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Relação entre otites bacterianas e infecção pelo circovírus tipo 2 (PCV2) em suínos.; Relationship between bacterial otitis and porcine circovirus type 2 (PCV2) infection in pigs

Asanome, William
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
Português
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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...

Detecção de possíveis agentes virais associados à circovirose suína.; Detection of possible viral agents associated with postweaning multisystemic wasting syndrome

Teixeira, Thais Fumaco
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
Português
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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...

Surto de Circovirose (síndrome definhante multissistêmica de suínos desmamados) no estado do Rio de Janeiro; Outbreak of Circovirosis (Porcine Postweaning Multisystemic Wasting Syndrome) in the state of Rio de Janeiro, Brazil

França, Taciana do Nascimento; Peixoto, Paulo Vargas; Brito, Marilene F.; Mores, Nelson; Zanella, Janice; Driemeier, David
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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Descreve-se o primeiro surto de Síndrome Definhante Multissistêmica de Suínos Desmamados (SDMSD) na Região Sudeste do Brasil, no estado do Rio de Janeiro. A enfermidade que afetou principalmente suínos desmamados com idade em torno de 4 meses, levou a morte pelo menos 14 animais. A granja onde o surto ocorreu, tinha péssimas condições sanitárias e de manejo. Clinicamente, a doença caracterizou-se por má condição corporal, pouco desenvolvimento, tosse, taquipnéia, dispnéia, diarréia, ataxia, tremores após estímulo, decúbito e convulsões, com evolução aguda a subaguda. À necropsia, os achados mais importantes foram um aumento de volume de linfonodos e pulmões não-colapsados, com áreas consolidadas, principalmente nos lobos craniais e porção anterior dos lobos médios. O exame histológico revelou, com maior freqüência, infiltração linfohistiocítica com células sinciciais em linfonodos, baço, placas de Peyer, rim, pulmão e fígado, depleção ou hiperplasia linfóide, bem como pneumonia bronco-intersticial linfo-histiocitária e áreas de broncopneumonia secundária. O diagnóstico firmouse pela observação dos sintomas e das lesões histológicas típicas e foi confirmado por exame imunohistoquímico e PCR. O estudo teve por objetivo caracterizar os aspectos epidemiológico e clínico- patológico desse surto...

Postweaning multisystemic wasting syndrome in farmed wild boars (Sus scrofa) in Rio Grande do Sul

Corrêa,André Mendes Ribeiro; Zlotowski,Priscila; Rozza,Daniela Bernadete; Borba,Mauro Riegert; Leal,Juliano de Souza; Cruz,Cláudio Estêvão Farias da; Driemeier,David
Fonte: Colégio Brasileiro de Patologia Animal - CBPA; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Publicador: Colégio Brasileiro de Patologia Animal - CBPA; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2006 Português
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This report concerns an outbreak of postweaning multisystemic wasting syndrome in wild boars from commercial herds in Rio Grande do Sul, Brazil. The main clinical signs were progressive wasting, respiratory distress, diarrhea, and ocular discharges. Enhanced lymph nodes and spleens, ascites, hydrothorax, and non collapsed lungs were the principal gross lesions. Varying degrees of lymphohistiocytic infiltrates in lymph nodes, spleen, and intestines were the most significant microscopic changes. Although a total of 26 animals had showed clinical and pathological findings consistent with the disease, only in 11 of them it was possible to confirm a PMWS diagnosis through the association of specific lesions in lymphoid tissues with the presence of the viral antigen detected by immunohistochemistry. These findings were similar to those reported in the swine disease.

