A polyphasic approach to study the dynamics of microbial population of an organic wheat sourdough during its conversion to gluten-free sourdough

To develop a method for organic gluten-free (GF) sourdough bread production, a long-term and original wheat sourdough was refreshed with GF flours. The dynamics of the sourdough microbiota during five months of back-slopping were analyzed by classical enumeration and molecular methods, including PCR-temporal temperature gel electrophoresis (PCR-TTGE), multiplex PCR, and pulsed field gel electrophoresis (PFGE). The results showed that the yeast counts remained constant, although Saccharomyces cerevisiae, present in the initial wheat sourdough, was no longer detected in the GF sourdough, while lactic acid bacteria (LAB) counts increased consistently. In the first phase, which was aimed at obtaining a GF sourdough from wheat sourdough, Lactobacillus sanfranciscensis, L. plantarum, and L. spicheri were the main LAB species detected. During the second phase, aimed at maintaining the GF sourdough, the L. plantarum and L. spicheri populations decreased whereas L. sanfranciscensis persisted and L. sakei became the predominant species. Multiplex PCRs also revealed the presence of several L. sakei strains in the GF sourdough. In a search for the origin of the LAB species, PCR-TTGE was performed on the flour samples but only L. sanfranciscensis was detected, suggesting a flour origin for this typical sourdough species. Thus, while replacement of the wheat flour by GF flour influenced the sourdough microbiota, some of the original sourdough LAB and yeast species remained in the GF sourdough. [Int Microbiol 2014; 17(1):1-9]Keywords: Lactobacillus spp. · Saccharomyces · Candida ·  sourdough · gluten-free food · organic · lactic acid bacteria · yeas

Fenfluramine for Treatment-Resistant Seizures in Patients With Dravet Syndrome Receiving Stiripentol-Inclusive Regimens A Randomized Clinical Trial

IMPORTANCE Fenfluramine treatment may reduce monthly convulsive seizure frequency in patients with Dravet syndrome who have poor seizure control with their current stiripentol-containing antiepileptic drug regimens. OBJECTIVE To determine whether fenfluramine reduced monthly convulsive seizure frequency relative to placebo in patients with Dravet syndrome who were taking stiripentol-inclusive regimens. DESIGN, SETTING, AND PARTICIPANTS This double-blind, placebo-controlled, parallel-group randomized clinical trial was conducted in multiple centers. Eligible patients were children aged 2 to 18 years with a confirmed clinical diagnosis of Dravet syndrome who were receiving stable, stiripentol-inclusive antiepileptic drug regimens. INTERVENTIONS Patients with 6 or more convulsive seizures during the 6-week baseline period were randomly assigned to receive fenfluramine, 0.4 mg/kg/d (maximum, 17 mg/d), or a placebo. After titration (3 weeks), patients’ assigned dosages were maintained for 12 additional weeks. Caregivers recorded seizures via a daily electronic diary. MAIN OUTCOMES AND MEASURES The primary efficacy end point was the change in mean monthly convulsive seizure frequency between fenfluramine and placebo during the combined titration and maintenance periods relative to baseline. RESULTS A total of 115 eligible patients were identified; of these, 87 patients (mean [SD], age 9.1 [4.8] years; 50 male patients [57%]; mean baseline frequency of seizures, approximately 25 convulsive seizures per month) were enrolled and randomized to fenfluramine, 0.4 mg/kg/d (n = 43) or placebo (n = 44). Patients treated with fenfluramine achieved a 54.0% (95% CI, 35.6%-67.2%; P < .001) greater reduction in mean monthly convulsive seizure frequency than those receiving the placebo. With fenfluramine, 54% of patients demonstrated a clinically meaningful (50%) reduction in monthly convulsive seizure frequency vs 5% with placebo (P < .001). The median (range) longest seizure-free interval was 22 (3.0-105.0) days with fenfluramine and 13 (1.0-40.0) days with placebo (P = .004). The most common adverse events were decreased appetite (19 patients taking fenfluramine [44%] vs 5 taking placebo [11%]), fatigue (11 [26%] vs 2 [5%]), diarrhea (10 [23%] vs 3 [7%]), and pyrexia (11 [26%] vs 4 [9%]). Cardiac monitoring demonstrated no clinical or echocardiographic evidence of valvular heart disease or pulmonary arterial hypertension. CONCLUSIONS AND RELEVANCE Fenfluramine demonstrated significant improvements in monthly convulsive seizure frequency in patients with Dravet syndrome whose conditions were insufficiently controlled with stiripentol-inclusive antiepileptic drug regimens. Fenfluramine was generally well tolerated. Fenfluramine may represent a new treatment option for Dravet syndrome. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT0292689

