Le circovirus porcin de type 2 (PCV2) est un pathogène majeur pour l’industrie porcine et est associé à une longue liste de maladies associées au circovirus porcin (MACVP). Les premières tentatives pour reproduire ces maladies ont montré que le virus doit être combiné à d’autres agents pathogènes du porc ou à différents stimulants du système immunitaire. De ces agents, le virus du syndrome reproducteur et respiratoire porcin (VSRRP) est celui qui est le plus souvent co-isolé avec le PCV dans les fermes. Une grande partie des efforts faits pour étudier les interactions entre ces deux virus ont été menés in vivo. Les interactions in vitro ont jusqu’à maintenant été peu étudiées du fait qu’il n’existe pas de modèle cellulaire permettant la réplication efficace des deux virus. L’objectif de ce projet était donc de développer un modèle cellulaire propice à la réplication des deux virus et d’étudier leur interaction en co-infection. Une lignée cellulaire provenant de la trachée d’un porcelet nouveau-né (NPTr), permissive au PCV, a été génétiquement modifiée pour exprimer la protéine CD163, un récepteur majeur du VSRRP. Ce projet a montré que cette nouvelle lignée cellulaire (NPTr-CD163) est permissive au VSRRP ainsi qu’à plusieurs génotypes de PCV (PCV1, PCV2a, PCV2b et PCV1/2a). De plus, les résultats obtenus lors d’infections mixtes suggèrent que la réplication du VSRRP et du PCV conditionne de façon génotype-dépendante celle du PCV puisque la réplication du PCV1 est inhibée en présence de VSRRP, alors que celle du PCV2b est significativement augmentée dans les mêmes conditions. Ni la mortalité cellulaire, ni la réponse cellulaire en cytokines n’a permis d’expliquer ces résultats. La modulation de la réplication du PCV par le VSRRP serait donc liée à un mécanisme spécifique qui demeure inconnu. De plus, cet effet varierait en fonction du génotype de PCV. / Porcine circovirus (PCV) type 2 (PCV2) is a major pathogen in the swine industry and has been described as the causative agent of a long list of conditions under the designation of porcine circovirus-associated diseases (PCVAD). Attempts to replicate PCVAD initially failed, as it was discovered that an immune trigger could facilitate the reproduction of clinical signs, either by co-infecting with other swine pathogens or using immune stimulants. Of these, porcine reproductive and respiratory syndrome virus (PRRSV) is the most frequently co-isolated agent in the field. Most effort has been made to understand this interaction in vivo since most in vitro cellular models lack the ability to efficiently replicate both viruses. To answer the lack of an in vitro model, we developed a cell line that allows the replication of both PRRSV and PCV. A neonate porcine tracheal cell line (NPTr) was genetically modified to stably express CD163 (NPTr-CD163), a major PRRSV receptor. NPTr-CD163 cells were able to replicate all PCV genotypes (PCV1, PCV1/2a, PCV2a and PCV2b) and PRRSV. A significant effect of PRRSV on PCV replication was found to be genotype dependent, as PCV1 replication was down regulated in the presence of PRRSV and PCV2b replication was up regulated in the same conditions. Neither cell mortality assays nor cytokine expression analysis were able to provide an explanation for these results. The effect of PRRSV on PCV1 and PCV2b replication is suggestive of a more specific, yet still unknown, mechanism. Furthermore, this effect is PCV-genotype dependant.

Le circovirus porcin de type 2 (PCV2) est un pathogène majeur pour l’industrie porcine et est associé à une longue liste de maladies associées au circovirus porcin (MACVP). Les premières tentatives pour reproduire ces maladies ont montré que le virus doit être combiné à d’autres agents pathogènes du porc ou à différents stimulants du système immunitaire. De ces agents, le virus du syndrome reproducteur et respiratoire porcin (VSRRP) est celui qui est le plus souvent co-isolé avec le PCV dans les fermes. Une grande partie des efforts faits pour étudier les interactions entre ces deux virus ont été menés in vivo. Les interactions in vitro ont jusqu’à maintenant été peu étudiées du fait qu’il n’existe pas de modèle cellulaire permettant la réplication efficace des deux virus. L’objectif de ce projet était donc de développer un modèle cellulaire propice à la réplication des deux virus et d’étudier leur interaction en co-infection. Une lignée cellulaire provenant de la trachée d’un porcelet nouveau-né (NPTr), permissive au PCV, a été génétiquement modifiée pour exprimer la protéine CD163, un récepteur majeur du VSRRP. Ce projet a montré que cette nouvelle lignée cellulaire (NPTr-CD163) est permissive au VSRRP ainsi qu’à plusieurs génotypes de PCV (PCV1, PCV2a, PCV2b et PCV1/2a). De plus, les résultats obtenus lors d’infections mixtes suggèrent que la réplication du VSRRP et du PCV conditionne de façon génotype-dépendante celle du PCV puisque la réplication du PCV1 est inhibée en présence de VSRRP, alors que celle du PCV2b est significativement augmentée dans les mêmes conditions. Ni la mortalité cellulaire, ni la réponse cellulaire en cytokines n’a permis d’expliquer ces résultats. La modulation de la réplication du PCV par le VSRRP serait donc liée à un mécanisme spécifique qui demeure inconnu. De plus, cet effet varierait en fonction du génotype de PCV. / Porcine circovirus (PCV) type 2 (PCV2) is a major pathogen in the swine industry and has been described as the causative agent of a long list of conditions under the designation of porcine circovirus-associated diseases (PCVAD). Attempts to replicate PCVAD initially failed, as it was discovered that an immune trigger could facilitate the reproduction of clinical signs, either by co-infecting with other swine pathogens or using immune stimulants. Of these, porcine reproductive and