The higher proximity among humans, domestic animals and wildlife favours disease spill-over both from wildlife to domestic animals and vice versa, which is a potential risk for the extinction of wildlife populations and could be influencing the emergence and/or re-emergence of zoonotic diseases. The domestic dog (Canis familiaris) is the most abundant and widely distributed carnivore worldwide and is known to be carrying many infectious diseases. Among these diseases, domestic dogs are known to be source of canine distemper virus (CDV), canine parvovirus (CPV) and Echinococcus granulosus to wild carnivores and human being. Populations of domestic dogs inhabiting urban areas can be the source of infection of directly transmitted pathogens, since in these areas a high density of domestic dogs can facilitate the maintenance of these infections to both domestic and wild carnivore populations. In addition, the knowledge of the diseases present in the domestic dog populations in close proximity to wildlife is essential for conservation planning and for control of both zoonotic diseases and diseases of conservation concern. This thesis explores the effect of urbanization on the epidemiology of CDV, CPV, and E granulosus in domestic dogs and wild carnivores of the Coquimbo region of Chile as for example, chilla (L. griseus) and culpeo (L. culpaeus) foxes and assess the risk factors that could be facilitate disease transmission between canid inhabiting urban and rural areas. The first of the chapters containing original data, Chapter 3, describe the demography of dogs in the study area, indicating that urban sites have a greater population and a higher density of domestic dogs, a high growth rate and therefore a high turnover of susceptible than rural areas, which can be of relevance for the differences in diseases transmission patterns between these sites. Chapter 4 describe the degree of interaction between wild and domestic carnivores and its effect on interespecific disease transmission; indicating that in the study area there are many opportunities for domestic/wild carnivores interactions, as for example livestock predation by carnivores, by approaching to peridomestic environments, facilitating in this scenario the transmission of CDV, CPV and also E. granulosus by predating on livestock contaminated with cyst echinococcosis. Chapter 5 indicate that urban areas hold domestic dog populations with higher CDV seroprevalence than rural sites and probably these areas are the source of infection to rural sites. In contrast, a more stable CPV seroprevalence was found between urban and rural areas, indicating that possibly this pathogen follow an endemic state across the study area. Chapter 6 describe the factors for E. granulosus prevalence in domestic dogs, livestock and human being, suggesting that more cases of E. granulosus in livestock and in humans are found in provinces of the Coquimbo region with higher percentage of rural population; however, and unexpectedly, more cases of E. granulosus in domestic dogs were found in urban areas, although analysis of risk factors indicated that those domestic dogs inhabiting in the borders of urban areas, were at greater risk of being infected with E. granulosus than those in the centre of these areas. The results of this study exemplify how three pathogens are found in urban areas which can be source of infection to domestic and wild carnivores in the study area.

PARV4 is a novel human parvovirus initially identified in an intravenous drug user at risk of HIV infection. PARV4 is a small single stranded DNA virus principally absent from the general population, but common in HCV- and HIV-infected individuals. Until 2009, most published PARV4 studies related to the prevalence of PARV4 in various risk groups. PARV4 has been detected in the liver of HCV-patients and the bone marrow of HIV-patients. Parvovirus B19, the closest related virus, elicits a strong immune response and can cause serious disease. Thus, this project was initiated to characterise the immune response to PARV4, and investigate the clinical significance of this virus. Cohorts of HCV-infected, HIV-infected, HCV-HIV co-infected, healthy and acute parvovirus B19-infected individuals were screened for humoral and cellular responses in both acute and chronic PARV4 infection. HCV- and HIV-related disease progression was also assessed relative to PARV4 infection. This study demonstrates that the highest prevalence of PARV4 infection is found in HCV-HIV co-infected intravenous drug users, and provides additional evidence for parenteral transmission. I present here the first data on the cellular immune response to PARV4 in acute and chronic infection and define PARV4 as a persistent virus. Although no clear correlation could be found between PARV4 and HCV or HIV disease progression, the high prevalence rates emphasize the importance of investigations into emerging infections such as PARV4.

