WorldCat Identities

Vayssier-Taussat, Muriel

Works: 17 works in 17 publications in 2 languages and 139 library holdings
Roles: Opponent, Thesis advisor, Other
Publication Timeline
Most widely held works by Muriel Vayssier-Taussat
Tiques et maladies à tiques : biologie, écologie évolutive, épidémiologie by Albert Agoulon( )

1 edition published in 2017 in French and held by 113 WorldCat member libraries worldwide

Présentes dans tous les écosystèmes, les tiques sont parmi les plus anciens arthropodes apparus sur Terre, exploitant leurs hôtes bien avant l'apparition de l'homme. Hématophages, elles sont responsables chez leurs hôtes d'une grande diversité de maladies, que ce soit par spoliation sanguine ou par transmission vectorielle de virus, de bactéries ou de parasites. Leur présence accrue dans l'environnement est à l'origine de nombreux cas d'encéphalites, de borrélioses de Lyme, de fièvres récurrentes, de babésioses ... Ainsi, les infestations par les tiques et les maladies qu'elles transmettent constituent un véritable problème de santé pour l'homme et pour les animaux domestiques, tant en zone tropicale que tempérée. Pour dresser un état des connaissances complet sur les tiques, cet ouvrage collectif adopte une approche pluridisciplinaire. Il décrit la systématique et l'évolution, la biologie et l'écologie des tiques ainsi que les relations complexes qu'elles entretiennent avec leur hôte. Les agents de maladies infectieuses transmis, les modes de transmission, les méthodes de prévention des risques ainsi qu'un état des lieux sur la lutte contre les tiques sont également présentés. Rédigé dans un langage accessible, ce livre constitue une référence actualisée sur un thème devenu un important enjeu de santé humaine et animale. Il est destiné aux étudiants, aux chercheurs, aux médecins et vétérinaires ainsi qu'aux autorités de santé
Epidemiology and genetic diversity of Anaplasma ovis in goats in Corsica, France by Alejandro Cabezas-Cruz( )

1 edition published in 2019 in English and held by 2 WorldCat member libraries worldwide

Mécanismes de persistance de Bartonella dans son hôte réservoir by Hongkuan Deng( )

1 edition published in 2011 in French and held by 2 WorldCat member libraries worldwide

Each Bartonella species appears to be highly adapted to one or a limited number of reservoir hosts, in which it establishes a long-lasting intraerythrocytic bacteremia as the hallmark of infection. Although the course of Bartonella infection has been precisely described, the molecular mechanisms of host specific erythrocyte infection and the stages of precedent the arrival in the bloodstream are poorly understood. In this thesis we purposed to identify the mechanisms of erythrocyte infection by Bartonella and characterize the possible locations of Bartonella during the days before the intraerythrocytic stage.By the establishment of an in vitro model of adhesion and invasion of erythrocytes by Bartonella spp., we demonstrated that host specificity was determined by the interaction between bacteria and erythrocytes. By screening signature-tagged mutagenesis (STM) library of B. birtlesii in vivo and in vitro and ectopic expression, we revealed that type IV Trw locus was required for host-restricted adhesion to erythrocytes in a wide range of mammals. After that, we further characterized that only TrwJ1 and TrwJ2 were expressed and present on the surface of the bacteria and had the ability to bind to mouse erythrocytes, and the receptor of them was erythrocyte band3 by different technology (phage display, electron microscopy, far western blot and adherence and invasion inhibition assay). By the model of experimental infection of laboratory normal Balb/C mice and splenectomized mice with B. birtlesii, we showed that during the first 7 days, no bacteria were recovered from lymph nodes, bone marrow and brain, but in the spleen, transient in the liver, And bacteremia was the same in both infection models during the first 7 days, thereafter, bacteremia was 10 fold higher in splenectomized mice than in normal mice and lasted 2 weeks longer. This suggested that the spleen was able to retain Bartonella.In conclusion, the host specific adhesion between Bartonella and erythrocyte was mediated by Trw and erythrocytic band 3, and spleen had a role in retention Bartonella
Candidatus Neoehrlichia mikurensis in ticks and rodents from urban and natural habitats of South-Western Slovakia by Zuzana Hamšíková Svitálková( )