Intestinal lesions in pigs affected with postweaning multisystemic wasting syndrome

Zlotowski,Priscila; Corrêa,André M.R.; Barcellos,David E.S.N.; Cruz,Cláudio E.F.; Asanome,William; Barry,Aline Fernandes; Alfieri,Amauri Alcindo; Driemeier,David
Fonte: Colégio Brasileiro de Patologia Animal - CBPA; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Publicador: Colégio Brasileiro de Patologia Animal - CBPA; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 Português
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Samples of mesenteric lymph nodes and intestines from 79 unthrifty 3- to 5-month-old postweaning pigs, confirmed as naturally affected with postweaning multisystemic wasting syndrome (PMWS), were studied. Pigs originated from 12 farms in southern Brazil and were selected on the basis of clinical signs and/or gross lesions suggestive of enteric disorder. Lymphohistiocytic infiltrates of varying intensity were associated with anti-porcine circovirus type 2 (anti-PCV2) immunostaining (IS) in samples of intestines and mesenteric lymph nodes from all pigs. Although most findings were similar to those described in PCV2-associated enteritis, anti-PCV2 IS in association with depletion of the goblet cell mucin stores (24 pigs), diffuse ileal villous atrophy and fusion (18 pigs), and dilatation of the lymphatic vessels (11 pigs) combined or not with lymphangitis were also observed. PCV2 antigen was immunohistochemically demonstrated in the cytoplasm and nuclei from intralesional epithelial cells, histiocytes, and endothelial-like cells in intestinal tissues. Together these findings imply an association with PCV2. The presence of co-infections by Lawsonia intracellularis, Brachyspira spp., Mycobacterium spp., Salmonella spp., rotavirus, parvovirus...

Gastric ulcers in pigs affected with postweaning multisystemic wasting syndrome

Corrêa,André Mendes Ribeiro; Zlotowsk,Priscila; Barcellos,David Emilio Santos Neves de; Cruz,Cláudio Estêvão Farias da; Driemeier,David
Fonte: Colégio Brasileiro de Patologia Animal - CBPA; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Publicador: Colégio Brasileiro de Patologia Animal - CBPA; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2008 Português
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Samples of gastric lymph nodes and the stomachs from 24 pigs selected from herds affected by postweaning multisystemic wasting syndrome (PMWS) and sudden death associated with gastric ulcers were studied. Pigs were selected on the basis of unthriftiness, decreased feed intake, and wasting. The stomachs were opened, inverted, and classified into 0-3 score according the severity of the gross lesions present in pars oesophagica (non-glandulargastric mucosa). Selected samples were processed for paraffin embedding and stained with hematoxylin and eosin. Immunohistochemistry using anti-PCV2 (porcine circovírus type 2) antibody, anti-Helicobacter pylori antibody and a wide-spectrum anti-cytokeratin antibody was performed. Gross changes in pars oesophagea were classified according to the severity of lesions as score 3, 2, and 1 in 8, 6, 5 stomachs respectivelly. Microscopically, hyperplastic lymphoid follicles, lymphohistiocytic inflammatory infiltrates and focci of necrosis in the gastric mucosa were common findings. Large amounts of PCV2 antigen were observed in the cytoplasm and nuclei from intralesional cells and debris from the gastric glandular mucosal zone; however, in the fundus, anti-PCV2 immunostaining was restricted to the surface mucosal cells and foveolar compartment. All gastric lymph nodes were positive for PCV2 antigen. Anti-H. pylori immunostaining was seen in eleven cases...

Genetic Characterization of Type 2 Porcine Circovirus (PCV-2) from Pigs with Postweaning Multisystemic Wasting Syndrome in Different Geographic Regions of North America and Development of a Differential PCR-Restriction Fragment Length Polymorphism Assay To Detect and Differentiate between Infections with PCV-1 and PCV-2

