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au, warren raye@vcp monash edu, and Warren Raye. "An investigation into the status of porcine circovirus in Australia." Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050705.135219.
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This thesis reports for the first time the detection of porcine circovirus virus (PCV) in the Australian pig herd.
PCV DNA was detected in the tissues of pigs from several Australian states using a multiplex polymerase chain reaction (PCR) assay, the primers for which were based on the sequence of PCV1 and PCV2 strains detected in North America and Europe. PCV type 1 or 2 was detected in 80 of 367 (21.7%) pigs tested. In the 80 positives, both PCV1 and PCV2 were detected in 14 samples. Virus was detected in pigs from all states from which samples were obtained: Western Australia, South Australia, New South Wales and Queensland.
The complete genomes of 13 strains of Australian PCV were sequenced. Analysis of the data indicated there was extremely high homology between the Australian strains of PCV1 and PCV2 and previously published sequences of PCV1 and PCV2 strains from North America and Europe.There were no consistent differences between the genome of the Australian strains and strains in North America and Europe.
The widespread occurrence of PCV in the tissues of pigs was confirmed by a small scale serological study of the Western Australian pig herd using an immunofluorescence assay, which did not discriminate antibody to PCV1 and PCV2. This assay detected PCV antibody in 11 of 14 pig herds in Western Australia, with a prevalence rate in positive herds varying from 25 to 47%, but it was unable to differentiate antibody to PCV1 and PCV2.
A PCV2-specific recombinant viral capsid protein was produced in insect cells with a baculovirus expression system and this was used to develop a PCV2-specific ELISA and a Western immunoblotting assay. These assays were applied to samples from a national pig serum bank and detected PCV2 antibody in 33% of 3933 serum samples. The highest seroprevalence to the recombinant PCV2 capsid antigen was detected in the samples from Victoria where there was a 51.3% seroprevalence rate, and the lowest in Western Australia where there was an 11.4% seroprevalence rate.
An in situ hybridisation (ISH) technique was developed for the detection of PCV in tissues of infected pigs and infected cell cultures. A monoclonal antibody specific for the capsid protein of PCV2 was also produced and has application for the development of immunocytochemical procedures for the detection of PCV2 in tissues and cell cultures.
The high prevalence of PCV in the Australian pig herd and the absence of reports of PMWS suggested that the Australian strains of PMWS detected may have been of low virulence. To examine the pathogenicity of Australian strains, two animal experiments were conducted where the type species of PCV1 present in persistently-infected PK15 pig kidney cells and an Australian PCV2 strain were cultured in vitro in cell cultures and inoculated into weaner pigs. As expected, the PCV1 replicated well in pigs but did not result in the induction of clinical signs or lesions in the inoculated pigs. The inoculation into weaner pigs of cell culture replicated PCV2 with an apparent virus titre of 103 virus particles/mL resulted in infection of only some of the inoculated pigs and it was concluded that the PCV2 inoculum contained insufficient virus to infect all pigs into which it was inoculated. The PCV2 did not induce any disease syndrome and could not be visualised in tissue sections of infected pigs using immunohistochemical techniques.
In conclusion, techniques were developed for the detection of PCV in the Australian pig herd. PCV of both genetic types were detected at prevalence rates similar to those reported in other countries where PMWS has occurred, and the widespread occurrence of PCV was confirmed by serological assays. The PCV strains present were genetically indistinguishable from those present in North America and Europe. The reason for the absence of PMWS in Australia is most likely not due to differences in the characteristics of the PCV strains present.
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Szikora, Florian. "Studie zum Vorkommen der Genotypen PCV2a und PCV2b des Porcinen Circovirus Typ 2 in schweinehaltenden Betrieben mit unterschiedlichen PCV2-Impfregimen." Diss., Ludwig-Maximilians-Universität München, 2015. http://nbn-resolving.de/urn:nbn:de:bvb:19-179461.
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Oliver, Ferrando Salvador. "Effect of Porcine circovirus 2 (PCV2) sow or piglet vaccination in different PCV2 subclinical infection scenarios." Doctoral thesis, Universitat Autònoma de Barcelona, 2017. http://hdl.handle.net/10803/461187.
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La present Tesi doctoral esta formada per tres estudis. El primer estudi va avaluar l'efecte de la vacunació de truges enfront a PCV2 sobre els paràmetres reproductius durant dos cicles gestacionals consecutius. Es van immunitzar 94 truges gestants amb una vacuna comercial enfront a PCV2, i 97 van ser injectades amb una solució salina tamponada amb fosfat (PBS). En el primer cicle reproductiu el tractament va ser aplicat a les 6 i 3 setmanes abans del part, i en el segon cicle es va aplicar una dosi de record o PBS a les 2 setmanes abans del part. Les truges vacunades van mostrar nivells d'anticossos significativament més elevats en comparació amb les no vacunades. L'ADN de PCV2 només es va detectar al part en 2 (4,2%) truges no vacunades. Les truges vacunades van tenir 1,3 garrins nascuts vius més per camada en el segon cicle que les no vacunades. El present estudi va demostrar per primera vegada que la vacunació de truges enfront a PCV2 pot tenir una influència positiva sobre la prolificitat i la vitalitat de la seva descendència en una explotació de reproductores subclínicament infectades per PCV2. En el segon estudi, es va avaluar l'efecte de la vacunació de truges enfront a PCV2 sobre la resposta immune humoral i cel·lular en truges i la seva progènie. A les 7 setmanes abans del part, es van seleccionar 15 truges negatives a PCV2 per PCR i amb valors d'anticossos mitjans-baixos. Aquestes truges es van distribuir aleatòriament en dos grups de tractament segons els seus nivells d'anticossos. A les 6 i 3 setmanes abans del part, 7 truges van ser vacunades amb una vacuna comercial enfront a PCV2 i 8 van ser injectades amb PBS. Els garrins nascuts de truges vacunades tenien nivells significativament més alts de citoquines vinculades a les cèl·lules Th1 de memòria (IFN-γ i TNF-α) en comparació amb els provinents de les femelles no vacunades. En conclusió, la vacunació de truges enfront a PCV2, a més de desencadenar una resposta immune humoral en truges i la seva progènie, podria estar associada a una major transferència d'immunitat cel·lular de la mare al garrí. L'objectiu del tercer estudi va ser determinar la dinàmica serològica i virològica de la infecció per PCV2 en garrins vacunats a diferents edats en un escenari de PCV2-SI. Es van seleccionar 644 garrins sans de 2 setmanes d'edat que foren distribuïts aleatòriament en quatre grups de tractament: vacunació enfront a PCV2 a les 3, 6 o 10 setmanes d'edat (grups 3W-VAC, 6W-VAC i 10W-VAC, respectivament) i porcs no vacunats (grup NON-VAC). Específicament, amb la vacunació enfront a PCV2 a les 3 o 6 setmanes d'edat es van obtenir resultats similars, ja que les dues pautes van desencadenar una seroconversió eficient i van reduir, en diferents punts de mostreig, la proporció d'animals virèmics en comparació amb el grup no vacunat. Per altra banda, la vacunació enfront a PCV2 a les 10 setmanes d'edat només va aconseguir aquesta reducció a les 25 setmanes d'edat; en aquest cas, la vacunació va coincidir amb l'augment del percentatge de porcs virèmics. En conclusió, sota les condicions del present estudi, el temps òptim de vacunació dels garrins per controlar la infecció per PCV2 va ser a les 3 o 6 setmanes d'edat. A més, els OF van demostrar ser una matriu útil per a la avaluació de la dinàmica de seroconversió, en canvi, la detecció del ADN de PCV2 en OF no va mostrar ser un mètode efectiu per a la avaluació del control de la infecció durant els programes vacunals estudiats.The present PhD thesis consists of three studies. The first study sought to evaluate the effect of sow vaccination against PCV2 on reproductive parameters during two consecutive reproductive cycles. Ninety-four pregnant sows were primo-immunized with a commercial PCV2 vaccine and ninety-seven were injected with phosphate-buffered saline at 6 and 3 weeks before farrowing, and then boosted at 2 weeks before the second one. Vaccinated sows showed significantly higher antibody levels compared to the non-vaccinated counterparts. PCV2 DNA was only detected at farrowing in 2 (4.2%) non-vaccinated sows. Vaccinated sows had 1.3 more live-born piglets per litter at the second cycle than non-vaccinated counterparts. The present study represents the first attempt to demonstrate that PCV2 sow vaccination may have a positive influence on prolificacy and vitality of the offspring in a subclinically infected breeding herd. In the second study, the effect of PCV2 sow vaccination on humoral and cell-mediated immune responses in sows and their progeny was assessed. At 7 weeks before farrowing, fifteen PCV2 PCR negative pregnant sows with medium-low antibody values were selected and randomly distributed in two groups according to the antibody levels. Seven sows were vaccinated with a commercial PCV2 vaccine and eight were injected with phosphate-buffered saline at 6 and 3 weeks before farrowing. Piglets from vaccinated sows had significantly higher levels of cytokines linked to Th1 memory cells (IFN-γ and TNF-α) in comparison to the ones from non-vaccinated dams. In conclusion, PCV2 sow vaccination, apart from triggering a humoral immune response in sows and their progeny, might be associated to an increased transfer of cell-mediated immunity from the dam to the piglet. The purpose of the third study was to determine the PCV2 serological and virological infection dynamics in piglets vaccinated at different ages in a PCV2-SI scenario. Six hundred and forty-four 2 week-old healthy piglets were selected and distributed into four treatment groups: vaccination at 3, 6 or 10 weeks of age (3W-VAC, 6W-VAC and 10W-VAC groups, respectively) and unvaccinated pigs (NON-VAC group). Specifically, PCV2 vaccination at 3 or 6 weeks of age yielded similar results, since they produced an earlier seroconversion and reduced, at different sampling points, the proportion of viraemic animals in comparison to the unvaccinated group. In contrast, PCV2 vaccination at 10 weeks of age only achieved such reduction at 25 weeks of age; in this case, vaccination coincided with the increase of the percentage of viraemic pigs in the population. In conclusion, under the present study conditions, the optimal time for piglet vaccination to control PCV2 infection was at either 3 or 6 weeks of age. In addition, OF proved to be a useful matrix for the evaluation of seroconversion dynamics, however, PCV2 DNA detection in OF did not show to be an effective method for the infection control assessment during the studied vaccine programs.
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Ceia, Joana Filipa Simões. "Avaliação do efeito de dois protocolos vacinais para PCV2 em leitões." Master's thesis, Universidade Técnica de Lisboa. Faculdade de Medicina Veterinária, 2012. http://hdl.handle.net/10400.5/4856.
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Dissertação de Mestrado Integrado em Medicina VeterináriaAs vacinas comerciais contra o circovírus porcino tipo 2 (PCV2) reduzem significativamente as perdas associadas a este vírus e melhoram os parâmetros produtivos dos efectivos suínos. A maioria dos produtores vacina os leitões ao desmame mas, sendo este um momento crítico da produção, a alteração do momento de vacinação poderá ser uma estratégia a adoptar quando os indivíduos são expostos a múltiplos agentes perturbadores da homeostasia num curto período de tempo. Este estudo teve como objectivo a avaliação do momento mais adequado à vacinação de leitões contra o PCV2, considerando parâmetros zootécnicos e imunitários. Foram avaliados as reacções adversas à vacinação, a morbilidade, a mortalidade, o ganho médio diário (GMD) e o peso dos animais. Os 453 leitões de dois desmames consecutivos foram distribuídos por dois grupos de tratamento. Efectuou-se a administração intramuscular de uma dose de 2 ml de Porcilis® PCV e de uma dose de 2 ml de M+PAC® em leitões 5 dias antes do desmame (grupo A) ou 5 dias após o desmame (grupo B). O peso corporal individual dos animais foi registado no dia 0 do ensaio e 45 dias depois. Realizaram-se colheitas de sangue em leitões de cada grupo às 12, 16 e 22 semanas de idade para detecção e quantificação de anticorpos anti-PCV2 e anticorpos baculomarcadores, de modo a aferir sobre a qualidade da imunização com a vacina de subunidades contendo a proteína da cápside de PCV2a expressa num sistema de baculovírus (Porcilis® PCV). A vacinação induziu hipertermia e diminuição da actividade e da ingestão. O grupo A exibiu morbilidade 4 vezes superior à do grupo B (P<0,0001), mas a mortalidade não diferiu entre grupos (P=0,578). O peso final e o GMD diferiram significativamente entre os dois grupos (P=0,009), tendo-se observado um melhor desempenho produtivo dos leitões do grupo A. Os resultados de Bacucheck® ELISA e de Synbiotics Serelisa® indicaram que Porcilis® PCV foi correctamente utilizada, não existindo diferenças em termos imunitários entre grupos. Sendo o crescimento na primeira semana após o desmame um factor de risco para o subsequente desempenho na recria, especulou-se que o custo metabólico e a perturbação derivados da vacinação 5 dias após o desmame nos leitões do grupo B, exerceram efeitos a mais longo prazo, o que justificou o seu pior desempenho produtivo. Deste modo, o efeito negativo da vacinação no desempenho da recria não pode ser menosprezado, devendo ser considerado aquando da concepção de estratégias vacinais.
ABSTRACT - EVALUATION OF THE EFFECT OF TWO VACCINATION PROTOCOLS FOR PCV2 IN PIGLETS - Commercial porcine circovirus type 2 (PCV2) vaccines significantly reduce losses associated to this virus and improve productive performance in swine herds. Most producers vaccinate piglets at weaning but being this one of the most critical moments of production, altering vaccination timing may be a strategy to adopt when individuals are exposed to multiple disturbing factors in a short period of time. The aim of this study was to evaluate the most adequate moment for piglet’s vaccination against PCV2 considering productive performance and immune parameters. Adverse reactions to vaccination, morbidity, mortality, average daily gain (ADG) and weight were assessed. 453 piglets of two consecutive weanings were distributed between two treatment groups. An intramuscular injection of a 2 ml dose of Porcilis® PCV and a 2 ml dose of M+PAC® was performed in piglets 5 days before weaning (group A) or 5 days after weaning (group B). Individual body weights of all animals were measured the day 0 of trial and 45 days later. Blood samples were taken from piglets of both groups at 12, 16 and 22 weeks of age for detection and quantification of anti-PCV2 antibodies and baculomarkers to evaluate vaccination quality with the subunit vaccine based on the PCV2a capsid protein expressed in baculovirus system (Porcilis® PCV). Vaccination induced hyperthermia, prostration and anorexia. Group A exhibited 4 times more morbidity than group B (P<0.0001) but mortality did not differ between groups (P=0.578). Final weight and ADG differed significantly between groups (P=0.009) with group A piglets having an increased performance. Bacucheck® ELISA and Synbiotics Serelisa® results indicated that Porcilis® PCV had been used correctly with no immune differences between groups. Being growth performance in the first week after weaning a risk factor for subsequent nursery performance, it is speculated that disturbance and metabolic cost of vaccination 5 days after weaning in group B piglets may have had greater potential for longer term effects, which explained their worst growth performance. Thus, negative effects of vaccination on nursery growth performance should not be underestimated when conceiving vaccine strategies.
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Szikora, Florian [Verfasser], and Mathias [Akademischer Betreuer] Ritzmann. "Studie zum Vorkommen der Genotypen PCV2a und PCV2b des Porcinen Circovirus Typ 2 in schweinehaltenden Betrieben mit unterschiedlichen PCV2-Impfregimen / Florian Szikora. Betreuer: Mathias Ritzmann." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2015. http://d-nb.info/1068767111/34.
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Fusaro, Laura <1981>. "Patologie da Porcine Circovirus tipo 2 (PCV2) nel suino." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3640/1/fusaro_laura_tesi.pdf.
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The main work involved the PMWS (Post-weaning multisystemic Wasting Syndrome), caused by PCV-2 (Porcine Circovirus type 2) that involved post-weaned pigs. Merial Italy has funded a study activity in which groups of 3-5 animals were sampled for lungs, tracheo-bronchial and superficial inguinal lymph nodes, ileum and tonsils. The protocol applied can be identified as a more diagnostic potential on the individual than on the group.
