Porcine circovirus 2 and 3 in wild boars in Southern Brazil / Circovírus suíno 2 e 3 em javalis no Sul do Brasil

Porcine circovirus 2 (PCV2) has a considerable economic impact on the pork industry worldwide for more than two decades. In 2016, a new circovirus, porcine circovirus 3 (PCV3), was described; since then, it has been reported to be associated with diseased or even in clinically healthy swine in several countries. Considering the importance of wild boars as reservoirs of swine pathogens and the extensive distribution of these animals in Rio Grande do Sul and throughout the national territory, we searched for PCV2 and PCV3 in twenty-six wild boars coupled with necropsy and histologic examination of the sampled animals. Using PCR, 182 tissue samples were analyzed, including the heart, kidneys, liver, lung, lymph nodes, spleen, and tonsils. PCV2 and PCV3 were detected in 57.7% (15/26) and 15.4% (4/26) of wild boars, respectively. Furthermore, co-infection with PCV2 and PCV3 was detected in one of these animals, with PCV2 or PCV3 DNA detection in multiple organs. Histological examination showed mild to moderate and multifocal lymphoplasmacytic interstitial nephritis distributed randomly throughout the renal cortex, apparently unrelated to PCV2 or PCV3 detection. The wild boar population in Brazil is extensive, indicating the presence of a larger number of swine pathogen hosts. In the present study, more than half of the wild boars harbored PCV2; and although less frequently, PCV3 was also detected. Therefore, free-living wild boars can serve as reservoirs of swine circoviruses in southern Brazil.

O circovírus suíno 2 (PCV2) tem causado impacto econômico na indústria suína em todo o mundo por mais de duas décadas. Em 2016, um novo circovírus foi descrito - circovírus suíno 3 (PCV3) - e desde então tem sido relatado em vários países associado a doenças ou mesmo suínos saudáveis. Diante da importância dos javalis como reservatórios de patógenos suínos, e da ampla distribuição desses animais no Rio Grande do Sul e em todo o território nacional, foi realizada pesquisa de PCV2 e PCV3 em vinte e seis javalis (10 fêmeas e 16 machos). Necropsia e exame histológico foram realizados. Utilizando PCR, foram analisadas 182 amostras de tecidos incluindo: coração, rins, fígado, pulmão, linfonodos, baço e tonsila. PCV2 e PCV3 foram detectados por PCR em 57,7% (15/26) e 15,4% (4/26) dos javalis, respectivamente. Um destes animais estava co-infectado por PCV2 e PCV3. O DNA do PCV2 ou PCV3 foi detectado em multiplos órgãos. No exame histológico foi observada nefrite intersticial linfoplasmocitária multifocal leve a moderada, distribuída aleatoriamente pelo córtex renal, aparentemente sem relação com a detecção de DNA viral. A população de javalis no Brasil é extensa, resultando em maior número de hospedeiros para patógenos de suínos. No presente estudo, mais da metade dos javalis capturados abrigavam PCV2 e, embora menos frequente, PCV3 também foi detectado. Os javalis de vida livre podem servir como reservatórios de circovírus suínos no sul do Brasil.

Histopathologic patterns and etiologic diagnosis of porcine respiratory disease complex in Brazil / Padrões histopatológicos e diagnóstico etiológico do complexo de doenças respiratórias dos suínos no Brasil

Porcine respiratory disease complex is a major health concern for the porcine industry, causing significant economic loss. In this study, a total of 156 samples from pigs referred to a diagnostic laboratory in Brazil for 15 months were analyzed by histopathology, bacterial isolation, PCR, and immunohistochemistry. Multiple infections were common, so 42.3% of the pigs had more than one pathogen detected in the lungs. Swine influenza virus was detected in 25.0% of the cases. Porcine circovirus type 2 was detected in 7.1% of the pigs, which was often associated with Pasteurella multocida. In addition, one case of porcine circovirus type 3 infection associated with granulomatous pneumonia was diagnosed. Bacteria were isolated in 125 cases, namely Pasteurella multocida (34.0%), Glaesserella (Haemophilus) parasuis (35.2%), Streptococcus suis (13.5%), and Actinobacillus pleuropneumoniae (7.7%). Mycoplasma hyopneumoniae was identified in 7.0% of the cases, and 18.6% of pigs carried Salmonella sp. The most common patterns of pulmonary inflammation were broncopneumonia, bronchointerstitial pneumonia, and pleuritis, in that order. This study demonstrated that histopathology is an efficient tool along with other laboratorial diagnostic tests for establishing an etiologic diagnosis in cases of porcine respiratory disease complex.

