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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Age- and sex-based variation in helminth infection of helmeted guineafowl (Numida meleagris) with comments on Swainson’s spurfowl (Pternistis swainsonii) and Orange River francolin (Scleroptila levaillantoides)

Davies, OR, Junker, K, Jansen, R, Crowe, TM, Boomker, J 20 August 2008 (has links)
Gastrointestinal tracts from 48 helmeted guineafowl (Numida meleagris), five Swainson’s spurfowl (Pternistis swainsonii) and a single Orange River francolin (Scleroptila levaillantoides) were examined for helminth parasites. Twelve species of helminths were found in helmeted guineafowl, comprising six nematodes, five cestodes and a single acanthocephalan.Six species of nematodes were recovered fromSwainson’s spurfowl and a single nematode was recovered from the Orange River francolin. First-year guineafowl had more than twice the intensity of infection than did adult guineafowl, particularly regarding the acanthocephalan Mediorhynchus gallinarum, the caecal nematodes Subulura dentigera and S. suctoria, and the cestodes Octopetalum numida, Hymenolepis cantaniana and Numidella numida. Female guineafowl had significantly higher intensities of infection than males, especially concerning M. gallinarum, S. dentigera and N. numida and the nematode Gongylonema congolense. The recovery of the cestode Retinometra sp. from helmeted guineafowl constitutes a new host-parasite record.
2

Helmintos gastrointestinais de toninha, Pontoporia blainvillei (Cetartiodactyla; Pontoporiidae), do litoral de São Paulo, Brasil. / Gastrointestinal helminths of porpoise, Pontoporia blainvillei (Cetartiodactyla; Pontoporiidae), of the coast São Paulo, Brazil.

Seabra, Camila Brandão 20 February 2018 (has links)
Submitted by Camila Brandão Seabra null (cah_brandao@hotmail.com) on 2018-03-17T20:03:34Z No. of bitstreams: 1 Dissertação Camila_ versão FINAL.pdf: 2400383 bytes, checksum: 5a0565b074f6f5c5b438fa06ae1b821e (MD5) / Rejected by Disleide Silvia Valerio Gounella null (disleide@clp.unesp.br), reason: Boa tarde. Favor fazer as seguintes alterações e inclusões: - alterar o título do arquivo, o mesmo deve ter o nome do trabalho; - Incluir palavras chaves em inglês; - Incluir resumo em inglês. Qualquer dúvida, entre em contato. abs. Disleide Silvia Valerio Gounella Bibliotecária CLP - São Vicente Fone: (13)3569-7154 Mailto: disleide@clp.unesp.br skype: disleidesilviavaleriogounella on 2018-03-19T20:13:46Z (GMT) / Submitted by Camila Brandão Seabra null (cah_brandao@hotmail.com) on 2018-03-20T15:13:01Z No. of bitstreams: 1 Helmintos gastrointestinais de toninha, Pontoporia blainvillei..pdf: 2400383 bytes, checksum: 5a0565b074f6f5c5b438fa06ae1b821e (MD5) / Rejected by Disleide Silvia Valerio Gounella null (disleide@clp.unesp.br), reason: boa tarde. O arquivo com o nome do título do trabalho não está aparecendo corretamente. Em alguns lugares aprece como"dissertação de mestrado". Favor alterar. abs. Disleide on 2018-03-20T19:19:11Z (GMT) / Submitted by Camila Brandão Seabra null (cah_brandao@hotmail.com) on 2018-03-24T00:04:14Z No. of bitstreams: 1 Helmintos gastrointestinais de toninha Pontoporia blainvillei do litoral de São Paulo Brasil.pdf: 1190582 bytes, checksum: 129440c881f7848abe0640e15defd45a (MD5) / Rejected by Disleide Silvia Valerio Gounella null (disleide@clp.unesp.br), reason: Bom dia. Por favor, coloque as palavras chaves em português e depois em inglês, mesmo que os termos se repitam; Não estou conseguindo abrir o arquivo com o texto da dissertação, favor, retira-lo e inseri-lo novamente. Tirar o nome "dissertação:" do nome do arquivo. Deixar somente o título do trabalho. abs. Disleide Silvia Valerio Gounella Bibliotecária CLP - São Vicente Fone: (13)3569-7154 Mailto: disleide@clp.unesp.br skype: disleidesilviavaleriogounella on 2018-03-26T14:54:25Z (GMT) / Submitted by Camila Brandão Seabra null (cah_brandao@hotmail.com) on 