RESUMO

Bats and dogs are the main reservoirs of rabies virus (RABV) in Latin America and are responsible for the maintenance of different cycles of infection. In the two neighbour and most southern Brazilian states of Rio Grande do Sul (RS) and Santa Catarina (SC), rabies in dogs has been successfully controlled for more than 30 years. However, rabies associated to the rural cycle remains endemic, with a significant, though oscillating-annual incidence of rabies in cattle. Despite the plethora of studies on genetic analyses of Brazilian RABV, isolates from southern Brazil have only scarcely been investigated. This work was performed to identify the genetic lineages of RABVs circulating in states of RS and SC. Fifty-nine RABV cattle isolates from RS and SC were selected and submitted to reverse transcription/polymerase chain reaction (RT-PCR) followed by sequencing of the nucleoprotein gene. In RS, the circulation of two sublineages (1A and 1B) of RABV was detected, both with characteristics of lineages usually detected in vampire bats (Desmodus rotundus). In SC, only one sublineage of RABV (1B) was detected. Nevertheless, the findings reported here are expected to contribute to the understanding of the biology of the virus in the region and its interactions with the natural host D. rotundus.

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RESUMO

Abstract Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus disease, a complex multisystem syndrome in domestic pigs. Despite the significant economic losses caused by porcine circovirus disease, the mechanisms of pathogenesis underlying the clinical findings remain largely unclear. As various reports have highlighted the potential key role of vascular lesions in the pathogenesis of porcine circovirus disease, the aim of this work was to investigate effects of PCV2 infection on vascular endothelial cells, focusing on cell viability and expression of adhesion/junction molecules. PCV2 infection reduced endothelial cell viability, while viral infection did not affected the viability of several other classical cell lines. Also, PCV2 infection in endothelial cells displayed a dual/biphasic effect: initially, infection increased ICAM-1 expression, which can favor leukocyte recruitment and emigration to tissues and possibly inducing characteristic porcine circovirus disease inflammatory lesions; then, secondarily, infection caused an increase in zonula occludens 1 tight junction protein (ZO-1) expression, which in turn can result in difficulties for cell traffic across the endothelium and a potential impairment the immune response in peripheral tissues. These virus-induced endothelial changes could directly impact the inflammatory process of porcine circovirus disease and associated vascular/immune system disturbances. Data suggest that, among the wide range of effects induced by PCV2 on the host, endothelial modulation can be a pivotal process which can help to explain PCV2 pathogenesis in some porcine circovirus disease presentations.

Assuntos

RESUMO

Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus disease, a complex multisystem syndrome in domestic pigs. Despite the significant economic losses caused by porcine circovirus disease, the mechanisms of pathogenesis underlying the clinical findings remain largely unclear. As various reports have highlighted the potential key role of vascular lesions in the pathogenesis of porcine circovirus disease, the aim of this work was to investigate effects of PCV2 infection on vascular endothelial cells, focusing on cell viability and expression of adhesion/junction molecules. PCV2 infection reduced endothelial cell viability, while viral infection did not affected the viability of several other classical cell lines. Also, PCV2 infection in endothelial cells displayed a dual/biphasic effect: initially, infection increased ICAM-1 expression, which can favor leukocyte recruitment and emigration to tissues and possibly inducing characteristic porcine circovirus disease inflammatory lesions; then, secondarily, infection caused an increase in zonula occludens 1 tight junction protein (ZO-1) expression, which in turn can result in difficulties for cell traffic across the endothelium and a potential impairment the immune response in peripheral tissues. These virus-induced endothelial changes could directly impact the inflammatory process of porcine circovirus disease and associated vascular/immune system disturbances. Data suggest that, among the wide range of effects induced by PCV2 on the host, endothelial modulation can be a pivotal process which can help to explain PCV2 pathogenesis in some porcine circovirus disease presentations.(AU)