Fenaux, Martijn; Halbur, Patrick G.; Gill, Mike; Toth, Thomas E.; Meng, Xiang-Jin
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /07/2000 Português
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Postweaning multisystemic wasting syndrome (PMWS) is an emerging disease in swine. Increasing evidence indicates that a variant strain of porcine circovirus (PCV), designated type 2 PCV (PCV-2), is responsible for PMWS. To determine the extent of genetic heterogeneity of PCV-2 isolates, the complete genomes of six PCV-2 isolates from different regions of North America were amplified by PCR and sequenced. Sequence and phylogenetic analyses confirmed that two distinct genotypes of PCV exist: nonpathogenic genotype PCV-1 and PMWS-associated genotype PCV-2. However, within the PCV-2 genotype, several minor branches that have been identified appear to be associated with geographic origins. The genomic sequences of two French PCV-2 isolates diverge the most from those of other PCV-2 isolates and form a distinct branch. Other minor but distinguishable branches have also been identified for a Taiwan PCV-2 isolate and two of the Canadian PCV-2 isolates. All the U.S. PCV-2 isolates are closely related, but the Canadian isolates vary, to some extent, in their genomic sequences. The data from this study indicate that although the genome of PCV-2 is generally stable among different isolates, PCV-2 isolates from different geographic regions vary in their genomic sequences. This variation may have important implications for PCV-2 diagnosis and research. On the basis of genetic analyses of available PCV strains...

Quantitative, Competitive PCR Analysis of Porcine Circovirus DNA in Serum from Pigs with Postweaning Multisystemic Wasting Syndrome

Liu, Qiang; Wang, Li; Willson, Phil; Babiuk, Lorne A.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2000 Português
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A competitive PCR (cPCR) assay was developed for monitoring porcine circovirus (PCV) DNA in serum samples from piglets. The cPCR was based on competitive coamplification of a 502- or 506-bp region of the PCV type 1 (PCV1) or PCV2 ORF2, respectively, with a known concentration of competitor DNA, which produced a 761- or 765-bp fragment, respectively. The cPCR was validated by quantification of a known amount of PCV wild-type plasmids. We also used this technique to determine PCV genome copy numbers in infected cells. Furthermore, we measured PCV DNA loads in clinical samples. More than 50% of clinically healthy piglets could harbor both types of PCV. While PCV1 was detected in only 3 of 16 pigs with postweaning multisystemic wasting syndrome (PMWS), all the sick piglets contained PCV2. A comparison of the PCV2 DNA loads of healthy and sick animals revealed a significant difference, indicating that the development of PMWS may require a certain amount of PCV2.

Detection of a Novel Strain of Porcine Circovirus in Pigs with Postweaning Multisystemic Wasting Syndrome

Morozov, Igor; Sirinarumitr, Theerapol; Sorden, Steven D.; Halbur, Patrick G.; Morgan, Marsha K.; Yoon, Kyoung-Jin; Paul, Prem S.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/1998 Português
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Swine infectious agents, especially viruses, are potential public health risks associated with the use of pig organs for xenotransplantation in humans. Therefore, there is a need for better characterization of swine viruses and for the development of diagnostic tests for their detection. We report here isolation of a novel strain of porcine circovirus (PCV) from pigs with postweaning multisystemic wasting syndrome (PMWS). Affected pigs exhibited severe interstitial pneumonia and lymphoid depletion. The complete nucleotide sequence (1,768 nucleotides) of the genome of the PCV isolate was determined and compared with the sequence of the PCV strain isolated from PK-15 cells. Sequence comparison revealed significant differences between the two PCV strains, with an overall DNA homology of 76%. Two major open reading frames (ORFs) were identified. ORF1 was more conserved between the two strains, with 83% nucleotide homology and 86% amino acid homology. ORF2 was more variable, with nucleotide homology of 67% and amino acid homology of 65%. PCR and in situ hybridization demonstrated abundant viral DNA in various organs of pigs with PMWS. In situ hybridization demonstrated that this strain of PCV targets multiple organs and infects macrophages...

