Université de Liège Réseau des Bibliothèques

Serveur institutionnel des thèses de doctorat

Nouvelles thèses
dans BICTEL/e - ULg
  • Marquet, Manon - Examining consequences of ageism on older adults and how ageist attitudes differ across cultural and socio-economic contexts
  • Shevchouk, Olesya Taisia - Steroid-dependent and -independent control of singing motivation and neural plasticity in a seasonal songbird
  • Dupuis, Nadine - Identification of chemical probes and signaling pathways for the orphan GPCR GPR27/Identification de modulateurs pharmacologiques et des voies de signalisation du RCPG orphelin GPR27
Présentation Recherche thèse Dépôt thèse Accès
Page de résumé pour ULgetd-05252010-105636

Auteur : Mauroy, Axel
E-mail de l'auteur : amauroy@ulg.ac.be
URN : ULgetd-05252010-105636
Langue : Français/French
Titre : Study of the zoonotic risk associated to animal enteric caliciviruses by analysis of sequences detected in the porcine and bovine species, and of the interactions between bovine noroviruses and cells/Etude du risque zoonotique lié aux calicivirus entériques animaux par l’analyse des séquences détectées dans les espèces porcine et bovine et des interactions entre les norovirus bovins et les cellules.
Intitulé du diplôme : Doctorat en sciences vétérinaires
Département : FMV - Département des maladies infectieuses et parasitaires
Jury :
Nom : Titre :
Antoine, Nadine Membre du jury/Committee Member
Bureau, Fabrice Membre du jury/Committee Member
China, Bernard Membre du jury/Committee Member
Daube, Georges Membre du jury/Committee Member
Desmecht, Daniel Membre du jury/Committee Member
Dewals, Benjamin Membre du jury/Committee Member
Rollin, Frédéric Membre du jury/Committee Member
Ruvoen-Clouet, Nathalie Membre du jury/Committee Member
Van Der Poel, Wim Membre du jury/Committee Member
Leroy, Pascal Président du jury/Committee Chair
Thiry, Etienne Promoteur/Director
Mots-clés :
  • zoonosis/zoonose
  • porcine/porcin
  • norovirus/norovirus
  • virus cell interactions/interactions virus cellules
  • phylogeny/phylogénie
  • human/humain
  • bovine/bovin
Date de soutenance : 2010-06-21
Type d'accès : Mixte
Résumé :

Enteric caliciviruses were detected in humans and animals incoming into food chain such as porcine and bovine species. Caliciviruses have a single stranded, positive, polyadenylated RNA genome. They share properties of high environmental stability, high excretion load and high genetic variation linked to point mutations and recombination. These properties have allowed the formulation of hypothesis about zoonotic transmission or animal reservoir for human strains. The aim of the thesis, composed of four studies, was to investigate the zoonotic risk associated to animal enteric caliciviruses.

In a first study, circulation of both sapoviruses and noroviruses was evidenced by molecular detection in Belgian pig farms. They were detected in both asymptomatic animals or in piglets showing clinical signs of enteritis.

In a second study, bovine noroviruses were molecularly detected in Belgian cattle. Strains phylogenetically related to those of the genotype 2 were predominant. In the same study, seroprevalence against bovine norovirus infection in cattle was investigated by indirect ELISA. Antigens included in the ELISA were virus-like particules obtained in the baculovirus system by expressing the capsid protein of a strain isolated by the laboratory during a previous study. Apparent seroprevalence was high (93.2%), confirming previous results about apparent molecular prevalence in diarrheic calves (7.5%).

In a third study about molecular detection of bovine noroviruses, diagnostic strategy was revised in order to improve the detection of genotype 1 strains and to deal with opportunity of recombination events. Bovine norovirus recombinant strains and also, surprisingly, some sequences genetically related to bovine kobuviruses were detected.

In a fourth study, attachment factors and internalization pathways for genotype 2 bovine noroviruses were studied with an original quantitative method based on flow cytometry analysis. Along with a galactosyl residue that seems to be essential, a sialic acid residue was also showed to be implied in the binding of genotype 2 bovine noroviruses or in a posterior step. Internalisation pathways related to lipid rafts and to macropinocytosis were found.

Together the results have contributed to the analysis of the zoonotic risk associated to enteric animal caliciviruses in the Belgian epidemiological situation. According to these results, the zoonotic risk seems to be low as no sequences genetically related to the human ones were detected. However, some results suggest to maintain a certain degree of vigilance. Indeed, molecular detection showed the co circulation of both bovine and porcine noroviruses in Belgian farms, implicating that hazard exposition exists and could be high in the Belgian epidemiological situation. Morevover, circulation of recombinant strains in the overall population of the bovine norovirus strains implies that this phenomenon was included in the risk assessment. Infection pressures and high prevalences for human and animal strains in a closed epidemiological context as the Belgian one could increase the risk of interspecific recombination. Finally, the sialic acid residue, possibly involved in the binding of genotype 2 bovine noroviruses, and a poorly specific internalisation pathway as macropinocytosis could also favor interspecies barrier crossing.

In the current knowledge, zoonotic risk associated to animal enteric caliciviruses can be communicated as low but a degree of vigilance has to be retained, associated for example to observation of genetic evolution in the populations of human and animal strains.

Autre version :
Fichiers :
Nom du fichier Taille Temps de chargement évalué (HH:MI:SS)
Modem 56K ADSL
[Restreint/Intranet] These AMauroy_complete.pdf 2.96 Mb 00:07:02 00:00:15
Fichiers accessibles par l'Internet [Public/Internet] ou que par l'Intranet [Restreint/Intranet].

Bien que le maximum ait été fait pour que les droits des ayants-droits soient respectés, si un de ceux-ci constatait qu'une oeuvre sur laquelle il a des droits a été utilisée dans BICTEL/e ULg sans son autorisation explicite, il est invité à prendre contact le plus rapidement possible avec la Direction du Réseau des Bibliothèques.

Parcourir BICTEL/e par Auteur|Département | Rechercher dans BICTEL/e

© Réseau des Bibliothèques de l'ULg, Grande traverse, 12 B37 4000 LIEGE