Assuntos

RESUMO

Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus disease, a complex multisystem syndrome in domestic pigs. Despite the significant economic losses caused by porcine circovirus disease, the mechanisms of pathogenesis underlying the clinical findings remain largely unclear. As various reports have highlighted the potential key role of vascular lesions in the pathogenesis of porcine circovirus disease, the aim of this work was to investigate effects of PCV2 infection on vascular endothelial cells, focusing on cell viability and expression of adhesion/junction molecules. PCV2 infection reduced endothelial cell viability, while viral infection did not affected the viability of several other classical cell lines. Also, PCV2 infection in endothelial cells displayed a dual/biphasic effect: initially, infection increased ICAM-1 expression, which can favor leukocyte recruitment and emigration to tissues and possibly inducing characteristic porcine circovirus disease inflammatory lesions; then, secondarily, infection caused an increase in zonula occludens 1 tight junction protein (ZO-1) expression, which in turn can result in difficulties for cell traffic across the endothelium and a potential impairment the immune response in peripheral tissues. These virus-induced endothelial changes could directly impact the inflammatory process of porcine circovirus disease and associated vascular/immune system disturbances. Data suggest that, among the wide range of effects induced by PCV2 on the host, endothelial modulation can be a pivotal process which can help to explain PCV2 pathogenesis in some porcine circovirus disease presentations.

Assuntos

RESUMO

O objetivo do presente estudo foi identificar a frequência de lesões macroscópicas e microscópicas e dos agentes bacterianos envolvidos em pericardites em suínos no abate no Estado do Rio Grande do Sul. As amostras foram coletadas em frigoríficos de suínos com Serviço de Inspeção Federal (SIF) entre fevereiro a outubro de 2010 e a condenação por pericardite dos animais acompanhados foi de 3,9 por cento(299/7.571). No total foram investigados 91 casos de pericardites, 89% deles foram classificados como crônicos por histopatologia e pleurite crônica foi observada em 47 porcento dos pulmões correspondentes, todavia não houve associação significativa entre as duas lesões. Os agentes bacterianos isolados a partir dos corações foram Streptococcus spp., Pasteurella multocida, Haemophilus parasuis e Streptococcus suis. DNA bacterianos mais detectados pela PCR foram de Mycoplasma hyopneumoniae e Actinobacillus pleuropneumoniae. Houve associação significativa entre isolamento de P. multocida e Streptococcus sp. nos corações e pulmões correspondentes. Esses resultados sugerem que a infecção no pulmão possa ter servido de porta de entrada para a colonização do pericárdio adjacente. Apesar de M. hyopneumoniae ter sido o agente detectado com maior frequência pela PCR em corações e pulmões correspondentes, não houve associação significativa da detecção dos agentes nos órgãos. Isto sugere que as infecções foram eventos independentes. Os demais agentes investigados não apresentaram associação significativa entre isolamento ou detecção de DNA em coração e pulmão correspondente. Outro achado importante foi a presença de coinfecções bacterianas em 2 por cento dos corações e por PCR foi detectado DNA bacteriano de dois ou mais agentes em 16,5 por cento dos corações. Esses resultados sugerem que as coinfecções em pericardites precisam ser melhor estudadas.

The objective of the study was to identify the frequency of macroscopic and microscopic lesions and bacterial agents involved with pericarditis in slaughter pigs in the State of Rio Grande do Sul, Brazil. The samples were collected in slaughterhouses with Federal Inspection Service (SIF) between February and October, 2010. Condemnation due to pericarditis in the examined animals was 3.9 percent (299/7,571). Ninety one cases of pericarditis were examined and by histopathology 89% were chronic and 47 percent of the corresponding lungs showed chronic pleuritis, but there was no significant association between both lesions. The bacterial agents isolated from the hearts were Streptococcus spp., Pasteurella multocida, Haemophilus parasuis and Streptococcus suis. Bacterial DNA from Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae were the most frequently detected by PCR. There was significant association between isolation of P. multocida and Streptococcus spp. in the hearts and corresponding lungs. The results suggest that lung infection could act as a port of entry to the colonization of the adjacent pericardium. In spite of the fact that M. hyopneumoniae was the agent more frequently identified by PCR in the heart and corresponding lung, there was no significant association of the agent in the organs. This suggests that the infections were independent events. The other agents investigated did not show significant association between isolation or DNA detection in heart and corresponding lungs. Another important finding was the presence of coinfection between bacterial agents in 2 percent of the hearts and by PCR were identified bacterial DNA of two or more agents in 16.5 percent of the hearts. These results suggest that coinfections in cases of pericarditis need further investigation.