O parvovírus humano B19 é um vírus não envelopado, que contém uma fita simples de DNA. Seu genoma é altamente conservado, com 98 a 99% de similaridade entre os isolados. Durante a última década, variantes do parvovírus B19, gênero Erythrovirus, foram descritas apresentando variabilidade genética de 11 a 14. Uma nova classificação foi proposta, dividindo o gênero em três diferentes genótipos (1, 2, 3a e 3b). Para avaliar a diversidade genética e o papel epidemiológico dos eritrovírus, 892 amostras brasileiras e chilenas, foram investigadas para a presença de DNA viral. As amostras positivas foram seqüênciadas e genotipadas através da analise da região VP1/VP2. Os resultados mostraram predominância do genótipo 1 (89 amostras), seguido do genótipo 3 (1 amostra), nas amostras brasileiras, enquanto que nas amostras chilenas, apenas o genótipo 1 foi observado (24 amostras). A única variante detectada, a amostra BR543, apresentou variabilidade de aproximadamente 13%, quando comparada ao B19, sendo classificada como genótipo 3, subtipo 3b. / Human Parvovirus B19 is a non-enveloped, ssDNA virus. The genome is highly conserved, showing 98 to 99% of nucleotide similarity between the isolates. During the last decade, parvovirus B19 variants, genus Erythrovirus, were described showing 11 to 14 %. A new classification was suggested, dividing the genus in three different genotypes (1, 2, 3a and 3b). To evaluate the epidemiology and the erythrovirus genetic diversity, 892 brazilians and chileans samples, were investigated for the virus DNA presence. The positive samples were sequenced and genotyped (VP1/VP2). The results showed the prevalence of genotype 1 (69 samples), followed by genotype 3 (1 sample), in the brazilians samples, and in the Chilean samples only genotype 1 was observed (24 samples). The variant detected, BR543, showed 13% of divergence when compared to B19, classified as genotype 3, subtype 3b.

O eritrovírus humano (parvovírus), gênero Erytrovírus, é o único representante da família Parvoviridae responsável por um amplo espectro de doenças. Estudos recentes têm demonstrado variações entre o eritrovírus e orientam a reclassificação destas variantes em três genótipos distintos: genótipos 1, 2 e 3. O papel do eritrovírus na etiopatogenia de doenças hematológicas em humanos permanece incerto. Este estudo teve como objetivo principal avaliar a relação etiopatogênica dos genótipos do eritrovírus e as citopenias de origem desconhecida. Materiais e Métodos: Participaram do estudo 285 indivíduos procedentes do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Destes, 120 apresentavam citopenias de origem desconhecida (grupo 1 Casos), 45 eram doadores de medula óssea (grupo 2 Controles Saudáveis) e 120 eram pacientes com doenças oncohematológicas crônicas (grupo 3 Controles com Neoplasias Hematológicas). A pesquisa do vírus foi realizada pelo método de semi-nested PCR (Reação em Cadeia da Polimerase) em amostras de medula óssea e de sangue periférico. As fitas complementares foram seqüenciadas diretamente do produto da PCR. Amostras de plasma de todos os indivíduos incluídos no estudo foram testadas para presença de anticorpos IgG e IgM específicos contra o eritrovírus por ensaio imunoenzimático. Resultados: Dos 40 indivíduos com resultado positivo na PCR em amostra da medula óssea, o genótipo 1 foi encontrado em 22 (55%), o genótipo 2 em 5 (12,5%), o genótipo 3 em 13 (32,5%). Quando comparadas as freqüências de positividade entre os casos e controles (Grupo 1 VS Grupos 2 e 3), não encontramos diferença significativa com relação ao genótipo 1 (p=0, 192) nem com relação aos genótipos 2 e 3 (p= 0.143). A soroprevalência encontrada na amostra foi de 71%. Conclusão: Concluímos que a infecção isolada pelo eritrovírus, independente do genótipo encontrado, não tem relação etiopatogênica com as citopenias de origem desconhecida, uma vez que o vírus foi encontrado com a mesma freqüência nos casos e nos controles estudados / The human erythrovirus (parvovirus), genus Erytrovirus, is the only representative of the family Parvoviridae responsible for a broad spectrum of diseases. Recent studies have shown variations within the erythrovirus and guide the classification of these variants in three distinct genotypes: genotypes 1, 2 and 3. The role of the erythrovirus in the