PNP. Another investigation has been conducted to study proliferative and necrotizing pneumonia (PNP), a form of interstitial pneumonia in weaning and post-weaning pigs characterized by hypertrophy and hyperplasia of type II pneumocytes, coagulative necrosis and granular debris within alveolar spaces. Many studies suggest porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) as the main causes of the disease, but Aujeszky disease virus (ADV) and swine influenza virus (SIV) are also considered. An immunohistochemical study was carried out to evaluate the role of these viruses in PNP lesions in Italy. PNP results primarily associated with PRRSV, even if co-infection is characterized by more severe histological features.
Reproductive pathology. A major risk factor for PCV2 infection is a viraemic episode taking place in pregnant sows with low antibody titer which is transmitted by specific PCV2 products of conception. PCV2 can infect the fetus even by vehicles through infected semen or ova, or as a result of infection of the genital tract. An investigation was carried out to identify the presence and localization of PCV2 in the genital tracts of sows experimentally infected with PCV2 and in their fetuses. The results obtained suggest that: conventional sows can be infected by intrauterine exposition; low antibody titres increase the probability of infection; PCV2 infection close to insemination time reduces the pregnancy rate; placental lesions may represent an additional cause of fetal suffering.
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Fusaro, Laura <1981>. "Patologie da Porcine Circovirus tipo 2 (PCV2) nel suino." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3640/.
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The main work involved the PMWS (Post-weaning multisystemic Wasting Syndrome), caused by PCV-2 (Porcine Circovirus type 2) that involved post-weaned pigs. Merial Italy has funded a study activity in which groups of 3-5 animals were sampled for lungs, tracheo-bronchial and superficial inguinal lymph nodes, ileum and tonsils. The protocol applied can be identified as a more diagnostic potential on the individual than on the group.
PNP. Another investigation has been conducted to study proliferative and necrotizing pneumonia (PNP), a form of interstitial pneumonia in weaning and post-weaning pigs characterized by hypertrophy and hyperplasia of type II pneumocytes, coagulative necrosis and granular debris within alveolar spaces. Many studies suggest porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) as the main causes of the disease, but Aujeszky disease virus (ADV) and swine influenza virus (SIV) are also considered. An immunohistochemical study was carried out to evaluate the role of these viruses in PNP lesions in Italy. PNP results primarily associated with PRRSV, even if co-infection is characterized by more severe histological features.
Reproductive pathology. A major risk factor for PCV2 infection is a viraemic episode taking place in pregnant sows with low antibody titer which is transmitted by specific PCV2 products of conception. PCV2 can infect the fetus even by vehicles through infected semen or ova, or as a result of infection of the genital tract. An investigation was carried out to identify the presence and localization of PCV2 in the genital tracts of sows experimentally infected with PCV2 and in their fetuses. The results obtained suggest that: conventional sows can be infected by intrauterine exposition; low antibody titres increase the probability of infection; PCV2 infection close to insemination time reduces the pregnancy rate; placental lesions may represent an additional cause of fetal suffering.
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Ferrari, Karen Linares. "Diversidade molecular do gene Cap (ORF-2) do circovírus suíno 2 (PCV2) detectado em amostras de pulmão com e sem lesões pneumônicas macroscópicas em suínos abatidos no Estado de São Paulo." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10134/tde-12082013-121700/.
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Circovirus suíno 2 (PCV2) associado a doenças (PCVAD do inglês Porcine circovirus associated disease) pode se manifestar como infecção sistêmica, enterite, problemas reprodutivos, síndrome de dermatite e nefropatia suína e complexo de doenças respiratórias (PRDC). A ocorrência de PRDC, que afeta, principalmente, animais de crescimento e terminação, caracteriza-se por crescimento lento, tosse prolongada e dispnéia, assim como lesões macroscópicas características em pulmão. PCV2 possui três principais regiões abertas de leitura (ORFs): ORF-1 codifica proteínas envolvidas na replicação (gene Rep); ORF-2 codifica proteína estrutural do capsídeo (gene Cap) e ORF-3 codifica proteína envolvida na indução de apoptose celular. O gene Cap é a região mais variável do PCV2, havendo indícios da associação entre a proteína Cap e patogenicidade. De acordo com a nomenclatura unificada proposta por Segalés et al., três diferentes genótipos são atualmente reconhecidos (PCV2a, - 2b, -2c). O aumento na incidência e gravidade da PCVAD foi atribuído ao surgimento do PCV2b tornando-se o mais prevalente subtipo em países da América do Norte, Europa, e no Brasil. Diante dos prejuízos que a PRDC acarreta, 200 amostras de pulmão com e sem lesões pneumônicas macroscópicas foram analisadas para PCV2 pela PCR; 88,5 % (177/200) foram positivas para PCV2 por PCR corroborando com estudos em que o PCV2 foi encontrado em um grande numero de amostras e poderia desenvolver um papel da PRDC. Entretanto, não houve associação significativa entre amostras positivas e presença ou ausência de lesões pneumônicas macroscópicas (p=0,26). A análise filogenética de 27 amostras PCV2 positivas sequênciadas (22 genoma completo e cinco ORF-2 completa) foram agrupadas no genótipo PCV2b. Devido à alta identidade de nucleotídeos e aminoácidos entre as sequencias obtidas e as recuperadas de estudos anteriores com presença e ausência de PCVAD, não há indícios de associação entre patogenicidade e o subtipo de PCV2 identificado neste trabalhoPorcine circovirus 2 (PCV2) associated disease (PCVAD) may manifest as systemic infection, enteritis, reproductive problems, dermatitis and nephropathy syndrome and porcine respiratory disease complex (PRDC). The occurrence of PRDC, which affects mainly the growing and finishing animals, characterized by slow growth, prolonged cough and dyspnea, as well as characteristic gross lesions in the lungs. PCV2 has three main regions denominated open reading frames (ORFs): ORF-1 encodes a protein involved in replication (Rep gene), ORF-2 encodes the capsid structural protein (Cap gene) and ORF-3 encodes a protein involved in the induction of cellular apoptosis. The Cap gene is the most variable region of PCV2, with evidence of association between the Cap protein and pathogenicity. According to an unified nomenclature proposed by Ségales et al., three different subtypes are currently recognized (PCV2a,-2b-2c). The increased incidence and severity of PCVAD was attributed to the rise of PCV2b becoming the most prevalent subtype in countries of North America, Europe, and Brazil. Given the damage that leads to PRDC, 200 samples of lungs with and without macroscopic pneumonic lesions were analyzed for PCV2 by PCR; 88.5% (177/200) were positive for PCV2 by PCR corroborating with studies in which PCV2 was found in a large number of samples and could develop a role in PRDC. However, there was no significant association between positive samples and the presence or absence of macroscopic pneumonic lesions (p=0.26). Phylogenetic analysis of the 27 samples PCV2 positive sequenced (22 complete genome and five complete ORF-2) were grouped in genotype PCV2b. Due to the high identity between the nucleotide and amino acid sequences obtained and retrieved from previous studies with presence and absence of PCVAD, there is no evidence of association between subtype and pathogenicity of PCV2 identified in this work
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Baldin, Cintia Manzatto. "Avaliação da transmissão horizontal e descrição da patogenia em leitões experimentalmente infectados com Circovírus suíno 2." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10134/tde-24032014-104754/.
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Circovírus suíno 2 (PCV2) é responsável pelas doenças associadas ao circovírus suíno (PCVAD do inglês Porcine circovirus associated disease) que engloba várias condições clínicas. Acomete suínos nas principais áreas produtoras do mundo causando grandes prejuízos. A situação acerca do conhecimento acerca da complexa patogenia e os múltiplos fatores de risco permitem compreender apenas em parte o verdadeiro impacto das PCVADs em suínos, sendo este um conhecimento mais amplo e dependente de resultados obtidos com infecções experimentais. Os objetivos do presente trabalho foram: i) verificar a infectividade do isolado brasileiro de PCV2 em animais infectados experimentalmente; ii) verificar a transmissão horizontal do isolado brasileiro de PCV2 em animais infectados experimentalmente; iii) avaliar a patologia do isolado brasileiro nos animais infectados experimentalmente; e iv) avaliar a resposta imune humoral nos animais infectados experimentalmente com o isolado brasileiro. Foram utilizados nove leitões divididos em três grupos com três animais cada: i) G1 animais inoculados por via intra-nasal, com aproximadamente 49 dias de idade; ii) G2 animais não inoculados mantidos na mesma baia que os G1; e iii) GC animais controle. Amostras de soro, suabes (nasal e fecal) e dados de desempenho foram coletados semanalmente. Amostras de tecidos foram coletadas durante a necropsia, aos 42 dias após a inoculação (dpi). Os animais do GC foram acompanhados até 140 dias de idade. A infecção pelo PCV2 foi avaliada através da descrição das manifestações clínicas, alterações anatômicas e histológicas, quantificação do DNA de PCV2 nas amostras de soro, suabes e tecidos e detecção de anticorpo anti-PCV2 no soro. As técnicas utilizadas foram coloração de tecido pela Hematoxilina-Eosina (HE), reação em cadeia pela polimerase quantitativa (PCRq), imunohistoquímica (IHQ) e ELISA ( do inglês enzyme-linked imunossorbente assay). Os resultados demonstraram que o isolado brasileiro induziu infecção subclínica nos animais inoculados (G1), demonstrado através da detecção de baixa carga de DNA viral nos tecido e soros, ausência de sinais clínicos e achados histopatológicos característicos de PCVAD, além da ausência de soroconversão nos três animais inoculados. A transmissão horizontal foi demonstrada, pois em um animal contactante (G2) foi recuperado o DNA de PCV2 em vários tecidos. No entanto, a ausência de soroconversão, não permitiu avaliar a resposta imune humoral nos diferentes grupos (G1 e G2). Fatores como idade dos animais no momento da inoculação (49 dias), via de inoculação, inóculo e ausência de co-agentes podem ter contribuído para o desencadeamento dos resultados observados.Porcine circovirus 2 (PCV2) is responsible for the porcine circovirus associated diseases (PCVAD) that encompasses several clinical conditions. It affects the main pig producing areas of the world, causing extensive damage. Currently, knowledge about the complex pathogenesis associated with the multiple risk factors provides insight into the true impact of PCVADs, depending on the extensive knowledge based on the experimental infections. The aims of this study were: i) verify the infectivity of the brazilian PCV2 in experimentally infected animals; ii) verify the horizontal transmission of the Brazilian PCV2 in experimentally infected animals; iii) evaluete the patology of Brasilian PCV2 in experimentally infected animals; iv) evaluete the humoral immune response in experimentally infected animals with the Brazilian isolate. Nine piglets were divided into three groups with three animal each: i) G1 inoculated animals by intranasally route, with approximately 49 days of age; ii) G2 non-inoculated animals maintained in the same pen that G1 and iii) GC control animals. Serum samples, swabs (nasal and fecal) and performance data were collected weekly. Tissue samples were collected during necropsy at 42 days post inoculation (dpi). Animals from GC were monitored up to 140 days of age. PCV2 infection was evaluated by clinical, anatomical and histological alteration, quantification of PCV2 DNA in serum samples, swabs and tissues and detection of PCV2 antibodies in serum. The techniques of tissue hematoxylin-eosin staining, polymerase chain reaction quantitative (PCRq), immunohistochemistry (IHC) and ELISA were used. The results showed that the Brazilian PCV2 virus induced subclinical infection in inoculated animals (G1), shown by the low viral DNA load in the tissue and serum, the lack of clinical and pathological signs of PCVAD and absence of seroconversion in the three inoculated animals. The horizontal transmission was demonstrated by the recovery of the viral DNA on one of contacting animals in various tissues. However, the absence of seroconversion, does not allowed the antibody levels evaluation in the different groups (G1 and G2). Factors such as age at the time of inoculation (49 days), route of inoculation, inoculum and absence of co-agents may contribute to the onset of the observed results.
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Ober, Rebecca Ariel. "Pre and post-infection microbiome associations with weight gain in pigs co-infected with porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2)." Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/38431.
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Master of ScienceDepartment of Diagnostic Medicine and Pathology
Megan Niederwerder
Evidence has shown that the gastrointestinal microbiome plays an important role in response to infectious disease. Porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) are two of the most important pathogens affecting the swine industry worldwide. Co-infections are common on a global scale, resulting in pork production losses through reducing weight gain and causing respiratory disease in growing pigs. Our initial microbiome work demonstrated that the fecal microbiome was associated with clinical outcome of pigs 70 days post-infection (dpi). However, it remained uncertain if microbiome characteristics could predispose response to viral challenge. The purpose of this study was to determine if microbiome characteristics present at the time of viral challenge were associated with outcome after co-infection. Using the Lawrence Livermore Microbial Detection Array, we profiled the microbiome in feces on 0 dpi from pigs identified as having high or low growth rates after co-infection. High growth rate pigs had less severe interstitial pneumonia, reduced PRRSV replication, and a significant increase in average daily weight gain throughout the study. At the level of the fecal microbiome, high growth rate pigs had increased microbial diversity on both a family and species level. Shifts in the microbiome composition of the high growth rate pigs included reduced Methanobacteriaceae species, increased Ruminococcaceae species, and increased Streptococcaceae species when compared to low growth rate pigs. Our results indicate that both microbiome diversity and composition prior to virus exposure may play a role in the subsequent response of pigs to PRRSV/PCV2 co-infection. We followed this study by investigating the microbiome characteristics that are present after co-infection and the role of the microbiome in subclinical infections. Microbiome analysis at 3 and 6 weeks post-infection showed no significant difference between high and low growth rate pigs. The results from both exploring the impact that the initial microbiome has on outcome as well as examining the trends in the microbiome during the post-infection period demonstrate that microbiome pre-infection composition may play a larger role in the outcome of subclinical disease in pigs than microbiome composition during viremia or after viral clearance.
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Gillespie, Jennifer Ann. "Genetic Stability of a Genetically-Engineered Chimeric Porcine Circovirus (PCV) Vaccine, PCV1-2." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/31475.
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Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus associated disease (PCVAD), an economically important swine disease that causes wasting in pigs 5-18 weeks of age. There exist two different types of porcine circoviruses: porcine circovirus type 1 (PCV1) was discovered as a contaminant of porcine kidney (PK-15) cells and was determined to be nonpathogenic in swine; whereas porcine circovirus type 2 (PCV2) is pathogenic. A recently released vaccine for PCVAD was generated by inserting the gene encoding the immunogenic capsid protein of PCV2 into the genetic backbone of the non-pathogenic PCV1. This chimeric PCV vaccine, called PCV1-2, was shown to induce protective immunity against PCV2 infection in pigs. The vaccine is currently on the market in a killed form. In order to develop a live version of the vaccine, the genetic stability of the chimeric PCV1-2 vaccine virus was investigated by in vitro and in vivo passaging of the vaccine virus. In vitro passaging of the PCV1-2 vaccine virus was done in a porcine kidney PK-15 cell line. Cells were infected with the PCV1-2 vaccine virus and then serially passaged 11 times. The passaged vaccine viruses recovered from passages 5 and 11 were sequenced, and the sequences were compared to that of the original PCV1-2 vaccine virus. The in vitro serial passage result showed that no mutation occurred during the 11 in vitro passages. The in vivo passaging was done using specific-pathogen-free (SPF) pigs. In in vivo â passage 1â , nine piglets were divided into 3 groups of 3 each: group 1 each inoculated with 200ug of PCV1-2 plasmid, group 2 each with 1Ã 103 TCID50 live PCV1-2 vaccine virus, and group 3 each with 3ml phosphate buffered saline (PBS) buffer as a control. One pig from each group was necropsied at 14, 21, and 28 days post-inoculation (DPI), respectively. A panel of tissue samples including lymph nodes and thymus were collected from each pig. Tissue homogenates from DPI 28 that were positive by PCR for PCV1-2 DNA were used to inoculate new piglets in the in vivo passage 2 experiment. Viruses recovered from passage 2 pigs were subsequently used for inoculation in the in vivo passage 3 experiment. The PCV1-2 vaccine virus DNA from pigs in each passage was amplified and sequenced. The results of the in vivo serial passage experiment showed that, after 3 passages of the PCV1-2 vaccine virus in pigs, there were no new mutations in the viruses recovered from pigs. The PCV1-2 vaccine contained an introduced marker mutation at amino acid position number 79, which is in the capsid region. During the in vivo passaging of the vaccine virus in pigs, this marker mutation quickly reverted back to its original nucleotide. This marker back mutation occurred between DPI 21 and DPI 28 of passage 1 in the PCV1-2 live vaccine virus group, and between DPI 28 of passage 1 and DPI 14 of passage 2 in the PCV1-2 vaccine plasmid group, and remained stable throughout the reminder of the in vivo study. Based upon the results from this study, we conclude that the PCV1-2 chimeric vaccine virus is genetically stable in vitro and in pigs, and thus should serve as a good candidate for a live vaccine against PCV2.Master of Science
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Feng, Hua. "New insights on PCV2 vaccination: thinking out of the box." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/330925.