2018-04-02T14:53:38Z No. of bitstreams: 1 Helmintos gastrointestinais de toninha Pontoporia blainvillei do litoral de São Paulo Brasil.pdf: 1190582 bytes, checksum: 129440c881f7848abe0640e15defd45a (MD5) / Approved for entry into archive by Disleide Silvia Valerio Gounella null (disleide@clp.unesp.br) on 2018-04-03T13:56:08Z (GMT) No. of bitstreams: 1 seabra_cb_me_svic.pdf: 1190582 bytes, checksum: 129440c881f7848abe0640e15defd45a (MD5) / Made available in DSpace on 2018-04-03T13:56:08Z (GMT). No. of bitstreams: 1 seabra_cb_me_svic.pdf: 1190582 bytes, checksum: 129440c881f7848abe0640e15defd45a (MD5) Previous issue date: 2018-02-20 / As infecções parasitárias são muito comuns em mamíferos marinhos e o estudo da helmintofauna em cetáceos tem sido utilizado como uma ferramenta para determinar aspectos biológicos e ecológicos dos hospedeiros, entre eles a definição de nichos, rotas de dispersão, hábitos alimentares e diferenciação de estoques populacionais. A toninha, Pontoporia blainvillei, pequeno cetáceo endêmico do Atlântico Sul Ocidental tem como principal causa de mortalidade em toda sua área de distribuição a captura acidental. O trato gastrointestinal de 87 toninhas, coletados de carcaças provenientes de captura acidental ou encalhe, no período de 2005 a 2017, no litoral de São Paulo foram analisados para identificar as espécies componentes da fauna parasitária gastrointestinal e avaliar variações nos níveis de infecção conforme o sexo, fase de desenvolvimento, sazonalidade e área de distribuição dos hospedeiros. Foram coletados 4.171 espécimes de helmintos, classificadas em cinco espécies: Anisakis sp. (Nematoda: Anisakidae); Andracantha sp., Bolbosoma turbinella, Corynosoma cetaceum (Acanthocephala: Polymorphidae), e Synthesium pontoporiae (Trematoda: Brachycladiidae). Os helmintos C. cetaceum, exclusivo do estômago e S. pontoporiae, encontrado tanto no estômago quanto no intestino apresentaram os maiores índices parasitológicos, enquanto as outras três espécies foram consideradas raras devido aos baixos índices parasitários. Houve diferença significativa na carga parasitária apenas para as fases de desenvolvimento, na qual indivíduos adultos e juvenis apresentaram maiores índices parasitológicos do que indivíduos filhotes. Os índices parasitológicos não variaram significativamente entre os sexos, sazonalidade ou área de distribuição dos hospedeiros. A comunidade parasitária componente do trato gastrointestinal de P. blainvillei no litoral de São Paulo difere parcialmente daquela descrita anteriormente, compreendendo duas espécies: Corynosoma cetaceum (Acanthocephala: Polymorphidae) e Synthesium pontoporiae (Digenea: Brachycladiidae). As espécies Anisakis sp., Bolbosoma turbinella e Andracantha sp. consistem em infecção acidental por ingestão de presa infectada e, portanto, não fazem parte da fauna parasitária do hospedeiro nesta área de estudo. Foram observadas variações de comprimento e forma em 18% (n= 377) dos helmintos Synthesium pontoporiae coletados, tratando-se de espécimes sexualmente maduros com tamanho inferior e superior ao descrito para a espécie. São necessários estudos moleculares para complementar a investigação sobre as causas da diferenciação de Synthesium pontoporiae em três morfotipos distintos no litoral de São Paulo, Brasil. / Parasitic infections are very common in marine mammals and the study of helminthfauna in cetaceans has been used as a tool to determine biological and ecological aspects of the hosts, as the definition of niches, dispersal routes, feeding habits and differentiation of population stocks. The franciscana dolphin, Pontoporia blainvillei, is a small cetacean endemic to the Western South Atlantic, beeing the bycath events the main cause of mortality throughout its distribution area. The gastrointestinal tract of 87 franciscanas, collected from carcasses from bycatch or stranding, from 2005 to 2017, in the coast of São Paulo were analyzed to identify the component