respiratory syndrome virus (PRRSV) is the most frequently co-isolated agent in the field. Most effort has been made to understand this interaction in vivo since most in vitro cellular models lack the ability to efficiently replicate both viruses. To answer the lack of an in vitro model, we developed a cell line that allows the replication of both PRRSV and PCV. A neonate porcine tracheal cell line (NPTr) was genetically modified to stably express CD163 (NPTr-CD163), a major PRRSV receptor. NPTr-CD163 cells were able to replicate all PCV genotypes (PCV1, PCV1/2a, PCV2a and PCV2b) and PRRSV. A significant effect of PRRSV on PCV replication was found to be genotype dependent, as PCV1 replication was down regulated in the presence of PRRSV and PCV2b replication was up regulated in the same conditions. Neither cell mortality assays nor cytokine expression analysis were able to provide an explanation for these results. The effect of PRRSV on PCV1 and PCV2b replication is suggestive of a more specific, yet still unknown, mechanism. Furthermore, this effect is PCV-genotype dependant.

Les interactions entre le circovirus porcin de génotype 2b (PCV2b), le virus du syndrome reproducteur et respiratoire porcin (VSRRP) et le virus de l’influenza porcine (VIP) dans le complexe respiratoire porcin (CRP) sont souvent associées à une augmentation des signes cliniques respiratoires chez les animaux. L’objectif général de cette étude était de caractériser les effets et les mécanismes moléculaires impliqués dans la pathogenèse de la co-infection de PCV2b avec le VSRRP ou le VIP dans des modèles cellulaires des voies respiratoires du porc. La réplication virale, la viabilité cellulaire, l’expression de l’ARNm des cytokines et la modulation de l’expression des gènes cellulaires induite par l’infection virale ont été évalués dans les cellules co-infectées versus les cellules infectées par un seul virus. Les résultats obtenus ont permis de confirmer que la réplication du PCV2b augmente en présence du VSRRP dans les cellules épithéliales des voies respiratoires porcines (NPTr) génétiquement modifiées pour exprimer le récepteur CD163 (NPTr-CD163), tandis que celle du VSRRP est diminuée. Il a été mis en évidence que le PCV2b provoque une diminution ou une augmentation de la réplication du VIP dans les cellules NPTr et les macrophages alvéolaires porcins (iPAM 3D4/21), respectivement. Cependant, la réplication du PCV2b n’est pas affectée en présence du VIP. L’expression des ARNm des cytokines varie différemment selon le modèle de co-infection analysé et le type cellulaire infecté. L’expression des interférons de type I (α/β) a été significativement réduite dans les cellules NPTr-CD163, co- infectées par le PCV2b et le VSRRP (PCV2b/VSRRP) par rapport aux mêmes cellules infectées uniquement par le PCV2b. Cependant, la co-infection du PCV2b et du VIP (PCV2b/VIP) a causé une augmentation synergique de l’expression des IFNs de type I et de type II dans les cellules NPTr, tandis que dans les cellules iPAM 3D4/21, le PCV2b a affecté la réponse des IFNs induite par le VIP. À la suite des analyses transcriptomiques, plusieurs gènes différentiellement exprimés ont été identifiés dans les cellules co-infectées ou infectées par un seul virus. Dans les cellules co-infectées PCV2b/VSRRP, le niveau d’expression de l’ARNm et de la protéine du gène cellulaire codant pour la phosphatase 1 à double spécificité (DUSP1) ont été significativement augmentés. La réduction de l’expression de DUSP1, à l’aide des petits ARN interférents (ou siRNA pour small interfering RNA) dans les cellules co-infectées a significativement réduit la réplication du PCV2b, suggérant un rôle de DUSP1 dans la pathogenèse de la co-infection PCV2b/VSRRP. / Interactions of porcine circovirus genotype 2b (PCV2b), porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza virus (SwIV) in the porcine respiratory complex (PRC) are often associated with increased respiratory clinical signs in animals. The general objective of this study was to characterize the effects and molecular mechanisms involved in the pathogenesis of PCV2b co-infection with PRRSV or SwIV using cellular models of the porcine respiratory tract. Viral replication, cell viability, cytokine mRNA expression and modulation of cell gene expression induced by viral infection were evaluated in co-infected cells versus single infected cells. The results obtained confirmed that PCV2b replication increases in the presence of PRRSV in porcine respiratory epithelial cells (NPTr) genetically modified to express the CD163 receptor (NPTr-CD163), whereas PRRSV is decreased. It was demonstrated that PCV2b causes a decrease or an increase in SwIV replication in NPTr cells and porcine alveolar macrophages (iPAM 3D4/21), respectively. However, PCV2b replication was not affected in the presence of SwIV. The impact of co-infections on cytokine mRNA expression varied according to the co- infection model and the type of infected cell. Type I IFNs (α/β) expression was significantly reduced in PCV2b/PRRSV co-infected NPTr-CD163 cells compared to PCV2b single-infected cells. However, PCV2b/SwIV co- infection caused a synergistic increase in type I IFNs expression in NPT cells, while in iPAM 3D4/21 cells, PCV2b affected SwIV-induced IFN response. As result of transcriptomic analyses, differentially expressed genes were identified in co-infected and single infected cells. It was observed that in PCV2b/PRRSV co- infected cells, the mRNA and protein expression levels of the cellular gene coding for the dual specificity protein phosphatase 1 (DUSP1) were significantly increased. Knockdown of DUSP1 expression in co- infected cells, using specific siRNA, significantly reduced PCV2b replication, suggesting a role for DUSP1 in the pathogenesis of PCV2b/PRRSV co-infection.

