HAL ENVT (Ecole Nationale Vétérinaire de Toulouse)
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Impact of global warming on host/pathogen interactions in a Novirhabdovirus / Rainbow trout (Oncorhynchus mykiss) model
No full textInternational audienceContext :The development of aquaculture, the world's fastest-growing agricultural sector, faces several challenges such as global warming, environmental pollution and the emergence of pathogens; impacting the health and welfare of both farm and wildlife animals. Climate modeling projections indicate that global surface temperatures of continents and surface waters (oceans and rivers) could rise by 0.4 to 2.6°C by 2050 according to the UN. Chronic exposure to increased water temperatures constitutes a strong physiological/metabolic stress, likely to alter fish immune responses and resilience to infectious diseases. In addition, the emergence of naturally thermo-adapted viral strains could represent a serious epidemic threat.Objectives :In a collaborative project, INRAE and ANSES characterized the impact of rising water temperatures on host pathogen interactions studying 1/ fish health (zootechnics, immune competences) and 2/ virus plasticity focusing on two salmonid viruses with a broad host spectrum and high evolutionary potential, viral hemorrhagic septicemia virus (VHSV) and infectious hematopoietic necrosis virus (IHNV). Methods :Twelve field strains of IHNV and VHSV were selected to represent the genetic diversity of viruses circulating worldwide. The in vitro characterization of their temperature sensitivity was initially conducted by assessing their replication kinetics and cytopathic effect at four temperatures ranging from 14 °C to 24 °C in carp and trout cells lines. Based on these results, three strains of each virus were further selected for in vivo investigations of pathogen virulence at different thermal regimes, ranging from zebrafish larvae (3R-compliant) to target species, in accordance with European animal welfare guidelines. Results and discussion :Our results demonstrate 1/ the existence of different thermo-sensitivity profiles depending on the viral strains both in vitro and in vivo, 2/ temperature dependent replication kinetics that are transposable from cells to fish, 3/ the appearance of clinical signs in zebrafish larvae characteristic of novirhabdovirus diseases in rainbow trout. Analyses of virus-induced immune responses are ongoing (in cells and zebrafish larvae). Finally, pathogenic strains capable of replicating beyond 24 °C will be selected to study their virulence in rainbow trout and better anticipate the emergence of epidemics
Création d'un outil de diagnose des espèces d'ongulés sauvages et domestiques de France métropolitaine à partir des os longs
No full textComparative osteology, although complex, constitutes a valuable tool for distinguishing between species. Differentiating between wild and domestic ungulates in metropolitan France, particularly in the context of investigations into the poisoning of large predators such as bears, lynx, and wolves, has become a key to the conservation of these species. The first part presents the ungulate species, their distribution, and the bones studied - the long bones of the appendicular skeleton. The core of the thesis focuses on the development of a key for field workers, particularly those from the OFB, to differentiate between species. The fourth part details the limitations and benefits of this key, which is based on morphological criteria of comparative osteology and can be used in the field. The key can distinguish most wild and domestic ungulates, except for the Sheep/Mouflon and Pig/Wild boar pairs, with reliability varying depending on the state of preservation of the bones.L’ ostéologie comparée, bien que complexe, constitue un outil précieux pour distinguer les espèces entre elles. Différencier les ongulés sauvages et domestiques de France métropolitaine, notamment dans le cadre des enquêtes sur l’empoisonnement des grands prédateurs, ours, lynx et loups est devenu un enjeu pour la conservation de ces espèces. La première partie présente les espèces d’ongulés, leur répartition et les os étudiés : les os longs du squelette appendiculaire. Le coeur de la thèse s’intéresse au développement d’une clé de détermination à visée des agents de terrain, notamment ceux de l’OFB (Office Français de la Biodiversité) pour différencier les espèces entre elles. La quatrième partie détaille les limites et les intérêts de cette clé, basée sur des critères morphologiques d’ostéologie comparée afin de pouvoir être utilisée sur le terrain. La clé permet de distinguer la plupart des ongulés sauvages et domestiques, à l’exception des couples Mouton/Mouflon et Porc/Sanglier, la fiabilité variant selon l’état de conservation des os
