Teses em Biologia de Agentes Infecciosos e Parasitários (Doutorado) - PPGBAIP/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/4698
O Doutorado em Biologia de Agentes Infecciosos e Parasitários teve início em 2005 e funciona no Programa de Pós-Graduação em Biologia de Agentes Infecciosos e Parasitários (PPGBAIP) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).
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Navegando Teses em Biologia de Agentes Infecciosos e Parasitários (Doutorado) - PPGBAIP/ICB por Orientadores "VASCONCELOS, Pedro Fernando da Costa"
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Item Acesso aberto (Open Access) Caracterização genética, correlação antigênica e ecoepidemiológica dos vírus do grupo C (Bunyaviridae, orthobunyavirus) isolados nas américas(Universidade Federal do Pará, 2005-02-28) NUNES, Márcio Roberto Teixeira; ROSA, Amélia Paes de Andrade Travassos da; VASCONCELOS, Pedro Fernando da Costa; http://lattes.cnpq.br/0973550817356564To date, no molecular studies on group C viruses (Bunyaviridae: Orthobunyavirus) have been published. The current work determined the complete small RNA segment and partial medium RNA segment nucleotide sequences for group C members. The full-length SRNA sequences ranged from 915 to 926 nucleotides in length, and revealed similar organization in comparison with other orthobunyaviruses. Based on the 705 nt of the N gene, group C members were distributed into 3 major phylogenetic groups, with the exception of Madrid virus that was placed outside of these 3 groups. Analysis of the Caraparu virus strain BeH 5546 revealed that it has an SRNA sequence nearly identical to that of Oriboca virus and is a natural reassortant virus. In addition, analysis of 345 nucleotides of the Gn gene for seven group C viruses and for strain BeH 5546 revealed a different phylogenetic topology, suggesting a reassortment pattern among them. These findings represent the first evidence for natural reassortment among the group C viruses, which include several human pathogens. Furthermore, our genetic data corroborate previous antigenic relationships determined using serologic assays (complement fixation, hemagglutination inhibition and neutralization tests), and suggest that a combination of informative molecular, serological and ecological data is a helpful tool to understand the molecular epidemiology of orthobunyavirus.Item Acesso aberto (Open Access) Caracterização molecular dos vírus do grupo Gamboa (Bunyaviridae, Orthobunyavirus) isolados nas américas e infecção experimental em pintos (Gallus gallus domesticus) com o vírus Gamboa cepa Be AN 439546(Universidade Federal do Pará, 2010-03-31) CHIANG, Jannifer Oliveira; VASCONCELOS, Pedro Fernando da Costa; http://lattes.cnpq.br/0973550817356564Presently, little information on Gamboa serogroup viruses (Bunyaviridae, Orthobunyavirus) is available. Thus, in this work, it was performed a comparative phylogenetic study on the members of the Gamboa serogroup and with other orthobunyaviruses to the level of the gene Gn (M-RNA); an experimental infections in the domestic bird (Gallus domesticus) using the strain Be AN 439546 of the Gamboa Virus (GAMV); and a serologic study using the Hemagglutination Inhibition (HI) test in serum samples of wild animals and humans collected in Tucuruí - Pará. The phylogenetic analysis of Gamboa group viruses demonstrated that they are genetically closely related to group Turlock viruses and less related to the Simbu group viruses. The group Gamboa viruses were distributed in two clades (I and II), that it is in agreement with the current serologic classification; the clade I correspond to the Gamboa complex and the clade II to the Alajuela complex. The strain Be AN 439546 presented tropism for chikens lung and liver, with viral replication in this organs confirmed by detection of viral antigens by immunohistochemistry. These results, demonstrate that this bird species is a susceptible host for GAMV replication. The detection of HI antibodies against GAMV, confirmed by neutralization tests were found in wild bird plasmas and reinforces the hypothesis that these animals constitute the main amplification hosts in the maintenance cycle of GAMV. Full length genome studies of the Gamboa serogroup viruses, as well as on the ecoepidemiology of their vectors and potential vertebrate hosts are needed to generate new data and to reinforce the understanding of the information already existent on those viruses.Item Acesso aberto (Open Access) Caracterização molecular e relação filogenética do genoma completo dos arbovírus Bussuquara, Iguape, Ilhéus e Rocio (Família Flaviviridae, Gênero Flavivirus)(Universidade Federal do Pará, 2009-11-27) MEDEIROS, Daniele Barbosa de Almeida; NUNES, Márcio Roberto Teixeira; http://lattes.cnpq.br/0299116892743368; VASCONCELOS, Pedro Fernando da Costa; http://lattes.cnpq.br/0973550817356564Flaviviruses have been known due their complex biological cycle and their relevance in public health and global economy. The ecologic aspected and clinic pictures are related with phylogeny and evolution of flaviviruses. This work aims the molecular characterization of Bussuquara (BSQV), Iguape (IGUV), Ilheus (VILH) e Rocio (VROC) flaviviruses genomes, determining their phylogenetic relationships with others members of genus Flavivirus. The study included: the full-length sequencing of the four Brazilian flaviviruses; analyzes of the predictive secondary structure of RNA and conserved sequences in the 3’NCR; determination of cleavage and glicosilation sites, cisteine residues and conserved motifs in the polyprotein; and similarity and phylogenetic analyzes. The BSQV, IGUV, VILH and VROC genomes present 10815 nt, 10922 nt, 10775 nt, and 10794 nt, respectively. The conserved standard sequences in 3’NCR of BSQV was RCS2-CS2-CS1, while to IGUV, ILHV and ROCV were CS3-RCS2-CS2-CS1. The secondary structure of RNA obtained for the Brazilian flaviviruses were similar to the other flaviviruses. The numbers of the glicosilation sites to PrM, E and NS1 proteins were distinct among the studied Brazilian