species of parasitic gastrointestinal fauna and to evaluate variations in levels of infection according to sex, stage of development, seasonality and range of the hosts. A total of 4,171 specimens of helminths were collected and classified into five species: Anisakis sp. (Nematoda: Anisakidae); Andracantha sp., Bolbosoma turbinella, Corynosoma cetaceum (Acanthocephala: Polymorphidae), and Synthesium pontoporiae (Trematoda: Brachycladiidae). The helminths C. cetaceum, exclusive to the stomach and S. pontoporiae, found in both, stomach and intestine, presented the highest parasitological indexes, while the other three species were considered rare due to the low parasitic indexes. There was a significant difference in parasite load only for the developmental stages, in which adult and juvenile individuals had higher parasitological indexes than calves. Parasitological indices did not vary significantly between the sexes, seasonality or range of the hosts. The parasite community component of the gastrointestinal tract of P. blainvillei on the São Paulo coast differs partially from that described previously, comprising two species: Corynosoma cetaceum (Acanthocephala: Polymorphidae) and Synthesium pontoporiae (Digenea: Brachycladiidae). The species Anisakis sp., Bolbosoma turbinella and Andracantha sp. consists of accidental infection by ingestion of infected prey and, therefore, are not part of the host parasitic fauna in this area of study. Length and shape variations were observed in 18% (n= 377) of the collected Synthesium pontoporiae parasites, being sexually mature specimens with inferior and superior sizes to those described for the species. Molecular studies are needed to complement the research on the causes of the differentiation of Synthesium pontoporiae in three distinct morphotypes in the coast of São Paulo.
3

Helmintos gastrointestinais de toninha, Pontoporia blainvillei (Cetartiodactyla; Pontoporiidae), do litoral de São Paulo, Brasil. /

Seabra, Camila Brandão. January 2018 (has links)
Orientador: Carolina Pacheco Bertozzi / Resumo: As infecções parasitárias são muito comuns em mamíferos marinhos e o estudo da helmintofauna em cetáceos tem sido utilizado como uma ferramenta para determinar aspectos biológicos e ecológicos dos hospedeiros, entre eles a definição de nichos, rotas de dispersão, hábitos alimentares e diferenciação de estoques populacionais. A toninha, Pontoporia blainvillei, pequeno cetáceo endêmico do Atlântico Sul Ocidental tem como principal causa de mortalidade em toda sua área de distribuição a captura acidental. O trato gastrointestinal de 87 toninhas, coletados de carcaças provenientes de captura acidental ou encalhe, no período de 2005 a 2017, no litoral de São Paulo foram analisados para identificar as espécies componentes da fauna parasitária gastrointestinal e avaliar variações nos níveis de infecção conforme o sexo, fase de desenvolvimento, sazonalidade e área de distribuição dos hospedeiros. Foram coletados 4.171 espécimes de helmintos, classificadas em cinco espécies: Anisakis sp. (Nematoda: Anisakidae); Andracantha sp., Bolbosoma turbinella, Corynosoma cetaceum (Acanthocephala: Polymorphidae), e Synthesium pontoporiae (Trematoda: Brachycladiidae). Os helmintos C. cetaceum, exclusivo do estômago e S. pontoporiae, encontrado tanto no estômago quanto no intestino apresentaram os maiores índices parasitológicos, enquanto as outras três espécies foram consideradas raras devido aos baixos índices parasitários. Houve diferença significativa na carga parasitária apenas para as fases d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Parasitic infections are very common in marine mammals and the study of helminthfauna in cetaceans has been used as a tool to determine biological and ecological aspects of the hosts, as the definition of niches, dispersal routes, feeding habits and differentiation of population stocks. The franciscana dolphin, Pontoporia blainvillei, is a