Das porzine Parvovirus (PPV), 2013 vom International Committee on taxonomy of Viruses (ICTV) in ungulate Protoparvovirus 1 umbenannt, ist ein unbehülltes, einzelsträngiges DNA Virus und gehört innerhalb der Familie Parvoviridae zur Subfamilie Parvovirinae. Es ist weltweit in allen Bereichen der Schweinehaltung endemisch und verursacht große wirtschaftliche Verluste in den Betrieben (TRUYEN und STRECK 2012). Anders als die verwandten caninen und felinen Parvoviren (seit 2013 arnivore Protoparvovirus 1) ist es nicht durch zum Teil tödlich verlaufende Durchfallerkrankungen, sondern durch Fruchtbarkeitsstörungen wie Abort, Mumifikation und Unfruchtbarkeit, auch bekannt als SMEDI – Syndrom (Stillbirth = Totgeburt, Mummification =Mumifikation, Embryonic Death = embryonaler Tod und Infertility = Unfruchtbarkeit), gekennzeichnet. Die Schwere des Verlaufs hängt dabei wesentlich vom Zeitpunkt sowie von dem, für die Infektion verantwortlichen Isolats ab. Als besonders gefährdet gelten ungeimpfte Jungsauen, die innerhalb der ersten 70 Tage der Trächtigkeit in Kontakt mit dem Virus treten. Das Virus verfügt über eine ausgesprochen hohe Tenazität gegenüber äußeren Einflüssen. Es ist hitzestabil, unempfindlich gegenüber pH-Werten zwischen 3-9 sowie äther- und chloroformresistent (CARTWRIGHT und HUCK 1967, MAYR et al. 1968, JOHNSON und COLLINGS 1969, BACHMANN 1970, MORIMOTO 1972). Einmal im Bestand bleibt es somit über Monate infektiös. Es stehen für die Bekämpfung nur wenige Mittel zur Verfügung. Eine entscheidende Möglichkeit ist die Einhaltung eines strikten Impfregimes, wobei Impfstoffe zum Einsatz kommen, die seit etwa 3 Jahrzehnten auf den gleichen inaktivierten Virus-Isolaten beruhen. In den letzten zehn Jahren wurden zunehmend neue Isolate entdeckt, die sich, wie das hochvirulente Isolat Kresse und das wenig virulente Isolat NADL2, nur in wenigen Aminosäuren unterscheiden. Zum Teil weisen sie aber gravierende Unterschiede in ihrer Pathogenität auf. Daraus ergeben sich neben dem dringenden Rat zur Beobachtung der aktuellen Entwicklung mehrere Fragen hinsichtlich der zukünftigen Handhabung des Virus (SOARES et al. 2003, ZIMMERMANN et al. 2006). So sollte geklärt werden: • wie verbreitet sind diese neuen Isolate • was könnte ihre Entwicklung begünstigt haben • wie effizient ist der Schutz, den herkömmliche Impfstoffe gegen die neuen Isolate bieten • kann eines der Isolate eine Grundlage für einen neuen, effizienteren Impfstoff liefernDiese Dissertation umfasst insgesamt drei Veröffentlichungen, welche versuchen, die gestellten Fragen zu beantworten. Im ersten Artikel wird die Wirksamkeit eines neuen Impfstoffes auf Grundlage des hochvirulenten, vorherrschenden Isolat 27a untersucht. Im zweiten Manuskript wird mit Hilfe von in vitro- und in silico- Modellen die Populationsdynamik demonstriert. Die dritte Veröffentlichung widmet sich der Beschreibung der neuen Parvotypen (PPV2, PPV3 und PPV4), welche aus Herzen und Tonsillen von deutschen, klinisch gesunden Schlachtschweinen isoliert werden konnten.

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.

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.

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.

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.