etiopathogenesis of hematological diseases in humans remains uncertain. This studys main objective was to evaluate the etiopathogenic relationship between the genotypes of the erythrovirus and the cyptopenias of unknown origins. Methods and Materials: 285 individuals coming from the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo participated in the study. Of these, 120 represented cytopenias of unknown origins (group one Cases), 45 were bone marrow donors (group two - Healthy Controls), and 120 were patients with chronic oncohematological diseases (group three Controls with Hematological Disorder). The research of the virus was done through the semi-nested PCR method (polymerase chain reaction) in bone marrow and peripheral blood samples. The complementary strands were sequenced directly from the product of the PCR. Plasma samples from all of the individuals included in the study were tested through immunosorbent assay for the presence of lgG and IgM antibodies specific to the eritrovírus. Results: Of the 40 individuals that had positive PCR bone marrow results, the genotype 1 was found in 22 (55%), the genotype 2 in 5 (12.5%), and genotype 3 in 13 (32.5%). When the frequency of positivity was compared between the cases and the controls (Group 1 vs. Groups 2 and 3), we did not find a significant difference in relation to genotype 1 (p=0.192), nor did we find a significant difference in relation to genotypes 2 and 3 (p=0.143). The overall seroprevalence found in the samples was 71%. Conclusion: We conclude that the infection isolated by the erytrovirus, independent of the genotype found, does not have a etiopathogenic relationship with the cytopenias of unknown origins, hence the virus was found with the same frequency in the cases and the controls studied

<div>Viruses are a group of contagious microbes that have compact structures, containing a nucleic acid core and a protein shell. The replication of viruses requires assistance from hosts which can be almost any cellular organism. Viral infections are often associated with diseases and have been a major threat to the human race. To cope with viral diseases, we need to understand viruses, including their structures, life cycle, pathogenesis and interactions with their hosts. The first structure of a human virus was determined by the Rossmann lab in 1985 using X-ray crystallography.</div><div>Thanks to the recent advances in both hardware and software, cryo-electron microscopy (cryo-EM) has emerged as a powerful tool to study virus structures. Cryo-EM allows structural determination for a wide range of specimens to high resolution comparable to what can be achieved by X-ray crystallography. Currently two techniques of cryo-EM are commonly used in structural virology: single particles analysis (SPA) and electron tomography (ET). </div><div>Single particle analysis has been used to determine the structures of viruses complexed with host factors in three studies that are to be discussed with more details in chapters 2-4. </div><div>The structure of B19 parvovirus complexed with Fabs of a neutralizing human antibody was determined to 3.2 Å resolution. This structure showed that amino acids from three neighboring VP2 proteins form a quaternary structure epitope. In addition, the structure of human rhinovirus-C (RV-C) complexed with its cellular receptor, CDHR3, was determined to 3.9 Å resolution. Despite the low occupancy of the receptors, a “powerful” localized 3D classification procedure helped to select viral particles that had more bound receptors. Furthermore, structures were determined to 10 Å resolution of bacteriophage ΦX174 bound to lipopolysaccharide (LPS) bilayers, before and after genome ejection. These structures showed a series of conformational changes that occurred when a phage penetrated the bacterial membranes. These studies are good examples of applying cryo-EM to investigate virus-host interactions.