O complexo de doenças respiratórias de suínos é um dos principais problemas sanitários na suinocultura, causando perdas econômicas significativas. O presente estudo incluiu amostras de 156 suínos, que foram encaminhados a um laboratório de diagnóstico no Brasil, durante um período de 15 meses, sendo realizados histopatologia, isolamento bacteriano, PCR e imuno-histoquímica. Coinfecções por múltiplos patógenos foram comuns, correspondendo a 42,3% dos animais, que tiveram mais de um agente identificado nos pulmões. O vírus da influenza suína foi detectado em 25,0%. O circovírus suíno tipo 2 foi detectado em 7,1% dos animais, frequentemente associado à Pasteurella multocida. Além disso, foi diagnosticado um caso de circovírus suíno tipo 3 associado à pneumonia granulomatosa. Foram isoladas bactérias em 125 casos, a saber: Pasteurella multocida (34,0%), Glaesserella (Haemophilus) parasuis (35,2%), Streptococcus suis (13,5%) e Actinobacillus pleuropneumoniae (7,7%). Mycoplasma hyopneumoniae foi identificado em 7,0%, e 18,6% dos animais tiveram isolamento de Salmonella sp. Os padrões mais frequentes de inflamação pulmonar foram: broncopneumonia, pneumonia broncointersticial e pleurite, nesta ordem. Este estudo demonstrou que a histopatologia é uma ferramenta eficiente, juntamente a outras técnicas laboratoriais de diagnóstico, para o estabelecimento de diagnóstico etiológico em casos do complexo de doenças respiratórias de suínos.

A molecular survey reveals high occurrence of co-infections in intensive pork production farms with increased rates of mummified swine fetuses in Southern Brazil / [Pesquisa molecular revela alta ocorrência de coinfecções em granjas de produção intensiva de suínos com altas taxas de mumificação fetal no sul do Brasil]

Neste estudo, 308 amostras de fetos mumificados foram testadas para parvovírus suíno (PPV), circovírus suíno tipos 2 e 3 (PCV2 e PCV3) e leptospiras patogênicas. A idade gestacional no momento da perda gestacional e a frequência da mumificação fetal de acordo com a ordem de parto também foram investigadas. As amostras foram coletadas em granjas comerciais de criação de suínos da região sul do Brasil que apresentassem taxas de mumificação fetal igual ou maiores a 2,5%. Fragmentos de pulmão, rim, fígado e coração de fetos suínos mumificados foram coletados para análise molecular. Resultados da PCR foram classificados de acordo com a região de origem das amostras, tendo Santa Catarina, Paraná e Rio Grande do Sul contabilizado 87 (28,25%), 89 (28,90%) e 132 (42,86%) do total de amostras de fetos suínos mumificados, respectivamente. Coinfecções foram observadas na maioria dos casos e PCV3 foi o agente mais prevalente detectado, encontrado em 298 amostras (96,75%). A maioria das perdas gestacionais foi observada entre 50 e 70 dias de gestação (168; 54,5%) e a mumificação fetal não foi associada à ordem de parto das matrizes. Os achados sugerem que as altas taxas de fetos suínos mumificados na região Sul do Brasil podem ser explicadas pela infecção com esses agentes virais.(AU)

Molecular detection and clinical aspects of porcine circovirus 3 infection in pigs from Brazil / [Detecção molecular e aspectos clínicos da infecção por circovírus suíno 3 em suínos do Brasil]

Porcine circovirus 3 (PCV-3) DNA has been detected in serum samples from apparently healthy pigs as well as pigs with different clinical conditions. Molecular detection of PCV-3 was observed in swine serum samples from Southeastern - Brazil using a nested PCR designed specifically for this study. The epidemiology and clinical aspects of PCV-3 infection were evaluated. The samples originated from 154 pigs of both genders from different production phases and with different clinical presentations, sampled from 31 pig farms visited between 2013 and 2018. In this study, PCV-3 was detected in 26.7% of samples from all populations across varying ages. Statistical association (P=0.0285) was observed only between animals with respiratory signs and PCV-3; no PCV-3-positive animal had diarrhea. No statistical association was observed between PCV-3 and age, or gender of the pigs. Because PCV-3 is a newly discovered virus, there is very little information about its epidemiology. We hope that these data can help in future studies investigating PCV-3 epidemiology.(AU)