Das porzine Parvovirus (PPV), 2013 vom International Committee on taxonomy of Viruses (ICTV) in ungulate Protoparvovirus 1 umbenannt, ist ein unbehülltes, einzelsträngiges DNA Virus und gehört innerhalb der Familie Parvoviridae zur Subfamilie Parvovirinae. Es ist weltweit in allen Bereichen der Schweinehaltung endemisch und verursacht große wirtschaftliche Verluste in den Betrieben (TRUYEN und STRECK 2012). Anders als die verwandten caninen und felinen Parvoviren (seit 2013 arnivore Protoparvovirus 1) ist es nicht durch zum Teil tödlich verlaufende Durchfallerkrankungen, sondern durch Fruchtbarkeitsstörungen wie Abort, Mumifikation und Unfruchtbarkeit, auch bekannt als SMEDI – Syndrom (Stillbirth = Totgeburt, Mummification =Mumifikation, Embryonic Death = embryonaler Tod und Infertility = Unfruchtbarkeit), gekennzeichnet. Die Schwere des Verlaufs hängt dabei wesentlich vom Zeitpunkt sowie von dem, für die Infektion verantwortlichen Isolats ab. Als besonders gefährdet gelten ungeimpfte Jungsauen, die innerhalb der ersten 70 Tage der Trächtigkeit in Kontakt mit dem Virus treten. Das Virus verfügt über eine ausgesprochen hohe Tenazität gegenüber äußeren Einflüssen. Es ist hitzestabil, unempfindlich gegenüber pH-Werten zwischen 3-9 sowie äther- und chloroformresistent (CARTWRIGHT und HUCK 1967, MAYR et al. 1968, JOHNSON und COLLINGS 1969, BACHMANN 1970, MORIMOTO 1972). Einmal im Bestand bleibt es somit über Monate infektiös. Es stehen für die Bekämpfung nur wenige Mittel zur Verfügung. Eine entscheidende Möglichkeit ist die Einhaltung eines strikten Impfregimes, wobei Impfstoffe zum Einsatz kommen, die seit etwa 3 Jahrzehnten auf den gleichen inaktivierten Virus-Isolaten beruhen. In den letzten zehn Jahren wurden zunehmend neue Isolate entdeckt, die sich, wie das hochvirulente Isolat Kresse und das wenig virulente Isolat NADL2, nur in wenigen Aminosäuren unterscheiden. Zum Teil weisen sie aber gravierende Unterschiede in ihrer Pathogenität auf. Daraus ergeben sich neben dem dringenden Rat zur Beobachtung der aktuellen Entwicklung mehrere Fragen hinsichtlich der zukünftigen Handhabung des Virus (SOARES et al. 2003, ZIMMERMANN et al. 2006). So sollte geklärt werden: • wie verbreitet sind diese neuen Isolate • was könnte ihre Entwicklung begünstigt haben • wie effizient ist der Schutz, den herkömmliche Impfstoffe gegen die neuen Isolate bieten • kann eines der Isolate eine Grundlage für einen neuen, effizienteren Impfstoff liefernDiese Dissertation umfasst insgesamt drei Veröffentlichungen, welche versuchen, die gestellten Fragen zu beantworten. Im ersten Artikel wird die Wirksamkeit eines neuen Impfstoffes auf Grundlage des hochvirulenten, vorherrschenden Isolat 27a untersucht. Im zweiten Manuskript wird mit Hilfe von in vitro- und in silico- Modellen die Populationsdynamik demonstriert. Die dritte Veröffentlichung widmet sich der Beschreibung der neuen Parvotypen (PPV2, PPV3 und PPV4), welche aus Herzen und Tonsillen von deutschen, klinisch gesunden Schlachtschweinen isoliert werden konnten.

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.