</div><div>However, single particle analysis requires samples to be isolated, homogenous and monodispersed. On the contrary, tomography allows in situ studies and is applicable to samples with more flexibility and more heterogeneity. In the case of ΦX174, the structural changes that are involved in the assembly of the H-tube during infection remains a huge mystery. To provide an environment that is more similar to the surface of a bacterial cell, LPS-containing liposomes were mixed with ΦX174 viruses. It was then observed that the ΦX174 particles bound to these liposomes in a very compact manner which was impossible interpret with single particle analysis. Using cryo-ET, 3D volumes of liposome-ΦX174 complexes were reconstructed and structural details were visualized by sub-tomogram classification and averaging.</div><div>The emergence of cryo-EM has not only made high-resolution structural studies possible but also broadened the scope of samples with which virologists could work. Moreover, studies on flexible and heterogeneous complexes between viruses and host factors are now possible using either single particle analysis or electron tomography. These techniques will help us to understand virus-host relationships and finally, to develop effective anti-viral therapies.</div>

O eritrovírus humano (parvovírus), gênero Erytrovírus, é o único representante da família Parvoviridae responsável por um amplo espectro de doenças. Estudos recentes têm demonstrado variações entre o eritrovírus e orientam a reclassificação destas variantes em três genótipos distintos: genótipos 1, 2 e 3. O papel do eritrovírus na etiopatogenia de doenças hematológicas em humanos permanece incerto. Este estudo teve como objetivo principal avaliar a relação etiopatogênica dos genótipos do eritrovírus e as citopenias de origem desconhecida. Materiais e Métodos: Participaram do estudo 285 indivíduos procedentes do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Destes, 120 apresentavam citopenias de origem desconhecida (grupo 1 Casos), 45 eram doadores de medula óssea (grupo 2 Controles Saudáveis) e 120 eram pacientes com doenças oncohematológicas crônicas (grupo 3 Controles com Neoplasias Hematológicas). A pesquisa do vírus foi realizada pelo método de semi-nested PCR (Reação em Cadeia da Polimerase) em amostras de medula óssea e de sangue periférico. As fitas complementares foram seqüenciadas diretamente do produto da PCR. Amostras de plasma de todos os indivíduos incluídos no estudo foram testadas para presença de anticorpos IgG e IgM específicos contra o eritrovírus por ensaio imunoenzimático. Resultados: Dos 40 indivíduos com resultado positivo na PCR em amostra da medula óssea, o genótipo 1 foi encontrado em 22 (55%), o genótipo 2 em 5 (12,5%), o genótipo 3 em 13 (32,5%). Quando comparadas as freqüências de positividade entre os casos e controles (Grupo 1 VS Grupos 2 e 3), não encontramos diferença significativa com relação ao genótipo 1 (p=0, 192) nem com relação aos genótipos 2 e 3 (p= 0.143). A soroprevalência encontrada na amostra foi de 71%. Conclusão: Concluímos que a infecção isolada pelo eritrovírus, independente do genótipo encontrado, não tem relação etiopatogênica com as citopenias de origem desconhecida, uma vez que o vírus foi encontrado com a mesma freqüência nos casos e nos controles estudados / The human erythrovirus (parvovirus), genus Erytrovirus, is the only representative of the family Parvoviridae responsible for a broad spectrum of diseases. Recent studies have shown variations within the erythrovirus and guide the classification of these variants in three distinct genotypes: genotypes 1, 2 and 3. The role of the erythrovirus in the etiopathogenesis of hematological diseases in humans remains uncertain. This studys main objective was to evaluate the etiopathogenic relationship between the genotypes of the erythrovirus and the cyptopenias of unknown origins. Methods and Materials: 285 individuals coming from the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo participated in the study. Of these, 120 represented cytopenias of unknown origins (group one Cases), 45 were bone marrow donors (group two - Healthy Controls), and 120 were patients with chronic oncohematological diseases (group three Controls with Hematological Disorder). The research of the virus was done through the semi-nested PCR method (polymerase chain reaction) in bone marrow and peripheral blood samples. The complementary strands were sequenced directly from the product of the PCR. Plasma samples from all of the individuals included in the study were tested through immunosorbent assay for the presence of lgG and IgM antibodies specific to the eritrovírus. Results: Of