Algumas espécies de morcegos têm sido reconhecidas como reservatórios naturais de várias famílias virais, desempenhando um importante papel na trasmissão e manutenção desses micro organismos. Devido à descaracterização e fragmentação de habitats naturais, esses mamíferos buscam alternativas de abrigo e alimento, e assim, ficam cada vez mais expostos aos meios antrópicos e em contato com humanos e animais domésticos. Com exceção do vírus rábico, existem poucos trabalhos realizados na detecção de vírus em morcegos no Brasil. Em virtude disso, o presente estudo objetivou a detecção de vírus (circovírus, astrovírus, coronavírus e lyssavírus relacionados ao vírus da raiva) em amostras de órgãos de morcegos do estado do Rio Grande do Sul. Os ácidos nucléicos foram extraídos das amostras de órgãos de morcegos e submetidos à detecão por PCR e RT-PCR. Após a detecção, os fragmentos obtidos foram sequenciados para realizar análise filogenética dos vírus encontrados. Ao total foram analisadas 108 amostras de diferentes espécies e localidades, das quais dez foram positivas para circovírus, seis para coronavírus e 25 para astrovírus, este último sendo o primeiro registro do vírus em morcegos para o Brasil. Todas as amostras foram negativas para lyssavírus relacionados ao vírus da raiva. Análises filogenéticas revelaram que as sequências de circovírus agruparam em ambos os gêneros Circovirus e Cyclovirus, coronavírus no gênero Alphacoronavirus em dois clados diferentes e astrovírus no gênero Mamastrovirus junto com outros astrovírus de morcegos, o qual formam um clado separado dos outros mamíferos. Os resultados demonstram uma diversidade genética entre os vírus encontrados em diferentes espécies de morcegos, que possuem dietas alimentares e habitats distintos. / Some bat species have been recognized as natural reservoirs of several viral families, playing an important role in the transmission and maintaining of these micoorganism. Due to mischaracterization and fragmentation of natural habitats, these mammals seek shelter alternatives and food, and thus are increasingly exposed to anthropism, which make the contact with humans and domestic animals closer. With the exception of the rabies virus, there are few studies on the detection of viruses in bats in Brazil. Therefore, the present study aimed the detection of viruses (circovirus, astrovirus, coronavirus and rabies-related virus) in bats organs samples from Rio Grande do Sul state. Nucleic acids were extracted from bat organs samples and submitted to detection by PCR and RT-PCR. After detection, the obtained fragments were sequenced to perform phylogenetic analysis of the viruses found. From a total of 108 samples analyzed of different species and locations, ten were positive for circoviruses, six for coronaviruse and 25 for astrovirus, which was the first report of this virus in bats in Brazil. All samples were negative for rabies-related virus. Phylogenetic analyzes revealed that the sequences of circoviruses grouped in both Circovirus and Cyclovirus genus, coronaviruses in Alphacoronavirus genus in two different clades and astroviruses in Mamastrovirus genus along with other bats astrovirus, which form a separate clade from other mammals. Results demonstrate a genetic diversity among viruses found in different species of bats, which have different diets and habitats.