Made available in DSpace on 2016-12-08T16:24:06Z (GMT). No. of bitstreams: 1 PGCA10MA046.pdf: 2836538 bytes, checksum: df03fbb548e05bbfeb41e5f0f1ba5a4f (MD5) Previous issue date: 2010-05-13 / Porcine parvovirosis is a disease that causes reproductive failure and its causative agent is the Porcine Parvovirus Type 1 (PPV1). This disease, with high prevalence and worldwide distribution, affects mostly non-immune nulliparous sows. Clinically, it is observed return to estrus, delayed parturition date, birth of unviable piglets, weak, stillborn and particularly mummified fetuses in different sizes. These reproductive problems lead economic losses demonstrated by low productivity. This study aimed to implement and validate techniques for laboratory diagnosis PPV1 in natural infections in pig herds with reproductive problems and perform the characterization of these isolates. More specifically, it aimed to diagnose through nested-PCR, and characterize, through phylogenetic analysis, PPV1 isolates from tissue samples and stomach fluid from fetuses and reproductive tract from culled sows. The objectives were to further evaluate histologically the tissues that were positive by nested-PCR; to standardize an internal amplification control (IAC) for PVS1 nested-PCR; to standardize immunohistochemistry technique (IHC) in fetal tissues and to standardize PCR for Porcine Parvovirus Type 4 (PPV4). A total of 27 pig herds were studied, where 230 fetuses stillborn, mummified, aborted and unviable piglets were necropsied to harvest organs and stomach fluid. PPPV1 viral DNA was detected by nested-PCR in organs of six (2.61%) out of 230 fetuses analyzed, the cerebellum and spinal cord were the organs where the virus was detected more frequently (50%). Stomach fluids of three (2.75%) fetuses were positive by nested-PCR, out of 109 examined. In addition, samples of reproductive organs from 83 culled sows were collected also ovarian follicular fluid from 71 of them. The genetic material of PPV1 was diagnosed in six organs from sows (7.23%) and follicular fluid of three (4.22%) of them. Histological lesions were observed in four of 19 PPV1 positive organs of fetuses. Also, six ovaries and six uteri of six culled sows were PPV1 positive by nested-PCR. Exams showed that five of those ovaries were cycling, one was in anestrous and four uterus had some degree of endometritis. The IAC developed for nested-PCR was amplified in all reactions, as expected. In the IHC test the virus presence was confirmed in fetal tissue. The PCR for PPV4 was standardized and tested in fetal organs and reproductive organs from culled sows. Some samples from sow s reproductive organs were positive for this new porcine parvovirus. The results from this study show a low detection of PPV1 in herds analyzed, as well as from the reproductive organs of culled sows, considering the reduced PPV1 involvement in reproductive failure. Moreover, standardized techniques can be incorporated into routine diagnostic of PPV1 and PPV4 / A parvovirose suína é uma doença causadora de falhas reprodutivas e seu agente etiológico é o Parvovírus Suíno Tipo 1 (PVS1). Essa enfermidade, de alta prevalência e distribuição mundial, afeta principalmente porcas nulíparas não imunes. Clinicamente observa-se retorno ao cio, atraso na data de parição, nascimento de leitões inviáveis, fracos, natimortos e, principalmente, mumificados em diferentes tamanhos. Estes problemas reprodutivos acarretam prejuízos econômicos demonstrados pelos baixos índices produtivos. O presente trabalho objetivou implantar e validar técnicas de diagnóstico laboratorial para detecção de PVS1 em infecções naturais em rebanhos suínos que apresentam problemas reprodutivos e realizar caracterização desses isolados. Mais especificamente, objetivou-se diagnosticar, através de nested-PCR, e caracterizar, através de análise filogenética, isolados de PVS1 em amostras de tecidos e líquido estomacal de fetos e em aparelho reprodutivo de porcas descartadas. Objetivou-se ainda avaliar histologicamente os tecidos que resultaram positivos na nested-PCR; padronizar um controle interno de amplificação (CIA) para a nested-PCR de PVS1; padronizar técnica de imunohistoquímica (IHQ) em tecidos fetais e padronizar PCR para Parvovírus Suíno Tipo 4 (PVS4). De 27 rebanhos de suínos, foram colhidos 230 fetos entre natimortos, mumificados e abortados, os quais foram necropsiados para colheita de órgãos e líquido estomacal. O DNA viral foi detectado por nested-PCR em órgãos de seis (2,61%) fetos dos 230 analisados, sendo o cerebelo e a medula os órgãos onde o vírus foi detectado com maior frequência (50%). Líquido estomacal de três (2,75%) fetos foram positivos por nested-PCR, de 109 analisados. Além disso, amostras de órgãos reprodutivos de 83 porcas descartadas foram colhidas e também fluido folicular ovariano de 71 delas. O material genético do PVS1 foi diagnosticado em órgãos de seis porcas (7,23%) e em fluido folicular de três (4,22%) delas. De 19 órgãos positivos de fetos na nested-PCR, quatro tiveram lesão histológica. De seis ovários e seis úteros das seis fêmeas suínas descartadas positivas na nested-PCR, cinco ovários estavam ciclando, um estava em anestro e quatro úteros tinham algum grau de endometrite. O CIA desenvolvido para a nested-PCR foi amplificado em todas as reações, conforme o esperado. Nos testes de IHQ a presença do vírus foi confirmada em tecido fetal. A PCR para o PVS4 foi padronizada e testada em órgãos fetais e de porcas descartadas. Algumas amostras de porcas foram positivas para este novo parvovírus suíno. Os resultados obtidos no estudo evidenciam baixa freqüência do PVS1 nos rebanhos analisados, bem como nos órgãos reprodutivos de porcas descartadas, considerando baixo o envolvimento do PVS1 nas falhas reprodutivas. Além disso, as técnicas padronizadas podem ser incorporadas na rotina de diagnóstico de PVS1 e PVS4