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La present tesi doctoral tenia com a objectiu complementar el coneixement actual sobre l’eficàcia de la vacuna enfront a PCV2 en condicions d’infecció subclínica i explorar dos conceptes nous (en quan a estratègies de vacunació enfront a aquest patogen) que poguessin augmentar l’eficàcia d’aquest tractament.
El primer estudi pretenia avaluar la possible interferència de la presència de diferents nivells d’anticossos d’origen maten (AOM) en el moment de la vacunació, en l’evolució del guany mig diari de pes (GMDP). En aquest estudi, només es va detectar una possible interferència en l’eficàcia de la vacuna sobre el GMDP, quan es va considerar la subpoblació d’animals amb els valors S/P més alts. Per tant, l’impacte d’aquesta possible interferència en condicions de camp es probablement negligible en la majoria d’animals i de les granges.
En el segon estudi, es va avaluar la viabilitat d’eradicar la infecció de PCV2 en una granja convencional infectada subclínicament amb PCV2 mitjançant una estratègia de vacunació en massa. L’aplicació durant una any de la vacunació en massa enfront a PCV2 (sense implementar mesures específiques de maneig o de bioseguretat) no va ser capaç d’eliminar l’infecció per PCV2. De fet, un cop la vacunació es va aturar, el virus es va detectar de nou. De totes maneres, la disminució dels nivells d’anticossos i la no detecció del virus durant la segona meitat del període de vacunació en massa deixa entreveure que la eradicació de la infecció de PCV2 mitjançant un programa de vacunació més llarg i més extensiu podria ser possible.This thesis aimed to complement the current knowledge on PCV2 vaccination efficacy under subclinical infection conditions and give new creative concepts (“thinking out of the box”) for future related studies. The first study had the objective to assess the putative interference of different maternally derived antibody (MDA) levels at the time of vaccination on the average daily weight gain (ADWG) evolution. In this study, an apparent interference of vaccine efficacy on ADWG was noticed only when a small subpopulation of pigs with the highest ELISA S/P ratios was considered, Therefore, the impact of this possible interference under field conditions is probably negligible for most of the animals and farms. In the second study, the feasibility to eradicate PCV2 in a conventional PCV2 infected farm by using a mass vaccination strategy was assessed.. One year period of mass PCV2 vaccination (without implementing further farm management practices or biosafety measures) was not able to clear out PCV2 infection. Indeed the virus became detectable again when vaccination was stopped. However, the decreasing antibody levels and the lack of viral detection during the second half of the vaccination period shed a light on eradicating this virus by applying a longer term vaccination in a wider area would be feasible.
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Beuter, Bettina [Verfasser], and Mathias [Akademischer Betreuer] Ritzmann. "Porzines Circovirus Typ 2 (PCV2) – Querschnittsuntersuchung über das Vorkommen von Virämie und Ausscheidung bei Sauen aus einem Bestand ohne PCV2-Impfung / Bettina Beuter ; Betreuer: Mathias Ritzmann." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1170582680/34.
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Stevenson, S. L. "Studies on the porcine cell-mediated immune response to PCV2 infection." Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487460.
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Porcine circovirus type 2 (PCV2) is recognised as the essential infectious agent of postweaning multisystemic wasting syndrome (PMWS). Although lymphocyte depletion and mon?cytic cell infiltration are characteristic features in PMWS-affected pigs, the mechanism for this remains to be elucidated. This thesis examined the interactions ofPCV2 with T lymphocytes and macrophages. Three immunodominant T lymphocyte epitopes were identified using lymphocyte proliferation assays and synthesised PCV2 peptides. However, the epitopes did not appear to be promiscuous suggesting that a single peptide vaccine for PCV2 infection may not be 100% efficacious. .: Porcine fibrocytes were identified as feasible target cells for a PCV2-specific cytotoxic T .lymphocyte (CTL) assay. However, an apparent PCV2-induced reduction in the population of CD25+ (lL-2Ra) T lymphocytes prevented completion of the assay and may indicate PCV2- induced interference with T lymphocyte proliferation. This appeared to be dependent on the PCV2 genogroup (SGI and SG3) suggesting potential differences in virulence. Pulmonary macrophage studies revealed that the proportion of cells containing PCV2 antigen appeared to be dependent on the PCV2 genogroup which may also contribute to potential differences in virulence. Potential detection of nuclear PCV2 antigen in a small proportion of cells may indicate a macrophage subset that is susceptible to PCV2 replication. Macrophage activation with lipopolysaccharide did not affect the rate ofnuclear PCV2 antigen detection. Cytokine profiling studies found that the only significant differences in the experimentally-induced, PMWS-affected piglets compared to the clinically healthy piglets were reduced IL-2 mRNA levels, increased C-reactive protein levels and increased IL-IO protein or mRNA levels. This may suggest an inappropriate immune response in PMWS-affected piglets. However, no differences were detected in piglets with naturally-acquired PMWS compared to clinically healthy piglets. These conflicting results may be attributable to other factors that influence .the porcine immune response 'including co-infecting pathogens, vaccinations, diet, environmental factors and genetics.
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Nickoll, Ina [Verfasser], and Mathias [Akademischer Betreuer] Ritzmann. "Porzines Circovirus Typ 2 (PCV2)-Infektionen in oberbayerischen Schweinemastbeständen mit routinemäßiger Impfung gegen PCV2 und deren Bedeutung für das Auftreten von Lungenveränderungen / Ina Nickoll ; Betreuer: Mathias Ritzmann." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1169572162/34.
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Köppen, Marion [Verfasser], and Mathias [Akademischer Betreuer] Ritzmann. "Untersuchung über intrauterine Infektionen von Ferkeln mit dem Porzinen Circovirus Typ 2 (PCV2) sowie der Ausscheidung von PCV2 bei Muttersauen in Bayern / Marion Köppen. Betreuer: Mathias Ritzmann." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2015. http://d-nb.info/107914028X/34.
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Kolb, Anna-Katharina. "Verlauf der mittleren Antikörperkonzentration von Haemophilus parasuis, Mycoplasma hyorhinis, PRRSV und PCV2." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-106866.
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Ferrara, Domenico <1977>. "Ruolo del Porcine Circovirus tipo 2 (PCV2) nella patologia riproduttiva del suino." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4560/2/ferrara_domenico_tesi.pdf.
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La tesi è organizzata in 4 capitoli:
-nel primo vengono brevemente riferite le patologie associate all’infezione da PCV2 con particolare riferimento all’iter diagnostico ed al ruolo rivestito dall’esame istologico e dalla identificazione dell’agente eziologico in situ contestualmente alle lesioni istologiche;
-nel secondo viene presentato un iter diagnostico originale da applicare in condizioni di campo, qualora si voglia accertare la presenza del PCV2 nei tessuti dei prodotti di natimortalità/aborto del suino. In specifico si riferisce all’applicazione del protocollo in 2 aziende ed i risultati vengono analizzati per una revisione critica del protocollo impiegato;
-nel terzo vengono presentati i risultati di un protocollo di infezione con PCV2 per via genitale tramite seme infetto. Scrofe convenzionali sono state sincronizzate per l’estro e fecondate con un’unica dose di seme PCV2 negativo alla PCR (gruppo controlli) o sperimentalmente esposto al PCV2 (gruppo infette). I risultati vengono analizzati in funzione delle ripercussioni che l’infezione precoce in gravidanza può produrre sulla scrofa (mancata gravidanza, ritorno in calore), sui feti e sugli invogli fetali. Viene stabilito il ruolo protettivo degli anticorpi circolanti al momento dell’infezione, stante l’evenienza che un basso titolo anticorpale si associa a viremia prolungata e maggiore numero di feti positivi al virus;
-nel quarto viene presentato un esperimento sovrapponibile a quello riferito nel capitolo 3, però con la presenza anche di un gruppo di soggetti convenzionali vaccinati ed infettati con PCV2 durante la fecondazione artificiale usando seme sperimentalmente esposto al virus. Nella discussione dei risultati vengono enfatizzati 2 aspetti importanti nell’epidemiologia dell’infezione da PCV2: la eliminazione di virus è fortemente ridotta dalla vaccinazione, con conseguenze verosimilmente positive sulla circolazione del virus negli effettivi dell’allevamento; l’esposizione uterina è protetta dalla vaccinazione, stante la bassa percentuale di placente infette nel gruppo dei soggetti vaccinati rispetto a quelli non vaccinati e nei controlli.The thesis is organized into 4 chapters: -in the first chapter, it is briefly overviewed the association of PCV2 with several diseases with particular emphasis to the diagnostic protocols and to the in situ identification of the virus in histological lesions; -in the second chapter, it is presented an original diagnostic protocol to be applied in field conditions, to check for the presence of PCV2 in piglet tissues obtained from stillbirth/abortion. It refers to the application of the protocol in 2 herds and the results are analyzed for a critical review of the used protocol; -in the third chapter, it is presented an experimental trial aimed to infect gilts during artificial insemination by PCV2 infected semen. Conventional gilts were synchronized for oestrus and inseminated with a single dose of semen PCV2 PCR-negative (control group) or experimentally exposed to PCV2 (infected group). The results are analyzed to evaluate the impact that infection in early pregnancy may have on the sow (no pregnancy, return to oestrus), foetuses and foetal membranes. It emphasizes the protective role of circulating antibodies at the time of infection, given the possibility that a low antibody titre is associated with prolonged viremia and increased number of PCV2 positive foetuses; -in the fourth chapter, it is presented a protocol similar to that of Chapter 3, but with the presence of a third group of animals: gilts vaccinated and infected with PCV2 using semen experimentally exposed to the virus. In the discussion 2 important aspects are emphasized: the shedding of the virus is greatly reduced by vaccination, with positive effects on the reduction of the circulation of the virus in the herds; uterine exposure is protected by vaccination, given the low percentage of infected placentas in the vaccinated group compared with not vaccinated and control groups.
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Ferrara, Domenico <1977>. "Ruolo del Porcine Circovirus tipo 2 (PCV2) nella patologia riproduttiva del suino." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4560/.
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La tesi è organizzata in 4 capitoli:
-nel primo vengono brevemente riferite le patologie associate all’infezione da PCV2 con particolare riferimento all’iter diagnostico ed al ruolo rivestito dall’esame istologico e dalla identificazione dell’agente eziologico in situ contestualmente alle lesioni istologiche;
-nel secondo viene presentato un iter diagnostico originale da applicare in condizioni di campo, qualora si voglia accertare la presenza del PCV2 nei tessuti dei prodotti di natimortalità/aborto del suino. In specifico si riferisce all’applicazione del protocollo in 2 aziende ed i risultati vengono analizzati per una revisione critica del protocollo impiegato;
-nel terzo vengono presentati i risultati di un protocollo di infezione con PCV2 per via genitale tramite seme infetto. Scrofe convenzionali sono state sincronizzate per l’estro e fecondate con un’unica dose di seme PCV2 negativo alla PCR (gruppo controlli) o sperimentalmente esposto al PCV2 (gruppo infette). I risultati vengono analizzati in funzione delle ripercussioni che l’infezione precoce in gravidanza può produrre sulla scrofa (mancata gravidanza, ritorno in calore), sui feti e sugli invogli fetali. Viene stabilito il ruolo protettivo degli anticorpi circolanti al momento dell’infezione, stante l’evenienza che un basso titolo anticorpale si associa a viremia prolungata e maggiore numero di feti positivi al virus;
-nel quarto viene presentato un esperimento sovrapponibile a quello riferito nel capitolo 3, però con la presenza anche di un gruppo di soggetti convenzionali vaccinati ed infettati con PCV2 durante la fecondazione artificiale usando seme sperimentalmente esposto al virus. Nella discussione dei risultati vengono enfatizzati 2 aspetti importanti nell’epidemiologia dell’infezione da PCV2: la eliminazione di virus è fortemente ridotta dalla vaccinazione, con conseguenze verosimilmente positive sulla circolazione del virus negli effettivi dell’allevamento; l’esposizione uterina è protetta dalla vaccinazione, stante la bassa percentuale di placente infette nel gruppo dei soggetti vaccinati rispetto a quelli non vaccinati e nei controlli.The thesis is organized into 4 chapters: -in the first chapter, it is briefly overviewed the association of PCV2 with several diseases with particular emphasis to the diagnostic protocols and to the in situ identification of the virus in histological lesions; -in the second chapter, it is presented an original diagnostic protocol to be applied in field conditions, to check for the presence of PCV2 in piglet tissues obtained from stillbirth/abortion. It refers to the application of the protocol in 2 herds and the results are analyzed for a critical review of the used protocol; -in the third chapter, it is presented an experimental trial aimed to infect gilts during artificial insemination by PCV2 infected semen. Conventional gilts were synchronized for oestrus and inseminated with a single dose of semen PCV2 PCR-negative (control group) or experimentally exposed to PCV2 (infected group). The results are analyzed to evaluate the impact that infection in early pregnancy may have on the sow (no pregnancy, return to oestrus), foetuses and foetal membranes. It emphasizes the protective role of circulating antibodies at the time of infection, given the possibility that a low antibody titre is associated with prolonged viremia and increased number of PCV2 positive foetuses; -in the fourth chapter, it is presented a protocol similar to that of Chapter 3, but with the presence of a third group of animals: gilts vaccinated and infected with PCV2 using semen experimentally exposed to the virus. In the discussion 2 important aspects are emphasized: the shedding of the virus is greatly reduced by vaccination, with positive effects on the reduction of the circulation of the virus in the herds; uterine exposure is protected by vaccination, given the low percentage of infected placentas in the vaccinated group compared with not vaccinated and control groups.
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Ma, Ching-man, and 馬靜雯. "Molecular epidemiology and characterization of the receptor binding ofporcine circovirus type 2 (PCV2)." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B38227204.
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Hohloch, Adriane Corinna [Verfasser]. "Untersuchungen zur PCV2-Infektion bei Wild- und Hausschweinen in Deutschland / Adriane Corinna Hohloch." Gießen : Universitätsbibliothek, 2013. http://d-nb.info/1064991750/34.
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Pinheiro, Albanno Leonard Braz Campos. "Investigação do potencial de roedores peridomésticos como reservatório do porcine circovirus 2 (PCV2)." Universidade Federal de Viçosa, 2011. http://locus.ufv.br/handle/123456789/5090.
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Previous issue date: 2011-11-22Porcine circovirus-2 (PCV2) has been related as the causative agent of the Postweaning Multissystemic Wasting Syndrome (PMWS) and other diseases called porcine circovirus associated diseases (PCVAD). They are responsible for economic losses in pork production worldwide. There is only a few scientific studies describing the infection in other species but swine and their hole at the epidemiologic dynamics of the diseases related to the PCV2. The aim of this study is to investigate the occurrence of infection by the PCV2 in wild mice (Mus musculus and Rattus rattus) captured in hog farms. The capture of the 40 sorted mice was made at 5 pig wean tofinish farms in Minas Gerais, an important state of pork production in Brazil. Samples of tissues (lymph nodes, spleen, kidney, heart and lungs) and blood were collected from the mice. The tissue fragments collected were submitted to immunohistochemistry and Nested PCR. Additionally, samples from spleen and lungs were analyzed by histology assays. Presence of antibodies anti-PCV2 was tested by ELISA assays. Immunohistochemical analysis showed positive prints in 12 animals, mostly on spleen (sub scapular area), lungs (alveolar macrophages) and kidney (inside the tubules). The 12 serum analyzed by ELISA hasn t detected antibodies anti-PCV2. Histopathological analyses revealed in some samples, a multifocal and lympho-neutrophilic interstitial bronchopneumonia, with some node formations. Moreover, spleen samples showed a mild to moderate lymphocyte depletion related to the PCVAD. The Nested PCR assays showed the presence of viral DNA at different tissues from 6 tested rodents. Thus, the results found in this work, indicate that mice from the species Mus musculus and Rattus rattus can be naturally infected by the PCV2 and they would play a hole in the epidemiology of PCVAD. However, more studies are necessary to confirm the transmission of the PCV2 from wild rodents to pigs.