the 40 individuals that had positive PCR bone marrow results, the genotype 1 was found in 22 (55%), the genotype 2 in 5 (12.5%), and genotype 3 in 13 (32.5%). When the frequency of positivity was compared between the cases and the controls (Group 1 vs. Groups 2 and 3), we did not find a significant difference in relation to genotype 1 (p=0.192), nor did we find a significant difference in relation to genotypes 2 and 3 (p=0.143). The overall seroprevalence found in the samples was 71%. Conclusion: We conclude that the infection isolated by the erytrovirus, independent of the genotype found, does not have a etiopathogenic relationship with the cytopenias of unknown origins, hence the virus was found with the same frequency in the cases and the controls studied

A conservação dos animais selvagens de vida livre é ameaçada pela fragmentação de habitat, caça, diminuição de presas e, em menor escala pela ocorrência de doenças infecciosas. Reconhecendo a importância das doenças para a conservação, e considerando que o crescimento da população humana no entorno de áreas protegidas propicia o aumento do contato de animais domésticos e selvagens, o presente estudo teve como objetivo pesquisar a exposição de carnívoros selvagens de vida livre e cães domésticos da região do Parque Nacional das Emas (PNE), Goiás à cinomose, parvovirose, brucelose e brucelose canina. Entre as espécies de carnívoros selvagens amostradas estão o lobo-guará, cachorro-do-mato, raposinha-do-campo, onça-parda, jaguatirica, gato-palheiro, gatomourisco, jaratataca e quati. Foram realizados os testes de soroneutralização, inibição de hemaglutinação, imunodifusão em gel ágar e PCR, para cinomose, parvovirose, brucelose canina e brucelose, respectivamente. Lobos-guará (12,7%, n=9), cachorros-do-mato (11,6%, n=7), jaguatiricas (18,2%, n=2) e cães domésticos (71,4%, n=25) foram expostos à cinomose. Todas as espécies de carnívoros selvagens amostradas, com exceção do quati, sendo 40,4% (n=65) dos indivíduos, e 37,1% (n=13) dos cães domésticos foram expostos à parvovirose. Apenas o lobo-guará (1,67%, n=2) foi exposto à brucelose canina e a raposinha-do-campo à Brucella spp. (1,47%, n=1). Este é o primeiro relato da exposição de gato-palheiro, gatomourisco e jaratataca ao parvovírus, e de lobo-guará à Brucella canis. A cinomose e a parvovirose merecem atenção no PNE pela possibilidade de envolvimento de cães domésticos na sua transmissão, embora não possa ser comprovada no presente estudo. A brucelose, no momento, parece não ser uma ameaça sanitária para as populações de carnívoros do PNE. / The conservation of free ranging wildlife is threatened by habitat fragmentation, hunting, decrease of prey and, to a lesser extent by the occurrence of infectious diseases. Recognizing the diseases importance for conservation, and considering that the increase of human population around protected areas provides increased contact with domestic and wild animals, the present study aimed to investigate the exposure of free ranging wild carnivores and domestic dogs in the region of Emas National Park (ENP), Goiás, Brazil for canine distemper virus (CDV), parvovirus, brucellosis and canine brucellosis. Among the species of wild carnivores sampled are the maned wolf, crab-eating fox, hoary fox, puma, ocelot, pampas cat, jaguarondi, skunk and coati. The tests performed for CDV, parvovirus, canine brucellosis and brucellosis tests were the serum neutralization test, hemagglutination inhibition, agar gel immunodiffusion and PCR, respectively. Maned wolves (12.7%, n = 9), crab-eating foxes (11.6%, n = 7), ocelots (18.2%, n = 2) and domestic dogs (71.4%, n = 25) were exposed to CDV. All species of wild carnivores sampled, except coatis, being 40.4% (n = 65) of individuals, and 37.1% (n = 13) of domestic dogs were exposed to parvovirus. Only maned wolves (1.67%, n = 2) were exposed to canine brucellosis and hoary fox to Brucella spp. (1.47%, n = 1). This is the first report of pampas cat, jaguarondi and skunk exposure to parvovirus, and of maned wolf to Brucella canis. CDV and parvovirus deserve attention in ENP by the possibility of involvement of domestic dogs in its transmission, although it can not be proven in this study. At the moment, brucellosis doesn\'t seem to be a sanitary threat for carnivores population at ENP.

