10 research outputs found
Ămergence, dynamique Ă©volutive et Ă©cologie de lignĂ©es pathogĂšnes de bivalves marins au sein de lâespĂšce bactĂ©rienne Vibrio aestuarianus
The oyster Crassostrea gigas is the most cultured species of bivalve in the world and is confronted with infectious diseases involving bacteria of the genus Vibrio. Among these Vibrio, the species V. aestuarianus, initially described in 1983 as a bacterium of estuarine environments, has been associated with mortality of adult oysters in Europe since 2001. In 2012, mortality of adult cockles Cerastoderma edule associated with this species have also been reported. However, the processes leading to the emergence of pathogenic bivalve lineages have remained unknown. During this thesis, we sought to clarify (1) the population structure of V. aestuarianus and their genomic determinants, (2) the evolutionary events that participated in the emergence and evolution of the subspecies, and (3) the habitats, cycles and species sensitive toV. aestuarianus. We have shown that pathogenic V. aestuarianus strains fall into two subspecies withdifferent evolutionary histories. V. aestuarianus francensis, described in 2008, includes pathogenic oyster strains while V. aestuarianus cardii includes pathogenic cockle strains. Both subspecies cause disease in their host populations in summer, and temperature has been identified as a favorable factor for disease development. V. aestuarianus francensis impacts oyster farming and we show that two distinct lineages have spread across Europe for at least 20 years. This subspecies is characterized by low genetic diversity and essentially clonal evolution. Strains of V. aestuarianus francensis have a specialist lifestyle, with a habitat restricted to oysters. One of the events that favored its emergence could be the acquisition and genomic integration of a mobile genetic element containing genes coding for proteins involved in copper export. Currently, the subspecies V. aestuarianus cardii impacts cockles only in France. The phenotypic and genetic diversity in this subspecies is greater than in the subspecies V. aestuarianus francensis. Several genetic groups with different levels of virulence towards cockles could be identified and the comparison of genomes between these groups made it possible to identify potential virulence factors.LâhuĂźtre creuse Crassostrea gigas est lâespĂšce de bivalve la plus cultivĂ©e dans le monde et est confrontĂ©e Ă des maladies infectieuses impliquant des bactĂ©ries du genre Vibrio. Parmi ces Vibrio, lâespĂšce V.aestuarianus, initialement dĂ©crite en 1983 comme bactĂ©rie des environnements estuariens, est associĂ©e Ă des mortalitĂ©s dâhuĂźtres creuses adultes en Europe depuis 2001. En 2012, des mortalitĂ©s de coques adultes Cerastoderma edule associĂ©es Ă cette espĂšce ont Ă©galement Ă©tĂ© rapportĂ©es. Cependant, les processus ayant menĂ© Ă lâĂ©mergence des lignĂ©es pathogĂšnes de bivalves sont restĂ©s inconnus. Au cours de cette thĂšse, nous avons cherchĂ© Ă prĂ©ciser (1) la structure des populations de V. aestuarianus et leurs dĂ©terminants gĂ©nomiques ; (2) les Ă©vĂšnements Ă©volutifs ayant participĂ© Ă lâĂ©mergence et lâĂ©volution dessous-espĂšces, et (3) les habitats, cycles et espĂšces sensibles Ă V. aestuarianus. Nous avons montrĂ© que les souches de V. aestuarianus pathogĂšnes se rĂ©partissent dans deux sous-espĂšces aux histoires Ă©volutives diffĂ©rentes. V. aestuarianus francensis, dĂ©crite en 2008, regroupe les souches pathogĂšnes dâhuĂźtres alors que V. aestuarianus cardii regroupe les souches pathogĂšnes de coques. Les deux sous espĂšces provoquent des maladies dans leurs populations dâhĂŽtes en Ă©tĂ©, et la tempĂ©rature a Ă©tĂ© identifiĂ©e comme un facteur favorable au dĂ©veloppement des maladies. V. aestuarianus francensis impacte lâostrĂ©iculture et nous montrons que deux lignĂ©es distinctes se sont propagĂ©es Ă lâĂ©chelle de lâEurope depuis au moins 20 ans. Cette sous-espĂšce se caractĂ©rise par une faible diversitĂ© gĂ©nĂ©tique et une Ă©volution essentiellement clonale. Les souches de V. aestuarianus francensis ont un mode de vie de spĂ©cialiste, avec un habitat restreint aux huĂźtres. Lâun des Ă©vĂšnements ayant favorisĂ© son Ă©mergence pourrait ĂȘtre lâacquisition et lâintĂ©gration gĂ©nomique dâun Ă©lĂ©ment gĂ©nĂ©tique mobile contenant des gĂšnes codant des protĂ©ines impliquĂ©es dans lâexport du cuivre. Actuellement, la sous-espĂšce V. aestuarianuscardii impacte les coques uniquement en France. La diversitĂ© phĂ©notypique et gĂ©nĂ©tique dans cette sous espĂšce est plus importante que dans la sous-espĂšce V. aestuarianus francensis. Plusieurs groupes gĂ©nĂ©tiques prĂ©sentant des niveaux de virulence diffĂ©rents envers les coques ont pu ĂȘtre identifiĂ©es et la comparaison des gĂ©nomes entre ces groupes a permis dâidentifier des facteurs de virulence potentiels