O porcine circovirus-2 (PCV2) é atribuído como um dos agentes relacionados a doenças associadas ao circovírus (PCVAD), ocasionando perdas econômicas significativas na produção mundial de suínos. Poucos trabalhos são realizados a respeito da infecção em outras espécies pelo PCV2 e sua participação na epidemiologia das doenças associadas ao vírus. O propósito desse estudo foi investigar a ocorrência de infecção em roedores peridomésticos das espécies Mus musculus e Rattus rattus pelo PCV2 em granjas comerciais de suínos. Animais dessas espécies foram capturados em importantes centros de produção no estado de Minas Gerais. Amostras de órgãos (linfonodos, baço, rins, fígado, pulmão) e sangue foram coletadas. Os fragmentos de tecidos coletados foram submetidos ao teste de imunohistoquímica e Nested PCR. Adicionalmente, foram realizadas avaliações histológicas em amostras de baço, rim e pulmão. Presença de anticorpos anti-PCV2 foram avaliados pela técnica de ELISA. O teste de imunohistoquímica demonstrou marcações encontradas em 12 animais, principalmente no baço (região subcapsular), no pulmão (macrófagos alveolares) e nos rins (interior dos túbulos). A análise do soro pela técnica de ELISA não detectou anticorpos contra o PCV-2 nas 12 amostras avaliadas.. A histopatologia demonstrou em algumas amostras, uma pneumonia bronco-intersticial neutrofílica e linfocítica, multifocal e moderada, com formação de nódulos linfóides associados a vasos e bronquíolos. No ensaio de nested-PCR foi detectado DNA viral em diferentes tecidos avaliados de seis animais. Os resultados citados demonstram que os roedores domésticos das espécies estudadas podem exercer importante papel na epidemiologia das doenças relacionadas ao PCV2. No entanto, mais estudos são necessários para comprovar a transmissão do PCV2 dos roedores para os suínos.
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Asanome, William. "Relação entre otites bacterianas e infecção pelo circovírus tipo 2 (PCV2) em suínos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2007. http://hdl.handle.net/10183/8822.
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A Síndrome Multissistêmica do Definhamento do Suíno (SMDS) é uma doença emergente e mundialmente distribuída, que tem trazido sérios prejuízos econômicos para a indústria suinícola. O Circovírus Suíno tipo 2 (PCV2), agente causal da doença, provoca lesões principalmente nos tecidos linfóides, e sugere-se que produza imunossupressão, predispondo o hospedeiro a infecções virais, bacterianas e fúngicas secundárias. Neste trabalho, é descrito um estudo da prevalência e bacteriologia das otites purulentas em suínos apresentando a SMDS, bem como em animais de baixo desenvolvimento e de crescimento normal. No total, foram examinados 385 suínos com idades entre 60 e 130 dias. De 242 animais com a SMDS, 57 (23,5%) apresentaram lesões purulentas no ouvido médio. Dentre 119 animais de baixo desenvolvimento, apenas 1 (0,7%) apresentou a lesão. Não foram detectadas lesões macroscópicas no ouvido médio dos 24 animais com crescimento normal (controles). Os agentes isolados com maior freqüência das lesões foram Arcanobacterium pyogenes, Streptococcus α– hemolíticos e Pasteurella multocida, encontrados em, respectivamente, 37 (43%), 32 (37,2%) e 24 (27,9%) dos 86 ouvidos submetidos à bacteriologia. A alta prevalência de lesões purulentas no ouvido médio de animais com a SMDS sugere que a infecção pelo PCV2 pode tornar o suíno mais suscetível às otites bacterianas. Por outro lado, a prevalência reduzida das lesões em suínos de baixo desenvolvimento sugere que a otite não representa uma causa importante de mau desempenho em suínos nas fases de crescimento e terminação. O isolamento do A. pyogenes, de Streptococcus α- hemolíticos e da P. multocida na maioria das lesões está de acordo com relatos anteriores, confirmando a importância desses organismos como agentes causais da otite média em suínos.Postweaning Multisystemic Wasting Syndrome (PMWS) is an emerging disease disseminated globally that causes severe losses to the pig industry. Porcine circovirus type 2 (PCV2) is the causal agent of the disease and causes lesions mainly in lymphoid tissue and it is suggested that it can cause immunosuppression, predisposing the host to viral, bacterial and mycotic infections. In the present work we describe a study on prevalence and bacteriology of purulent otitis in pigs with PMWS, as well as in pigs with attrition and pigs with normal growth. A total amount of 385 animals were examined, with ages ranging from 60 to 130 days. Among 242 pigs with PMWS, 57 (23,5%) showed purulent lesions in the middle ear. Among 119 pigs with attrition, only 1 (0,7%) presented the lesion. In 24 control pigs, middle ear lesions were not detected. The agents most frequently isolated from the lesions were Arcanobacterium pyogenes, α–hemolytic Streptococci and Pasteurella multocida, found respectively in 36 (43%), 32 (37,2%) and 24 (27,9%) of 86 ears bacteriologically examined. The high prevalence of purulent lesions found in middle ear of PMWS affected pigs suggests that PCV2 infection can increase susceptibility of swine to bacterial otitis. On the other hand, the small prevalence of lesions in piglets with attrition suggests that otitis does not represent a significant cause for depressed growth in pigs from growing and finishing ages. The isolation of A. pyogenes, α-hemolytic Streptococci and P. multocida from most lesions agrees with previous reports, confirming the importance of these organisms as causal agents in the etiology of otitis media in pigs.
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SALES, Tatyane Penha. "Diagnóstico da circovirose suína em criações intensivas no Estado de Goiás." Universidade Federal de Goiás, 2011. http://repositorio.bc.ufg.br/tede/handle/tde/857.
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Previous issue date: 2011-03-25Circovirosis, a disease associated to porcine circovirus 2 (PCV2), has been clinically reported as postweaning multisystemic wasting syndrome (PMWS), porcine dermatitis and nephropathy syndrome (PDNS) and other diseases presenting reproductive, respiratory and digestive clinical manifestations. Such diseases are considered emergent and economically important for the pig industry. This study aimed to identify the agent and characterize the clinical, gross and microscopic changes of circovirosis in pig intensive production farms in the state of Goiás, Brazil. For that purpose, 20 pigs with clinical signs of circovirosis from six farms were used. After clinical examination, the pigs were slaughtered, submitted to gross inspection and samples from the spleen, kidneys, lungs, liver and lymph nodes were collected for microscopic analysis and PCV2 identification by PCR. Microscopic changes typical of PCV2 infection were found. PCV2 DNA was identified in all tested animals; however, when compared to clinical signs and gross findings data, only 16 of 20 pigs showed signs of circovirosis. Taken together, the data may support a routine protocol of circovirosis identification and prevention in the state of Goias.
A circovirose, causada por circovírus suíno tipo 2 (PCV2), tem se manifestado clinicamente como Síndrome Multissistemica do Definhamento dos Suínos (SMDS), Síndrome Dermatite Nefropatia dos Suínos (SDNS) e outras doenças que cursam com sintomas reprodutivos, pneumônicos e entéricos. Essas doenças são consideradas emergentes e de significativo impacto econômico na suinocultura. O objetivo deste estudo foi identificar o PCV2, caracterizar alterações macroscópicas e microscópicas em animais com suspeita clinica de circovirose em rebanhos suínos criados de forma intensiva no estado de Goiás. Para isso, foram identificadas seis propriedades e 20 animais com suspeita clínica. Esses animais foram submetidos à eutanásia e necropsia na qual foram identificadas alterações macroscópicas e colhidos baço, rim, pulmão, fígado e linfonodos para exames histopatológico e identificação do agente por PCR. Foram observados achados microscópicos compatíveis com os já descritos para a circovirose. Foi identificado o DNA do PCV2 em todos os animais testados advindos de granjas de sistema intensivo de produção do estado de Goiás. Entretanto, quando comparado com as lesões macroscópicas, em apenas 16 dos 20 suínos foi identificada a doença clínica.
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au, maodea@agric wa gov, and Mark O'Dea. "Pathogenesis and Detection of Porcine Circovirus Type 2 in the Australian Pig Herd." Murdoch University, 2008. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20081128.125816.
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The diagnosis of porcine circovirus-associated disease (PCVAD) in pigs requires the detection of characteristic clinical signs and pathological changes, and the detection of virus in tissues of affected pigs. To increase Australias capacity to independently diagnose PCVAD in Australia, techniques for the detection of Porcine circovirus type 2 (PCV2) infection in pigs were developed and are reported in this thesis. These techniques were applied to samples obtained from normal pigs and pigs with disease and confirmed the presence of PCV2 and PCVAD in the Australian pig herd.
Viral DNA was detected in tissues of infected pigs by both standard PCR and real-time PCR techniques. The real-time PCR was more sensitive. While the conventional PCR was able to detect approximately 100 copies of the viral genome, the real-time PCR was able to detect 20 copies of the genome. An immunohistochemical (IHC) technique which was also developed enabled the visualisation of PCV2 antigen in fixed tissues of pigs with PCVAD.
The techniques that were developed were applied to an examination of tissues from pigs affected by illthrift and increased weaner mortality in herds in South Australia, New South Wales and Western Australia. Lesions suggestive of the PCVAD postweaning multisystemic wasting syndrome (PMWS) were detected and virus antigen was detected in association with lesions. The nature of the clinical signs and histopathological lesions detected, coupled with the presence of PCV2 antigen, suggested that PCVAD was present in some Australian pig herds. Phylogenetic analysis of the strains of PCV2-associated with these disease outbreaks demonstrated they were of a type not previously detected in Australia and similar to strains associated with PMWS in North America.
To further assist in investigation of PCV2 infections in the Australian pig herd, an enzyme-linked immunosorbent assay (ELISA) was developed that specifically detected antibody to PCV2 and not the related and non-pathogenic Porcine circovirus type 1. The development of this assay required the production of a virus capsid protein antigen using a prokaryotic protein production system. The ELISA was used to test serum samples form the Australian national pig serum bank. A high prevalence of PCV2 infection was detected in most pig herds examined in all Australian states.
International trade in pig meat has resulted in many countries placing restrictions on the importation of pig meat, requiring imported pig meats to be cooked to destroy viral agents. This study investigated the in vitro resistance of an Australian strain of PCV2 to heat treatment at temperatures between 56°C and 85°C. The viability of the virus was determined by a combination of reverse transcriptase polymerase chain reaction (RT-PCR), and IHC to visualise viral capsid antigen within infected cells. This study indicated that PCV2 retained its infectivity following heating up to and including 75°C for 15 mins, but was inactivated following heating to 80°C and above.
The investigations reported make a significant contribution to PCV2 research in Australia and ensure Australias capacity to independently investigate PCVAD in the Australian pig herd.
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Ma, Ching-man. "Molecular epidemiology and characterization of the receptor binding of porcine circovirus type 2 (PCV2)." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B38227204.
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Alberti, Kyle Anthony. "Effect of vaccination against porcine circovirus type 2 (PCV2) on ejaculate characteristics and the shedding of virus in boar semen." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/32965.
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Research has demonstrated that porcine circovirus type 2 (PCV2) can be shed into boar semen, raising the possibility that artificial insemination may be an important route by which disease associated with PCV2 is transmitted. The objective of this experiment was to determine the effect of vaccination against PCV2 on ejaculate characteristics and PCV2-specific antibody titers in serum of PCV2-positive boars viremia and viral shedding in semen. Semen and blood samples were collected weekly from week 0 to week 8. After collections at week 0, boars were vaccinated with a commercial vaccine against PCV2 (n = 5) (Suvaxyn PCV2 One dose; Fort Dodge Animal Health, Fort Dodge, IA) or served as controls and received 2 ml 0.9% saline (n = 5). Sperm concentrations and characteristics of sperm motility were assessed using a computer-assisted sperm analysis system (Hamilton Thorne Research, Beverly, MA) and sperm morphology was evaluated after staining using light microscopy. The PCV2 antibody titers were determined in serum using an ELISA (Iowa State Veterinary Diagnostic Laboratory; Ames, IA). The genomic copy number of PCV2 DNA in serum and semen was determined by PCR (Iowa State Veterinary Diagnostic Laboratory; Ames, IA). There were no effects of treatment or treatment by week on semen characteristics (P > 0.05). An effect of treatment by week was detected for serum antibody titers (P < 0.01). Compared with controls, antibody titers in vaccinated boars tended to be greater at week 0 (1.13 ± 0.05 titer/ml vs 1.01 ± 0.05 titer/ml; P = 0.09) and were greater at week 2 (1.15 ± 0.05 titer/ml vs 1.01 ± 0.05 titer/ml; P < 0.05) but lesser at week 7 (1.01 ± 0.05 titer/ml vs 1.23 ± 0.05 titer/ml; P < 0.01) and tended to be lesser at week 8 (1.05 ± 0.05 titer/ml vs 1.17 ± 0.05 titer/ml; P = 0.07). There were no effects of treatment, week, or treatment by week for serum genomic copy number of PCV2 DNA (P > 0.1). An effect of week was detected for semen genomic copy number of PCV2 DNA (P < 0.04). During week 3, PCV2 genomic copy number was at its greatest numerical value, however, semen PCV2 genomic copy number was at its lowest point. This was followed by an increase in semen PCV2 genomic copy number during week 7. This increase could be related to the increase in viral shedding in the serum. In summary, vaccination against PCV2 can lower antibody titers when given post-infection and has no effect on indicators of semen fertility. Vaccination also can decrease the length of reoccurring infection by decreasing the length of viral shedding in serum.Master of Science
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Fenaux, Martijn. "Molecular Pathogenesis and Development of a Genetically Engineered Vaccine for Type-2 Porcine Circovirus." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/27171.
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Porcine circovirus type 2 (PCV2) is the primary causative agent of postweaning multisystemic wasting syndrome (PMWS), whereas the ubiquitous porcine circovirus type 1 (PCV1) is nonpathogenic for pigs. Since its initial detection in a Canadian commercial swine herd in 1991, PMWS has been detected in all swine producing regions of the world and is now a serious economic problem to the swine industry. The objectives of this dissertation were to biologically, genetically and experimentally characterize both PCV1 and PCV2, to identify the genetic determinant(s) for virulence and replication, and to develop an effective genetically-engineered vaccine against PCV2 infection and PMWS.
The genetic heterogeneity of PCV2 and PCV1 isolates from different geographic origins were determined. We found that, although PCV1 and PCV2 genomes were very conserved, some minor genomic variation exists among PCV1 isolates and PCV2 isolates. The nonpathogenic PCV1 and pathogenic PCV2 share only about 76% nucleotide sequence identity but have similar genomic organization. The highest sequence variability among PCV isolates is found in the immunogenic ORF2 capsid gene. Based on the sequence data in this dissertation, a universal polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was developed that is capable of detecting all known PCV isolates and differentiating between infections by nonpathogenic PCV1 and pathogenic PCV2.
In order to study the structural and functional relationship of PCV genes and to develop a genetically-engineered vaccine, we constructed infectious DNA clones of both PCV1 and PCV2. By using the PCV2 infectious clone, we showed that pigs can be infected by direct intrahepatic injection of PCV2 infectious DNA clone. The pathological lesions and clinical disease associated with PCV2 infection were more definitively characterized by using the infectious DNA clone. We found that PCV2 is the primary but not the sole causative agent of PMWS, as the full spectrum of clinical PMWS was not reproduced by the infectious PCV2 DNA clone although pathological lesions characteristic of PMWS were reproduced.
A chimeric vaccine was constructed by cloning the immunogenic capsid gene of the pathogenic PCV2 into the genomic backbone of the non-pathogenic PCV1 virus. We showed that the resulting chimeric PCV1-2 vaccine virus, retained the non-pathogenic nature of PCV1 but induced a protective immune response against a wild-type PCV2 challenge. In vaccinated pigs, the chimeric PCV1-2 vaccine reduced PCV2 viremia length and serum virus loads and reduced pathological lesions such as lymphoid depletion (LD) and histiocytic replacement (HR) in lymphoid tissues, inflammation and discoloration of the lymph nodes. The amounts of PCV2 antigen and PCV2 genomic copy loads in lymph node tissues were also significantly reduced. Our results indicated that the attenuated chimeric PCV1-2 virus induces protective immunity against PCV2 infection and thus could serve as an effective vaccine against PCV2 and PMWS.