O parvovírus suíno (PPV) apresenta grande importância, principalmente em fêmeas nãoimunes, por causar perdas reprodutivas significativas. O primeiro trabalho foi desenvolvido sobre forma de revisão, e serviu como base para realização dos estudos seguintes. O segundo trabalho foi conduzido para determinar a resposta de anticorpos para PPV em 127 leitoas após a vacinação, avaliar a transferência de imunidade passiva e estimar a queda de anticorpos colostrais para PPV na leitegada. Foi realizada coleta de sangue nas leitoas em: (A) antes da primeira vacinação para PPV, (B) após a segunda dose; (C) no parto e (D) durante a segunda gestação. Além disto, colostro também foi coletado (E). Três leitões de cada fêmea foram selecionados e amostras de sangue foram coletadas: antes de mamar o colostro, 7, 21, 57, 87 e 128 dias de idade, a fim de verificar o declínio da imunidade passiva e estimar a meia-vida de anticorpos para PPV. O número de fetos mumificados, natimortos, nascidos vivos e nascidos totais do primeiro e segundo parto foram analizados. Os anticorpos para PPV foram testados por inibição da hemaglutinação (HI) e enzymelinked immunosorbent assay (ELISA), a fim de verificar a concordância entre estes dois métodos. A possível associação entre os títulos de anticorpos das fêmeas e dos leitões no soro e no colostro com os dados reprodutivos também foi investigada. A maioria das fêmeas (85,83%) tiveram anticorpos para PPV antes da vacinação, mas depois da vacina, todas as fêmeas soroconverteram. Aos sete dias de idade a maioria dos leitões apresentaram anticorpos para PPV e em torno dos 57 dias de idade somente 35,29% dos leitões eram positivos, alcançando a nulidade de anticorpos para PPV aos 87 dias de idade. A meia-vida estimada dos anticorpos colostrais foi 29,80 dias. A correlação entre o soro dos leitões e da fêmea no momento do parto foi r=0,77 (P<0,001) e com o colostro o valor de r foi 0,72 (P<0.001). A concordância entre os testes de ELISA e HI foi moderada (Spearman’s ρ= 0,89 e R2= 0.67). Houve diferença somente no número de mumificados entre o primeiro e segundo parto (P<0,001). O terceiro trabalho objetivou avaliar o perfil de anticorpos para PPV em diferentes sistemas de reposição de leitoas, correlacionando com dados reprodutivos. Cento e cinquenta 11 nulíparas com duas doses de vacina para PPV foram selecionadas de três sistemas de reposição diferentes: quarto sítio - A (n=36), granja receptora do quarto sítio - B (n=57) e granja multiplicadora - C (n=57). Os anticorpos para PPV foram medidos utilizando um teste de ELISA. Houve diferença entre as três granjas com relação ao título de anticorpos (P<0,05). Ao comparar os dados reprodutivos entre as granjas, houve diferença entre elas no número de nascidos totais e nascidos vivos, mas não foi observada diferença no percentual de natimortos e de mumificados (P>0,05). A correta preparação da leitoa, objetivando a proteção no momento da cobertura é fundamental para alcançar bom desempenho reprodutivo, independente do sistema de reposição utilizado. / Porcine parvovirus (PPV) has a great importance because causes significantly reproductive losses, mainly in non-immune gilts. The first study was developmented as a review, and served as a basis to carry out the following studies. The second study was conducted to determine the antibody response for PPV of 127 gilts in field conditions after vaccination, to evaluate the transfer of passive immunity and to estimate the decay of acquired colostral antibodies to PPV in the littermate. Gilts were bled at: (A) before the first vaccination to PPV, (B) after the second dose; (C) at farrowing and (D) during the second pregnancy. Added to these, colostrum was also collected (E). Three piglets of each gilt were selected and blood samples were collected: prior to initial colostrum intake, 7, 21, 57, 87 and 128 day-old, in order to verify the decrease of passive immunity and estimate the half-life of PPV antibodies. The number of mummified fetus, stillbirths, born alive and total born were analyzed from first and second parturition. The PPV antibodies were tested both with haemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA) in order to study the agreement between these methods. The possible association between gilts and piglets antibody titers in serum and colostrum with reproductive data was also investigated. Most gilts (85.83%) had antibodies to PPV before vaccination, but after vaccine, all gilts seroconverted. At 7 day-old most part of piglets had PPV antibodies and around 57 days-old only 35.29% of piglets were positive, reaching the PPV antibodies nullity at 87 days-old. The estimated average half-life of acquired colostral antibodies was 29.80 days. The correlation between piglets serum with gilt serum at farrowing time was r=0.77 (P<0.001) and with colostrum the r value was 0.72 (P<0.001). The agreement between ELISA and HI tests was moderate (Spearman’s ρ= 0.89 and R2= 0.67). The only difference between first and second parturition was observed on mummified fetuses (P<0.001). The objective of the third study was to evaluate the PPV antibodies profile in different gilts replacement systems, correlating with reproductive data. A hundred and fifty gilts with two doses of 13 PPV vaccine were selected from three different gilts replacement systems: Fourth site - A (n=36), fourth site receiver herd - B (n=57) and a farm producing dam lines - C (n=57). The PPV antibodies were measured by an ELISA test. There were a difference on antibody titers among the three herds (P<0.05). When we compared the reproductive data among herds, there were difference on total born and born alive, but this difference was not observed on the percentual of stillbirths and mummified (P>0.05). The correct gilt preparation, aiming the protection on mating time is fundamental to reach a great reproductive performance, independent of the replacement gilt system used.