Im Zuge der Überarbeitung der DVG-Richtlinie zur Prüfung der Viruzidie chemischer Desinfektionsmittel in der Nutztierhaltung wurden BVDV, EAV und PPV auf ihre Eignung als potentielle Prüfviren getestet. Das bisher vorgeschriebene Newcastle-Disease-Virus und das Vacciniavirus sollen mit anderen behüllten Viren wie BVDV oder EAV verglichen werden. Beweggründe für einen möglichen Austausch sind die derzeitige Situation in der Tierseuchenbekämpfung, die Erhöhung der Anwendersicherheit durch Wegfall des zoonotischen Potentials, die einfachere Kultivierung und Handhabung der Prüfviren sowie speziell bei NDV die höhere Aussagekraft der gewonnenen Ergebnisse. Die Desinfektionsmittelversuche wurden gemäß DVG-Richtlinie auf Pappelholzkeimträgern durchgeführt, wobei das jeweilige, mit fetalem Kälberserum vermischte, Virus auf die Keimträger aufgetragen und angetrocknet wurde. Die DVG schreibt eine Trocknung im Brutschrank von 60 Minuten bei 37°C vor. Um die Trocknungsverluste der eingesetzten Viren zu untersuchen, wurden vergleichende Trocknungsversuche wie vorgeschrieben im Brutschrank und im Exsikkator bei Raumtemperatur durchgeführt. Die nach der Trocknung im Brutschrank durchgeführten Desinfektionsmittelversuche wurden mit chemischen Grundsubstanzen kommerziell erhältlicher Desinfektionsmittel durchgeführt. Dabei kamen verschiedene Anwendungskonzentrationen von Ameisensäure, Glutaraldehyd, Natriumhypochlorit, Natronlauge und Peressigsäure zum Einsatz. Bei der vorgeschriebenen Trocknung im Brutschrank kam es zu Titerverlusten von 0,8 bis zu 2,75 log10KID50/ml. Durch eine Trocknung der Holzkeimträger von 30 Minuten bei Raumtemperatur im Exsikkator konnten die Titerverluste auf 0,3 bis 1,0 log10KID50/ml reduziert werden. In den nachfolgenden Desinfektionsversuchen zeigte sich die besonders hohe Tenazität von PPV. Es war den eingesetzten Desinfektionsmitteln gegenüber deutlich resistenter als alle anderen untersuchten Viren. In den Trocknungsversuchen zeigte PPV mit Abstand die niedrigsten Titerverluste. Mit BVDV und EAV konnten zwar ausreichend hohe Titer erzielt werden, allerdings waren die Trocknungsverluste beider Viren sehr hoch. In den Keimträgerversuchen konnte nur in wenigen Versuchen eine Titerreduktion von mehr als 3 Logarithmusstufen erreicht werden. Hier könnte zukünftig die Trocknung im Exsikkator Abhilfe schaffen, um die Trocknungsverluste zu minimieren und eine höhere Titerreduktion zu ermöglichen. Die Ergebnisse einer früheren Arbeit zeigen identische Ergebnisse von NDV und BVDV im Keimträgertest. Ein Ersatz von NDV durch BVDV ist somit zu empfehlen. Eine Verwendung der untersuchten Viren gemäß den derzeitigen DVG-Richtlinien ist möglich, allerdings müssten im Zuge der weiteren Harmonisierung von CEN- und DVG-Richtlinie die Kontrolltiter entsprechend erhöht werden, um die von der CEN geforderte Titerreduktion von vier Logarithmusstufen für eine vollständige Virusinaktivierung einzuhalten. Die Vermehrung der untersuchten Viren zu höheren Ausgangs-, bzw. Kontrolltitern sollte daher Gegenstand weiterer Forschungsarbeit sein. Einer weiteren Verwendung der bisherigen Prüfviren BEV und REOV steht nichts im Wege. Aufgrund der Ergebnisse der vergleichenden Trocknungsversuche wird für alle untersuchten Viren zukünftig eine 30 minütige Trocknung im Exsikkator empfohlen.