1 edition published in 2015 in English and held by 2 WorldCat member libraries worldwide

Tick-borne pathogen detection in midgut and salivary glands of adult Ixodes ricinus by Emilie Lejal( )

1 edition published in 2019 in English and held by 2 WorldCat member libraries worldwide

Genetic characterization of the human relapsing fever spirochete Borrelia miyamotoi in vectors and animal reservoirs of Lyme disease spirochetes in France by Jean-François Cosson( )

1 edition published in 2014 in English and held by 2 WorldCat member libraries worldwide

Strategies of exploitation of mammalian reservoirs by Bartonella species by Hongkuan Deng( )

1 edition published in 2012 in English and held by 2 WorldCat member libraries worldwide

The scale affects our view on the identification and distribution of microbial communities in ticks by Thomas Pollet( )

1 edition published in 2020 in English and held by 2 WorldCat member libraries worldwide

A three-years assessment of Ixodes ricinus-borne pathogens in a French peri-urban forest by Emilie Lejal( )

1 edition published in 2019 in English and held by 2 WorldCat member libraries worldwide

Issues and special features of animal health research by Christian Ducrot( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

A review on the eco-epidemiology and clinical management of human granulocytic anaplasmosis and its agent in Europe by Ioana A Matei( )

1 edition published in 2019 in English and held by 2 WorldCat member libraries worldwide

Detection of Orientia sp. DNA in rodents from Asia, West Africa and Europe by Jean François Cosson( )

1 edition published in 2015 in English and held by 2 WorldCat member libraries worldwide

La dynamique du Pathobiome des tiques, l'exemple d'Ixodes ricinus by Emilie Lejal( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

In Europe, ticks are the primary vectors of pathogens for both humans and animals, and thus represent a serious issue in terms of public and veterinary health. Ixodes ricinus, the predominant tick species in Western Europe, is known to transmit the largest variety of pathogens, including Borrelia burgdorferi s.l., the Lyme disease agent. In addition to pathogens, ticks also carry a multitude of other microorganisms, which can influence the acquisition and / or transmission of pathogens, and thus affect the tick vector competence. This information led to take into account the concept of pathobiome, which aims to consider the pathogen in its biotic environment, including other microorganisms hosted by ticks. Moreover, these microbial communities constitute dynamic systems whose composition and diversity are likely to vary at different scales. On one hand at the scale of the tick, according to the tick species, the individual, the stage, or organs, and on the other hand at the temporal or spatial scale. In this context, the understanding of the different factors that can influence the vector competence of ticks, requires to consider first the notion of pathobiome, but also, the scale concept and the dynamic aspect of this system. In this context, my research project aimed to characterize the dynamics of the I. ricinus pathobiome. For this purpose, two scales were considered: the temporal scale and the tick organs. The first part of my thesis consisted to identify the dynamics of pathogens, on one hand, in ticks collected monthly for three consecutive years, and on the other hand, in two key organs: the digestive tract and salivary glands. We used a high-throughput screening technique, the microfluidic PCR. At the organ scale, the results led us to put into perspective previous postulates regarding the transmission mechanisms of certain pathogens, and more particularly the Borrelia. At the temporal scale, we characterized the dynamics of several pathogenic species belonging to the genera, Borrelia, Anaplasma, Rickettsia and Babesia, well known to circulate in I. ricinus ticks in the studied area. We also highlighted significant differences in prevalence for several of these pathogens depending on the season or years. Then, the microbiota of ticks collected for the temporal study was characterized by high-throughput sequencing of the 16S RNA gene. We also tried to identify potential interactions between the different members of these microbial communities using network analysis. After an in depth methodological development to remove potential contaminations, we showed that tick microbiota is highly dominated by several bacterial genera corresponding to common maternally inherited bacteria in different arthropod species (Arsenophonus, Candidatus Midichloria, Rickettsia, Wolbachia and Spiroplasma). This study also allowed us to observe an effect according to the season at which the ticks were sampled, which appeared to be mainly due to microorganisms commonly found in the environment. Finally, we identified a large number of links between members of the microbiota, some of which involving several taxa of the Rickettsia genus, potentially pathogenic. All our results confirm that the pathobiome of ticks is a dynamic system, which must be studied at different scales
Le rôle de systèmes à phosphorelais dans l'infection de la puce Xenopsylla cheopis par Yersinia pestis by Marion Fernandez( )