A conservação dos animais selvagens de vida livre é ameaçada pela fragmentação de habitat, caça, diminuição de presas e, em menor escala pela ocorrência de doenças infecciosas. Reconhecendo a importância das doenças para a conservação, e considerando que o crescimento da população humana no entorno de áreas protegidas propicia o aumento do contato de animais domésticos e selvagens, o presente estudo teve como objetivo pesquisar a exposição de carnívoros selvagens de vida livre e cães domésticos da região do Parque Nacional das Emas (PNE), Goiás à cinomose, parvovirose, brucelose e brucelose canina. Entre as espécies de carnívoros selvagens amostradas estão o lobo-guará, cachorro-do-mato, raposinha-do-campo, onça-parda, jaguatirica, gato-palheiro, gatomourisco, jaratataca e quati. Foram realizados os testes de soroneutralização, inibição de hemaglutinação, imunodifusão em gel ágar e PCR, para cinomose, parvovirose, brucelose canina e brucelose, respectivamente. Lobos-guará (12,7%, n=9), cachorros-do-mato (11,6%, n=7), jaguatiricas (18,2%, n=2) e cães domésticos (71,4%, n=25) foram expostos à cinomose. Todas as espécies de carnívoros selvagens amostradas, com exceção do quati, sendo 40,4% (n=65) dos indivíduos, e 37,1% (n=13) dos cães domésticos foram expostos à parvovirose. Apenas o lobo-guará (1,67%, n=2) foi exposto à brucelose canina e a raposinha-do-campo à Brucella spp. (1,47%, n=1). Este é o primeiro relato da exposição de gato-palheiro, gatomourisco e jaratataca ao parvovírus, e de lobo-guará à Brucella canis. A cinomose e a parvovirose merecem atenção no PNE pela possibilidade de envolvimento de cães domésticos na sua transmissão, embora não possa ser comprovada no presente estudo. A brucelose, no momento, parece não ser uma ameaça sanitária para as populações de carnívoros do PNE. / The conservation of free ranging wildlife is threatened by habitat fragmentation, hunting, decrease of prey and, to a lesser extent by the occurrence of infectious diseases. Recognizing the diseases importance for conservation, and considering that the increase of human population around protected areas provides increased contact with domestic and wild animals, the present study aimed to investigate the exposure of free ranging wild carnivores and domestic dogs in the region of Emas National Park (ENP), Goiás, Brazil for canine distemper virus (CDV), parvovirus, brucellosis and canine brucellosis. Among the species of wild carnivores sampled are the maned wolf, crab-eating fox, hoary fox, puma, ocelot, pampas cat, jaguarondi, skunk and coati. The tests performed for CDV, parvovirus, canine brucellosis and brucellosis tests were the serum neutralization test, hemagglutination inhibition, agar gel immunodiffusion and PCR, respectively. Maned wolves (12.7%, n = 9), crab-eating foxes (11.6%, n = 7), ocelots (18.2%, n = 2) and domestic dogs (71.4%, n = 25) were exposed to CDV. All species of wild carnivores sampled, except coatis, being 40.4% (n = 65) of individuals, and 37.1% (n = 13) of domestic dogs were exposed to parvovirus. Only maned wolves (1.67%, n = 2) were exposed to canine brucellosis and hoary fox to Brucella spp. (1.47%, n = 1). This is the first report of pampas cat, jaguarondi and skunk exposure to parvovirus, and of maned wolf to Brucella canis. CDV and parvovirus deserve attention in ENP by the possibility of involvement of domestic dogs in its transmission, although it can not be proven in this study. At the moment, brucellosis doesn\'t seem to be a sanitary threat for carnivores population at ENP.