Os vírus influenza A (VIA) e circovírus suíno tipo 2 (PCV2) são os agentes etiológicos da influenza suína (IS) e da circovirose suína (CS), respectivamente. Estas doenças têm um impacto econômico significativo na suinocultura mundial. Adicionalmente, o VIA pode ser transmitido entre animais e humanos, sendo por isso, importante para a saúde pública. O presente trabalho teve o objetivo de pesquisar a ocorrência desses vírus em suínos de abate no sul de Moçambique. As amostras foram coletadas em um abatedouro na cidade da Matola, nos períodos de dezembro de 2014 a fevereiro de 2015 e dezembro de 2015 a fevereiro de 2016. Os materiais e métodos aplicados e resultados obtidos estão apresentados em dois artigos científicos. O primeiro relata a infecção pelo VIA associada à caracterização anatomopatológica e imuno-histoquímica (IHQ) das lesões pulmonares. Foram avaliados 457 pulmões de suínos, e amostras de 38 (8.3%) pulmões, que apresentaram áreas de consolidação, foram coletadas e submetidas ao exame histopatológico e IHQ para a detecção de antígenos do VIA, PCV2 e Mycoplasma hyopneumoniae. Antígenos do VIA foram detectados em 32/38 (84.3%) dos pulmões com pneumonia através da IHQ, e os suínos positivos eram provenientes dos distritos de Matutuine (5/32), Moamba (2/32), Namaacha (21/32), Boane (3/32) e Cidade da Matola (1/32). Todos os pulmões com pneumonia foram negativos no exame de IHQ para PCV2 e M. hyopneumoniae. O segundo artigo teve o objetivo de detectar lesões histológicas, antígenos e DNA de PCV2 em linfonodos mesentéricos de suínos e realizar a caracterização filogenética de isolados de PCV2 circulantes no sul de Moçambique. Foram coletados aleatoriamente 111 linfonodos mesentéricos de suínos de abate provenientes de nove distritos do sul de Moçambique. As amostras foram submetidas ao exame histopatológico, IHQ e reação em cadeia da polimerase (PCR). Uma amostra positiva para PCV2 na PCR de cada distrito (n=9) foi selecionada aleatoriamente e submetida ao sequenciamento da região aberta de leitura ORF2. DNA de PCV2 foi detectado em 53.8% (62/111) das amostras e em 73.8% de granjas dos nove distritos. No exame de IHQ, linfonodos mesentéricos de seis suínos positivos para PCV2 na PCR apresentaram antígenos desse vírus associados à depleção linfoide e infiltrado de histiócitos e células gigantes multinucleadas. Na análise filogenética, sequências dos isolados dos distritos de Namaacha, Moamba e Maputo ficaram agrupadas no genótipo PCV2d-2; as sequências de isolados dos distritos de Manhiça e Matola, no genótipo PCV2d-1; enquanto os isolados dos distritos de Boane, Matutuine, Chibuto e Xai-Xai, no genótipo PCV2b-1A/B. Os resultados do trabalho permitem concluir que o VIA e PCV2 circulam na população suína em vários distritos da região sul de Moçambique. / Influenza A virus (IAV) and porcine circovirus type 2 (PCV2) are the etiological agents of swine influenza (SI) and porcine circovirus associated diseases (PCVAD) respectively. These diseases represent a significant economic impact on pig production worldwide. In addition, IAV can be transmitted between animals and humans with consequences for public health. The objective of this study was to investigate the occurrence of these viruses in slaughter pigs in Southern Mozambique. Samples were collected in a slaughterhouse in Matola city, from December 2014 to February 2015 and December 2015 to February 2016. The materials and methods applied and the results obtained are presented in two manuscripts. The first article reports IAV infection in pigs and characterize the anatomopathological and immunohistochemical features of the associated lung lesions. Lungs from 457 slaughtered pigs were evaluated grossly, and samples from 38 (8.3%) of these that presented pulmonary consolidation were collected and examined for histopathology and immunohistochemistry (IHC) for the presence of IAV, PCV2 and Mycoplasma hyopneumoniae antigens. IAV antigens were detected in 32/38 (84.3%) of pneumonic lungs, and positive pigs were from Matutuine district (5/32), Moamba district (2/32), Namaacha district (21/32), Boane district (3/32) and Matola City (1/32). All lung samples were immunohistochemically negative for PCV2 and M. hyopneumoniae. The second article aimed to detect histological lesions, PCV2 antigens and DNA and perform phylogenetic analysis of PCV2 strains circulating in Southern Mozambique. At slaughter, mesenteric lymph nodes were collected from 111 randomly selected pigs from nine districts of Southern Mozambique. Samples were submitted to histopathological examination, IHC and polymerase chain reaction (PCR). One PCV2 PCR positive sample from each district (n=9) was randomly selected in order to obtain sequences covering the ORF2 region. PCV2 DNA was detected in 53.8% (62/111) of the samples and 73.8% of the farms from all nine districts. PCV2 antigen was detected by IHC in six lymph nodes that were positive for PCV2 by PCR and antigens were associated with lymphoid depletion and infiltrate of histiocytes and multinucleated giant cells. Phylogenetic analysis demonstrated that three sequences from Maputo, Namaacha and Moamba were grouped with PCV2d-2, two sequences from Manhiça and Matola were grouped as PCV2d-1, and four sequences from Boane, Matutuine, Chibuto, and Xai-Xai were closely related to PCV2b-1A/B genotypes. The results of this study indicate that IAV and PCV2 circulate in the swine population in several districts of the southern region of Mozambique.