small cetacean endemic to the Western South Atlantic, beeing the bycath events the main cause of mortality throughout its distribution area. The gastrointestinal tract of 87 franciscanas, collected from carcasses from bycatch or stranding, from 2005 to 2017, in the coast of São Paulo were analyzed to identify the component species of parasitic gastrointestinal fauna and to evaluate variations in levels of infection according to sex, stage of development, seasonality and range of the hosts. A total of 4,171 specimens of helminths were collected and classified into five species: Anisakis sp. (Nematoda: Anisakidae); Andracantha sp., Bolbosoma turbinella, Corynosoma cetaceum (Acanthocephala: Polymorphidae), and Synthesium pontoporiae (Trematoda: Brachycladiidae). The helminths C. cetaceum, exclusive to the stomach and S. pontoporiae, found in both, stomach and intestine, presented the highest parasitological indexes, while the other three species were considered rare due to the low parasitic indexes. There was a significant difference in parasite load only for the developmental stages, in which adult and juvenile individuals had higher parasito... (Complete abstract click electronic access below) / Mestre
4

Resistência anti-helmíntica de nematódeos gastrointestinais de ruminantes naturalmente infectados no estado do Rio Grande do Sul, Brasil / Anthelminthic resistance of gastrointestinal nematodes of ruminants naturally infected in the state of Rio Grande do Sul, Brazil

Ramos, Fernanda 19 February 2016 (has links)
Among the main diseases that affect ruminants around the world, infections by gastrointestinal nematodes display an important role. These infections, negatively impact the performance of the animals, compromising the economic viability of the systems, if the correct control of these parasites is not made. In this sense, were performed the evaluation of different compounds with anthelminthic action in sheep and cattle in the state of Rio Grande do Sul. The first chapter presents the study whose objective was to evaluate the anthelminthic resistance of gastrointestinal nematodes from naturally infected cattle with different anti-helminthic therapy commercially available in the state of Rio Grande do Sul; and test the effectiveness of combinations of these principles on multiresistant populations. For both, were selected 70-100 animals, with ages between 7 to 9 months, naturally infected and with egg counts per gram of feces (EPG) ≥200. These individuals were from ten different property located in Rio Grande do Sul, which had received no anthelmintic treatment in the 60 days preceding the beginning of the study. The animals were randomly divided in ten groups (7- 10 animals each) and treated with ivermectin, doramectin, eprinomectin, fenbendazole, closantel, disophenol, nitroxynil, albendazole, levamisole or moxidectin. Additional groups of 7 to 10 calves were used to test six combinations of two drugs each in four of studied properties. In general, the fenbendazole was the most effective drug, followed by levamisole, disofenol and moxidectin. However parasites of genera Cooperia, Trichostrongylus and Haemonchus were the most resistant to different treatments employed. The combinations of moxidectin+levamisole, doramectin+fenbendazole and levamisole+closantel were the most effective. The results of this study demonstrated the existence of multidrug-resistant populations to most of the anthelmintic substances commercially available, while combinations of these may represent an alternative for improvement of the efficacy of treatments. The second chapter had as objective to verify the efficacy of monepantel (Zolvix ®) on gastrointestinal nematodes of naturally infected lambs from two properties in the central region of the state of Rio Grande do Sul, Brazil. For it, 64 animals being, 17 animals treated with Zolvix and 17 control animals not treated in property 1, and 20 animals treated with the same