Assuntos

RESUMO

O objetivo do presente estudo foi identificar a frequência de lesões macroscópicas e microscópicas e dos agentes bacterianos envolvidos em pericardites em suínos no abate no Estado do Rio Grande do Sul. As amostras foram coletadas em frigoríficos de suínos com Serviço de Inspeção Federal (SIF) entre fevereiro a outubro de 2010 e a condenação por pericardite dos animais acompanhados foi de 3,9 por cento(299/7.571). No total foram investigados 91 casos de pericardites, 89% deles foram classificados como crônicos por histopatologia e pleurite crônica foi observada em 47 porcento dos pulmões correspondentes, todavia não houve associação significativa entre as duas lesões. Os agentes bacterianos isolados a partir dos corações foram Streptococcus spp., Pasteurella multocida, Haemophilus parasuis e Streptococcus suis. DNA bacterianos mais detectados pela PCR foram de Mycoplasma hyopneumoniae e Actinobacillus pleuropneumoniae. Houve associação significativa entre isolamento de P. multocida e Streptococcus sp. nos corações e pulmões correspondentes. Esses resultados sugerem que a infecção no pulmão possa ter servido de porta de entrada para a colonização do pericárdio adjacente. Apesar de M. hyopneumoniae ter sido o agente detectado com maior frequência pela PCR em corações e pulmões correspondentes, não houve associação significativa da detecção dos agentes nos órgãos. Isto sugere que as infecções foram eventos independentes. Os demais agentes investigados não apresentaram associação significativa entre isolamento ou detecção de DNA em coração e pulmão correspondente. Outro achado importante foi a presença de coinfecções bacterianas em 2 por cento dos corações e por PCR foi detectado DNA bacteriano de dois ou mais agentes em 16,5 por cento dos corações. Esses resultados sugerem que as coinfecções em pericardites precisam ser melhor estudadas.(AU)

The objective of the study was to identify the frequency of macroscopic and microscopic lesions and bacterial agents involved with pericarditis in slaughter pigs in the State of Rio Grande do Sul, Brazil. The samples were collected in slaughterhouses with Federal Inspection Service (SIF) between February and October, 2010. Condemnation due to pericarditis in the examined animals was 3.9 percent (299/7,571). Ninety one cases of pericarditis were examined and by histopathology 89% were chronic and 47 percent of the corresponding lungs showed chronic pleuritis, but there was no significant association between both lesions. The bacterial agents isolated from the hearts were Streptococcus spp., Pasteurella multocida, Haemophilus parasuis and Streptococcus suis. Bacterial DNA from Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae were the most frequently detected by PCR. There was significant association between isolation of P. multocida and Streptococcus spp. in the hearts and corresponding lungs. The results suggest that lung infection could act as a port of entry to the colonization of the adjacent pericardium. In spite of the fact that M. hyopneumoniae was the agent more frequently identified by PCR in the heart and corresponding lung, there was no significant association of the agent in the organs. This suggests that the infections were independent events. The other agents investigated did not show significant association between isolation or DNA detection in heart and corresponding lungs. Another important finding was the presence of coinfection between bacterial agents in 2 percent of the hearts and by PCR were identified bacterial DNA of two or more agents in 16.5 percent of the hearts. These results suggest that coinfections in cases of pericarditis need further investigation.(AU)

Assuntos

RESUMO

Scrapie is a transmissible spongiform encephalopathy of sheep and goats and is associated with the deposition of an abnormal isoform of prion protein (PrP(sc)). This isoform presents an altered conformation that leads to its aggregation in the host's central nervous and lymphoreticular systems. A predisposition to the prion-agent infection can be influenced by specific genotypes that are related to polymorphisms in the ovine prnp gene. The most characterized polymorphisms occur at codons 136, 154, and 171, with genotype VRQ being the most susceptible and ARR the most resistant. In the current study, a real-time quantitative polymerase chain reaction (qPCR) technique based on allele-specific TaqMan probes was developed to identify single nucleotide polymorphisms in the prnp gene from Brazilian herds. Specific primers and TaqMan probes were designed for all 3 codons of interest. Samples from a total of 142 animals were analyzed by qPCR, followed by DNA sequencing of the amplicons. All of the genotypes determined by qPCR were in agreement with the data determined by DNA sequencing. In all 3 of the analyzed breeds, the majority of the animals were AA homozygous for the 136 codon. The most frequent genotype for codon 154 was RR, and genotypes QQ and QR were the most frequent for codon 171. The results are discussed in relation to establishing scrapie control measures and breeding programs for Brazilian herds.