Nucleotide Sequence of Porcine Circovirus Associated with Postweaning Multisystemic Wasting Syndrome in Pigs

Hamel, Andre L.; Lin, Lihua L.; Nayar, Gopi P. S.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /06/1998 Português
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This article describes the nucleotide sequence of a porcine circovirus (PCV) which possesses a high degree of association with postweaning multisystemic wasting syndrome (PMWS), a newly described disease of young pigs. The DNA sequence of this PMWS-associated PCV (pmws PCV) has 68% homology with that of a previously published nonpathogenic strain of PCV. The strains appear to be closely related yet distinct from one another.

Detection of Porcine Circovirus Types 1 and 2 in Serum and Tissue Samples of Pigs with and without Postweaning Multisystemic Wasting Syndrome

Calsamiglia, Maria; Segalés, Joaquim; Quintana, Josefina; Rosell, Carles; Domingo, Mariano
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /05/2002 Português
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Presence of porcine circovirus type 1 (PCV1) and PCV2 was studied in sera and superficial inguinal lymph nodes from postweaning multisystemic wasting syndrome (PMWS)-affected and non-PMWS-affected pigs by using in situ hybridization and PCR. PCV1 and PCV2 were found in less than 3% and more than 50% of the samples, respectively. The most sensitive technique and site was PCR in superficial inguinal lymph nodes, but in situ hybridization correlated better with presence of characteristic lesions.

Sequence analysis of old and new strains of porcine circovirus associated with congenital tremors in pigs and their comparison with strains involved with postweaning multisystemic wasting syndrome

Choi, Jiwon; Stevenson, Gregory W.; Kiupel, Matti; Harrach, Balázs; Anothayanontha, Lavun; Kanitz, Charles L.; Mittal, Suresh K.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/2002 Português
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The entire genomes of 7 isolates of porcine circovirus (PCV) from pigs with congenital tremors (CT), type A2, or postweaning multisystemic wasting syndrome (PMWS) were cloned and sequenced. One isolate (CT-PCV-P7) originated from the late 1960s from a neonatal pig with CT, type A2. Two recent PCV isolates (CT-PCV-P5, CT-PCV-P6) were from 2 affected neonatal pigs, from different farms, with unrelated outbreaks of CT; type A2. Four isolates (PMWS-PCV-P1, PMWS-PCV-P2, PMWS-PCV-P3, PMWS-PCV-P4) originated from pigs with PMWS from 4 different farms. A comparative analysis of these PMWS and PCV isolates demonstrated 99% sequence identity with each other, and over 96% sequence identity with previously sequenced PCV2 isolates. The CT-PCV-P5 and CT-PCV-P6 isolates, however, shared 99% of the same identity with each other, and interestingly also with PMWS PCV isolates. There were no consistent genomic differences between PMWS and recent CT isolates. The CT-PCV-P7 showed 98% identity similarity to PK-15-derived PCV1 and demonstrated only 72% identity similarity to either CT-PCV-P5 or CT-PCV-P6. Phylogenetic analysis confirmed that the old isolate (CT-PCV-P7), and the new isolates (CT-PCV-P5, CT-PCV-P6, PMWS-PCV-P1, PMWS-PCV-P2, PMWS-PCV-P3, PMWS-PCV-P4) were correctly classified as PCV1 and PCV2...

Multiplex nested PCR compared with in situ hybridization for the differentiation of porcine circoviruses and porcine parvovirus from pigs with postweaning multisystemic wasting syndrome

Kim, Junghyun; Chae, Chanhee
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/2003 Português
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Multiplex nested polymerase chain reactions (PCRs) were developed for the simultaneous detection and differentiation of genomic material of porcine circovirus 1 (PCV1), porcine circovirus 2 (PCV2), and porcine parvovirus (PPV) in formalin-fixed, paraffin-embedded tissues. Multiplex conventional and nested PCR and in situ hybridization were compared for their ability to detect the 3 viruses in such tissues. Xylene deparaffinization followed by proteinase K digestion yielded DNA of sufficient quality for reliable and consistent PCR analyses. The DNA from PCV1, PCV2, and PPV was detected by both multiplex nested PCR and in situ hybridization in lymph-node tissue from 12 pigs experimentally co-infected with the 3 viruses, as well as in formalin-fixed, paraffin-embedded lymph-node tissue from 30 pigs with naturally occurring postweaning multisystemic wasting syndrome; the agreement rates for the 2 methods were 100% in both groups of pigs. Thus, multiplex nested PCR could be applied successfully to formalin-fixed, paraffin-embedded tissues for simultaneous detection of these 3 porcine viruses.