principle and 10 control on the property 2, were used. In both properties, the animals did not receive any anthelmintic treatment in the 30 days prior to the study and had EPG ≥200. The efficacy of monepantel was 25.8% and 78.4%, respectively, in the properties 1 and 2, being Haemonchus spp., Trichostrongylus spp. and Cooperia spp. the genera that presented greater resistance to it. It was demonstrated that the status of anthelminthic resistance in sheep is getting worse once the last drug launched in the Brazilian market for the treatment of gastrointestinal infections of the animals proved ineffective, and further studies are needed to delay the appearance of new cases of resistance to this drug and the other compounds commercially available. / Entre as principais enfermidades que afetam ruminantes ao redor do mundo, as infecções por nematódeos do trato gastrointestinal ocupam papel de destaque. Estas infecções impactam negativamente o desempenho dos animais, comprometendo a viabilidade econômica dos mesmos, uma vez que não se faça o controle adequado destes parasitas. Neste sentido, foi realizada a avaliação de diferentes compostos com ação anti-helmíntica em bovinos e ovinos no estado do Rio Grande do Sul. O primeiro capítulo, apresenta o estudo cujo objetivo foi avaliar a resistência anti-helmíntica de nematódeos gastrointestinais de bovinos naturalmente infectados à diferentes anti-helmínticos comercialmente disponíveis no estado do Rio Grande do Sul; e testar a eficácia de combinações destes princípios sobre populações multirresistentes. Para tanto, foram selecionados 70 a 100 bovinos, com idades entre sete a nove meses, naturalmente infectados e com contagens de ovos por grama de fezes (OPG) ≥200. Estes indivíduos eram oriundos de 10 propriedades diferentes localizadas no Rio Grande do Sul, as quais não haviam realizado tratamento anti-helmíntico nos 60 dias precedentes ao início do estudo. Os animais foram aleatoriamente alocados em dez grupos (7- 10 animais cada) e tratados com ivermectina, doramectina, eprinomectina, fenbendazole, closantel, nitroxinil, disofenol, levamisole, albendazole ou moxidectina. Grupos adicionais de 7 a 10 bezerros foram utilizados para testar seis combinações, de duas drogas cada, em quatro das propriedades estudadas. De maneira geral o fenbendazole foi a droga mais eficaz, seguido pelo levamisole, disofenol e moxidectina. Parasitas dos gêneros Cooperia, Trichostrongylus e Haemonchus foram os mais resistentes aos diferentes tratamentos empregados. As combinações de moxidectina+levamisole, doramectina+fenbendazole e levamisole+closantel foram as mais eficazes. Os resultados deste estudo demonstraram a existência de populações multirresistentes a maioria dos anti-helmínticos comercialmente disponíveis, enquanto combinações destes podem representar uma alternativa para melhora de eficácia dos tratamentos. O segundo capítulo teve por objetivo verificar a eficácia do monepantel (Zolvix ®) sobre nematódeos gastrointestinais de cordeiros naturalmente infectados oriundos de duas propriedades da região central do estado do Rio Grande do Sul, Brasil. Para tanto, 64 animais sendo, 17 animais tratados com zolvix e 17 animais controle não tratados na propriedade 1, e 20 animais tratados com o mesmo princípio e 10 controle na propriedade 2, foram utilizados. Em ambas as propriedades, os animais não receberam tratamento anti-helmíntico nos 30 dias anteriores ao estudo e possuíam OPG ≥200. A eficácia do monepantel foi de 25,8% e 78,4%, respectivamente, nas propriedades 1 e 2, sendo que os gêneros que apresentaram resistência foram Haemonchus, Trichostrongylus e Cooperia. Demonstrou-se que a resistência anti-helmíntica em ovinos vem se agravando dada a ineficácia da última droga lançada no mercado brasileiro em combater a infecção dos animais, sendo necessários mais estudos para retardar o aparecimento de novos casos de resistência a este e aos demais compostos disponíveis comercialmente.
