Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-02-11T16:15:35Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_InfeccaoExperimentalHamsters.pdf: 2790075 bytes, checksum: 7188971dc75068f0e71978c12c97f993 (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-04-14T14:16:05Z (GMT) No. of bitstreams: 2 Dissertacao_InfeccaoExperimentalHamsters.pdf: 2790075 bytes, checksum: 7188971dc75068f0e71978c12c97f993 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2014-04-14T14:16:05Z (GMT). No. of bitstreams: 2 Dissertacao_InfeccaoExperimentalHamsters.pdf: 2790075 bytes, checksum: 7188971dc75068f0e71978c12c97f993 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2007 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os flebovírus (família Bunyaviridae; gênero Phlebovirus), possuem importância considerável em saúde publica, pois podem causar uma variedade de síndromes clínicas. Na região amazônica brasileira até o momento já foram isolados 23 flebovírus sendo que quatro se destacam por terem sido isolados de humanos: Virus Alenquer, Virus Candiru, Virus Morumbi e Virus Serra Norte. Estes mais o Virus Itaituba, isolado de Didelphis marsupialis, fazem parte do Complexo Candiru (grupo Candiru) e foram utilizados para estudos de caracterização genética e de infecção experimental em hamsters dourados (Mesocricetus auratus). Os Hamsters mostraram-se suscetíveis a infecção por esses flebovírus, apesar de não terem apresentado sinais de doença. A análise histopatológica demonstrou aspectos lesionais no fígado, nos rins, no baço, nos pulmões e no sistema nervoso central, sendo as lesões mais intensas no fígado comprovadas pela presença dos antígenos virais empregando a técnica de imunohistoquímica. A análise das seqüências nucleotídicas parciais dos segmentos PRNA e MRNA obtidas para os cinco flebovírus estudados mostraram maior similaridade genética entre si do que com outros membros do gênero Phlebovirus. Sendo as mesmas geneticamente mais relacionadas ao Virus Punta Toro. Filogeneticamente, independentemente do segmento genômico analisado, os cinco flebovírus constituem um grupo monofilético, sendo que a análise pelo método de máxima verossimilhança demonstrou diferentes origens evolutivas para os segmentos de RNA o que sugere a ocorrência de rearranjo genético em natureza entre estes cinco flebovírus amazônicos. / The phleboviruses (family Bunyaviridae, genus Phlebovirus) are of considerable public health importance, due to their association with human diseases causing different clinical syndromes. In the Brazilian Amazon region, 23 phlebovirus were presently isolated, four of them have been isolated from humans: Alenquer virus, Candiru virus, Morumbi virus, and Serra Norte virus. These and Itaituba virus, isolated from Didelphis marsupialis belong to the Candiru Complex (Candiru group) and were used for studies on genetic characterization and experimental infection using gold hamsters (Mesocricetus auratus) as animal model. Hamsters showed to be susceptible to infection by these viruses; however signs of disease were not observed. The histophatological analysis demonstrated damages in the liver, kidneys, lung, and central nervous system. More intense lesions were observed in the liver which were characterized by the presence of viral antigens detected by immunohistochemistry assay. The analysis of the partial SRNA and MRNA nucleotide sequences obtained for the five studied phleboviruses showed more similarity among them than with other members of the genus Phlebovirus.More over, is was demonstrated that these phleboviruses were more genetically related to Punta Toro virus. Phylogenetically, regardless of the genome segment analyzed, the five phleboviruses constitute a monophyletic group. In addition the analysis by maximum likelihood method demonstrated different evolutionary origins for the RNA segments, suggesting the occurrence of natural genetic reassortment among the five Amazonian phleboviruses.