Orientador: João Pessoa Araujo Junior / Resumo: A suinocultura vem alcançando grande desenvolvimento de técnicas eficientes associadas ao melhoramento genético, nutrição, manejo e sanidade. Entretanto, devido aos métodos intensivos de criação, os suínos se tornaram mais susceptíveis a um grande número de doenças infecciosas. Entre os mais importantes patógenos que afetam a indústria suinícola mundial está o circovírus suíno 2 (PCV2), um pequeno vírus icosaédrico, não-envelopado, de DNA circular, de fita simples (ssDNA), ambisenso, composta por 1767-1768 nucleotídeos. Este vírus é altamente resistente a variações ambientais e agentes desinfetantes, é endêmico no mundo todo e está associado a várias manifestações clínicas distintas, que acarretam importantes perdas econômicas aos produtores. Um dos fatores possivelmente implicados na patogenicidade do PCV2 é a proteína Cap, a unidade fundamental constituinte do capsídeo deste vírus. Estudos realizados pela equipe do Prof. Dr. João Pessoa Araújo Jr., do Instituto de Biotecnologia da Unesp em Botucatu/SP, comprovaram que vírus com mutações em suas proteínas Cap isolados a partir de cultivo celular aumentavam a morte celular em culturas celulares infectadas. Estes resultados evidenciaram a importância do capsídeo nos mecanismos de infecção e patogenicidade do PCV2, tornando interessante a realização de estudos estruturais com as proteínas Cap mutantes. A execução de estudos estruturais in silico mostrou a baixa frequência das mutações identificadas na proteína Cap dos vírus pro... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Swine breeding has achieved a high development based on genetic improvement, nutrition, management and sanity. However, due to the intensive breeding methods, swine have become more susceptible to a higher number of infectious diseases. Among the most important pathogens that affect the swine world industry is the porcine circovirus 2 (PCV2), a small, icosahedral, non-enveloped virus, ambisense single-stranded circular DNA, composed by 1,767-1,768 nucleotides. This virus is highly resistant to environmental variations and disinfecting agents, endemic worldwide and has been associated to several distinct clinical manifestations that entail important economic losses to the producers. One of the factors possibly implicated on the PCV2 pathogenicity is the Cap protein, the fundamental unity that constitutes this virus capsid. Studies performed by the group of Dr. João Pessoa Araújo Jr. rom the Instituto de Biotecnologia da Unesp em Botucatu/SP, confirmed that viruses with mutated Cap proteins from cell culture increased cell death in infected cultures. Such results highlight the importance of capsid in the infection mechanisms and pathogenicity of PCV2 and the importance of structural and comparative studies with Cap protein structures. In silico structural studies showed the low frequency of the mutations identified in the mutant Cap proteins and also indicated a clear difference between the physico-chemical properties of the new amino acid residues in comparison to those found ... (Complete abstract click electronic access below) / Mestre

Submitted by Pâmela Merlo Marson (pam.marson@aluno.ibb.unesp.br) on 2018-06-05T17:11:43Z No. of bitstreams: 1 Dissertação_Mestrado_Pamela-Merlo-Marson_2018_vf.pdf: 1757229 bytes, checksum: ed7b8faed4d956e7a1ba89178199507d (MD5) / Approved for entry into archive by Sulamita Selma C Colnago null (sulamita@btu.unesp.br) on 2018-06-07T14:10:28Z (GMT) No. of bitstreams: 1 marson_pm_me_bot.pdf: 1757229 bytes, checksum: ed7b8faed4d956e7a1ba89178199507d (MD5) / Made available in DSpace on 2018-06-07T14:10:28Z (GMT). No. of bitstreams: 1 marson_pm_me_bot.pdf: 1757229 bytes, checksum: ed7b8faed4d956e7a1ba89178199507d (MD5) Previous issue date: 2018-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A suinocultura vem alcançando grande desenvolvimento de técnicas eficientes associadas ao melhoramento genético, nutrição, manejo e sanidade. Entretanto, devido aos métodos intensivos de criação, os suínos se tornaram mais susceptíveis a um grande número de doenças infecciosas. Entre os mais importantes patógenos que afetam a indústria suinícola mundial está o circovírus suíno 2 (PCV2), um pequeno vírus icosaédrico, não-envelopado, de DNA circular, de fita simples (ssDNA), ambisenso, composta por 1767-1768 nucleotídeos. Este vírus é altamente resistente a variações ambientais e agentes desinfetantes, é endêmico no mundo todo e está associado a várias manifestações clínicas distintas, que acarretam importantes perdas econômicas aos produtores. Um dos fatores possivelmente implicados na patogenicidade do PCV2 é a proteína Cap, a unidade fundamental constituinte do capsídeo deste vírus. Estudos realizados pela equipe do Prof. Dr. João Pessoa Araújo Jr., do Instituto de Biotecnologia da Unesp em Botucatu/SP, comprovaram que vírus com mutações em suas proteínas Cap isolados a partir de cultivo celular aumentavam a morte celular em culturas celulares infectadas. Estes resultados evidenciaram a importância do capsídeo nos mecanismos de infecção e patogenicidade do PCV2, tornando interessante a realização de estudos estruturais com as proteínas Cap mutantes. A execução de estudos estruturais in silico mostrou a baixa frequência das mutações identificadas na proteína Cap dos vírus provenientes do cultivo in vitro e também indicou uma clara diferença entre as propriedades físico-químicas dos novos resíduos de aminoácidos em relação àqueles substituídos. Estas alterações, associadas à localização dos resíduos na superfície viral e a menor flexibilidade das proteínas Cap dos vírus mutantes, indicaram a possibilidade de alterações estruturais/funcionais relevantes, incluindo a alteração da afinidade por receptores celulares e diminuição da efetividade de anticorpos produzidos contra vírus vacinais. Foram também realizados trabalhos experimentais para a produção heteróloga da proteína Cap de um vírus selvagem, os