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RESUMO

Swine influenza (SI) is caused by the type A swine influenza virus (SIV). It is a highly contagious disease with a rapid course and recovery. The major clinical signs and symptoms are cough, fever, anorexia and poor performance. The disease has been associated with other co-infections in many countries, but not in Brazil, where, however, the first outbreak has been reported in 2011. The main aim of this study was to characterize the histological features in association with the immunohistochemical (IHC) results for influenza A (IA), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) in lung samples from 60 pigs submitted to Setor de Patologia Veterinária at the Universidade Federal do Rio Grande do Sul (SPV-UFRGS), Brazil, during 2009-2010. All of these lung samples had changes characterized by interstitial pneumonia with necrotizing bronchiolitis, never observed previously in the evaluation of swine lungs in our laboratory routine. Pigs in this study had showed clinical signs of a respiratory infection. Swine samples originated from Rio Grande do Sul 31 (52%), Santa Catarina 14 (23%), Paraná 11 (18%), and Mato Grosso do Sul 4 (7%). Positive anti-IA IHC labelling was observed in 45% of the cases, which were associated with necrotizing bronchiolitis, atelectasis, purulent bronchopneumonia and hyperemia. Moreover, type II pneumocyte hyperplasia, alveolar and bronchiolar polyp-like structures, bronchus-associated lymphoid tissue (BALT) hyperplasia and pleuritis were the significant features in negative anti-IA IHC, which were also associated with chronic lesions. There were only two cases with positive anti-PCV2 IHC and none to PRRSV. Therefore, SIV was the predominant infectious agent in the lung samples studied. The viral antigen is often absent due to the rapid progress of SI, which may explain the negative IHC results for IA (55%); therefore, IHC should be performed at the beginning of the disease. This study has shown how important a careful histological evaluation is for the diagnosis. Since 2009, a new histological feature of swine pneumonia in animals with respiratory clinical signs has been observed in samples from pigs with clinical respiratory disease submitted to SPV-UFRGS. In addition, the results proved the importance of histological evaluation for swine herd health management.

Influenza suína (IS) é uma doença altamente contagiosa, de curso rápido e pronta recuperação, causada pelo vírus influenza tipo A (SIV). Os principais sinais clínicos são tosse, febre, anorexia e baixo desenvolvimento. A doença está presente em outros países e, geralmente, está associada com outros agentes infecciosos. No Brasil, a primeira descrição ocorreu em 2011 e foi associada ao vírus H1N1 pandêmico (pH1N1). O principal objetivo deste estudo foi caracterizar as alterações histológicas em casos de doença respiratória suína sugestiva de IS e estudar a associação dessas alterações com os resultados de imuno-histoquímica (IHQ) anti-vírus da influenza A (SIV), anti-circovírus suíno tipo 2 (PCV2) e anti-vírus da síndrome reprodutiva e respiratória (PRRSV). Para tanto, foram estudadas amostras de pulmões de 60 suínos selecionadas dos materiais do arquivo do Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul (SPV-UFRGS), de casos de doença respiratória remetidos no período de 2009 a 2010 e que apresentavam alterações histopatológicas compatíveis com pneumonia viral causada pelo SIV. Todas as amostras apresentavam pneumonia intersticial e bronquiolite necrótica muito peculiar que não eram vistas antes na rotina do nosso laboratório. Trinta e uma amostras (52%) tiveram origem no estado do Rio Grande do Sul, 14 (23%) do Paraná, 11 (18%) de Santa Catarina e quatro (7%) do Mato Grosso do Sul. A IHQ para IA confirmou a presença do agente viral em 45% das amostras analisadas. Os achados histológicos mais significativos associados à IHQ positiva para IA foram bronquiolite necrótica, atelectasia, broncopneumonia purulenta e hiperemia. Por outro lado, as alterações histológicas dos pulmões estudados, mais significativamente associadas às IHQ negativa para IA foram hiperplasia dos pneumócitos tipo II, estruturas similares a pólipos em alvéolo e bronquíolo, hiperplasia de tecido linfoide associado a brônquios (BALT) e pleurite, que são alterações associadas a processos crônicos. Somente dois casos apresentaram marcação positiva na IHQ para PCV2 e nenhum pulmão foi positivo para PRRSV. Esses resultados sugerem que as lesões histológicas encontradas no presente estudo foram, predominantemente, causadas pelo SIV. Os casos negativos de IHQ para IA (55%) podem ser explicados pela ausência do antígeno viral nos tecidos estudados. Como o curso da doença é muito rápido, o teste de IHQ é mais indicado para diagnóstico no início da doença. Este estudo possibilitou demonstrar um conjunto de novas alterações histológicas pulmonares de suínos com problemas respiratórios, observadas em amostras pulmonares enviadas ao SPV-UFRGS a partir de 2009. O presente trabalho também reforça a importância de estudos histopatológicos dos casos de campo para auxiliar na monitoria da sanidade dos rebanhos suínos.