To improve the safety of the vaccine, we attempted to identify the genetic determinant(s) for PCV2 virulence. An isolate of PCV2 was serially passaged for 120 times in PK-15 cells. After 120 passages, a total of two amino acid mutations were identified in the capsid protein of the passage 120 virus (VP120), P110A and R191S. Compared to other known PCV1 and PCV2 sequences, the two amino acid mutations in PCV2 VP120 are unique. The VP120 virus was biologically characterized in vitro and experimentally characterized in specific-pathogen-free (SPF) pigs. The two amino acid mutations resulted in an enhanced replication ability of PCV2 VP120 in PK-15 cells and an attenuated phenotype in infected pigs. The P110A and R191S mutations in the capsid protein either alone or collectively are likely important for PCV2 virulence and replication.
In summary, we genetically characterized PCV2 isolates from different geographic regions and developed a PCR-RFLP assay. We constructed and characterized infectious DNA clones of PCV1 and PCV2, and developed a genetically engineered vaccine against PCV2 infection. We also identified the genetic determinants for PCV2 virulence and replication. The vaccine developed in this study, when it becomes available, will help the swine industry control this important pathogen.Ph. D.
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Teixeira, Fernandes Lana. "Microarray-based gene expression analysis in natural and experimental cases of porcine circovirus type 2 infection." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/299793.
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La presente Tesis se orientó a la caracterización molecular de la infección causada por PCV2 utilizando la tecnología de los microarrays. Este virus es el agente infeccioso esencial de la enfermedad sistémica (ES) por PCV2, una enfermedad de carácter multifactorial que afecta principalmente a cerdos en las fases de transición y engorde, y es una de las enfermedades porcinas más importantes económicamente a nivel mundial. La tecnología de los microarrays permite la determinación simultánea de los niveles de ARNm de miles de genes y ha sido utilizada en los últimos años para investigar los perfiles de expresión génica de tejidos y líneas celulares, ayudando a descifrar las interacciones huésped-patógeno que son relevantes para la patogénesis de varias enfermedades. Es por ello que esta Tesis se orientó a identificar genes y procesos biológicos implicados en la respuesta inmune de cerdos subclinicamente infectados por el PCV2 y también de animales naturalmente afectados por la ES-PCV2.
La primera parte de esta Tesis consistió en un trabajo exploratorio dirigido a evaluar la utilidad de la plataforma Affymetrix Porcine GeneChip® para estudiar el perfil global del transcriptoma de lechones de la raza Duroc, derivados por cesárea y privados de calostro (DCPC), experimentalmente infectados por PCV2. A partir del análisis de los datos de los microarrays, se seleccionaron 25 y 33 genes que resultaron diferencialmente expresados (DE) entre los grupos control e inoculados con PCV2 en linfonodos mesentéricos y pulmones, respectivamente. La gran mayoría de los genes sobre-expresados en el grupo inoculado con PCV2 estaba relacionada a la respuesta inmune. Desde el punto de vista del transcriptoma, los animales inoculados con PCV2 fueron capaces de activar la respuesta mediada por células y desarrollar anticuerpos específicos para PCV2, hechos que se asocian a la generación de una infección subclínica. Los resultados de este trabajo indicaron que la técnica de los microarrays es una herramienta útil para el estudio de la patogénesis de la infección por el PCV2.
El segundo estudio fue dirigido a caracterizar los mecanismos moleculares de la respuesta inmune que tienen lugar en las fases temprana y tardía de la infección subclínica por PCV2. Los genes sub-expresados en las muestras de linfonodo mediastínico (LM) se relacionaron principalmente a la adhesión celular y migración, lo que sugiere la participación de esos genes en los procesos inflamatorios observados en la infección por PCV2. La inmunidad innata se desarrolló en la primera semana p.i. y se demostró por la sobre-expresión de varios genes estimulados por interferón (ISGs) entre las muestras de LM y de sangre total (ST) de los animales inoculados con PCV2. También se detectó un aumento en la expresión de genes relacionados con la activación linfocitaria en la primera semana p.i. en las muestras de LM de los cerdos infectados, lo que indica la activación temprana de la respuesta adaptativa. Se obtuvieron resultados similares en las fases tardías de la infección, dada la sobre-expresión de los genes que codifican para el interferón (IFN)-γ y para la inmunoglobulina (Ig)-G en el día 29 p.i en las muestras de LM.
El tercer estudio consistió en investigar los cambios globales en el transcriptoma de animales naturalmente afectados por ES-PCV2 y congéneres sanos. Tras los análisis de datos, se encontraron 366 tránscritos con significativa abundancia diferencial en el grupo de animales afectados por ES-PCV2 en relación al grupo control. Los resultados de este estudio identificaron mecanismos (daño mediado por el complemento e inmunosupresión) potencialmente involucrados en la inflamación y depleción linfocitaria en tejidos linfoides, características histopatológicas claves de la ES-PCV2.This PhD Thesis aimed to characterize the molecular mechanisms underlying the porcine circovirus type 2 (PCV2) infection using the microarray technology. This virus is the essential infectious agent of PCV2- systemic disease (SD), a multifactorial condition that mainly affects nursery and growing pigs, and is considered one of the most economically important pig diseases worldwide. Microarray technology allows simultaneous measurement of the mRNA levels of thousands of genes and have been used during recent years to examine gene expression profiles of tissues or cell lines subjected to infection, helping to unravel host–pathogen interactions relevant to pathogenesis of a variety of diseases. Therefore, this Thesis aimed to identify genes and biological processes implicated in the immune response of pigs subclinically infected by PCV2 and also of animals naturally affected by PCV2-SD. In the study of this Thesis, an exploratory work was conducted to evaluate the technical feasibility of utilizing the Affymetrix Porcine GeneChip® platform to study the global transcriptional profile of caesarean-derived, colostrum-deprived (CDCD) Duroc piglets experimentally infected with PCV2. The microarray analysis detected 25 and 33 significantly differentially expressed (DE) between control and PCV2 groups for mesenteric lymph node and lung, respectively. Most up-regulated genes in PCV2 group were closely related to the immune response. From a transcriptional point of view, PCV2-inoculated pigs were able to activate a cell-mediated response and develop PCV2-specific antibodies, which probably led to a subclinical infection. The results from this study also indicate that a microarray-based approach is a helpful tool to better understand the pathogenesis of PCV2 infection. The second study was aimed to characterize the early and late molecular events underlying the immune response taking place during a subclinical PCV2 infection. Down-regulated genes from mediatinal lymph nodes (MLN) samples were mainly related to cell adhesion and migration, suggesting the participation of these genes in the inflammatory processes (granulomatous infiltration) observed in the PCV2 infection. Innate immunity developed within the first week post-infection (p.i.) and it was demonstrated by the up-regulation of several interferon-stimulated genes (ISGs) both in MLN and whole blood (LWB) samples from PCV2-infected pigs. An increased expression of genes related to lymphocyte activation was also detected during the first week p.i. in LWB samples of infected animals, indicating an early activation of adaptive responses. Similar results were obtained at late stages of infection by the up-regulation of genes coding for interferon (IFN)-γ and the immunoglobulin (Ig)-G at 29 days p.i. in MLN samples. The aim of the third study was to investigate the global transcriptional profile of MLNs from pigs naturally affected by PCV2-SD, as well as healthy counterparts. The microarray data analysis detected 366 transcripts with significant differential abundance in the PCV2-SD group of pigs relative to healthy animals. Results from this study identified potential mechanisms (complement mediated damage and immunosuppression) underlying the inflammation and lymphocyte depletion in lymphoid tissues, which are key features of PCV2-SD.
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Fort, de Puig Maria. "Characterization of immune responses to porcine circovirus type 2 (PCV2) infection and vaccination in pigs." Doctoral thesis, Universitat Autònoma de Barcelona, 2009. http://hdl.handle.net/10803/5619.
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El Circovirus porcí tipus 2 (PCV2) és l'agent causal de la circovirosi porcina (CP), una malaltia multifactorial que afecta porcs en fases de transició i engreix i que causa importants pèrdues econòmiques a la indústria porcina d'arreu del món. Les característiques histopatològiques de la CP i el fet que els animals malalts pateixin sovint infeccions secundàries i oportunístiques indica que aquesta malaltia implica una greu alteració del sistema immunitari del porc. Durant molts anys, el control de la CP es centrava principalment en la millora d'estratègies de maneig i en el control dels factors de risc que influeixen la presentació clínica de la malaltia. A dia d'avui, s'han introduït al mercat internacional quatre vacunes enfront PCV2 i la seva implementació al camp ha disminuït dràsticament la incidència de la CP. La present Tesi tenia com objectiu la caracterització de les respostes immunitàries desenvolupades pel porc en el curs de la infecció i vacunació per PCV2. En la primera part (Estudis I i II), es va caracteritzar el perfil immunològic de porcs sub-clínicament infectats amb PCV2, amb especial èmfasi en les respostes mediades per cèl·lules i el paper de les proteïnes capside (Cap) i replicasa (Rep) de PCV2 en el seu desenvolupament. Es va demostrar que el virus sencer, però no Cap i Rep indueix l'alliberació d'interleuquina (IL)-10 en cèl·lules mononuclears de sang perifèrica (CMSP), fins i tot en els cultius procedents d'animals verges, indicant l'origen innat d'aquesta resposta. Addicionalment, es va observar que, en fases inicials de la infecció per PCV2, es pot detectar interferó (IFN)-α en sèrum (dia 5 post-inoculació (PI)). Per altra banda, nivells detectables d'IL-10 només s'observaren de forma esporàdica, suggerint que els animals infectats sub-clínicament per PCV2 no es caracteritzen per tenir nivells elevats d'aquesta citoquina en sèrum. En relació a la immunitat adaptativa enfront a PCV2, es va veure que la resposta humoral es desenvolupa entra la segona i tercera setmana PI i que es caracteritza per la producció d'anticossos totals i neutralitzants, essent els neutralitzants d'aparició més tardana. La immunitat mediada per cèl·lules apareix entre la primera i segona setmana PI, i tant Cap com Rep estan implicades en el seu desenvolupament. A la segona part d'aquesta Tesi (Estudis III i IV), es va avaluar la immunogenicitat i eficàcia d'una vacuna comercial (una i dues dosis) basada en la Cap d'una soca de genotipus PCV2a en porcs convencionals. Els resultats d'aquests estudis van demostrar que la vacunació indueix el desenvolupament d'immunitat humoral i cel·lular i redueix la viremia, l'excreció i la càrrega vírica en teixits després de la infecció amb PCV2, tant amb soques de genotipus PCV2a com PCV2b. També es va observar que els anticossos maternals (AM) protegeixen enfront la infecció per PCV2 i influeixen en el desenvolupament de la resposta humoral després de la vacunació. Els resultats de l'estudi IV suggereixen que porcs amb títols d'IPMA per sota 5 log2 són potencialment més susceptibles a infectar-se amb PCV2. D'altra banda, es va veure que títols d'IPMA per sobre 10 log2 poden interferir amb el desenvolupament d'anticossos en resposta a la vacunació. En base a aquestes observacions, es proposa una "finestra de vacunació", definida com el rang de títols d'anticossos en el que els porcs s'haurien de vacunar per minimitzar la interferència amb els AM i, al mateix temps, assegurar el desenvolupament d'immunitat protectiva abans que els animals s'exposin a PCV2.Porcine circovirus type 2 (PCV2) is the causative agent of Postweaning multisystemic wasting syndrome (PMWS), a multifactorial disease of nursery and fattening pigs that causes considerable economic losses to the swine industry worldwide. The histopathological features of PMWS and the fact that secondary and opportunistic infections are common in PMWS-affected pigs indicate that this disease involves a deep alteration of the immune system. For years, control of PMWS was limited mainly to the improvement of management strategies and to the control of risk factors thought to influence the infection outcome. At present, four vaccines against PCV2 are being sold on the international market and their application in the field drastically reduced the incidence of PMWS. This Thesis aimed to characterize the immune responses developed by pigs upon PCV2 infection and vaccination. In the first part (Studies I and II), the immune features of PCV2 experimental sub-clinical infections were characterized, with particular emphasis on cell-mediated responses, and on the role of PCV2 capsid (Cap) and replicase (Rep) proteins on it. Results from these studies showed that whole PCV2, but not Cap or Rep, induces the release of interleukin (IL)-10 in peripheral blood mononuclear cells (PBMC), even in those cultures obtained from PCV2-naïve pigs, a fact that indicates the innate origin of this response. In addition, it was found that interferon (IFN)-α can be detected in serum at early stages of the sub-clinical infection (5 days post inoculation (PI)). In contrast, IL-10 in serum could only be sporadically detected, suggesting that increased levels of this cytokine are not characteristic of PCV2 sub-clinically infected pigs. With regards to the acquired immunity to PCV2, humoral responses were developed mostly between the second and third week PI, characterized by the production of PCV2 total and neutralizing antibodies (NA), appearing NA later than total antibodies. Cell-mediated immunity developed within the first two weeks PI and it was demonstrated that both Cap and Rep proteins of PCV2 are involved in its development. In the second part of this thesis (Studies III and IV), the immunogenicity and efficacy of a commercial PCV2a-based sub-unit vaccine used in one- and two-dose schedules was evaluated in conventional piglets. Results from these studies demonstrated that vaccination induced the development of humoral and cell-mediated responses and significantly reduced viremia, shedding, and viral load in tissues upon challenge with either PCV2a or PCV2b isolates. It was also found that maternally derived PCV2 antibodies (MDA) protect against PCV2 infection and influence the humoral response developed after vaccination. Results from study IV suggest that pigs with IPMA titres below 5 log2 are potentially more susceptible to PCV2 infection. Besides, IPMA titres beyond 10 log2 were seen to interfere with the development of antibodies following PCV2 vaccination. Based on these observations a "vaccination window" was proposed, defined as the range of antibody titres at which piglets should be vaccinated to minimize interference with MDA and, at the same time, ensure the development of protective immunity before PCV2 exposure.
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Hofmeister, Regina Marietta [Verfasser]. "Untersuchungen zur genetischen Variabilität porciner Circoviren (PCV2) aus geimpften und ungeimpften Herden / Regina Marietta Hofmeister." Gießen : Universitätsbibliothek, 2016. http://d-nb.info/109806691X/34.
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Dezen, Diogenes. "Desenvolvimento de uma vacina recombinante para circovirose suína e ensaios para diagnóstico molecular de PCV2." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/32147.