quais envolveram ensaios de subclonagem da sequência de interesse em um vetor de expressão, testes de transcrição e experimentos de expressão protéica. Os resultados destes procedimentos foram compatíveis com a produção da proteína Cap, porém novos estudos são necessários para confirmar a produção da molécula alvo e melhorar o rendimento dos ensaios de expressão. / Swine breeding has achieved a high development based on genetic improvement, nutrition, management and sanity. However, due to the intensive breeding methods, swine have become more susceptible to a higher number of infectious diseases. Among the most important pathogens that affect the swine world industry is the porcine circovirus 2 (PCV2), a small, icosahedral, non-enveloped virus, ambisense single-stranded circular DNA, composed by 1,767-1,768 nucleotides. This virus is highly resistant to environmental variations and disinfecting agents, endemic worldwide and has been associated to several distinct clinical manifestations that entail important economic losses to the producers. One of the factors possibly implicated on the PCV2 pathogenicity is the Cap protein, the fundamental unity that constitutes this virus capsid. Studies performed by the group of Dr. João Pessoa Araújo Jr. rom the Instituto de Biotecnologia da Unesp em Botucatu/SP, confirmed that viruses with mutated Cap proteins from cell culture increased cell death in infected cultures. Such results highlight the importance of capsid in the infection mechanisms and pathogenicity of PCV2 and the importance of structural and comparative studies with Cap protein structures. In silico structural studies showed the low frequency of the mutations identified in the mutant Cap proteins and also indicated a clear difference between the physico-chemical properties of the new amino acid residues in comparison to those found in the wild-type virus. These mutations, associated with the location of the mutated residues on the viral surface and the lower mutated Cap protein flexibility, could lead to relevant structural/functional changes, including alteration of affinity for cellular receptors and decreased effectiveness of antibodies produced against vaccine viruses. Experimental works aiming the heterologous production of a wild-type Cap protein were also carried out, which involved expression vector subcloning, transcription tests and protein expression experiments. The results of these procedures were compatible with the production of the Cap protein, but further studies are needed to confirm the production of the target molecule and improve the yield of the expression assays.

Algumas espécies de morcegos têm sido reconhecidas como reservatórios naturais de várias famílias virais, desempenhando um importante papel na trasmissão e manutenção desses micro organismos. Devido à descaracterização e fragmentação de habitats naturais, esses mamíferos buscam alternativas de abrigo e alimento, e assim, ficam cada vez mais expostos aos meios antrópicos e em contato com humanos e animais domésticos. Com exceção do vírus rábico, existem poucos trabalhos realizados na detecção de vírus em morcegos no Brasil. Em virtude disso, o presente estudo objetivou a detecção de vírus (circovírus, astrovírus, coronavírus e lyssavírus relacionados ao vírus da raiva) em amostras de órgãos de morcegos do estado do Rio Grande do Sul. Os ácidos nucléicos foram extraídos das amostras de órgãos de morcegos e submetidos à detecão por PCR e RT-PCR. Após a detecção, os fragmentos obtidos foram sequenciados para realizar análise filogenética dos vírus encontrados. Ao total foram analisadas 108 amostras de diferentes espécies e localidades, das quais dez foram positivas para circovírus, seis para coronavírus e 25 para astrovírus, este último sendo o primeiro registro do vírus em morcegos para o Brasil. Todas as amostras foram negativas para lyssavírus relacionados ao vírus da raiva. Análises filogenéticas revelaram que as sequências de circovírus agruparam em ambos os gêneros Circovirus e Cyclovirus, coronavírus no gênero Alphacoronavirus em dois clados diferentes e astrovírus no gênero Mamastrovirus junto com outros astrovírus de morcegos, o qual formam um clado separado dos outros mamíferos. Os resultados demonstram uma diversidade genética entre os vírus encontrados em diferentes espécies de morcegos, que possuem dietas alimentares e habitats distintos. / Some bat species have been recognized as natural reservoirs of several viral families, playing an important role in the transmission and maintaining of these micoorganism. Due to mischaracterization and fragmentation of natural habitats, these mammals seek shelter alternatives and food, and thus are increasingly exposed to anthropism, which make the contact with humans and domestic animals closer. With the exception of the rabies virus, there are few studies on the detection of viruses in bats in Brazil. Therefore, the present study aimed the detection of viruses (circovirus, astrovirus, coronavirus and rabies-related virus) in bats organs samples from Rio Grande do Sul state. Nucleic acids were extracted from bat organs samples and submitted to detection by PCR and RT-PCR. After detection, the obtained fragments were sequenced to perform phylogenetic analysis of the viruses found. From a total of 108 samples analyzed of different species and locations, ten were positive for circoviruses, six for coronaviruse and 25 for astrovirus, which was the first report of this virus in bats in Brazil. All samples were negative for rabies-related virus. Phylogenetic analyzes revealed that the sequences of circoviruses grouped in both Circovirus and Cyclovirus genus, coronaviruses in Alphacoronavirus genus in two different clades and astroviruses in Mamastrovirus genus along with other bats astrovirus, which form a separate clade from other mammals. Results demonstrate a genetic diversity among viruses found in different species of bats, which have different diets and habitats.