5

Apports de la paléogénétique à l'étude des helminthes gastro-intestinaux anciens / Paleogenetics to study ancient gastrointestinal helminths

Côté, Nathalie 16 December 2015 (has links)
La paléoparasitologie est l’étude des restes de parasites préservés dans des échantillons archéologiques et permet de mieux comprendre l’état de santé des populations anciennes et d’obtenir des informations d’ordre anthropologique ou ethnologique, sur les régimes alimentaires ou les conditions d’hygiène au quotidien. Les restes de parasites peuvent être retrouvés sous forme de macro-restes (vers ou larves), d’antigènes, d’ADN ou d’œufs. Cesderniers peuvent être particulièrement bien préservés au cours du temps car ils sont composés en partie de chitine, les rendant résistants aux processus de dégradation. L’observation microscopique de leurs caractéristiques morphologiques et micrométriques permet d’identifier les taxons au niveau du genre ou de la famille. Dans le cadre de cette thèse, plusieurs helminthes gastro-intestinaux, dont les œufs sont fréquemment retrouvés dans des échantillons archéologiques, ont été ciblés par une approche génétique. Il s’agit des vers plats Tæniasaginata, T. solium, T. asiatica, Echinococcus granulosus, E. multilocularis, Diphyllobothriumlatum, D. dendriticum et D. nihonkaiense, des nématodes Trichuris trichiura, Enterobiusvermicularis et Ascaris sp. et des douves Fasciola hepatica, F. gigantica, Dicrocoeliumdendriticum et D. chinensis.La méthode « aMPlex Torrent » permet de détecter, dans un grand nombre d’échantillons archéologiques, une faible quantité d’ADN de parasites. Cette approche combine la spécificité et la sensibilité de la PCR au haut-débit du séquençage de nouvelle génération. Plusieurs vestiges, provenant de périodes et de régions géographiques diverses, ont été analysés. Des résultats génétiques ont été obtenus pour des échantillons aussi anciens que 7200 BP. Nous avons par ailleurs obtenus les premières séquences anciennes de Taenia sp., Diphyllobothriumsp., Echinococcus sp., et les premières séquences européennes d’Enterobius vermicularis. Auvu de ces résultats, notre approche apparait comme étant complémentaire à la microscopie. / Palaeoparasitogy, the study of parasite remains from archaeological samples, is adiscipline that can highlight questions about the health status of the ancient populations. It can give important anthropological or ethnological information such as the diet and the hygiene conditions of past societies. The remains can be preserved as macroremains (worms or larvae),antigens, DNA or eggs. Because they are partially made of chitin, eggs of gastrointestinalhelminths resist well over time to the taphonomic degradation process. It is possible to distinguish between different families or genera of parasites by looking at the morphological features of eggs. However, since several taxa share common features, the determination is rarelypossible at the species level. For this thesis, several parasite species for which eggs arecommonly observed in archeological samples have been studied by a genetic approach. Westudied the tapeworms Tænia saginata, T. solium, T. asiatica, Echinococcus granulosus, E.multilocularis, Diphyllobothrium latum, D. dendriticum, and D. nihonkaiense; the nematodesTrichuris trichiura, Enterobius vermicularis, and Ascaris sp.; and the flukes Fasciola hepatica,F. gigantica, Dicrocoelium dendriticum, and D. chinensis.The “aMPlex Torrent” approach has been set up to detect minute amounts of DNA from parasites in multiple archaeological samples. This approach combines the specificity andsensitivity of PCR to the throughput of Next-Generation sequencing. Several samples have been analyzed by this approach. We obtained genetic results for samples as old as 7200 BP and from various geographical and archeological contexts. We obtained the first ancient DNA sequences for Taenia sp., Diphyllobothrium sp., Echinococcus sp. and the first European sequences forEnterobius vermicularis. Genetic analyses and microscopic observations appear to be complementary. Indeed, at least one taxon per sample was detected by one of the two approaches.
6

Communautés de parasites, immunité et succès d'invasion des rongeurs commensaux : le cas de la souris domestique du rat noir au Sénégal / Parasite communities, immunity and invasion success of commensal rodents : the case of black rat and house mouse in Senegal.