O DNA do circovírus suíno 3 (PCV-3) foi detectado em amostras de soro de suínos aparentemente saudáveis, bem como em suínos com diferentes condições clínicas. A detecção molecular do PCV-3 foi observada em amostras de soro de suínos da região Sudeste do Brasil, com uma nested PCR desenhada especificamente para este estudo. A epidemiologia e os aspectos clínicos da infecção por PCV-3 foram avaliados. As amostras foram coletadas de 154 suínos de ambos os sexos, de diferentes fases de produção e com diferentes sinais clínicos. Os animais pertenciam a 31 granjas visitadas entre 2013 e 2018. Neste estudo, o PCV-3 foi detectado em 26,7% das amostras de animais saudáveis e de animais com variados sinais clínicos, de ambos os sexos e de idades variadas. Associação estatística (P=0,0285) foi observada apenas entre animais com sinais respiratórios e PCV-3; nenhum animal positivo para PCV-3 apresentava diarreia. Não foi observada associação estatística entre o PCV-3 e a idade ou o sexo dos suínos. Por se tratar de um vírus recém-descoberto, existem poucas informações sobre sua epidemiologia. Espera-se que os dados deste trabalho possam contribuir para futuros estudos sobre a epidemiologia do PCV-3.(AU)

Infectious diseases dynamics in growing/finishing pigs in Southern Brazil (2005-2016) / Dinâmica de ocorrência das doenças infecciosas em suínos nas fases de crescimento e terminação no sul do Brasil (2005-2016)

This study aimed to determine the frequency and distribution of infectious diseases diagnosed through necropsy examination and histopathological analysis in growing/finishing pigs along 12 years (2005-2016) in Southern Brazil. We evaluated 1906 anatomopathological exams of pigs at growing/finishing phases, of which the infectious diseases corresponded to 75.6% of the cases (1,441/1,906). Porcine circovirus type 2 (PCV2) infections were the most frequent, accounting for 51.3% of the cases (739/1,441) with a higher frequency from 2005 to 2007, characterizing an epidemic distribution, with a gradual decline after 2008. Infectious diseases affecting the respiratory system were the second major cause with 30.1% of the cases. Among these, necrotizing bronchiolitis caused by swine Influenza (15.1%, 218/1,441) and bacterial pneumonia (15%, 216/1,441) were the main conditions. Influenza was mostly diagnosed from 2010 to 2013, accounting for 43.1% (167/387) of the cases. After this period, both respiratory infectious diseases were endemic. Digestive system infectious diseases accounted for 10.5% of the diagnoses (151/1,441), with the following main conditions: Salmonella spp. enterocolitis (43.7%, 66/151), Lawsonia spp. proliferative enteropathy (41.7%, 63/151), and Brachyspira spp. colitis (14.6%, 22/151). The latter had a higher incidence from 2012 to 2014 with all cases detected in this period. Polyserositis and bacterial meningitis represented, respectively, 5.8% (84/1,441) and 2.3% (33/1,441) of the cases diagnosed, with a constant endemic character.(AU)

O objetivo deste estudo consistiu em determinar a frequência e a distribuição das doenças infecciosas diagnosticadas através de exame de necropsia e análise histopatológica em suínos nas fases de crescimento/terminação ao longo de 12 anos (2005-2016) no sul do Brasil. Foram avaliados 1906 laudos anatomopatológicos de suínos nas fases de crescimento/terminação, dos quais as doenças infecciosas corresponderam a 75,6% (1441/1906) do total. As infecções por circovírus suíno tipo 2 (PCV2) foram as mais frequentes, contabilizando 51,3% (739/1441) dos casos, com uma alta frequência de 2005 a 2007 caracterizando uma distribuição epidêmica neste período, e um declínio gradual após o ano de 2008. A segunda principal causa incluiu as doenças infecciosas que afetam o sistema respiratório (30,1% dos casos). Dentre essas, destacaram-se a influenza suína (15,1%; 218/1441) e pneumonias bacterianas (15%; 216/1441). O diagnóstico de influenza apresentou uma frequência elevada de 2010 a 2013, totalizando 43,1% (167/387) dos casos. Após este período, ambas doenças infecciosas respiratórias exibiram caráter endêmico. As doenças infecciosas do sistema digestório totalizaram 10,5% (151/1441) dos diagnósticos, com as seguintes principais condições: enterocolite por Salmonella spp. (43,7%; 66/151), enteropatia proliferativa por Lawsonia spp. (41,7%; 63/151) e colite por Brachyspira spp. (14,6%; 22/151). A colite por Brachyspira spp. apresentou uma alta incidência de 2012 a 2014 com todos os casos detectados no período. As polisserosites e meningites bacterianas representaram 5,8% (84/1441) e 2,3% (33/1441) dos casos diagnosticados, respectivamente, com um caráter endêmico constante.(AU)