Eucaryotic Expression of the Nucleocapsid Protein Gene of Porcine Circovirus Type 2 and Use of the Protein in an Indirect Immunofluorescence Assay for Serological Diagnosis of Postweaning Multisystemic Wasting Syndrome in Pigs

Racine, Sébastien; Kheyar, Ali; Gagnon, Carl A.; Charbonneau, Benoît; Dea, Serge
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /07/2004 Português
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The purpose of this study was to develop a sensitive, rapid, and inexpensive immunofluorescence assay (IFA) using a recombinant porcine circovirus type 2 (PCV2) nucleocapsid protein for the serological detection of PCV2-specific antibodies in pig sera. The viral nucleocapsid protein encoded by the PCV2 ORF2 gene has recently been identified as the most immunoreactive viral protein that carries type-specific antigenic determinants. The ORF2 sequence of the IAF-2897 strain of PCV2 has been cloned into a pCEP5 eucaryotic expression vector under the control of the cytomegalovirus promoter, downstream of a polyhistidine sequence tag. The recombinant plasmid was used in transfection experiments with human epithelial kidney 293 cells that were further tested, and positive expression of the viral nucleocapsid protein was confirmed by IFA and Western blotting. Strong, specific fluorescence was observed in the nuclei of transfected cells. Test specificity to PCV2 was verified with several related infectious agents. Sensitivity was compared to that of standard IFA using PCV2-infected cells by evaluating the reactivities of 44 field serum samples from pigs on farms with a porcine population suffering from postweaning multisystemic wasting syndrome. The recombinant nucleocapsid-based test was able to detect 15 more positive-testing pigs than the PCV2-based IFA. Therefore...

The role of immunostimulation in the development of postweaning multisystemic wasting syndrome in pigs under field conditions

Haruna, Julius; Hanna, Paul; Hurnik, Daniel; Ikede, Basil; Miller, Lisa; Yason, Carmencita
Fonte: Canadian Veterinary Medical Association Publicador: Canadian Veterinary Medical Association
Tipo: Artigo de Revista Científica
Publicado em /10/2006 Português
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We evaluated the effects of immunostimulation in the development of postweaning multisystemic wasting syndrome (PMWS) in 930 pigs 53 to 54 d old in a grower/finisher barn with a history of PMWS. The pigs were allocated to 5 treatment groups: 4 groups received a single intramuscular injection of RespiSure-ONE (a commercial Mycoplasma hyopneumoniae vaccine; n = 197), Emulsigen (an oil-based adjuvant; n = 172), Alhydrogel (an aluminum-hydroxide-based adjuvant; n = 172), or physiologic saline (n = 218); 1 group received no treatment (n = 171). Pigs affected by PMWS were found in all the groups. Antigen to Porcine circovirus type 2 (PCV-2) was detected by immunohistochemical testing within lesions of mesenteric lymph node, spleen, Peyer’s patch, and lung of affected pigs. There was no significant difference in the incidence of PMWS among the groups. The findings indicate that immunostimulation did not influence the expression of PMWS in this study. Thus, routine vaccination against swine diseases may not significantly contribute to the occurrence of PMWS under field conditions.