Diagne, Christophe 11 December 2015 (has links)
Les invasions biologiques sont de plus en plus fréquentes, avec des conséquences importantes sur la biodiversité et la santé humaine. Étudier les mécanismes qui les expliquent permet simultanément (i) d’envisager des stratégies efficaces de contrôle et de prévention et (ii) d’étudier divers processus écologiques et évolutifs sur des échelles de temps contemporaines. Plusieurs hypothèses basées sur le parasitisme et l’immunité des hôtes sont proposées pour expliquer le succès des espèces envahissantes. Ainsi, au cours de l’invasion, les hôtes exotiques (1) perdraient leurs parasites naturels (Enemy Release, ER), (2) transfèreraient leurs parasites exotiques aux hôtes natifs (Spill-Over, SO) et/ou (3) amplifieraient les cycles des parasites natifs au sein des hôtes locaux (Spill-Back, SB). En relation avec ces changements dans les interactions hôtes-parasites, l’hypothèse EICA (Evolution of Increased Competitive Ability) prédit une modulation des ressources de l’hôte envahissant via un investissement moins important dans les réponses immunitaires coûteuses (inflammation) au profit de réponses immunitaires beaucoup moins coûteuses (réponses médiées par les anticorps) et de capacités de reproduction et de dispersion des populations sur le front d’invasion. Le but de ma thèse est de tester ces prédictions dans le cadre de deux invasions actuellement en cours au Sénégal : celles du rat noir Rattus rattus et de la souris domestique Mus musculus domesticus, deux espèces envahissantes majeures tant par leurs impacts (économique, sanitaire, écologique) que par leur distribution quasiment mondiale. Mes travaux se basent sur un dispositif d’échantillonnage en populations naturelles et sur le développement d’approches comparatives le long d’un gradient d’invasion pour chacune des deux espèces exotiques. Les patrons de structure (prévalence, abondance, richesse) de deux communautés de parasites (helminthes gastro-intestinaux, bactéries pathogènes) et les profils immunitaires (réponses médiées par les anticorps naturels, inflammation) des rongeurs commensaux exotiques (M. m. domesticus, R. rattus) et/ou natifs (Mastomys spp.) ont été comparés pour des localités situées dans des régions anciennement envahies (depuis plus de 100 ans), récemment envahies (depuis moins de 30 an : front d’invasion), et non envahies. Mes résultats montrent des variations dans la structure des communautés de parasites et les réponses immunitaires des hôtes natifs et exotiques. Les tendances observées, aussi bien pour les communautés de parasites que pour les composantes immunitaires étudiées le long des deux routes d’invasion, attestent de patrons globalement plus complexes qu’attendu sous les hypothèses de départ, suggérant l’existence de relations complexes entre caractéristiques des communautés d’hôtes et de parasites, investissement immunitaire, conditions environnementales et invasions biologiques. Des approches expérimentales doivent être envisagées afin de déterminer les conséquences et les mécanismes sous-jacents aux différents phénomènes observés. / Biological invasions are increasingly phenomenon worldwide having deleterious impacts on biodiversity and human health. Studying the mechanisms explaining them allows both (i) to define efficient strategies for controlling and preventing invaders and (ii) to study ecological and evolutionary processes at contemporary scales. Some major hypotheses rely on parasitism and host immunity to explain invasion success. Thus, exotic host populations (1) may benefit of an " Enemy Release " (ER) through impoverishment of their original parasite communities, and may affect native hosts by (2) transferring exotic parasites (Spill-Over, SO) and/or (3) by increasing transmission risk of native parasites (Spill-Back, SB). In turn, according to the refined “Evolution of Increased Competitive Ability” (EICA) theory, invasive populations should experience immune trade-offs by favouring less expensive antibody-mediated responses over costly inflammation, to increase their competitive ability (dispersion, reproduction). The aim of my thesis is to test these predictions along the invasion routes of two commensal exotic species in Senegal, the domestic mouse (Mus musculus domesticus) and the black rat (Rattus rattus). These rodent species are considered to be major invasive species worldwide inducing high economic, sanitary and ecological damages. My research is based on comparative analyses along one invasion route for each invasive species. We focused on gastrointestinal helminths and pathogenic bacteria as parasite communities, and inflammation and natural antibody-mediated responses as immune estimates. Comparisons were performed for invasive and/or native (Mastomys spp.) rodents between localities of long-established invasion (100-200 years ago), recent invasion (10-30 years ago; invasion front), and non-invaded localities. My findings showed variations along both invasion routes in parasite community structure and immune patterns, but in a more complex way than expected under the initial predictions. The heterogeneity of changes observed highlights the existence of particular relations between host and parasite traits, host immune investment, environmental conditions and biological invasions. Further experimental works are needed to assess the consequences and mechanisms underlying the changes observed along both invasion routes.

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