Made available in DSpace on 2016-06-02T20:21:32Z (GMT). No. of bitstreams: 1 5451.pdf: 3223679 bytes, checksum: 330bb99725d861546288b6adcca1e31b (MD5) Previous issue date: 2013-03-22 / Universidade Federal de Sao Carlos / The cattle egret (Bubulcus ibis), native from Africa, invaded the American continent by the end of the XIX century, initiating the process of colonization through the north of South America and spreading throughout the continent. Haemoparasites are found in all continents in the world, with the exception of Antarctica, and in preliminary tests it was verified they are present in the cattle egret population. The objectives of this work were to estimate the prevalence of the haemoparasites Plasmodium and Haemoproteus on African and Brazilian populations of B. ibis and to identify the repertoire of the lineages in these populations. Blood samples and blood slides were acquired from B. ibis nestlings in six brazilian populations and in 15 african populations, located at the west coast, totalling around 859 individuals. For the molecular diagnosis, fragments of the cytochrome B gene of the Plasmodium spp. and the Haemoproteus spp. were amplified. The DNA of the parasite in the infected individuals was sequenced and the identification of the genus and the lineages present was performed through phylogenetic analysis via the bayesian method using the Mr. Bayes software. These results were partially confirmed by the morphological diagnosis. The prevalences in Africa for the Plasmodium genus decreased from Senegal and Guinea-Bissau to South Africa, while Brazilian prevalences increased from Pará to Rio Grande do Sul. The diversities of African lineages of Plasmodium spp. were higher in regions close to and above the Equator line; the highest Brazilian diversity was also found near the Equator. The G pair to pair statistical test did not reveal difference between the prevalences of African and Brazilian cattle egret populations, both for the Plasmodium and for the Haemoproteus genera. Significant difference was detected relative to the richness of the lineages of the Plasmodium genus found in Africa and Brazil, partially confirming the predictions of the Enemy Release Hypothesis. Some evidence points to African countries near and above the Equator line as African source-founder populations of the cattle egret that colonized Brazil. / A garça-vaqueira (Bubulcus ibis), nativa da África, invadiu o continente americano no final do século XIX, iniciando o processo de colonização pelo norte da América do Sul e se espalhando por toda a área do continente. Os hemoparasitas são encontrados em todos os continentes do mundo, com exceção da Antártida e em testes preliminares verificamos que estão presentes na população de garça vaqueira. Os objetivos desse trabalho foram estimar a prevalência dos hemoparasitas, Plasmodium e Haemoproteus, nas populações de B. ibis africanas e brasileiras e identificar o repertório das linhagens nessas populações. Amostras de sangue e lâminas foram obtidas de ninhegos de B. ibis em seis populações brasileiras e em 14 populações africanas, localizadas na costa oeste, totalizando cerca 859 indivíduos. Para o diagnóstico molecular, foram amplificados fragmentos do gene do citocromo B do Plasmodium spp e do Hemoproteus spp . O DNA do parasita dos indivíduos infectados foi sequenciado e a identificação do gênero e das linhagens presentes foi feita por análise filogenética pelo método bayesiano no programa Mr. Bayes. Esses resultados foram parcialmente confirmados com o diagnóstico morfológico. As prevalências da África para o gênero Plasmodium decresceram de Senegal e Guiné Bissau para a África do Sul, ao passo que as brasileiras aumentaram do Pará para o Rio Grande do Sul. As diversidades das linhagens africanas de Plasmodium spp. foram maiores nas regiões próximas e acima à linha do Equador; a maior diversidade brasileira foi encontrada próximo ao Equador também. O teste estatístico G par a par não revelou diferença entre as prevalências das populações de garças vaqueiras africanas e brasileiras, tanto para o gênero Plasmodium quanto para o Haemoproteus. Foi detectada diferença significativa com relação à riqueza das linhagens do gênero Plasmodium encontradas na África e no Brasil, confirmando parcialmente as previsões da Hipótese da Liberação do Inimigo. Algumas evidências apontaram para os países africanos próximos e acima da linha do Equador como populações fonte-fundadora africana de garças vaqueiras que colonizaram o Brasil.