Resilience and Robustness in the Service of Longevity and Sustainable Efficiency in Dairy Production
No full textInternational audienceDairy cattle industries navigating increasingly frequent climate disruptions and volatile input costs must maintain productivity while simultaneously minimizing environmental impacts. This article examines how resilience (ability to recover from short-term disturbances) and robustness (capacity for long-term adaptation to challenging environments) contribute to longevity and lifetime efficiency in farm animals. Resilience reduces aging costs by enhancing recovery from environmental perturbations, e.g., health challenges, whereas robustness involves resource allocation strategies that facilitate survival in constraining environments. Both traits exhibit moderate heritability, offering opportunities for genetic improvement. However, their expression varies significantly across environments, necessitating context-specific selection approaches. Simulation studies, using models that incorporate robustness and resilience mechanisms, demonstrate that genotype-by-environment interactions strongly influence the economic and environmental benefits of selecting for these traits. In conclusion, incorporating resilience and robustness into breeding objectives can improve lifetime efficiency, particularly in challenging environments, but their economic value must be evaluated carefully in relation to specific production systems and anticipated future conditions
Analysis of the mycovirome of Diplodia seriata, a grapevine-infecting Botryosphaeriaceae species
No full textInternational audienceIn order to identify putative mycoviruses impacting the virulence of Diplodia seriata, a Botryosphaeriaceae species causing several symptoms (canker, dieback, fruit rot and leaf spot diseases) on various host plants including grapevine, we investigated the mycovirome of a collection of D. seriata isolates obtained from symptomatic and asymptomatic grapevines. A total of 74 isolates of D. seriata were collected from four cultivars of Vitis vinifera in four wine-growing regions in France. Their virulence was estimated by measuring the growth rate at three temperatures and the sizes of superficial bark canker and wood tissue necrosis induced after inoculation on grapevine Cabernet Sauvignon plantlets. The mycovirome of each strain was characterized by RNAseq analysis of total RNAs purified from mycelia cultivated on PDA plates. A total of 22 mycoviruses were identified, 10 of which are potentially novel viruses, belonging to the Narnaviridae, Endornaviridae, Hypoviridae, Botourmiaviridae, Virgaviridae, and Deltaflexiviridae families. The majority of D. seriata isolates (80%) were f infected by at least one mycovirus, with a mean of 2.2 +/- 2 viruses per isolate. Based on the virome composition, a hierarchical clustering was performed and allowed to distinguish four distinct viromic profiles. Analyses aiming to determine a correlation between phenotypical traits (growth rate, necrosis and canker size) will be presented and discussed
Optimized use of the FilmArray Meningitis/Encephalitis panel for early discontinuation of antibiotic therapy
No full textInternational audienceIntroduction : La prise en charge des suspicions de méningite ou d’encéphalite repose sur une antibiothérapie empirique immédiate, souvent initiée avant la confirmation microbiologique. Dans ce contexte, le panel syndromique FilmArray® Méningite/Encéphalite (FAME) offre une réponse diagnostique rapide, mais son coût élevé soulève la question de son utilisation rationnelle. L’étude multicentrique FAMOuS (FilmArray® Meningitis/Encephalitis Optimization Study) visait à évaluer l’impact réel de FAME sur les décisions thérapeutiques précoces et à proposer un algorithme d’aide à la décision pour optimiser son emploi en routine hospitalière.Méthodes : Nous avons analysé rétrospectivement les données biologiques, les traitements instaurés avant et après obtention des résultats FAME, ainsi que les évolutions cliniques de 783 patients pris en charge dans six hôpitaux français sur une période de trois ans. Les