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Fibropapillomatosis (FP) is a benign tumoral disease that affects sea turtles, hampering movement, sight and feeding, ultimately leading to death. In Brazil, the disease was described for the first time in 1986. Research suggests the involvement of a herpesvirus in association with environmental and genetic factors as causal agents of FP. The objective of the present study was to detect and characterize this herpesvirus in sea turtles living in the coast of state Rio Grande do Sul (RS), Brazil. From October 2008 to July 2010, 14 turtles were observed between the beaches of Torres and Tavares, of which 11 were green turtles (Chelonia mydas) and 3 were loggerhead turtles (Caretta caretta). All turtles were young and mean curved carapace length was 37.71±7.82cm, and varied from 31 to 55cm. Only one green turtle presented a 1cm, papillary, pigmented fibropapilloma. Skin and fibropapilloma samples were analyzed by conventional and real time PCR assays to detect and quantify herpesvirus. All skin samples were negative, though the fibropapilloma specimen was positive in both tests. Viral load was 9,917.04 copies of viral genome per milligram of tissue. The DNA fragment amplified from the fibropapilloma sample was sequenced and allocated in the Atlantic phylogeographic group. This study reports the first molecular characterization of herpesvirus associated with fibropapilloma in turtles from the coast of RS.

A fibropapilomatose (FP) é uma doença tumoral benigna que pode causar a morte das tartarugas marinhas por dificultar a sua locomoção, visão e alimentação. Pesquisas sugerem o envolvimento de um herpesvirus em associação com fatores ambientais e genéticos como agentes causais da FP. No Brasil, foi descrita pela primeira vez em 1986. O objetivo do presente trabalho foi detectar e caracterizar esse herpesvírus em tartarugas marinhas do litoral do Estado do Rio Grande do Sul (RS). De outubro de 2008 a julho de 2010, foram encontradas 14 tartarugas marinhas entre as praias de Torres e Tavares, das quais 11 eram tartarugas verdes (Chelonia mydas) e 3 eram tartarugas cabeçudas (Caretta caretta). Todas as tartarugas eram jovens e o comprimento curvilíneo de carapaça médio foi de 37,71±7,82cm, variando de 31 a 55cm. Apenas uma tartaruga verde apresentou um fibropapiloma de 1cm, pigmentado e de superfície papilar. Amostras de pele e do fibropapiloma foram submetidas a PCR convencional e PCR em tempo real para detecção e quantificação do herpesvírus. Todas as amostras de pele foram negativas e o fibropapiloma foi positivo em ambas as técnicas, apresentando uma carga viral de 9.917,04 cópias de genoma viral/mg de tecido. O fragmento de DNA amplificado na amostra de fibropapiloma foi sequenciado e revelou pertencer ao grupo filogeográfico do Atlântico. Essa é a primeira caracterização molecular do herpesvirus associado ao fibropapiloma em tartarugas do litoral do RS.