Im Zuge der Überarbeitung der DVG-Richtlinie zur Prüfung der Viruzidie chemischer Desinfektionsmittel in der Nutztierhaltung wurden BVDV, EAV und PPV auf ihre Eignung als potentielle Prüfviren getestet. Das bisher vorgeschriebene Newcastle-Disease-Virus und das Vacciniavirus sollen mit anderen behüllten Viren wie BVDV oder EAV verglichen werden. Beweggründe für einen möglichen Austausch sind die derzeitige Situation in der Tierseuchenbekämpfung, die Erhöhung der Anwendersicherheit durch Wegfall des zoonotischen Potentials, die einfachere Kultivierung und Handhabung der Prüfviren sowie speziell bei NDV die höhere Aussagekraft der gewonnenen Ergebnisse. Die Desinfektionsmittelversuche wurden gemäß DVG-Richtlinie auf Pappelholzkeimträgern durchgeführt, wobei das jeweilige, mit fetalem Kälberserum vermischte, Virus auf die Keimträger aufgetragen und angetrocknet wurde. Die DVG schreibt eine Trocknung im Brutschrank von 60 Minuten bei 37°C vor. Um die Trocknungsverluste der eingesetzten Viren zu untersuchen, wurden vergleichende Trocknungsversuche wie vorgeschrieben im Brutschrank und im Exsikkator bei Raumtemperatur durchgeführt. Die nach der Trocknung im Brutschrank durchgeführten Desinfektionsmittelversuche wurden mit chemischen Grundsubstanzen kommerziell erhältlicher Desinfektionsmittel durchgeführt. Dabei kamen verschiedene Anwendungskonzentrationen von Ameisensäure, Glutaraldehyd, Natriumhypochlorit, Natronlauge und Peressigsäure zum Einsatz. Bei der vorgeschriebenen Trocknung im Brutschrank kam es zu Titerverlusten von 0,8 bis zu 2,75 log10KID50/ml. Durch eine Trocknung der Holzkeimträger von 30 Minuten bei Raumtemperatur im Exsikkator konnten die Titerverluste auf 0,3 bis 1,0 log10KID50/ml reduziert werden. In den nachfolgenden Desinfektionsversuchen zeigte sich die besonders hohe Tenazität von PPV. Es war den eingesetzten Desinfektionsmitteln gegenüber deutlich resistenter als alle anderen untersuchten Viren. In den Trocknungsversuchen zeigte PPV mit Abstand die niedrigsten Titerverluste. Mit BVDV und EAV konnten zwar ausreichend hohe Titer erzielt werden, allerdings waren die Trocknungsverluste beider Viren sehr hoch. In den Keimträgerversuchen konnte nur in wenigen Versuchen eine Titerreduktion von mehr als 3 Logarithmusstufen erreicht werden. Hier könnte zukünftig die Trocknung im Exsikkator Abhilfe schaffen, um die Trocknungsverluste zu minimieren und eine höhere Titerreduktion zu ermöglichen. Die Ergebnisse einer früheren Arbeit zeigen identische Ergebnisse von NDV und BVDV im Keimträgertest. Ein Ersatz von NDV durch BVDV ist somit zu empfehlen. Eine Verwendung der untersuchten Viren gemäß den derzeitigen DVG-Richtlinien ist möglich, allerdings müssten im Zuge der weiteren Harmonisierung von CEN- und DVG-Richtlinie die Kontrolltiter entsprechend erhöht werden, um die von der CEN geforderte Titerreduktion von vier Logarithmusstufen für eine vollständige Virusinaktivierung einzuhalten. Die Vermehrung der untersuchten Viren zu höheren Ausgangs-, bzw. Kontrolltitern sollte daher Gegenstand weiterer Forschungsarbeit sein. Einer weiteren Verwendung der bisherigen Prüfviren BEV und REOV steht nichts im Wege. Aufgrund der Ergebnisse der vergleichenden Trocknungsversuche wird für alle untersuchten Viren zukünftig eine 30 minütige Trocknung im Exsikkator empfohlen.