Prevalence of infection with porcine circovirus-2 (PCV-2) and porcine reproductive and respiratory syndrome virus (PRRSV) in an integrated swine production system experiencing postweaning multisystemic wasting syndrome

Fraile, Lorenzo; Calsamiglia, Maria; Mateu, Enric; Espinal, Anna; Cuxart, Anna; Seminati, Chiara; Martín, Marga; Domingo, Mariano; Segalés, Joaquim
Fonte: Canadian Veterinary Medical Association Publicador: Canadian Veterinary Medical Association
Tipo: Artigo de Revista Científica
Publicado em /10/2009 Português
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The objective of this study was to evaluate the prevalence of infection with porcine circovirus-2 (PCV-2) and porcine reproductive and respiratory syndrome virus (PRRSV) through a longitudinal study in an integrated swine production system (7 farms) experiencing postweaning multisystemic wasting syndrome (PMWS). Risk factors for PCV-2 infection and for PCV-2 and PRRSV coinfection were also evaluated. Fifteen sows from each herd and 4 non-cross-fostered piglets from each sow were randomly selected at farrowing and ear-tagged at birth. Serum samples were analyzed for antibodies to PCV-2 and for detection of the PCV-2 and PRRSV genomes. Statistical analyses involved 2 approaches. The 1st approach characterized the dynamics of PCV-2 infection and their relationship with PRRSV infection. The 2nd approach analyzed the probability of being infected by PCV-2 or by both PCV-2 and PRRSV through a generalized linear mixed model incorporating sow and farm characteristics. At the 1st sampling time (1 wk of age), there was a significant relationship between sow PCV-2 infection and piglet PCV-2 infection (P < 0.0001). The risk of PCV-2 and PRRSV coinfection was 1.85 times greater in piglets from a sow with low titers of PCV-2 antibodies than in piglets from sows with medium to high titers (P = 0.03) and was 2.54...

Experimental Airborne Transmission of Porcine Postweaning Multisystemic Wasting Syndrome

Kristensen, C. S.; Hjulsager, C. K.; Vestergaard, K.; Dupont, K.; Bille-Hansen, V.; Enøe, C.; Jorsal, S. E.; Bækbo, P.; Larsen, L. E.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Português
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The objective of these studies was to investigate if porcine postweaning multisystemic wasting syndrome (PMWS) could be induced in healthy pigs following contact with air from pigs with clinical signs of PMWS. The pigs were housed in different units. Either 31 (study I) or 25 (study II) pigs with clinical symptoms of PMWS from a PMWS-affected herd and 25 healthy pigs from a PMWS-free, but PCV2-positive, herd were housed in unit A. Fifty pigs from a PMWS-free herd were housed in unit B, which were connected by pipes to unit A. In unit C, 30 pigs from a PMWS-free herd were housed as controls. In study II, the pigs in units A and B from the PMWS-free herd developed clinical signs of PMWS 2-3 weeks after arrival. PMWS was confirmed at necropsy and the diseased pigs had increased PCV2 load and increased antibody titers against PCV2 in serum that coincided with the development of clinical signs typical of PMWS. Sequence analysis revealed that the PCV2 isolate belonged to genotype 2b. In conclusion, the present study showed that PMWS can be induced in pigs from a PMWS-free herd by airborne contact with pigs from a PMWS-affected herd.

Comparative serologic and virologic study of commercial swine herds with and without postweaning multisystemic wasting syndrome