Algumas espécies de morcegos têm sido reconhecidas como reservatórios naturais de várias famílias virais, desempenhando um importante papel na trasmissão e manutenção desses micro organismos. Devido à descaracterização e fragmentação de habitats naturais, esses mamíferos buscam alternativas de abrigo e alimento, e assim, ficam cada vez mais expostos aos meios antrópicos e em contato com humanos e animais domésticos. Com exceção do vírus rábico, existem poucos trabalhos realizados na detecção de vírus em morcegos no Brasil. Em virtude disso, o presente estudo objetivou a detecção de vírus (circovírus, astrovírus, coronavírus e lyssavírus relacionados ao vírus da raiva) em amostras de órgãos de morcegos do estado do Rio Grande do Sul. Os ácidos nucléicos foram extraídos das amostras de órgãos de morcegos e submetidos à detecão por PCR e RT-PCR. Após a detecção, os fragmentos obtidos foram sequenciados para realizar análise filogenética dos vírus encontrados. Ao total foram analisadas 108 amostras de diferentes espécies e localidades, das quais dez foram positivas para circovírus, seis para coronavírus e 25 para astrovírus, este último sendo o primeiro registro do vírus em morcegos para o Brasil. Todas as amostras foram negativas para lyssavírus relacionados ao vírus da raiva. Análises filogenéticas revelaram que as sequências de circovírus agruparam em ambos os gêneros Circovirus e Cyclovirus, coronavírus no gênero Alphacoronavirus em dois clados diferentes e astrovírus no gênero Mamastrovirus junto com outros astrovírus de morcegos, o qual formam um clado separado dos outros mamíferos. Os resultados demonstram uma diversidade genética entre os vírus encontrados em diferentes espécies de morcegos, que possuem dietas alimentares e habitats distintos. / Some bat species have been recognized as natural reservoirs of several viral families, playing an important role in the transmission and maintaining of these micoorganism. Due to mischaracterization and fragmentation of natural habitats, these mammals seek shelter alternatives and food, and thus are increasingly exposed to anthropism, which make the contact with humans and domestic animals closer. With the exception of the rabies virus, there are few studies on the detection of viruses in bats in Brazil. Therefore, the present study aimed the detection of viruses (circovirus, astrovirus, coronavirus and rabies-related virus) in bats organs samples from Rio Grande do Sul state. Nucleic acids were extracted from bat organs samples and submitted to detection by PCR and RT-PCR. After detection, the obtained fragments were sequenced to perform phylogenetic analysis of the viruses found. From a total of 108 samples analyzed of different species and locations, ten were positive for circoviruses, six for coronaviruse and 25 for astrovirus, which was the first report of this virus in bats in Brazil. All samples were negative for rabies-related virus. Phylogenetic analyzes revealed that the sequences of circoviruses grouped in both Circovirus and Cyclovirus genus, coronaviruses in Alphacoronavirus genus in two different clades and astroviruses in Mamastrovirus genus along with other bats astrovirus, which form a separate clade from other mammals. Results demonstrate a genetic diversity among viruses found in different species of bats, which have different diets and habitats.