The genera Haemoproteus and Plasmodium are widespread genera of blood parasites from phylum Apicomplexa. Both genera have dixenous life cycle and their definitive hosts belong to the order Diptera. Both parasites can be found in birds where asexual division takes place. The infection with genera Haemoproteus and Plasmodium is usually asymptomatic; during long lasting chronic phase relapses of the infection can occur. We gained 1 092 blood samples from 29 trapped species of passerines in Milovice forest during seasons 2017-2019. Haemosporidians were detected in 48 % of samples. The prevalence of genus Plasmodium was 16 %, the prevalence of genus Haemoproteus was 22 % and 10 % we could not specify the parasite. We have found six new lineages of genus Haemoproteus, provisionally named Haemoproteus lineages coccoc_1, coccoc_2, coccoc_3, coccoc_4, embcit, fricoe which total prevalence was 14 %. Lineage Haemoproteus sp. coccoc_1 was the most noticed one and its prevalence was 12 %. Plasmodium relictum clone Peng14-121Br2AF and isolate Cc_P1 was the second most prevalent (13 %). Infection dynamics was studied in samples gained in years 2014-2019. Forty individuals were examined between years and twenty-seven individuals were examined intraseasonally. Three individuals were trapped both intra- and...

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Avian malaria is a devastating disease that has decimated numerous bird species. This study sought to identify the vectors of avian malaria at four central Virginia Prothonotary warbler breeding sites. Twenty one thousand mosquitoes were collected and Culex salinarius, Cx. erraticus, and Cx. pipiens/restuans were found to be the dominant species at these sites. Geographic factors, such as crop land and forest type, were determined to be potential indicators for species abundance variation between sites. Of the mosquitoes collected, ninety one (0.4%) were identified as blood fed. The blood fed mosquitoes were found to have fed on avian, mammalian, amphibian, and reptilian hosts and a 12.1% Plasmodium infection rate. Of the non-blood fed mosquito pools tested, Deep Bottom had the highest rate of infection (10.5%). Of the species tested, Cx. salinarius, Cx. erraticus, and Cx. pipiens/restuans were determined to be the most probable vectors of avian malaria the four sites.

Si les parasites sont étudiés depuis très longtemps, la plupart des connaissances concernent des parasites présentant un intérêt médical ou vétérinaire. Ainsi, malgré leur omniprésence au sein du monde vivant, le rôle des infections parasitaires sur les populations naturelles est encore très mal maîtrisé. <br />Un objectif de ce travail était d'étudier la pathogénicité de deux groupes de parasites (tiques et Haemosporidae) au sein de populations de Merles noirs. Ces deux groupes de parasites se sont révélés associés aux indices de condition corporelle et de réponse immunitaire des individus. Cependant, l'étude d'une population urbaine ne nous a pas permis de confirmer un effet des Haemosporidae sur la survie et la dynamique de la population de Merles.<br />L'incidence du milieu de vie (structuration spatiale) sur le fonctionnement de la relation hôte-parasite a été également abordée. En effet, le Merle est une espèce ubiquiste. Nous avons montré que les populations de milieu urbanisé présentent des infections parasitaires plus faibles que celles vivant en milieu forestier. Ce résultat pourrait expliquer en partie les fortes densités de Merles en zones urbaines, même si d'autres interprétations restent bien sûr envisageables.<br />Enfin, divers travaux récents suggèrent le rôle des caroténoïdes comme lien entre l'immunité des mâles et l'intensité de leur signaux colorés. Cependant, ces études utilisent des mesures de l'immunité par challenge immunitaire pour « mimer » les infections parasitaires. Cette démarche a été récemment discutée car les challenges pourraient ne pas toujours refléter la résistance parasitaire. Nos résultats vont dans ce sens. De plus, nos travaux semblent montrer que le contexte social module la relation entre immunité et signaux colorés. Ceci pourrait remettre partiellement en cause l'idée selon laquelle les caroténoïdes constituent un mécanisme universel garant de l'honnêteté des signaux.