Rapport annuel du Laboratoire de Référence des Maladies des Mollusques Marins. Année 2019
Emergence and clonal expansion of Vibrio aestuarianus lineages pathogenic for oystersin Europe
International audienceCrassostrea gigas oysters represent a significant global food source, with 4.7 million tons harvested per year. In 2001, the bacterium Vibrio aestuarianus francensis emerged as a pathogen that causes adult oyster mortality in France and Ireland. Its impact on oyster aquaculture has increased in Europe since its reemergence in 2012. To better understand the evolutionary mechanisms leading to the emergence and persistence over time of this pathogen, we conducted a survey of mollusk diseases through national reference laboratories (NRLs) across Europe. We analyzed54 new genomes of Vibrio Aestuarianus (Va) isolated from multiple environmental compartments since 2001, in areas with and withoutbivalve mortalities. We used a combination of comparative genomics and population genetics approaches and show thatVa has a classical epidemic population structure from which the pathogenic Va francensis subspecies emerged and clonally expanded. Furthermore, we identified a specific cus-cop-containing island conferring copper resistance to Va francensis whose acquisition may have favored the emergence of pathogenic lineages adapted and specialized to oysters
Emergence and clonal expansion of Vibrio aestuarianus lineages pathogenic for oysters in Europe
Crassostrea gigas oysters represent a significant global food source with 4.7 million tons harvested per year. In 2001, the bacterium Vibrio aestuarianus subsp. francensis emerged as a pathogen that causes adult oyster mortality in France and Ireland. Its impact on oyster aquaculture has increased in Europe since its re-emergence in 2012. To better understand the evolutionary mechanisms leading to the emergence and persistence over time of this pathogen, we conducted a survey of mollusc diseases through national reference laboratories across Europe. We analysed 54 new genomes of Vibrio aestuarianus (Va) isolated from multiple environmental compartments since 2001, in areas with and without bivalve mortalities. We used a combination of comparative genomics and population genetics approaches and show that Va has a classical epidemic population structure from which the pathogenic Va francensis subspecies emerged and clonally expanded. Furthermore, we identified a specific cus-cop-containing island conferring copper resistance to Va francensis whose acquisition may have favoured the emergence of pathogenic lineages adapted and specialized to oysters.info:eu-repo/semantics/acceptedVersio
Pseudoxanthoma Elasticum overlaps Hereditary Spastic Paraplegia Type 56
International audienc
Nation et nations au Moyen Ăge
Il peut sembler paradoxal, au moment oĂč l'histoire globale semble conquĂ©rir chaque jour un terrain plus vaste, quelle qu'en soit la pĂ©riode, de rĂ©flĂ©chir encore Ă la « nation ». Toutefois, en rĂ©ponse Ă une mondialisation vĂ©cue comme la dissolution d'entitĂ©s et d'identitĂ©s historiques spĂ©cifiques et durables, la nation semble ici et lĂ accomplir un retour qui ne pouvait laisser les mĂ©diĂ©vistes indiffĂ©rents, tant il est vrai que c'est souvent au Moyen Ăge, prĂ©tend-on, que les nations modernes se seraient formĂ©es. Cependant, le mot « nation » a Ă©tĂ© Ă ce point investi de sens nouveaux depuis au moins le xviiie siĂšcle que parler des nations au Moyen Ăge suppose un aller-retour permanent entre Moyen Ăge et modernitĂ©, exige de prĂȘter attention Ă la maniĂšre dont des processus territoriaux, politiques, Ă©tatiques et aristocratiques qui appartiennent en propre Ă l'ethnogenĂšse mĂ©diĂ©vale ont Ă©tĂ© rĂ©troactivement « nationalisĂ©s » au sens moral, affectif, guerrier et idĂ©ologique du terme