Os vírus influenza A (VIA) e circovírus suíno tipo 2 (PCV2) são os agentes etiológicos da influenza suína (IS) e da circovirose suína (CS), respectivamente. Estas doenças têm um impacto econômico significativo na suinocultura mundial. Adicionalmente, o VIA pode ser transmitido entre animais e humanos, sendo por isso, importante para a saúde pública. O presente trabalho teve o objetivo de pesquisar a ocorrência desses vírus em suínos de abate no sul de Moçambique. As amostras foram coletadas em um abatedouro na cidade da Matola, nos períodos de dezembro de 2014 a fevereiro de 2015 e dezembro de 2015 a fevereiro de 2016. Os materiais e métodos aplicados e resultados obtidos estão apresentados em dois artigos científicos. O primeiro relata a infecção pelo VIA associada à caracterização anatomopatológica e imuno-histoquímica (IHQ) das lesões pulmonares. Foram avaliados 457 pulmões de suínos, e amostras de 38 (8.3%) pulmões, que apresentaram áreas de consolidação, foram coletadas e submetidas ao exame histopatológico e IHQ para a detecção de antígenos do VIA, PCV2 e Mycoplasma hyopneumoniae. Antígenos do VIA foram detectados em 32/38 (84.3%) dos pulmões com pneumonia através da IHQ, e os suínos positivos eram provenientes dos distritos de Matutuine (5/32), Moamba (2/32), Namaacha (21/32), Boane (3/32) e Cidade da Matola (1/32). Todos os pulmões com pneumonia foram negativos no exame de IHQ para PCV2 e M. hyopneumoniae. O segundo artigo teve o objetivo de detectar lesões histológicas, antígenos e DNA de PCV2 em linfonodos mesentéricos de suínos e realizar a caracterização filogenética de isolados de PCV2 circulantes no sul de Moçambique. Foram coletados aleatoriamente 111 linfonodos mesentéricos de suínos de abate provenientes de nove distritos do sul de Moçambique. As amostras foram submetidas ao exame histopatológico, IHQ e reação em cadeia da polimerase (PCR). Uma amostra positiva para PCV2 na PCR de cada distrito (n=9) foi selecionada aleatoriamente e submetida ao sequenciamento da região aberta de leitura ORF2. DNA de PCV2 foi detectado em 53.8% (62/111) das amostras e em 73.8% de granjas dos nove distritos. No exame de IHQ, linfonodos mesentéricos de seis suínos positivos para PCV2 na PCR apresentaram antígenos desse vírus associados à depleção linfoide e infiltrado de histiócitos e células gigantes multinucleadas. Na análise filogenética, sequências dos isolados dos distritos de Namaacha, Moamba e Maputo ficaram agrupadas no genótipo PCV2d-2; as sequências de isolados dos distritos de Manhiça e Matola, no genótipo PCV2d-1; enquanto os isolados dos distritos de Boane, Matutuine, Chibuto e Xai-Xai, no genótipo PCV2b-1A/B. Os resultados do trabalho permitem concluir que o VIA e PCV2 circulam na população suína em vários distritos da região sul de Moçambique. / Influenza A virus (IAV) and porcine circovirus type 2 (PCV2) are the etiological agents of swine influenza (SI) and porcine circovirus associated diseases (PCVAD) respectively. These diseases represent a significant economic impact on pig production worldwide. In addition, IAV can be transmitted between animals and humans with consequences for public health. The objective of this study was to investigate the occurrence of these viruses in slaughter pigs in Southern Mozambique. Samples were collected in a slaughterhouse in Matola city, from December 2014 to February 2015 and December 2015 to February 2016. The materials and methods applied and the results obtained are presented in two manuscripts. The first article reports IAV infection in pigs and characterize the anatomopathological and immunohistochemical features of the associated lung lesions. Lungs from 457 slaughtered pigs were evaluated grossly, and samples from 38 (8.3%) of these that presented pulmonary consolidation were collected and examined for histopathology and immunohistochemistry (IHC) for the presence of IAV, PCV2 and Mycoplasma hyopneumoniae antigens. IAV antigens were detected in 32/38 (84.3%) of pneumonic lungs, and positive pigs were from Matutuine district (5/32), Moamba district (2/32), Namaacha district (21/32), Boane district (3/32) and Matola City (1/32). All lung samples were immunohistochemically negative for PCV2 and M. hyopneumoniae. The second article aimed to detect histological lesions, PCV2 antigens and DNA and perform phylogenetic analysis of PCV2 strains circulating in Southern Mozambique. At slaughter, mesenteric lymph nodes were collected from 111 randomly selected pigs from nine districts of Southern Mozambique. Samples were submitted to histopathological examination, IHC and polymerase chain reaction (PCR). One PCV2 PCR positive sample from each district (n=9) was randomly selected in order to obtain sequences covering the ORF2 region. PCV2 DNA was detected in 53.8% (62/111) of the samples and 73.8% of the farms from all nine districts. PCV2 antigen was detected by IHC in six lymph nodes that were positive for PCV2 by PCR and antigens were associated with lymphoid depletion and infiltrate of histiocytes and multinucleated giant cells. Phylogenetic analysis demonstrated that three sequences from Maputo, Namaacha and Moamba were grouped with PCV2d-2, two sequences from Manhiça and Matola were grouped as PCV2d-1, and four sequences from Boane, Matutuine, Chibuto, and Xai-Xai were closely related to PCV2b-1A/B genotypes. The results of this study indicate that IAV and PCV2 circulate in the swine population in several districts of the southern region of Mozambique.