1 edition published in 2019 in French and held by 1 WorldCat member library worldwide

Les systèmes à deux composants sont utilisés par les bactéries afin de percevoir un stimulus environnemental et de s'y adapter, via une modulation de l'expression génétique. Ils sont composés d'une histidine kinase, un capteur, qui transmet le signal perçu à un régulateur de réponse par un mécanisme de phosphotransfert. Y. pestis est un bacille à Gram négatif responsable de la peste, une zoonose, transmis par les puces. La formation d'un biofilm bactérien obstruant le proventricule de la puce infectée, qualifiée alors de bloquée, est un élément essentiel dans le processus de transmission de la bactérie par l'arthropode. Au cours de son cycle de vie, Y. pestis transite via différents environnements auxquels elle doit s'adapter afin de survivre et de disséminer. C'est pourquoi, l'étude des systèmes à deux composants a été pressentie par le laboratoire comme d'intérêt afin de mieux comprendre les mécanismes de pathogénicité de Y. pestis. Nos travaux ont mis au jour que le système OmpR/EnvZ est activé suite à l'entrée des bactéries dans le tractus digestif de la puce. Cette activation n'est pas engendrée par les changements d'osmolarité ni de pH rencontrés chez l'arthropode, mais pourrait être le fruit de la digestion du repas sanguin et du manque de nutriments en résultant. Par ailleurs, l'activation du système OmpR/EnvZ est requis pour le blocage optimal du tube digestif de la puce car il permet la mise en place d'un biofilm dense au niveau du proventricule de l'arthropode ; cet effet repose en partie sur l'activation de ompF. Les travaux de thèse associés aux précédents du laboratoire ont également permis de mettre en évidence qu'un autre système, GlrKR-YfhG et plus précisément la phosphorylation du régulateur de réponse GlrR, est important pour le blocage et la colonisation de la puce. De façon surprenante, le rôle de ce système dans l'insecte est multiple. Au niveau du proventricule, ce système est requis pour la formation d'un biofilm dense permettant le blocage du tube digestif de l'insecte. Il contrôlerait notamment la production de biofilm via la synthèse de c-di-GMP, selon un mécanisme encore inconnu. Dans l'intestin, ce système promeut la survie du pathogène en lui permettant de maintenir son intégrité membranaire via la régulation concomitante des gènes codant les ARN non codants, GlmY et GlmZ. Cependant, cette régulation n'explique que partiellement le rôle du système dans la colonisation de l'estomac. Finalement, le phénotype des mutant du système GlrKR-YfhG illustre que le tractus digestif de la puce est un environnement toxique pour Y. pestis et que le proventricule et l'intestin moyen de la puce sont deux environnements différents
Interactions entre le moustique tigre et son microbiote : réponse aux perturbations anthropiques et impact dans la nutrition by Morgane Guegan( )

1 edition published in 2019 in French and held by 1 WorldCat member library worldwide