Infectious diseases dynamics in growing/finishing pigs in Southern Brazil (2005-2016) / Dinâmica de ocorrência das doenças infecciosas em suínos nas fases de crescimento e terminação no sul do Brasil (2005-2016)

This study aimed to determine the frequency and distribution of infectious diseases diagnosed through necropsy examination and histopathological analysis in growing/finishing pigs along 12 years (2005-2016) in Southern Brazil. We evaluated 1906 anatomopathological exams of pigs at growing/finishing phases, of which the infectious diseases corresponded to 75.6% of the cases (1,441/1,906). Porcine circovirus type 2 (PCV2) infections were the most frequent, accounting for 51.3% of the cases (739/1,441) with a higher frequency from 2005 to 2007, characterizing an epidemic distribution, with a gradual decline after 2008. Infectious diseases affecting the respiratory system were the second major cause with 30.1% of the cases. Among these, necrotizing bronchiolitis caused by swine Influenza (15.1%, 218/1,441) and bacterial pneumonia (15%, 216/1,441) were the main conditions. Influenza was mostly diagnosed from 2010 to 2013, accounting for 43.1% (167/387) of the cases. After this period, both respiratory infectious diseases were endemic. Digestive system infectious diseases accounted for 10.5% of the diagnoses (151/1,441), with the following main conditions: Salmonella spp. enterocolitis (43.7%, 66/151), Lawsonia spp. proliferative enteropathy (41.7%, 63/151), and Brachyspira spp. colitis (14.6%, 22/151). The latter had a higher incidence from 2012 to 2014 with all cases detected in this period. Polyserositis and bacterial meningitis represented, respectively, 5.8% (84/1,441) and 2.3% (33/1,441) of the cases diagnosed, with a constant endemic character.(AU)

O objetivo deste estudo consistiu em determinar a frequência e a distribuição das doenças infecciosas diagnosticadas através de exame de necropsia e análise histopatológica em suínos nas fases de crescimento/terminação ao longo de 12 anos (2005-2016) no sul do Brasil. Foram avaliados 1906 laudos anatomopatológicos de suínos nas fases de crescimento/terminação, dos quais as doenças infecciosas corresponderam a 75,6% (1441/1906) do total. As infecções por circovírus suíno tipo 2 (PCV2) foram as mais frequentes, contabilizando 51,3% (739/1441) dos casos, com uma alta frequência de 2005 a 2007 caracterizando uma distribuição epidêmica neste período, e um declínio gradual após o ano de 2008. A segunda principal causa incluiu as doenças infecciosas que afetam o sistema respiratório (30,1% dos casos). Dentre essas, destacaram-se a influenza suína (15,1%; 218/1441) e pneumonias bacterianas (15%; 216/1441). O diagnóstico de influenza apresentou uma frequência elevada de 2010 a 2013, totalizando 43,1% (167/387) dos casos. Após este período, ambas doenças infecciosas respiratórias exibiram caráter endêmico. As doenças infecciosas do sistema digestório totalizaram 10,5% (151/1441) dos diagnósticos, com as seguintes principais condições: enterocolite por Salmonella spp. (43,7%; 66/151), enteropatia proliferativa por Lawsonia spp. (41,7%; 63/151) e colite por Brachyspira spp. (14,6%; 22/151). A colite por Brachyspira spp. apresentou uma alta incidência de 2012 a 2014 com todos os casos detectados no período. As polisserosites e meningites bacterianas representaram 5,8% (84/1441) e 2,3% (33/1441) dos casos diagnosticados, respectivamente, com um caráter endêmico constante.(AU)

Structure analysis of capsid protein of Porcine circovirus type 2 from pigs with systemic disease