Etude de la traduction mitochondriale chez la levure Schizosaccharomyces pombe

La mitochondrie, organite spécialisé dans la production d énergie, possède son propre génome et son propre système d expression. Le système de traduction mitochondriale est dérivé du système procaryotique et présente une conservation des facteurs impliqués. Ces facteurs sont plus conservés entre les eucaryotes supérieurs et S. pombe, alors que leur étude est classiquement menée chez S. cerevisiae. Nous avons donc étudié la traduction mitochondriale chez S. pombe.L étape d élongation de la traduction mitochondriale implique trois facteurs chez les eucaryotes supérieurs et S. pombe , et seulement deux de ces facteurs sont conservés chez S. cerevisiae. Les facteurs conservés, EF-G et EF-Tu, sont des GTPases et le facteur absent chez S. cerevisiae, EF-Ts, est le facteur d échange des nucléotides de EF-Tu. Nous avons montré que l absence de EF-Ts chez S. pombe conduit à une diminution drastique de la traduction et une absence de respiration. De plus, nous avons montré que la traduction mitochondriale est essentielle à la viabilité chez S. pombe. En présence de la mutation nucléaire ptp1-1, qui permet la viabilité en absence d ADNmt, l abolition de la traduction mitochondriale conduit à une déplétion de l ADNmt. Nous avons aussi démontré que le facteur EF-Tu de S. cerevisiae est bien indépendant d un facteur d échange, contrairement au facteur de S. pombe. Enfin, nous avons isolé des variants du facteur EF-Tu de S. pombe ne nécessitant plus de facteur d échange.De plus, nous avons débuté l analyse de l étape d initiation chez cette levure par l étude de l homologue au facteur d initiation IF3 bactérien qui ne semble pas être conservé chez S. cerevisiae.Mitochondria, the organelle that produces energy, have is own genome and is own system of expression. Mitochondrial translation is derived from prokaryotes and shows conservation of factors implied. These factors are more conserved between higher eukaryotes and fission yeast, whereas studies are mostly investigated in budding yeast. So we have started studying mitochondrial translation in the fission yeast.The elongation step of mitochondrial translation implies three factors in higher eukaryotes and fission yeast, and only two of them are conserved in budding yeast. The conserved factors, EF-Tu and EF-G, are GTPases and the factor absent in budding yeast is the nucleotide exchange factor of EF-Tu; EF-Ts. We have shown that EF-Ts absence in fission yeast leads to a drastic decrease of mitochondrial translation and leads to respiratory deficiency. We have also shown that mitochondrial translation is essential in fission yeast. In a ptp1-1 genetic background, which leads to viability in absence of mtDNA, abolition of mitochondrial translation leads to a mtDNA depletion. Moreover, we have shown that budding yeast EF-Tu is independent of exchange factor, in contrast with fission yeast EF-Tu. And we have isolated several variants of fission yeast EF-Tu independent of exchange factor.We have also started studying the initiation step of translation in this yeast with the study of the bacterial IF3 homolog which seems to be absent in the budding yeast.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Non-tuberculous mycobacterial pulmonary diseases in France: an 8 years nationwide study

International audienceBackgroundThe objective of the study was to describe the epidemiology, management and cost of non-tuberculous mycobacteria pulmonary disease (NTM-PD) in France.MethodsA retrospective analysis was performed using the SNDS (“Système national des données de santé”) database over 2010–2017. Patients with NTM-PD were identified based on the ICD10 codes during hospitalizations and/or specific antibiotics treatment regimens. The study population was matched (age, sex and region) to a control group (1:3) without NTM-PD.Results5628 patients with NTM-PD (men: 52.9%, mean age = 60.9 years) were identified over the study period and 1433 (25.5%) were treated with antibiotics. The proportion of patients still receiving treatment at 6 and 12 months was 40% and 22%, respectively. The prevalence of NTM-PD was estimated at 5.92 per 100,000 inhabitants and the incidence rate of NTM-PD remained stable over time between 1.025/100,000 in 2010 and 1.096/100,000 in 2017. Patients with NTM-PD had more co-morbidities compared to controls: corticoids (57.3% vs. 33.8%), chronic lower respiratory disease (34.4% vs. 2.7%), other infectious pneumonia (24.4% vs. 1.4%), malnutrition (based on hospitalization with the ICD-10 code reported during a hospital stay as a main or secondary diagnosis) (22.0% vs. 2.0%), history of tuberculosis (14.1% vs. 0.1%), HIV (8.7% vs. 0.2%), lung cancer and lung graft (5.7% vs. 0.4%), cystic fibrosis (3.2% vs. 0.0%), gastro-esophageal reflux disease (2.9% vs. 0.9%) and bone marrow transplant (1.3% vs. 0.0%) (p  50% of the total expense).ConclusionPatients with NTM-PD in France were shown to have many comorbidities, their mortality risk is high and mainly driven by NTM-PD, and their management costly. Only a minority of patients got treated with antibiotics and of those patients treated, many stopped their therapy prematurely. These results underline the high burden associated with NTM-PD and the need for improvement of NTM-PD management in France

A Pathogenic Cytochrome b Mutation Reveals New Interactions between Subunits of the Mitochondrial bc1 Complex

International audienc