Porcine parvovirus (PPV) is considered to be one of the most important causes of reproductive failure in swine. Fetal death, mummification, stillbirths and delayed return to estrus are some of the clinical signs commonly associated with PPV infection in a herd. The virus genome is considered to be conservative, with substitution rates near to that of their host. However, it has been shown that some parvoviruses exhibit a substitution rate close to that commonly determined for RNA viruses. In this scenario, new PPV phenotypes may reduce the effectiveness of the currently used vaccines, recommending the continuous monitoring of the currently prevalent PPV strains. In addition, a number of novel porcine parvoviruses have been described during the last decade, but the importance and characteristics of these viruses remain unknown. In the present dissertation, three studies were performed to address the PPV genetic variability, to monitor the emergence of new PPV strains and the prevalence of novel parvoviruses. In the first study, recent PPV field isolates from Austria, Brazil, Germany and Switzerland were sequenced and analyzed. These samples, together with sequences retrieved from GenBank, were included in three datasets (viral protein complete gene, viral protein partial gene and non-structural protein complete gene). For each dataset, the nucleotide substitution rate was determined and a molecular clock estimated. The analysis revealed that for the new strains, the amino acids substitutions were located mainly in the viral capsid loops. Only the capsid protein datasets present the higher suitability for phylogenetic analysis. In them, a higher divergence was found, with three well defined clusters. By inferring the evolutionary dynamics of the PPV sequences, a nucleotide substitution rate of approximately 10 -4 substitutions per site per year was found for these datasets. An association of the phylogenetic tree with the molecular clock revealed that the main divergence of the PPV strains for the viral protein ocurred in the last 30 years. In the second study, the population dynamic of PPV isolates from swine herds was analyzed using PPV complete protein gene and partial sequences deposited in GenBank. The population dynamic of the virus was calculated using a Bayesian approach with a Bayesian skyline coalescent model. Additionally, an in vitro model was performed by twenty-one consecutives passages of the Challenge strain (a virulent field strain) and NADL2 strain (a vaccine strain) in PK15 cell-line supplemented with polyclonal antibodies raised against the vaccine strain (negative control was not supplemented). The Bayesian analysis indicated a decrease in the population diversity over the years and the predominance of some PPV strains. In agreement, the in vitro study revealed that a lower number of mutations appeared for both viruses in the presence of anti-PPV antibodies in comparison with the control passages without antibodies. In the third study, tonsils and hearts from 100 pigs were collected in a German slaughterhouse in 2010 and tested for PPV, porcine parvovirus 2 (PPV2), porcine parvovirus 3 (PPV3) and porcine parvovirus 4 (PPV4). Positive samples of PPV, PPV2 and PPV3 were sequenced. PPV was observed in 60/100 hearts and 61/100 tonsils and PPV2 in 55/100 hearts and 78/100 tonsils. PPV3 and PPV4 could not be detected in the heart samples but 20/100 and 7/100, respectively, of the tonsils were tested positive. The phylogenetic analysis of the PPV, PPV2 and PPV3 sequences revealed that the German samples could be divided in at least two clusters or clades for each virus. Altogether, it can be concluded that PPV is continuously evolving. Apparently, PPV vaccines largely used in the last 30 years probably have reduced the genetic diversity of the virus and induced the predominance of strains with distinct capsid profile from the original vaccine-based strain. Moreover, the high prevalence of the PPV, PPV2 and PPV3 and their genetic diversity highlight the importance of the continuous monitoring of these viruses.