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RESUMO

Swine influenza (SI) is caused by the type A swine influenza virus (SIV). It is a highly contagious disease with a rapid course and recovery. The major clinical signs and symptoms are cough, fever, anorexia and poor performance. The disease has been associated with other co-infections in many countries, but not in Brazil, where, however, the first outbreak has been reported in 2011. The main aim of this study was to characterize the histological features in association with the immunohistochemical (IHC) results for influenza A (IA), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) in lung samples from 60 pigs submitted to Setor de Patologia Veterinária at the Universidade Federal do Rio Grande do Sul (SPV-UFRGS), Brazil, during 2009-2010. All of these lung samples had changes characterized by interstitial pneumonia with necrotizing bronchiolitis, never observed previously in the evaluation of swine lungs in our laboratory routine. Pigs in this study had showed clinical signs of a respiratory infection. Swine samples originated from Rio Grande do Sul 31 (52%), Santa Catarina 14 (23%), Paraná 11 (18%), and Mato Grosso do Sul 4 (7%). Positive anti-IA IHC labelling was observed in 45% of the cases, which were associated with necrotizing bronchiolitis, atelectasis, purulent bronchopneumonia and hyperemia. Moreover, type II pneumocyte hyperplasia, alveolar and bronchiolar polyp-like structures, bronchus-associated lymphoid tissue (BALT) hyperplasia and pleuritis were the significant features in negative anti-IA IHC, which were also associated with chronic lesions. There were only two cases with positive anti-PCV2 IHC and none to PRRSV. Therefore, SIV was the predominant infectious agent in the lung samples studied. The viral antigen is often absent due to the rapid progress of SI, which may explain the negative IHC results for IA (55%); therefore, IHC should be performed at the beginning of the disease. This study has shown how important a careful histological evaluation is for the diagnosis. Since 2009, a new histological feature of swine pneumonia in animals with respiratory clinical signs has been observed in samples from pigs with clinical respiratory disease submitted to SPV-UFRGS. In addition, the results proved the importance of histological evaluation for swine herd health management.(AU)

Influenza suína (IS) é uma doença altamente contagiosa, de curso rápido e pronta recuperação, causada pelo vírus influenza tipo A (SIV). Os principais sinais clínicos são tosse, febre, anorexia e baixo desenvolvimento. A doença está presente em outros países e, geralmente, está associada com outros agentes infecciosos. No Brasil, a primeira descrição ocorreu em 2011 e foi associada ao vírus H1N1 pandêmico (pH1N1). O principal objetivo deste estudo foi caracterizar as alterações histológicas em casos de doença respiratória suína sugestiva de IS e estudar a associação dessas alterações com os resultados de imuno-histoquímica (IHQ) anti-vírus da influenza A (SIV), anti-circovírus suíno tipo 2 (PCV2) e anti-vírus da síndrome reprodutiva e respiratória (PRRSV). Para tanto, foram estudadas amostras de pulmões de 60 suínos selecionadas dos materiais do arquivo do Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul (SPV-UFRGS), de casos de doença respiratória remetidos no período de 2009 a 2010 e que apresentavam alterações histopatológicas compatíveis com pneumonia viral causada pelo SIV. Todas as amostras apresentavam pneumonia intersticial e bronquiolite necrótica muito peculiar que não eram vistas antes na rotina do nosso laboratório. Trinta e uma amostras (52%) tiveram origem no estado do Rio Grande do Sul, 14 (23%) do Paraná, 11 (18%) de Santa Catarina e quatro (7%) do Mato Grosso do Sul. A IHQ para IA confirmou a presença do agente viral em 45% das amostras analisadas. Os achados histológicos mais significativos associados à IHQ positiva para IA foram bronquiolite necrótica, atelectasia, broncopneumonia purulenta e hiperemia. Por outro lado, as alterações histológicas dos pulmões estudados, mais significativamente associadas às IHQ negativa para IA foram hiperplasia dos pneumócitos tipo II, estruturas similares a pólipos em alvéolo e bronquíolo, hiperplasia de tecido linfoide associado a brônquios (BALT) e pleurite, que são alterações associadas a processos crônicos. Somente dois casos apresentaram marcação positiva na IHQ para PCV2 e nenhum pulmão foi positivo para PRRSV. Esses resultados sugerem que as lesões histológicas encontradas no presente estudo foram, predominantemente, causadas pelo SIV. Os casos negativos de IHQ para IA (55%) podem ser explicados pela ausência do antígeno viral nos tecidos estudados. Como o curso da doença é muito rápido, o teste de IHQ é mais indicado para diagnóstico no início da doença. Este estudo possibilitou demonstrar um conjunto de novas alterações histológicas pulmonares de suínos com problemas respiratórios, observadas em amostras pulmonares enviadas ao SPV-UFRGS a partir de 2009. O presente trabalho também reforça a importância de estudos histopatológicos dos casos de campo para auxiliar na monitoria da sanidade dos rebanhos suínos.(AU)

Assuntos