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O circovírus suíno tipo 2 (PCV2) é o principal agente da síndrome multissistêmica do definhamento do suíno (SMDS), uma doença mundialmente disseminada e que provoca perdas econômicas significativas para a suinocultura. Visando contribuir no diagnóstico da síndrome, o presente trabalho padronizou e comparou testes para a detecção do PCV2. Para isso, foram utilizadas as técnicas de amplificação por círculo rolante (ACR) e variações da PCR (convencional, tempo-real e competitiva). Utilizando a ACR foi possível obter a amplificação total de genomas do PCV2, os quais foram clonados, sequenciados e agrupados no genótipo PCV2b. Os genomas clonados foram isolados, recircularizados e transfectados em células PK-15. Este procedimento possibilitou a recuperação do vírus infeccioso em títulos de até 105,55 DICC50/mL. Portanto, a ACR foi uma ferramenta útil em estratégias de isolamento e sequenciamento do vírus. No entanto, a ACR foi menos sensível que a PCR para fins de detecção do PCV2. No segundo estudo, buscando métodos auxiliares no diagnóstico da SMDS, dois ensaios para a quantificação do PCV2 foram desenvolvidos. Estes ensaios foram baseados nas técnicas de PCR competitivo (cPCR) e de PCR em tempo real. Visando determinar qual seria o mais adequado para estimar a carga viral do PCV2, os dois métodos foram comparados. Ambos os ensaios foram capazes de detectar diferenças significativas entre o número de cópias de DNA de PCV2 encontradas em tecidos de animais saudáveis e acometidos pela SMDS (≥ 2,5 log10). No entanto, uma diferença média de 1,8 log10 na carga viral foi encontrada entre ensaios, onde as maiores cargas virais foram detectadas pela PCR em tempo real. Outro objetivo deste trabalho foi gerar vacinas baseadas na proteína do capsídeo (Cap) do PCV2. Assim, no terceiro estudo, três baculovírus recombinantes foram construídos de modo a expressar a proteína Cap. Em dois recombinantes, a seqüência de nucleotídeos do peptídeo sinal (PS) da glicoproteína I do herpesvírus bovino (BoHV-gI) foi inserida na extremidade 5’ do gene cap (ORF2). Além disso, um recombinante contendo a seqüência de nucleotídeos do PS foi construído sem o sinal de localização nuclear (NLS) de proteína Cap. Através do ensaio de imunoperoxidase em monocamada (IPMA), antígenos de PCV2 foram detectados em células Sf21 infectadas pelos três vírus recombinantes. Este resultado sugere que os recombinantes construídos são potenciais candidatos vacinais, uma vez que eles foram capazes de produzir antígenos de PCV2.Porcine circovirus type 2 (PCV2) is the major agent of postweaning multisystemic wasting syndrome (PMWS), a worldwide spread disease that causes significant economic losses to the swine productive chain. Aiming to contribute in the diagnosis of the syndrome, this thesis compared and developed tests for PCV2 detection. For this, multiply-primed rolling-circle amplification (MPRCA) and PCR-based assays (conventional, real-time and competitive) were tested. The MPRCA allowed amplifying the full-length PCV2 genomes, which were cloned, sequenced and grouped on PCV2b genotype. The cloned genomes were isolated from the plasmids, recircularized and used for transfection in PK-15 cells. This procedure led to the production of infectious virus to titres up to 105.55 TCID50/mL. It was concluded that MPRCA is a useful tool to amplify PCV2 genomes in sight of sequencing and virus isolation strategies. However, it was less sensitive than PCR for diagnostic purposes. In the second study, searching for methods in support to PMWS diagnosis, two PCR assays were developed: a competitive PCR (cPCR) and a SYBR green real-time PCR. The quantitative PCR methods were compared to determine which would be more suitable to estimate the PCV2 DNA load. Both assays were able to detect significant differences between the numbers of PCV2 DNA copies found in tissues of PMWS-affected and non-PMWS-affected pigs (≥2.5 log10). However, a mean difference of 1.8 log10 on the viral load was found between assays, where the highest viral loads were detected by SYBR green real-time PCR. In the work outlined herein, another purpose was to generate vaccine candidates based on PCV2 capsid protein (Cap). Therefore, in the third study, three types of recombinant baculoviruses were constructed to express the Cap protein. In two recombinants, the nucleotide sequence from the signal peptide (SP) of bovine herpesvirus glycoprotein I (BoHV-gI) was inserted at the 5’ end of the cap gene (ORF2). Additionally, one recombinant containing the SP nucleotide sequence was constructed lacking the nuclear localization signal (NLS) of Cap protein. Through immunoperoxidase monolayer assay (IPMA), the PCV2 antigen was detected in Sf21 cells infected by the three recombinant viruses. This result suggests that the recombinants here constructed are potential vaccine candidates, once they were able to produce PCV2 antigens.
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Schelleckes, Sandra [Verfasser]. "Assoziation des Auftretens von PCV2 zu pathomorphologischen und pathohistologischen Läsionen sowie Koinfektionen bei Schweinen / Sandra Schelleckes." Hannover : Stiftung Tierärztliche Hochschule Hannover, 2019. http://d-nb.info/1203630670/34.
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Favero, Cíntia Maria. "Pesquisa e caracterização genética de amostras do Torque teno sus virus 1 e 2 circulantes em suínos domésticos do estado de São Paulo e porco Monteiro do Pantanal." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/10/10134/tde-12012015-144154/.
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O Torque teno vírus suíno é classificado como pertencente à família Anelloviridae gênero Iotatorquevirus que compreende as espécies: Torque teno sus virus 1a (TTSuV1a) e Torque teno sus virus 1b (TTSuV1b); e o gênero Kapatorquevirus que compreende apenas a espécie Torque teno sus virus k2 (TTSuVk2). O TTSuV foi identificado como potencial agente causador de falhas reprodutivas em porcas, como agente desencadeante nos quadros de doenças associadas ao circovírus suíno tipo 2 (PCVAD) e em associação com outros agentes como o vírus da síndrome respiratória e reprodutiva dos suínos (PRRSV), vírus da influenza suína (SIV) e Mycoplasma hyopneumoniae como co-agentes na manifestação clínica do complexo respiratório suíno (PRDC). No presente estudo foi utilizada uma PCR direcionada a região não traduzida do genoma viral (UTR), e foi investigado um total de 391 amostras divididas entre fetos abortados e mumificados, leitões natimortos, soro, fezes e pulmão de suínos de dez propriedades localizadas no Estado de São Paulo. Diferenças entre as frequências do TTSuV1 e do TTSuVk2 foram comparadas entre amostras de porcas com problemas reprodutivos (fetos abortados e mumificados e leitões natimortos), diferentes fases da criação de suínos (porcas, leitões da creche e crescimento), leitões apresentando ou não diarréia, entre animais da terminação vacinados ou não contra o PCV2 e ainda entre amostras positivas e negativas para o PCV2. Amostras positivas de pulmão de suíno e um pool de soro de Porco Monteiro do Pantanal foram submetidos a uma PCR para amplificação da ORF1 de ambos os gêneros do TTSuV, seguida pela clonagem e posterior sequenciamento para reconstrução da filogenia. Foi investigada a ocorrência de eventos de recombinação entre as amostras, pressão de seleção e propriedades da proteína relacionadas à ligação com anticorpos. O TTSuVk2 foi mais presente infectando tanto fetos abortados quanto leitões natimortos. Porcas e leitões da creche foram mais frequentemente infectados pelo TTSuV1 enquanto que leitões do crescimento pelo TTSuVk2. A coinfecção (TTSuV1 + TTSuVk2 + PCV2) foi mais frequente em amostras fecais diarreicas que nas não diarreicas. Animais da terminação apresentaram alta frequência de coinfecção (TTSuV1 + TTSuVk2), sendo ainda maior na associação com o PCV2. A filogenia construída pelo método neighborjoing baseada na sequência da ORF1 revelou existir quatro tipos do TTSuV1 (1a, 1b, 1c e 1d) e sete subtipos do TTSuVk2 (2a, 2b, 2c, 2d, 2e, 2f, 2g) circulantes nas populações de suínos domésticos e ferais do Brasil. Entre as estirpes virais circulantes foram detectados eventos de recombinação intra-hospedeiro, inter-hospedeiro, intra-genótipo e inter-genótipo. A região carboxi-terminal da proteína demonstrou agrupar características relacionadas à ligação com anticorpos. Este estudo é o primeiro a caracterizar geneticamente amostras de TTSuV circulantes em suínos domésticos e ferais do Brasil e contribui para um melhor entendimento sobre a epidemiologia do vírus.The porcine torque teno virus is classified within the Anelloviridae family, genus Iotatorquevirus comprising the species: Torque teno sus virus 1a (TTSuV1a) and Torque teno sus virus 1b (TTSuV1b). The genus Kapatorquevirus comprises only one species, the Torque teno sus virus k2 (TTSuVk2). TTSuV was identified as a potential agent of reproductive failure causes in sows, as a trigger agent associated with porcine circovirus associated diseases (PCVAD) and in combination with other agents such as porcine reproductive and respiratory syndrome (PRRSV), swine influenza virus (SIV) and Mycoplasm hyopneumoniae as a co-agent in the clinical manifestation of porcine respiratory disease complex (PRDC). In this study, PCR targeting the untranslated region (UTR) of the virus genome was used to investigate a total of 391 samples within aborted and mummified fetuses, stillborn piglets, serum, feces and lungs of pigs from ten different properties located at São Paulo State. Differences between frequencies of TTSuV1 and TTSuVk2 were compared among samples of sows with reproductive failure (aborted and mummified fetuses and stillborn piglets), different phases of pig breeding (sows, nursery and growing piglets), samples from piglets with diarrhea or not, finishing pigs vaccinated or not against PCV2 and between positive and negative samples for PCV2. Positive lung samples from pigs and a pool of sera from feral pigs were used to PCR amplification for the ORF1 of both genera of TTSuV, followed by cloning and subsequent sequencing to reconstruct the phylogeny. The occurrence of recombination events among the samples, selection pressure and protein-related antibodies binding properties was investigated. The TTSuVk2 was more frequent infecting both aborted fetuses as stillborn piglets. Sows and nursery piglets were frequently more infected by TTSuV1 while growing piglets by TTSuVk2. The coinfection (TTSuV1 + TTSuVk2 + PCV2) was more frequent in diarrheic stool samples than in the non-diarrheic. Finishing pigs showed high frequency of coinfection (TTSuV1 + TTSuVk2) and and increase of the coinfection in association with PCV2. Phylogeny constructed by neighborjoing method based on the ORF1 sequence revealed the existence of four types TTSuV1 (1a, 1b, 1c and 1d) and seven subtypes of TTSuVk2 (2a, 2b, 2c, 2d, 2e, 2f, 2g) circulating within populations of domestic and feral pigs in Brazil. Among circulating viral strains, intra-host, inter-host, intra-and inter-genotype recombination events were detected. The carboxy-terminal region of the protein showed the have characteristics related with antibodies binding activity. This study is the first to genetically characterize samples of TTSuV circulating in domestic and feral pigs from Brazil and contributes to a better understanding of the epidemiology of the virus.
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Myers, Amanda Jean. "The Effects of porcine intestinal mucosa products on nursery pig growth performance and feeder trough space and adjustment on finishing pigs." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/11982.
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Master of ScienceDepartment of Animal Sciences and Industry
Robert D. Goodband
A total of 5,480 pigs involving 10 experiments were conducted. Experiment 1 evaluated 3 feeder gap settings: 1.27, 1.91, or 2.54 cm, while Exp. 2 evaluated the effects of feeder trough space (4.45 vs. 8.9 cm/pig) and minimum feeder gap opening of 1.27 vs. 2.54 cm. In Exp. 1, pigs fed with increasing feeder gap had decreased (linear; P < 0.03) G:F due to increased (linear; P <0.02) ADFI. In Exp. 2, there was a tendency (P = 0.08) for increased ADG as feeder trough space increased from 4.45 to 8.9 cm/pig. Pigs fed with the wide feeder gap setting had increased (P < 0.01) ADFI and decreased (P < 0.01) G:F compared to pigs with the narrow feeder gap setting. Experiments 3 and 4 were conducted to determine the effects of diet form (meal vs. pellet) and feeder design (conventional dry vs. wet-dry) on finisher pig performance. In Exp. 3, pigs fed pelleted diets or via a wet-dry feeder had greater (P < 0.07 and 0.01, respectively) ADG then those fed meal diets or with a dry feeder. Diet × feeder interactions (P < 0.02) were observed for G:F. When pelleted diets were presented in dry feeders, G:F decreased, while no difference in G:F was observed between meal and pelleted diets presented in wet-dry feeders. In Exp. 4, pigs fed with wet-dry feeders had increased (P < 0.02) ADG and ADFI compared to those with dry feeders, while pigs presented pelleted diets had improved (P = 0.05) G:F compared to those presented meal diets. Experiments 5 to 9 were conducted to determine the effects of porcine intestinal mucosa products, PEP2+, Peptone 50, and PEP-NS, on the growth performance of nursery pigs. In Exp. 5, pigs fed increasing PEP2 had increased (quadratic; P < 0.02) overall ADG, ADFI, and G:F with the greatest response observed at 4% PEP2. In Exp. 6, pigs fed PEP2 had improved (P < 0.03) G:F compared to pigs fed select menhaden fish meal (SMFM) and increasing PEP2 improved (quadratic; P < 0.04) G:F with the greatest improvement seen when diets contained 4% PEP2. In Exp. 7 pigs fed PEP2+, Peptone 50 and PEP-NS had increased (P < 0.05) ADG and ADFI compared to pigs fed a negative control diet. In Exp. 8, pigs fed diets containing 6% SMFM, PEP2+, or PEP-NS had improved (P < 0.05) ADG and ADFI compared to pigs fed the negative control or 6% Peptone 50. In Exp. 9, pigs fed increasing PEP-NS had improved (quadratic; P < 0.01) ADG and G:F, with the greatest improvement observed in pigs fed 6% PEP-NS. Experiment 10 evaluated the effects of Liquitein and PCV2/M. hyo vaccine regimen on the growth performance of weanling pigs. Overall, there were no effects of Liquitein on growth performance and vaccinated pigs had decreased (P < 0.01) ADG and ADFI compared to non-vaccinated pigs.
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Teixeira, Thais Fumaco. "Detecção de possíveis agentes virais associados à circovirose suína." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/13371.
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O Circovirus suíno tipo 2 (PCV2) é um vírus ubíquo que tem sido associado a um número de síndromes em suínos. Entre elas, a Síndrome Multissistêmica do Definhamento dos Suínos (SMDS) tornou-se uma das principais causas de perdas econômicas na suinocultura nacional. No entanto, existe incerteza se o PCV2 é, de fato, o único agente responsável por esse quadro, essencialmente porque a administração isolada do vírus a animais suscetíveis não tem sido capaz de reproduzir experimentalmente a síndrome. Em vista disso, um número de outros agentes infecciosos (e não infecciosos) tem sido examinados e sua potencial participação no desenvolvimento da SMDS tem sido pesquisada. No presente estudo foram realizados experimentos visando determinar se outro(s) agente(s) com genoma de DNA circular poderia(m) desempenhar algum papel no desenvolvimento da SMDS. Para tanto, a técnica denominada “amplificação por círculo rolante com múltiplos primers” (ACRMP) foi empregada. A ACRMP é baseada na atividade da DNA polimerase do fago phi29, uma enzima capaz de sintetizar novas moléculas de DNA a partir de um molde de DNA circular. Numa segunda etapa, o DNA amplificado é clivado com enzimas de restrição, ocasionando a linearização de grande quantidade de cópias do DNA alvo original. Como a ACRMP é realizada com primers aleatórios, nenhum conhecimento prévio da seqüência de nucleotídeos alvo é necessário. Portanto, pode-se teoricamente amplificar DNA circular de qualquer microorganismo, o que a torna ideal para o propósito do presente estudo. O DNA extraído de soros de 67 suínos com sinais clínicos de SMDS, assim como de 63 suínos saudáveis, foram submetidos à ACRMP. O principal achado deste estudo foi que o genoma de um (ou mais) anelovírus foi(ram) detectado(s) em 88,9% (56/63) dos suínos saudáveis, ao passo que o(s) mesmo(s) agente(s) somente foi(ram) detectado(s) em 16,4% (11/67) dos soros de suínos com sinais clínicos da SMDS. Alguns fragmentos de DNA potencialmente correspondentes a fragmentos de genomas virais foram seqüenciados, revelando que pelo menos um deles corresponde a uma seqüência de anelovírus suíno ainda não descrita. No entanto, outro genoma correspondente a um anelovírus foi encontrado na mesma amostra, sugerindo que mais de um vírus pode estar presente em amostras de soro. Estes resultados demonstraram que os anelovírus, de grande variabilidade genética, são significativamente mais prevalentes em suínos clinicamente saudáveis do que em suínos com SMDS.Porcine circovirus type 2 (PCV2) is an ubiquitous virus that has been associated to a number of syndromes in swine. Among these, Postweaning Multisystemic Wasting Syndrome (PMWS) has become a major cause of economic losses in swine worldwide. However, there is uncertainty as to whether PCV2 is in fact the sole agent responsible for the disease, essentially because the disease has not been experimentally reproduced when PCV2 is inoculated onto susceptible animals. In view of that, a number of other infectious (and non infectious) agents have been examined and their potential role in PMWS searched for. This study was carried out to determine whether any other agent(s) with circular DNA genome might be playing some role in PMWS. In order to achieve that, a technique called “randomly primed rolling circle amplification” (RPRCA) was employed. RPRCA is based on the activity of bacteriophage phi29 DNA polymerase, an enzyme that synthesizes new DNA molecules starting from a circularized DNA template. In a second phase, the amplified DNA is cleaved with restriction enzymes, so giving rise to large amounts of linearized copies of the original target DNA. As RPRCA is performed with random priming, no previous knowledge of the target nucleotide sequence is necessary. Therefore, it is theoretically possible to amplify circular DNA of any microorganism, thus making it ideal for the purpose of the present study. DNA extracted from sera of 67 pigs with clinical signs of PMWS as well as from 63 healthy pigs was submitted to RPRCA. The major finding of this study was that the genome of one (or more) anelloviruses was detected in 88,9% (56/63) of the healthy pigs, whereas the same agent was only detected in 16,4% (11/67) of pigs with clinical signs of PMWS. Some of the DNA fragments corresponding to the putative virus genomes were sequenced and revealed at least one non-previously described anellovirus sequence. However, other anellovirus could be found on the same sample, suggesting that more than one genome are present in samples of serum. These results demonstrate that anelovírus, of great genetic variability, were significantly more prevalent in healthy pigs than in pigs with PMWS.