Larochelle, Renée; Magar, Ronald; D'Allaire, Sylvie
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/2003 Português
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A comparative serologic and virologic study was performed in pigs from 5 herds with postweaning multisystemic wasting syndrome (PMWS) and 2 herds without PMWS in Quebec. In each herd, 60 blood samples were collected at 4-wk intervals from pigs from 3 to 23 wk of age. The serum was evaluated for the presence of antibodies to porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV), as well as for the presence of nucleic acid of PCV2, PRRSV, and porcine parvovirus (PPV), by means of the polymerase chain reaction (PCR). Serologic profiles for PCV2 were very similar in 6 of the 7 herds, including the 2 without PMWS, and were characterized by a gradual decrease in antibody titres from 3 until 11 wk of age, followed by seroconversion at 15 wk, and high PCV2 antibody titres thereafter in all pigs. Only starting at 11 to 15 wk of age could PCV2 viremia be detected, except in 1 herd, in which clinical signs were observed at 6 to 7 wk of age. A PCV2 viremia could be detected within the same pigs for a minimum of 8 wk, and the virus could still be detected in 41% of the serum samples obtained at 23 wk of age. The antibody level did not appear to influence the occurrence of disease, since titres were similar in pigs in the herds with or without PMWS. Infection with PRRSV...

Changes in CD4+, CD8+, CD4+ CD8+, and Immunoglobulin M-Positive Peripheral Blood Mononuclear Cells of Postweaning Multisystemic Wasting Syndrome-Affected Pigs and Age-Matched Uninfected Wasted and Healthy Pigs Correlate with Lesions and Porcine Circovirus Type 2 Load in Lymphoid Tissues

Darwich, Laila; Segalés, Joaquim; Domingo, Mariano; Mateu, Enric
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2002 Português
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Forty-one 8- to 12-week-old wasted pigs were selected from several conventional farms with histories of postweaning multisystemic wasting syndrome (PMWS) and classified into two groups according to their porcine circovirus type 2 (PCV2) infection status, as determined by in situ hybridization (ISH). Twenty-four pigs tested positive for PCV2 (PCV2-positive group), while 17 pigs tested negative for PCV2 (PCV2-negative group). In addition, eight uninfected healthy pigs from an experimental farm were used as controls. Heparinized blood samples were taken to obtain peripheral blood mononuclear cells. The CD4+, CD8+, CD4+ CD8+ (double-positive [DP]), and immunoglobulin M-positive (IgM+) cell subsets were analyzed by flow cytometry with appropriate monoclonal antibodies. Histopathological studies were done to evaluate the apparent degrees of lymphocyte depletion in different lymphoid organs (superficial inguinal and mesenteric lymph nodes, Peyer's patches, tonsils, and spleen) and to determine the viral load of the PCV2 genome by using an ISH technique. Animals of the PCV2-positive group showed a significant downshift of the CD8+ and DP cell subsets compared to the other groups (P < 0.05). Moreover, in PCV2-positive pigs, the amount of PCV2 genome in lymphoid tissues was related to the degree of cell depletion in those tissues (P < 0.05) as well as to the relative decrease in IgM+ and CD8+ cells in peripheral blood. These data support the notion that PCV2-positive pigs might have an impaired immune response.

Isolation of circovirus from lesions of pigs with postweaning multisystemic wasting syndrome.

Ellis, J; Hassard, L; Clark, E; Harding, J; Allan, G; Willson, P; Strokappe, J; Martin, K; McNeilly, F; Meehan, B; Todd, D; Haines, D
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/1998 Português
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Postweaning multisystemic wasting syndrome (PMWS), an apparently new disease, has been recognized in swine herds in western Canada. Young pigs with this disease have progressive weight loss, tachypnea, dyspnea, and jaundice, accompanied by interstitial pneumonia, lymphadenopathy, hepatitis, and nephritis. We examined more than 400 pigs from more than 70 herds in Alberta, Saskatchewan, and Manitoba with cases of PMWS. A small virus was isolated from a range of tissues from 8 of 8 affected pigs examined. The agent was identified as a circovirus-like virus using electron microscopy, immunohistochemical staining with porcine and rabbit immune serum, and in situ hybridization. Immunohistochemical examination of tissues from more than 100 affected pigs has revealed widespread viral antigen, often contained in circovirus-like inclusion bodies, in lesions from numerous organs. Although Koch's postulates remain to be fulfilled, these results demonstrate a high degree of association between the presence of the circovirus-like virus and PMWS in affected swine.