Discordance du temps
La centralité de l'urgence et les bouleversements des rythmes sociaux produisent de nouveaux régimes temporels, qui remettent en cause les liens et les pratiques communicationnels, les pratiques de transmission et de médiation. Ces mutations, dont les multiples conséquences restent à évaluer, ont déjà retenu l'attention d'anthropologues, d'historiens, d'économistes, de politologues ou de philosophes. Le présent ouvrage propose une approche communicationnelle des enjeux et des problÚmes suscités par ces mutations temporelles. Le laboratoire MICA (Médiation, Information, Communication, Arts), équipe d'accueil de la formation doctorale en Sciences de l'information de la Communication et en Arts de l'Université Michel de Montaigne - Bordeaux 3, a déjà tenu plusieurs colloques et réalisé des travaux sur les temporalités médiatiques et l'urgence communicationnelle. Il s'agit ici, à partir des bénéfices de ces premiÚres investigations et des éclairages apportés par les recherches les plus récentes, de prolonger cette réflexion
Effect of general anaesthesia on functional outcome in patients with anterior circulation ischaemic stroke having endovascular thrombectomy versus standard care: a meta-analysis of individual patient data
Background:
General anaesthesia (GA) during endovascular thrombectomy has been associated with worse patient outcomes in observational studies compared with patients treated without GA. We assessed functional outcome in ischaemic stroke patients with large vessel anterior circulation occlusion undergoing endovascular thrombectomy under GA, versus thrombectomy not under GA (with or without sedation) versus standard care (ie, no thrombectomy), stratified by the use of GA versus standard care.
Methods:
For this meta-analysis, patient-level data were pooled from all patients included in randomised trials in PuMed published between Jan 1, 2010, and May 31, 2017, that compared endovascular thrombectomy predominantly done with stent retrievers with standard care in anterior circulation ischaemic stroke patients (HERMES Collaboration). The primary outcome was functional outcome assessed by ordinal analysis of the modified Rankin scale (mRS) at 90 days in the GA and non-GA subgroups of patients treated with endovascular therapy versus those patients treated with standard care, adjusted for baseline prognostic variables. To account for between-trial variance we used mixed-effects modelling with a random effect for trials incorporated in all models. Bias was assessed using the Cochrane method. The meta-analysis was prospectively designed, but not registered.
Findings:
Seven trials were identified by our search; of 1764 patients included in these trials, 871 were allocated to endovascular thrombectomy and 893 were assigned standard care. After exclusion of 74 patients (72 did not undergo the procedure and two had missing data on anaesthetic strategy), 236 (30%) of 797 patients who had endovascular procedures were treated under GA. At baseline, patients receiving GA were younger and had a shorter delay between stroke onset and randomisation but they had similar pre-treatment clinical severity compared with patients who did not have GA. Endovascular thrombectomy improved functional outcome at 3 months both in patients who had GA (adjusted common odds ratio (cOR) 1·52, 95% CI 1·09â2·11, p=0·014) and in those who did not have GA (adjusted cOR 2·33, 95% CI 1·75â3·10, p<0·0001) versus standard care. However, outcomes were significantly better for patients who did not receive GA versus those who received GA (covariate-adjusted cOR 1·53, 95% CI 1·14â2·04, p=0·0044). The risk of bias and variability between studies was assessed to be low.
Interpretation:
Worse outcomes after endovascular thrombectomy were associated with GA, after adjustment for baseline prognostic variables. These data support avoidance of GA whenever possible. The procedure did, however, remain effective versus standard care in patients treated under GA, indicating that treatment should not be withheld in those who require anaesthesia for medical reasons