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Corrêa, André Mendes Ribeiro. "Detecção do circovírus suíno tipo -2 (PCV2) e de Helicobacter pylori por imunoistoquímica em úlceras gástricas de suínos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/13368.
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O objetivo deste estudo foi analisar a participação do PCV2 no desenvolvimento de ulcerações gástricas em suínos. Descrevem-se as lesões macroscópicas e histopatológicas nas diferentes zonas do estômago de suínos naturalmente infectados pelo PCV2 e H. pylori. As lesões foram descritas nas diferentes zonas do estômago. Os estômagos coletados eram provenientes de granjas com diagnóstico prévio de infecção pelo PCV2 durante os anos de 2006 à 2008. A presença dos agentes foi verificada por técnicas de imunoistoquímica (IHQ). Dentre os 63 estômagos processados, 30 não apresentavam ulcerações no quadrilátero, sendo que 16 deles apresentavam marcação anti-PCV2 positiva em alguma das regiões analisadas. Apenas 06 casos não apresentavam marcação anti-PCV2 nos dos tecidos testados (estômago e linfonodo). Marcação positiva anti-PCV2 foi verificada em 56 linfonodos, dos quais 28 estômagos foram positivos para PCV2 em alguma zona da mucosa glandular. Grandes quantidades de antígeno do PCV2 foram observadas pela IHQ no citoplasma, núcleo e restos necróticos de células intralesionais das glândulas gástricas nas regiões do antro e cárdia; entretanto, na região do fundo, a marcação de IHQ anti-PCV2 foi restrita às células da superfície mucosa e fossetas gástricas. Marcação de IHQ anti-H. pylori foi identificada em 27 casos, principalmente, na superfície mucosa e fossetas gástricas no antro. A associação de antígenos PCV2 com células produtoras de muco lesadas na zona glandular gástrica sugere o envolvimento de PCV2 como um fator adicional para o desenvolvimento de úlceras gástricas em suínos.The aim of this study was to describe macroscopical and histopathological found in different zones of stomachs collected from pigs naturally infected with PCV2 and H. pylori. lesions were described in the different zones of the stomach. Stomachs were collected during the years of 2006 to 2008 from herds previously diagnosed as positive for PCV2 infection. The presence of the agents was determined by immunohistochemical techniques. Among 63 stomachs examined, ulceration of the Pars oesophagica was not observed in 30 stomachs, although, 16 of them showed positive PCV2 immunostaining in some of the areas tested. PCV2 immunostaining was not observed in only six cases in any of the tested tissues (stomach and lymph node). PCV2 positive immunostaining was observed in 56 lymph nodes and in some zones of the glandular mucosa, in 28 stomachs. Large amounts of PCV2 antigen were observed in the cytoplasm and nucleus of intralesional cells and in debris of gastric glands of antrum and cardia. However, anti-PCV2 immunostaining was restricted to superficial mucosal cells and gastric pits, in the fundus. H. pylori immunostaining was observed in 27 cases, mainly pn the mucosal surface and gastric pits of the antrum. The association of PCV2 antigen with damaged glandular mucus-producing cells in the gastric glandular zone suggests a role of PCV2 as an additional factor for the development of swine gastric ulcers.
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Li, Yick-yeung, and 李亦揚. "Molecular and phylogenetic analysis of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2(PCV2)." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B29297102.
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Trible, Benjamin R. "Expression of recombinant porcine circovirus 2 (PCV2) capsid polypeptides for mapping antibody epitopes following vaccination, infection, and disease." Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/13350.
Full textAbstract:
Master of ScienceDepartment of Diagnostic Medicine/Pathobiology
Raymond R. R. Rowland
Open reading frame 2 (ORF2) of porcine circovirus type 2 (PCV2) codes for the 233 amino acid capsid protein (CP). Baculovirus-based vaccines that express only ORF2 are protective against clinical disease following experimental challenge or natural infection. The goal of this study was to identify regions in CP preferentially recognized by sera from experimentally infected and vaccinated pigs, and compare these responses to pigs diagnosed with porcine circovirus-associated disease (PCVAD). The approach was to react porcine sera with different CP polypeptide fragments that each contained one or more immunoreactive regions. Expression of polypeptides was performed using E.coli. Initial results showed that sera from vaccinated pigs preferentially recognized only the largest CP(43-233) polypeptide fragment and showed low levels of binding to other CP polypeptide fragments. The results of sera from pigs diagnosed with PMWS showed only minimal reactivity with CP polypeptide fragments, including the largest CP(43-233). PCV2 infected or PDNS diagnosed pigs reacted to all CP polypeptides: however, the strongest reactivity was primarily directed towards CP polypeptides containing residues in the 160-180 region. For this purpose, finer mapping studies were performed. These experiments involved reacting sera from experimentally infected PCV2 pigs and PDNS pigs with overlapping oligopeptides that covered amino acids 141-200. Overall, the results showed a subset of experimentally infected pigs and pigs with PDNS preferentially recognized the CP oligopeptide, 169-STIDYFQPNNKR-180. Alanine scanning identified Y-173, F-174, Q-175 and K-179 as important for antibody recognition. The results from this study support the notion of PCV2 modulation of immunity, including antibody responses that may represent a precursor for disease. The results from this study support the notion of PCV2 modulation of immunity. Furthermore, the methods incorporated in this study provide a means for characterizing the immune response upon vaccination, natural infection and disease.
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Dezen, Diogenes. "Amplificação do genoma de circovírus suíno tipo 2 (PCV2) por círculo rolante e produção de um clone viral." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2007. http://hdl.handle.net/10183/10412.
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O circovírus suíno tipo 2 (PCV2) é o principal agente envolvido na Síndrome Multissistêmica do Definhamento dos Suínos (SMDS). Na maioria dos países onde a suinocultura tem expressiva importância econômica, a SMDS vem causando sérios prejuízos. Com o objetivo de contribuir para a caracterização genética de isolados brasileiros de PCV2, duas amostras autóctones foram clonadas e seqüenciadas na íntegra. Para tanto, o genoma viral foi extraído de tecidos de animais com SMDS e amplificado pelo método denominado “amplificação em círculo rolante com múltiplos primers” (ACRMP). Ambas seqüências apresentaram 1.767 nucleotídeos e diferiram entre si em apenas um nucleotídeo. A análise filogenética destas duas seqüências mostrou maior identidade com o grupo (1A) formado por isolados holandeses, franceses e chineses. Um isolado brasileiro previamente sequenciado, de Minas Gerais, foi classificado em outro grupo e a seqüência diferiu em até 16 nucleotídeos em relação aos isolados do Rio Grande do Sul. Na etapa seguinte desses estudos, visando o futuro desenvolvimento de vacinas, um dos genomas aqui seqüenciados foi transfectado em células de testículo de suíno (ST). Antígenos virais nas células transfectadas foram detectados por imunoperoxidase, demonstrando assim a infecciosidade do clone produzido. Entretanto, o clone infeccioso obtido não foi capaz de multiplicar-se a ponto de fornecer massa antigênica que viabilizasse a produção de uma vacina. Em vista disso, realizou-se uma tentativa de criar uma linhagem celular persistentemente infectada. Para isso, o DNA de PCV2 foi novamente transfectado em células ST com um plasmídeo contendo o gene de resistência a geneticin, visando a seleção de colônias celulares resistentes. Após a transfecção, porém, observou-se um efeito negativo na formação de colônias resistentes a esta droga. Este efeito foi dose-dependente em relação à quantidade de DNA de PCV2, o que impossibilitou o estabelecimento de uma linhagem celular persistentemente infectada. Isto pode estar relacionado com a expressão da proteína da ORF3 que induz apoptose ou à indução de citocinas, como interferons, embora outros mecanismos não possam ser excluídos, como efeito tóxico do alto número de cópias de genomas de PCV2. Analisando os resultados obtidos durante a realização destes estudos, conclui-se que as amostras de PCV2 circulantes no Brasil apresentam de identidade alta (99,09 %).Porcine circovirus type 2 is the main etiological agent implicated in the postweaning multisystemic wasting syndrome (PMWS) in pigs. In countries with considerable swine production, PMWS is a major cause of economic losses. In order to perfom a genetic analysis on Brazilian PCV2 isolates, two PCV2 isolates inform the state of Rio Grande do Sul - Brazil, were cloned and fully sequenced. Viral genomes were extracted from tissues of animals with PMWS and amplified using multiply-primed rolling circle amplification (MPRCA). Both PCV2 sequences were 1,767 nucleotides long and differed in only one nucleotide from each other. Phylogenetic analysis of both sequences showed the highest sequence identity with a group of viruses (group 1A) that also harbors many Dutch, French and Chinese isolates. This suggests that the Brazilian PCV2 isolates examineed here might have been imported from one of such countries. Interestingly, a Brazilian isolate from Minas Gerais previously sequenced by others, was observed to belong to another group of PCV2 isolates and differs at 16 different sites from the isolates from Rio Grande do Sul. In order to develop a vaccine, one of the isolates here sequenced was transfected into swine testis (ST) cells. Viral antigens were detected in the transfected ST cells by immunoperoxidase, indicating that such PCV2 clone could give rise to infectious virus. However, the cloned virus was not able to multiply to high titers, what would be a major drawback in vaccine development. In attempting to solve this problem, the development of a PCV2- persistently infected cell line was targeted. PCV2 DNA was cotransfected with a plasmid carrying the geneticin resistance gene in order to allow clone selection by identification of geneticin resistant cells. However, the PCV2 DNA had a negative effect on the number of geneticin resistant colonies. Interestingly, this negative effect of PCV2 DNA was dose dependent and for this reason, it was not possible to establishing a persistently infected cell line. This might be linked to ORF3 protein expression, which induces apoptosis or production of interferon. Analyzing the results obtained in this study, the Brazilian PCV2 isolates had high identity (99.05 %).
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Cecere, Thomas E. "Porcine circovirus associated disease: Modulation of the host immune response to PCV2 and PRRSV by regulatory T cells." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77098.
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Porcine circovirus associated disease (PCVAD) is currently one of the most economically important diseases facing the global swine industry. Porcine circovirus type 2 (PCV2) is the primary and essential causative agent of PCVAD, but development of clinical disease typically requires co-infection with other swine pathogens such as porcine reproductive and respiratory syndrome virus (PRRSV). The specific mechanisms of co-infection that lead to clinical disease are not fully understood, but immune modulation by the co-infecting viruses is thought to play a critical role. The ability of dendritic cells (DC) infected with PRRSV, PCV2 or both to induce regulatory T cells (Tregs) was evaluated in vitro. DCs infected with PCV2 significantly increased CD4+CD25+FoxP3+ Tregs (p<0.05) and DCs co-infected with PRRSV and PCV2 induced significantly higher numbers of Tregs than with PCV2 alone (p<0.05). This Treg induction was found to be dependent on TGF-β and not IL-10. Further investigation of the in vivo swine immune response to acute co-infection with PCV2 and PRRSV failed to detect activation of Tregs in peripheral blood mononuclear cells (PBMCs) or bronchoalveolar lavage samples. The Treg response to in vitro and in vivo PRRSV challenge in pigs persistently infected with PCV2 or vaccinated against PCV2 was evaluated. There was no significant difference in Tregs in PBMCs among chronically PCV2-infected, vaccinated PCV2 challenged or negative control pigs. However, following in vitro infection of monocyte-derived dendritic cells with PCV2, PRRSV, or both viruses, co-cultured lymphocytes from chronically infected and PCV2 vaccinated pigs had significantly (p<0.05) decreased Treg expression in the virus infected groups compared to the negative controls. In separate experiments, pigs vaccinated against PCV2 and subsequently challenged with an attenuated PRRSV strain and its pathogenic parental strain developed increased CD4+CD25+FoxP3+ Tregs (p<0.05) in PBMC samples compared to uninfected controls, and this correlated with increased suppressor activity and IL-10 expression. The findings from these studies indicate that the interaction of PCV2 and PRRSV in swine modulates the host immune response mediated in part through the activity of Tregs. However, the extent to which Tregs orchestrate a dysregulated immune response in the pathogenesis of PCVAD in vivo remains to be determined.Ph. D.
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Eisele, Simon. "Bestimmung der Wirksamkeit eines inaktivierten One-Shot Impfstoffes bei Ferkeln in der 1. oder 3. Lebenswoche mit Porcilis® PCV gegen das porcine Circovirus Typ 2 (PCV2) in zwei süddeutschen Betrieben." München Verl. Dr. Hut, 2009. http://edoc.ub.uni-muenchen.de/10484/.
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Rist, Beate. "Beurteilung der Wirksamkeit einer Einfachvakzination bei Ferkeln in der 1. und 3. Lebenswoche mit Porcilis(R) PCV gegen das porcine Circovirus Typ 2 (PCV2) in einem Betrieb mit hohen maternalen Antikörpertitern." München Dr. Hut, 2009. http://edoc.ub.uni-muenchen.de/10214/.
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Rist, Beate. "Beurteilung der Wirksamkeit einer Einfachvakzination bei Ferkeln in der 1. und 3. Lebenswoche mit Porcilis® PCV gegen das porcine Circovirus Typ 2 (PCV2) in einem Betrieb mit hohen maternalen Antikörpertitern." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-102143.
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Eisele, Simon. "Bestimmung der Wirksamkeit eines inaktivierten One-Shot Impfstoffes bei Ferkeln in der 1. oder 3. Lebenswoche mit Porcilis® PCV gegen das porcine Circovirus Typ 2 (PCV2) in zwei süddeutschen Betrieben." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-104843.
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Marks, Fernanda Simone. "Caracterização in vivo e in vitro dos efeitos da infecção pelo circovírus suíno tipo 2 (PCV2) no sistema vascular." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/23896.