flaviviruses, therefore the pattern 6,12,12 Cis residues and the cleavage sites were conserved. In the E protein, some singles mutations were observed in fusion peptide of BSQV, IGUV and ROCV, and the RGD motif were distinct for the flaviviruses under study. The motif that determines the MTase-SAM activity in NS5, as well as the helicase and protease activity in NS3 were conserved. Among the eight polimerase motifs in NS5, only the V, VI and VII motifs were observed single mutations in ILHV and ROCV. The similarity analyzes showed that BSQV presents high relationship with VIGU, while ILHV and ROV were more related among themselves, however those viruses were considerated distincts species. Based in the phylogenetic analyzes, molecular and biological characteristics, it was proposed the establishment of three distinct genetic groups: the Rocio group, grouping ILHV and ROCV, Bussuquara group formed by BSQV and Naranjal virus; and Aroa group, that include Aroa virus and IGUV.Item Acesso aberto (Open Access) Imunopatologia hepática da infecção experimental do vírus dengue em Callithrix penicillata(Universidade Federal do Pará, 2015-09-25) HENRIQUES, Daniele Freitas; VASCONCELOS, Pedro Fernando da Costa; http://lattes.cnpq.br/0973550817356564Dengue is one of most important public health problem in the world, and one of the factors that contribute with this situation is the lack of an effective vaccine against the disease, and in part, this difficulty to obtain is due clinical the lack of an experimental model that mimic the infection and manifestation of the disease as those observed in humans. Then, the Evandro Chagas Institute showed the presence of dengue antigens using the Immunohistochemistry assay, in the liver of a non-human primate (NHP) of the species Callithrix jacchus, with a fatal outcome following dengue hemorrhagic fever. Based in the above considerations and in addition to the fact that the liver is the targetb organ for Dengue Virus (DENV) in humans, it is important to analyze the liver of primates of the genus Callithrix in order to study the pathogenesis and the immunopathology of sequential infection by DENV. A total of 26 NHP Callithrix penicillata were submitted to primary infection (PI) subcutaneously with DENV-3 (3.23 x 103 PFU/mL), and 13 of these animals anesthetized and sacrificed daily for seven days post-infection (dpi) (acute phase) and in random intervals until 60 dpi (convalescent phase); the secondary infection (SI) with DENV-2 (4.47 x 104 PFU/mL) was performed two months after the PI in the remaining 13 animals. Uninfected sentinels animals were reserved up ending of the experiment. The liver of the animals were processed for histopathology and Immunohistochemical assay using polyclonal antibodies to DENV and antibodies for analyses of the innate and cellular immune response as well as the cytokine expression . The NHP were susceptible to sequential infection by DENV-3 and DENV-2; in the liver viral antigens were expressed in hepatocytes, Kupffer cells and Councilman bodies; the histopathological changes in liver was characterized by the presence of apoptosis, focal lytic necrosis, steatosis, swelling cellular, inflammation (acinar, EP and HCV), hyperplasia/hypertrophy in Kupffer cells, hemosiderin in Kupffer cells and sinusoidal dilatation; the intensity of the liver damage was prominent in the acute phase of PI and SI resulting in acute hepatitis. In addition the apoptosis was the most frequent mechanism of death of hepatocytes; lytic necrosis and inflammatory infiltrate showed predominant distribution pattern in Z2. An increase of the acinar expression of activated macrophages, NK cells, S-100 protein and B-lymphocytes during the stages of PI and SI; as well as, increased acinar expression of TCD4 + lymphocytes during the acute phase of PI; as to the quantification of cytokines and molecules, was observed an increase in acinar expression of: IFN- during the stages of PI and SI, TNF-α and IL-8 with higher prevalence in SI, TGF-β and IL-10 with prevalence in acute phase of PI, Fas protein during the acute phase of PI and SI and VCAM in acute phase of SI, as well as increase in expression in the EP. These findings were similar to those observed in livers from fatal cases of dengue fever in humans, but with lower intensity and amplitude, thus indicating that NHP Callithrix penicillata species is a good experimental model for infection by DENV, involving immunopathologic studies.Item Acesso aberto (Open Access) Soroprevalência de anticorpos e padronização do teste ELISA sanduíche indireto para 19 tipos de arbovírus em herbívoros domésticos(Universidade Federal do Pará, 2010-09-30) CASSEB, Alexandre do Rosário; VASCONCELOS, Pedro Fernando da Costa; http://lattes.cnpq.br/0973550817356564The brazilian Amazon region maintains the largest variety of arboviruses and the state of Pará is responsible for 26% of this territory, so the major goal of this work was to determine the prevalence and distribution of HI antibodies to 19 domestic arbovirus in domestic herbivores in the state of Pará and to standardize an indirect sandwich IgG ELISA test to serum samples of equines, cattle, buffaloes and sheep. In all species studied and throughout the State of Pará a large prevalence of HI antibodies to all arbovirus analyzed was observed and SLEV, ILHV, EEEV, MAGV and WEEV, showed higher prevalence, where the SLEV was the most prevalent. Regarding the virus families HI antibodies to MAGV was the most prevalent Bunyaviridae in all species, the most prevalent Flaviviridae was SLEV in all species and in the family Togaviridae the EEEV was more prevalent in horses. In order to analyze the prevalence of HI antibodies by animal species was observed that horses did not show significant differences compared to buffaloes, however, showed significant difference compared to cattle and sheep; there was not observed significant difference between the ruminant species. Using sandwich indirect IgG ELISA a large number of crossed reactions were found. This enzymatic test can be used to detect IgG antibodies among families of arboviruses studied.