indications, les résultats FAME, les modifications thérapeutiques et les examens complémentaires ont été comparés afin d’identifier les leviers d’optimisation.Résultats : Parmi les 783 panels réalisés, 80 % étaient négatifs, 7 % positifs pour une étiologie bactérienne et 13 % pour une origine virale. Aucun faux négatif bactérien n’a été observé. Les résultats positifs ont entraîné une modification thérapeutique dans 74 % des cas, contre 50 % pour les résultats négatifs. Les détections dans des prélèvements contenant <10 leucocytes ont concerné exclusivement des patients immunodéprimés ou des enfants de moins de 2 ans.Conclusion : L’étude FAMOuS a permis de concevoir un algorithme décisionnel basé sur les résultats du panel FAME et les profils cliniques des patients. Ce flowchart, appliqué en routine, pourrait éviter jusqu’à 33 % d’examens complémentaires non nécessaires et favoriser l’arrêt précoce de certaines antibiothérapies, sans compromettre la sécurité des patients
Clinical profiling of skin microbiome and metabolome during re-epithelialization
No full textInternational audienceWe investigated changes in skin microbiome and metabolome linked to wound healing and how these are affected by a formula known to improve re-epithelialization. In a clinical study with 21 subjects, forearm lesions were induced by epidermal laser ablation. The areas were left untreated or treated with the formula. Re-epithelialization was monitored for 18 days. Skin swabs were analyzed for microbiome diversity using 16 S rRNA gene sequence analysis. Selected species analyzed using digital droplet polymerase chain reaction. Metabolomic profiles were analyzed by ultra-high performance liquid chromatography-high-resolution mass spectrometry. Microbiota alpha-diversity (richness and evenness) was markedly reduced by laser ablation and returned to pre-ablation levels on Day 5. Formula application accelerated the re-epithelialization time (RT), which was more efficient for slow healing (RTs of 15–19 days) than quick healing (10–12 day RTs) subjects. The repairing effect was associated with greater microbiota diversity and species-specific growth of commensal bacteria. Levels of several metabolites on untreated skin at the RT and the extent of the impact of the formula were different in slow and quick healers. The formula significantly modified the skin metabolome, whereby metabolites involved in promoting wound healing were increased and metabolites consumed by the commensal bacteria were decreased
Performance sportive du cheval et microbiote : une influence réciproque
No full textInternational audienceLa performance sportive est-elle déterminée par la génétique ?Le destin du cheval est-il codé par son génome ?</div
Rôle de Neospora caninum lors de troubles de la reproduction chez la chienne : investigation sero-épidémiologique et facteurs de risque
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IPEC-J2 comme modèle cellulaire pour l'étude du mucus intestinal
No full textInternational audienceMucus in the proximal small intestine serves critical protective and transport functions, regulating nutrient absorption to enterocytes. The porcine jejunal epithelial cell line IPEC-J2 is widely used to study epithelial barrier function, yet its capacity to express mucins remains inconsistently described. This study aimed to investigate the ability of IPEC-J2 cells to express mucins under various culture conditions: 5% or 10% porcine serum (5PS, 10PS), with agitation (5PSAg and 10PSAg) and air-liquid interface (ALI). Mucus production was assessed using functional and structural approaches. Expression of secreted mucin MUC2 and goblet cell marker TFF3 was limited under most conditions but markedly enhanced in ALI and 5PSAg cultures. Immunohistochemistry revealed membrane-associated mucins (MUC3, MUC13) although MUC13 localisation differed between IPEC-J2 and jejunal tissue. Flow cytometry revealed that ~8% of IPEC-J2 cells expressed MUC2 in 5PSAg, comparable to the proportion of jejunum’s goblet cells in vivo (~5%). This study demonstrated that IPEC-J2 cells can differentiate into mucus-secreting cells under specific culture conditions, and they are a suitable in vitro model for investigating interactions between mucus and food components, providing a valuable tool for nutritional research
LEAP - Learn and Evaluate Affiliation databanks on an online Platform
No full textNational audienceA web platform for taxonomic exploration of metabarcoding databank