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O circovírus suíno tipo 2 (PCV2) é um vírus pequeno, sem envelope e com genoma DNA circular de fita simples pertencente ao gênero Circovirus da família Circoviridae. O PCV2 está associado a uma síndrome multissistémica, atualmente denominada de porcine circovirus–associated disease (PCVAD) que acomete suínos e causa sérios prejuízos econômicos. Esta doença caracteriza-se por apresentar uma variedade de manifestações clínicas, como diminuição do ganho de peso, distúrbios respiratórios e entéricos, desordens reprodutivas e alta mortalidade. Além disso, PCVAD está fortemente associada a manifestações de dermatite, comprometimento renal e depleção linfóide. Apesar das grandes perdas econômicas e das inúmeras manifestações clínicas, a patogenia e o mecanismo de infectividade do PCV2 ainda não estão totalmente esclarecidos. O objetivo deste trabalho é avaliar a patogenia do PCV2 em suínos naturalmente infectados e em cultivo celular através da caracterização dos efeitos da infecção no sistema vascular. Primeiramente, foi realizada uma investigação para determinar os parâmetros hemostáticos de suínos naturalmente infectados por PCV2. Além disso, avaliou-se, in vitro, as alterações nas propriedades hemostáticas em células endoteliais infectadas pelo PCV2. Nossos resultados, mostram que suínos naturalmente infectados pelo PCV2 apresentam um estado protrombótico, demonstrado pela diminuição do tempo de coagulação e dos níveis de fibrinogênio, ativação e consumo plaquetário, aumento na atividade de trombina no plasma, e presença de vasculite nos capilares sanguíneos. In vitro, foi demonstrado que as células endoteliais infectadas pelo PCV2 apresentam um fenótipo ativado, caracterizado pelo aumento na atividade procoagulante na superfície celular. Além disso, foi observado que o tratamento com trombina exógena nos cultivos celulares infectados por PCV2 induz um aumento na carga viral. A partir disso, evidencia-se a participação do endotélio na infecção pelo PCV2, e a capacidade do vírus em modular a hemostasia. O conjunto destes dados permite um melhor entendimento dos fenômenos que ocorrem no hospedeiro durante a infecção pelo PCV2, especialmente no sistema vascular, permitindo uma maior compreensão dos mecanismos patogênicos da PCVAD e fornecendo novos conhecimentos dos processos envolvendo a interação PCV2-suíno.Porcine circovirus type 2 (PCV2) is a small non-enveloped virus with a single-strand DNA genome, which belongs to the Circovirus genus of the Circoviridae family. PCV2 is related to a multisystemic syndrome nowadays called porcine circovirus-associated disease (PCVAD), which affects pigs and causes considerable economic losses. The disease is characterized by a variety of clinical manifestations, such as decrease in weight gain, respiratory and enteric disturbance, reproductive disorders and high mortality rates. Apart from this, PCVAD is also associated to dermatitis, renal failure and lymphoid depletion. In spite of the large economic losses and of the numerous clinical manifestations, the pathogenesis and infection mechanism of PCV2 have not been fully clarified. The aim of this study is to evaluate the PCV2 pathogenesis in naturally infected pigs and in cell culture, by characterizing the effects of the infection in the vascular system. Firstly, an investigation aimed at determining the hemostatic parameters in naturally infected pigs was conducted. Also, an in vitro evaluation of the hemostatic properties of PCV2-infected endothelial cells was performed. Our results show that pigs naturally infected with PCV2 presented a prothrombotic state manifested as decreased coagulation time and fibrinogen levels, reduced platelet activation and consumption, increased thrombin plasma activity, and as the occurrence of vasculitis in capillary vessels. In vitro, it was demonstrated that endothelial cells infected with PCV2 presented an activated phenotype characterized by a higher procoagulant activity on the cell surface. Apart from this, the treatment with exogenous thrombin in PCV2 infected cell cultures induces an increase in viral load. These findings reveal the role played by the endothelium in the PCV2 infection and the capacity of the virus to modulate hemostasis. Taken together, these results afford to better understand the phenomena taking place in the host during PCV2 infection, namely in the vascular system, shedding new light on the pathogenic mechanisms of PCVAD and on the processes involved in the swine-PCV2 interaction.
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Zlotowski, Priscila. "Lesões intestinais em suínos naturalmente infectados por circovírus suíno tipo 2 (PCV2) e detecção de agentes intestinais que causam diarréia." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/15495.
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O resultado deste estudo foi dois artigos relacionados às lesões intestinais encontradas e presença de agentes associados a infecção por PCV2 e um terceiro artigo sobre a associação entre a presença de lesões histopatológicas em diferentes porções do trato intestinal e a carga viral presente nestas regiões e nas fezes. O primeiro artigo apresenta as lesões macroscópicas e microscópicas encontradas em 79 animais da fase de crescimento. As principais lesões macroscópicas foram: aumento de tamanho dos linfonodos mesentéricos (56), enterite necrótica (24), edema mesentérico (20), linfangectasia (15) e espessamento da parede do íleo (5). Marcação IHQ anti-PCV2 foi associada com depleção de células caliciformes (24), atrofia e fusão de vilosidades do íleo (18) e dilatação de vasos linfáticos (11). Foi observada a presença de co-infecções por Escherichia coli (5) Lawsonia intracellularis (1), Brachyspira spp.(4), Salmonella spp. (17), rotavírus (6) e calicivírus entérico (6). O segundo artigo avaliou 63 casos de enterite necrótica, nos quais o cólon foi o principal local onde foi observada necrose, aparecendo em 55 casos. Em 24 casos observou-se co-infecção de PCV2 e Salmonella spp. As alterações descritas: depleção de células caliciformes, índice apoptótico elevado em enterócitos do cólon, e marcação de IHQ positiva no citoplasma de enterócitos sugerem o envolvimento de PCV2 nos casos de enterocolite necrótica. A carga viral de PCV2 no trato intestinal, fezes e sangue de suínos, avaliada pela técnica de PCR em tempo real, associada com lesões histológicas e marcação de IHQ, bem como a interpretação destes resultados foi detalhadamente descrita no terceiro artigo.The result of this study are presented in two articles describing intestinal lesions and the presence of associated agents with PCV2 and a third article that describes the association between the presence of histopathological lesions in different areas of the intestinal tract and viral load present in those areas and in the feces. The first report showed macroscopical and microscopical lesions in samples collected from 79 growing pigs. The main macroscopical lesions were: enlargement of mesenteric lymph-nodes (56), necrotic enteritis (24), mesenteric edema (20), limphangectasy (15) and thickening of the ileal wall (5). Immunohistochemistry (IHC) staining anti-PCV2 was associated with depletion of goblet cells (24), villous fusion and atrophy of the ileum (18) and dilatation of lymphatic vessels (11). It was observed the presence of co-infections with Escherichia coli (5) Lawsonia intracellularis (1), Brachyspira spp. (4), Salmonella spp. (17), rotavirus (6) and enteric caliciviruses (6). The second article evaluated 63 cases of necrotic enteritis, in which the colon was the main target of necrotic lesions, observed in 55 cases. In 24 cases co-infection with PCV2 and Salmonella spp. was observed. The main findings described: depletion of goblet cells, high apoptotic rate in colon enterocites and positive anti-PCV2 IHC staining in cytoplasm of enterocites suggests the involvement of PCV2 in cases of necrotic enterocolitis. The viral load of PCV2 in intestinal tract, feces and blood of swine, associated with histological lesions and IHC staining, evaluated by Real time PCR technique, as well as the interpretation of these results were described in details in the third article.
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Ognjen, Stevančević. "Serološki odgovor prasadi vakcinisane protiv cirkovirusnihNR infekcija 15. i 21. dana starosti." Phd thesis, Univerzitet u Novom Sadu, Poljoprivredni fakultet u Novom Sadu, 2014. https://www.cris.uns.ac.rs/record.jsf?recordId=85632&source=NDLTD&language=en.
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Cilj ovog istraživanja bio je da se na osnovu praćenja titra antitela klase G kod prasadi i tovljenika utvrdi uticaj vakcinacije na visinu titra antitela specifičnih za PCV2, kao i da se utvrdi uticaj vakcinacije na proizvodne osobine svinja.Mere imunoprofilakse, koje se ipak smatraju nezamenljivim u kontroli ove bolesti kod nas do sada nisu bile deo kontrole, nasuprot velikom broju vakcinisanih krmača i prasadi u svetu. Iz tog razloga, kao i činjenica da u našoj zemlji nisu preduzimana ozbiljnija istraživanja, rezultati ispitivanja efikasnosti Ingelvac@ CircoFLEX vakcine proizvođača Boehringer Ingelheim, Ingelheim/Rhein, Germany, mogli bi predstavljati solidnu osnovu za eventualno uključivanje pomenute vakcine u tehnologiju preveniranja cirkovirusnih infekcija u našim zapatima svinja.Ogled je urađen na 900 prasadi podeljenih u 3 grupe po 300 prasadi. Prva grupa (A) vakcinisana je 15. dana života, druga (B) 21. dana , dok je treća grupa (C) bila kontrolna. Određivanje visine titra antitela specifičnih za PCV2 utvrđeno je indirektnom ELISA metodom.Na sam dan vakcinacije sva prasad su pokazala prisustvo antitela specifičnih za PCV2. Najveći titar antitela konstatovan je 7 dana nakon vakcinacije u grupi B i iznosio je 9,63, u grupi A 8,59, a u grupi C 7.33. Najniže prosečne vrednosti tira antitela kod vakcinisanih grupa utvrđene su 35. dana a najviše 90.dana nakon vakcinacije. U kontrolnoj grupi od momenta početka ogleda prosečan titar opada kontinuirano do 60. dana, nakon čega titar antitela speifičnih za PCV2 ima tendenciju rasta. Vakcinisana prasad imala su signifikanto veći prosečni dnevni prirast (+54g/dan kod A grupe i + 60g/dan kod Bgrupe), niži mortalitet (- 1.67% kod A grupe i - 2.67% kod B grupe) i niži procenat škartova ( A grupa -5.67% i B grupa -6%). u odnosu na kontrolnu grupu.Daleko bolji rezultati dobijeni su kod prasadi iz grupe B, pa bi vakcinacija prasadi 21. dana života imala nesumnjivu prednost u odnosu na vakcinaciju 15. dana života, sa napomenom da je 15. dana života daleko veći uticaj maternalnih antitela na stvaranje i na razvoj sopstvenog imunološkog odgovora prasadi nakon vakcinacije.U našim ispitivanjima konstatovani su povoljni efekti u svim fazama ogleda, te stoga primenjena vakcina zaslužuje da bude deo svakog zdravstvenog programa koji se primenjuje u proizvodnji kvalitetnih i zdravih svinja.The aim of this research was to determine the effect of vaccination on the amount of antibody titers specific for PCV2, and to determine the effect of vaccination on characteristics of pig production, based on the observed class G antibody titers in piglets and fattener pigs.Immunoprophylaxis measures, that are still considered indispensable in this disease prevention have not been part of the control in our country, as opposed to a large number of vaccinated sows and piglets in the world. For this reason and the fact that significant researches are not undertaken in our country, the results of Ingelvac@ CircoFLEX vaccine efficiency testing of manufacturer Boehringer Ingelheim, Ingelheim/Rhein, Germany, could constitute a solid basis for the eventual inclusion of this vaccine in prevent tecnology of circovirus infections in our swine herds.The experiment was conducted on 900 piglets divided into 3 groups of 300 piglets. The first group (A) was vaccinated at 15 days old, the second (B) at 21 days old while the third group (C) was the control group. Determining the antibody titers specific for PCV2 was performed by an indirect ELISA method.On the day of vaccination, all pigs showed the presence of antibodies specific for PCV2. The highest antibody titer was found 7 days after vaccination in group B and was 9.63; in group A it was 8.59, while in group C the value was 7.33. The lowest values of antibody titers in vaccinated groups were found on 35th day and the highest on 90th day after vaccination. In the control group, from the moment the trial started, the average titer decreased continuously until the 60th day, after which the antibody titer specific for PCV2 tended to rise. Vaccinated piglets had significantly greater average daily weight gain (+54 g/day in group A; +60 g/day in group B), lower mortality (-1.67% in group A; -2.67% in group B) and a lower percentage of rejects (-5.67% group A; -6% group B) compared to the control group.Group B piglets attained the best results, so the vaccination of piglets at 21 days old would have an advantage compared to vaccination at 15 days old, although we note that at 15 days old, there is a far greater influence of maternal antibodies on the creation and development of immune responses in the piglets after vaccination.In our examinations the favorable effects at all stages of the experiment are ascertained, therefore applied vaccine deserves to be part of any health program which is applied in the production of high-quality and healthy pigs.
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Turner, Megan Jenny. "Epidemilogical Studies of the Emerging Pig Disease Postweaning Multisystemic Wasting Syndrome (PMWS): The role of Porcine Circovirus Type 2 (PCV2)." Thesis, University of Warwick, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488499.
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Schulze, Esking Wiebke. "Einflussfaktoren bei der Etablierung, Validierung und praktischen Umsetzung von Testverfahren zur Mehrparameterdiagnostik von Infektionskrankheiten beim Schwein am Beispiel von Flüssigchip-Technologie und Multiplex-PCR." Doctoral thesis, Universitätsbibliothek Leipzig, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:15-20081022-142212-0.
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Respiratorische Krankheitsbilder, an denen mehr als ein Pathogen ursächlich beteiligt ist, gewinnen in der Schweinepopulation zunehmend an Bedeutung. Diagnostische Methoden zum simultanen Nachweis mehrerer Erreger sind Bestandteil einer schnellen und effizienten Therapie und tragen zum ökonomischen Bestandsmanagement bei. Im Rahmen dieser Arbeit sollten Methoden für den Multiplex-Nachweis von Antikörpern und Nukleinsäuren viraler Erreger von respiratorischen Krankheitsgeschehen des Schweins entwickelt werden. Die Methode für den Multiplex-Nachweis von Antikörpern sollte auf Basis der xMAP® Flüssigchip-Technologie (Luminex Corporation, Austin, T, USA) an der LiquiChip®- Workstation (Qiagen, Hilden, D) etabliert werden. Da es sich um eine für den Antikörpernachweis im veterinärmedizinischen Bereich bislang nicht genutzte Methode handelte, erfolgte die Prüfung der Machbarkeit zunächst im Einfach-Format am Beispiel des Porzinen Circovirus Typ 2. Im Laufe der Arbeit wurde deutlich, daß die Kopplung des PCV2 ORF2-Proteins als Capture-Molekül sowie die Erstellung der Versuchsansätze mit akzeptablem Aufwand ohne Spezialtechniken durchführbar war. Aufgrund der Anordnung der Proben auf Platten im 96-well-Format und der vollautomatischen Messung war ein hoher Probendurchsatz möglich. Nach der Einführung von Waschschritten in die Versuchsansätze konnten hohe Fluoreszenzsignale erzeugt werden. Im Laufe der Optimierungsversuche wurde allerdings die fehlende Korrelation dieser Fluoreszenzsignale mit den Ergebnissen der Referenzmethode deutlich. Aufgrund der unbekannten Testeigenschaften sowie fehlender Kontrollmöglichkeiten wurden diese nicht sogleich als unspezifische bzw. falsch positive Signale erkannt. Erst durch die Testung von positiven und negativen Feldseren an verschiedensten Bead-Arten wurde ersichtlich, daß die Fluoreszenzen nicht ausschließlich durch die spezifische Bindung der PCV2-Antikörper an das Capture-Protein entstanden. Im Ausschlussverfahren konnte die Ursache eingegrenzt werden. Bestandteile aus dem Schweineserum führten vermutlich durch unspezifische Bindungen an die LiquiChip®-Beads zu einem Fluoreszenzereignis. Durch Vorinkubation der Beads in Pferdeserum und der Feldseren mit einem Block-Puffer wurde versucht, diese Serumbestandteile abzusättigen und so eine Bindung an die Beads zu verhindern. Die Inkubationsvarianten führten weder zu einer Minimierung der unspezifischen Bindung noch zu einer verbesserten Differenzierung PCV2-positiver und negativer Seren. Die in der vorliegenden Arbeit verwendeten Bead-Arten sind für den Nachweis von Antikörpern gegen das PCV2 ORF2-Protein nicht geeignet. Alternative Bead-Arten für einen vergleichbaren Versuchsansatz stehen derzeit nicht zur Verfügung. Ein weiteres Ziel der Arbeit bestand darin, eine bereits in der Diagnostik von Schweineviren etablierte Methode, die PCR, zu einer Multiplex-PCR zu erweitern. Als zu detektierende Parameter wurden die derzeit bedeutendsten viralen Erreger von respiratorischen Erkrankungen des Schweins, das PRRS-Virus (Typ 1 und Typ 2), das Porzine Influenzavirus mit den Subtypen H1N1, H3N2 und H1N2 und PCV2 gewählt. Es wurden die Primersequenzen von bereits etablierten Einfach-PCRs an die besonderen Ansprüche einer Multiplex-PCR angepasst und die Methode zunächst im Einzelansatz auf Funktionsfähigkeit überprüft. Im Anschluss wurden die Parameter zu einer Multiplex-PCR zusammengeführt, die Methode optimiert und auf Spezifität, Sensitivität und Verhalten in der Routinediagnostik überprüft. Aufgrund der im Gegensatz zur Einfach-PCR zum Teil herabgesetzten Sensitivität ist diese Methode für Ausschlussuntersuchungen weniger geeignet. Für die Untersuchung von Probenmaterial klinisch erkrankter Tiere ist sie jedoch gut geeignet und bietet die Möglichkeit einen schnellen Überblick über das Erregerspektrum zu erhalten. Es muss jedoch berücksichtigt werden, daß bestimmte Parameter, z.B. PCV2, die Sensitivität des Nachweises der anderen Parameter sehr deutlich herabsetzen kann. Dies ist insbesondere von Bedeutung, da PCV2-DNA in Probenmaterial von klinisch erkrankten Tieren in sehr hohen Mengen vorhanden ist und dadurch die weiteren Parameter noch zusätzlich beeinflusst werden können.