The Asian tiger mosquito Aedes albopictus is a major public health concern due to its ability to transmit various pathogens, linked to its invasive capacity. In addition to its strong ecological plasticity, its global expansion has been largely favored by global changes. In recent years, increasing researches on microbiota have demonstrated the importance of this component in key functions of mosquito biology. Improved knowledge on the relationships between the mosquito and its microbiota offers new insights into the understanding of the functioning of the mosquito holobiont. In this context, the main purpose of this PhD was to evaluate the microbiota response to abiotic disturbances and its role in the fructose metabolism, a major component of mosquito nutrition. The results showed differential impacts of antibiotics and temperature decrease on the composition and structure of the bacterial microbiota and several bacterial and fungal genera able to metabolize fructose were highlighted, along with the characterization of active metabolic pathways. These data open up new research avenues focused on the impact of anthropic disturbances on the mosquito functional microbiota as well as their consequences on both the transmission of pathogens and trophic interactions within the mosquito holobiont
Identification et caractérisation des gènes impliqués dans la virulence des Leptospires by Célia Fontana( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Leptospirosis is a worldwide zoonosis responsible for more than 1 million human cases and severe infections in animals. The causative agents are pathogenic species of Leptospira. The virulence mechanisms of these atypical bacteria remain largely unknown. Human and animal vaccines exist but the protection is restricted to a few serovars, representing only partially the complex and fluctuating epidemiology of the disease. The aims of the thesis presented in this manuscript were to characterize new virulence factors on Leptospira on the one hand and to identify new cross-protective vaccine candidates on the other hand, in the context of the COVALEPT collaborative project led by Merial, gathering industrial and academic partners. First, a flow cytometry based enumeration method for leptospires was developed, more rapid and efficient than the current standard technique. Then, the study of mutants generated by random transposition and spontaneously avirulent strains led to the identification of three virulence factors: LIC12144, required for lipopolysaccharides biosynthesis, FliM, essential for motility, and LIC11221 which may be involved in chemotaxis. Finally, two vaccine candidates conferring partial protection against the disease in a rodent model were conceived, a recombinant protein and a live attenuated strain. Altogether, this work brings new knowledge on Leptospira virulence and supports the development of broad spectrum vaccines against leptospirosis
The Trw type IV secretion system of Bartonella mediates host-specific adhesion to erythrocytes( )

1 edition published in 2010 in English and held by 0 WorldCat member libraries worldwide

Bacterial pathogens typically infect only a limited range of hosts; however, the genetic mechanisms governing host-specificity are poorly understood. The alpha-proteobacterial genus Bartonella comprises 21 species that cause host-specific intraerythrocytic bacteremia as hallmark of infection in their respective mammalian reservoirs, including the human-specific pathogens Bartonella quintana and Bartonella bacilliformis that cause trench fever and Oroya fever, respectively. Here, we have identified bacterial factors that mediate host-specific erythrocyte colonization in the mammalian reservoirs. Using mouse-specific Bartonella birtlesii, human-specific Bartonella quintana, cat-specific Bartonella henselae and rat-specific Bartonella tribocorum, we established in vitro adhesion and invasion assays with isolated erythrocytes that fully reproduce the host-specificity of erythrocyte infection as observed in vivo. By signature-tagged mutagenesis of B. birtlesii and mutant selection in a mouse infection model we identified mutants impaired in establishing intraerythrocytic bacteremia. Among 45 abacteremic mutants, five failed to adhere to and invade mouse erythrocytes in vitro. The corresponding genes encode components of the type IV secretion system (T4SS) Trw, demonstrating that this virulence factor laterally acquired by the Bartonella lineage is directly involved in adherence to erythrocytes. Strikingly, ectopic expression of Trw of rat-specific B. tribocorum in cat-specific B. henselae or human-specific B. quintana expanded their host range for erythrocyte infection to rat, demonstrating that Trw mediates host-specific erythrocyte infection
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Audience level: 0.73 (from 0.68 for Tiques et ... to 1.00 for Tiques et ...)

Alternative Names
Muriel Vayssier Frans microbiologe

Muriel Vayssier französische Mikrobiologin

Muriel Vayssier French microbiologist

Muriel Vayssier microbióloga francesa

Muriel Vayssier microbiologa francese

Muriel Vayssier microbiologista francesa

Vayssier Muriel

English (11)

French (6)