring immunosuppressed patients and testing for antibiotic susceptibility and beta-lactamase production

Porphyromonas gingivalis Participates in Pathogenesis of Human Abdominal Aortic Aneurysm by Neutrophil Activation. Proof of Concept in Rats

International audienceBACKGROUND: Abdominal Aortic Aneurysms (AAAs) represent a particular form of atherothrombosis where neutrophil proteolytic activity plays a major role. We postulated that neutrophil recruitment and activation participating in AAA growth may originate in part from repeated episodes of periodontal bacteremia. METHODS AND FINDINGS: Our results show that neutrophil activation in human AAA was associated with Neutrophil Extracellular Trap (NET) formation in the IntraLuminal Thrombus, leading to the release of cell-free DNA. Human AAA samples were shown to contain bacterial DNA with high frequency (11/16), and in particular that of Porphyromonas gingivalis (Pg), the most prevalent pathogen involved in chronic periodontitis, a common form of periodontal disease. Both DNA reflecting the presence of NETs and antibodies to Pg were found to be increased in plasma of patients with AAA. Using a rat model of AAA, we demonstrated that repeated injection of Pg fostered aneurysm development, associated with pathological characteristics similar to those observed in humans, such as the persistence of a neutrophil-rich luminal thrombus, not observed in saline-injected rats in which a healing process was observed. CONCLUSIONS: Thus, the control of periodontal disease may represent a therapeutic target to limit human AAA progression

Drying colloidal systems: laboratory models for a wide range of applications

The drying of complex fluids provides a powerful insight into phenomena that take place on time and length scales not normally accessible. An important feature of complex fluids, colloidal dispersions and polymer solutions is their high sensitivity to weak external actions. Thus, the drying of complex fluids involves a large number of physical and chemical processes. The scope of this review is the capacity to tune such systems to reproduce and explore specific properties in a physics laboratory. A wide variety of systems are presented, ranging from functional coatings, food science, cosmetology, medical diagnostics and forensics to geophysics and art

Interaction Testing and Polygenic Risk Scoring to Estimate the Association of Common Genetic Variants with Treatment Resistance in Schizophrenia

Importance: About 20% to 30% of people with schizophrenia have psychotic symptoms that do not respond adequately to first-line antipsychotic treatment. This clinical presentation, chronic and highly disabling, is known as treatment-resistant schizophrenia (TRS). The causes of treatment resistance and their relationships with causes underlying schizophrenia are largely unknown. Adequately powered genetic studies of TRS are scarce because of the difficulty in collecting data from well-characterized TRS cohorts. Objective: To examine the genetic architecture of TRS through the reassessment of genetic data from schizophrenia studies and its validation in carefully ascertained clinical samples. Design, Setting, and Participants: Two case-control genome-wide association studies (GWASs) of schizophrenia were performed in which the case samples were defined as individuals with TRS (n = 10501) and individuals with non-TRS (n = 20325). The differences in effect sizes for allelic associations were then determined between both studies, the reasoning being such differences reflect treatment resistance instead of schizophrenia. Genotype data were retrieved from the CLOZUK and Psychiatric Genomics Consortium (PGC) schizophrenia studies. The output was validated using polygenic risk score (PRS) profiling of 2 independent schizophrenia cohorts with TRS and non-TRS: a prevalence sample with 817 individuals (Cardiff Cognition in Schizophrenia [CardiffCOGS]) and an incidence sample with 563 individuals (Genetics Workstream of the Schizophrenia Treatment Resistance and Therapeutic Advances [STRATA-G]). Main Outcomes and Measures: GWAS of treatment resistance in schizophrenia. The results of the GWAS were compared with complex polygenic traits through a genetic correlation approach and were used for PRS analysis on the independent validation cohorts using the same TRS definition. Results: The study included a total of 85490 participants (48635 [56.9%] male) in its GWAS stage and 1380 participants (859 [62.2%] male) in its PRS validation stage. Treatment resistance in schizophrenia emerged as a polygenic trait with detectable heritability (1% to 4%), and several traits related to intelligence and cognition were found to be genetically correlated with it (genetic correlation, 0.41-0.69). PRS analysis in the CardiffCOGS prevalence sample showed a positive association between TRS and a history of taking clozapine (r2 = 2.03%; P =.001), which was replicated in the STRATA-G incidence sample (r2 = 1.09%; P =.04). Conclusions and Relevance: In this GWAS, common genetic variants were differentially associated with TRS, and these associations may have been obscured through the amalgamation of large GWAS samples in previous studies of broadly defined schizophrenia. Findings of this study suggest the validity of meta-analytic approaches for studies on patient outcomes, including treatment resistance

Place de la médecine bucco-dentaire fondée sur la preuve

National audienceDans une vingtaine de jours s'ouvrira l'édition 2011 du Congrès de l'Association Dentaire Française (ADF). Comme chaque année, le Palais des congrès de paris sera, pendant une semaine, le lieu d'informations, de formations, d'échanges entre les professionnels de santé investis dans la médecine buccodentaire. << Le bien-être du patient, thème retenu cette année, sera au coeur des préoccupations de tous. Autour des secrétaires généraux, du staff de l'ADF, du président du Congrès, le comité scientifique a préparé un programme dans lequel les séances classiques et les essentielles côtoieront ]es incontournables et les fondamentales