Economic losses with high mortality rate associated with Porcine circovirus type 2 (PCV2) is reported worldwide. PCV2 commercial vaccine was introduced in 2006 in U.S. and in 2008 in Brazil. Although PCV2 vaccines have been widely used, cases of PCV2 systemic disease have been reported in the last years. Eleven nursery or fattening pigs suffering from PCV2 systemic disease were selected from eight PCV2-vaccinated farms with historical records of PCV2 systemic disease in Southern Brazil. PCV2 genomes were amplified and sequenced from lymph node samples of selected pigs. The comparison among the ORF2 amino acid sequences of PCV2 isolates revealed three amino acid substitutions in the positions F57I, N178S and A190T, respectively. Using molecular modeling, a structural model for the capsid protein of PCV2 was built. Afterwards, the mutated residues positions were identified in the model. The structural analysis of the mutated residues showed that the external residue 190 is close to an important predicted region for antibodies recognition. Therefore, changes in the viral protein conformation might lead to an inefficient antibody binding and this could be a relevant mechanism underlying the recent vaccine failures observed in swine farms in Brazil.(AU)

Structure analysis of capsid protein of Porcine circovirus type 2 from pigs with systemic disease

Abstract Economic losses with high mortality rate associated with Porcine circovirus type 2 (PCV2) is reported worldwide. PCV2 commercial vaccine was introduced in 2006 in U.S. and in 2008 in Brazil. Although PCV2 vaccines have been widely used, cases of PCV2 systemic disease have been reported in the last years. Eleven nursery or fattening pigs suffering from PCV2 systemic disease were selected from eight PCV2-vaccinated farms with historical records of PCV2 systemic disease in Southern Brazil. PCV2 genomes were amplified and sequenced from lymph node samples of selected pigs. The comparison among the ORF2 amino acid sequences of PCV2 isolates revealed three amino acid substitutions in the positions F57I, N178S and A190T, respectively. Using molecular modeling, a structural model for the capsid protein of PCV2 was built. Afterwards, the mutated residues positions were identified in the model. The structural analysis of the mutated residues showed that the external residue 190 is close to an important predicted region for antibodies recognition. Therefore, changes in the viral protein conformation might lead to an inefficient antibody binding and this could be a relevant mechanism underlying the recent vaccine failures observed in swine farms in Brazil.

DETECÇÃO MOLECULAR DE CIRCOVÍRUS SUÍNO 3 EM FLUÍDO ORAL DE SUÍNOS EM FASE DE TERMINAÇÃO NO OESTE DE SANTA CATARINA

A suinocultura nacional tem evoluído de forma contínua há décadas, melhorando índices reprodutivos, zootécnicos, de biosseguridade e bem-estar animal. Da mesma forma, a intensificação do confinamento dos animais favoreceu a transmissão de agentes infeciosos, resultando em desafios sanitários. Os vírus estão entre os principais desafios para manutenção da sanidade das granjas de suínos. Um dos principais, se não o principal agente patogênico na suinocultura é o circovírus suíno 2 (PCV2). Em 2015, um novo circovírus foi descrito em suínos com quadro clínico de circovirose, incluindo inflamação multissistêmica e problemas reprodutivos. Devido as similaridades estruturais dos vírions e a doença relacionada, este agente foi denominado circovírus suíno 3 (PCV3). Desde então, diversos estudos têm demonstrado o potencial patogênico deste agente, assim como a ampla distribuição deste vírus em suínos domésticos e selvagens em diversos países. Desta forma, o objetivo deste trabalho foi realizar o diagnóstico e sequenciamento molecular de PCV3 em suínos em fase de terminação de granjas no oeste de Santa Catarina, importante região produtora de suínos no Brasil. As amostras foram obtidas através de coleta de fluido oral (FO), amostra de alta qualidade e utiliza um processo não invasivo e que leva em consideração o comportamento natural dos suínos. Foram acessadas amostras de 110 granjas de fase de terminação, de animais clinicamente saudáveis com idade aproximada de 100 dias. Utilizando cordas, pools de FO de 110 granjas (um pool por baia contendo 12 animais cada), contemplando desta forma uma amostragem de 1.320 suínos. As amostras foram processadas e o DNA viral foi extraído e submetido a PCR. Um total de 79 dos 110 pools (72%) foram positivos na PCR para PCV3. A sequência parcial de nucleotídeos do gene do capsídeo (ORF2) de cinco amostras foi obtida e submetidos ao banco de dados GenBank. Quando realizada a análise filogenética utilizando sequências de amostras brasileiras e de países da Europa e Ásia, fica evidente a diversidade entre as sequências obtidas. Os resultados deste estudo demonstram que o PCV3 está amplamente distribuído no oeste de Santa Catarina, maior produtor de suínos do Brasil.

National swine farming has evolved continuously for decades, improving reproductive, zootechnical, biosecurity and animal welfare rates. Likewise, the intensification of the animals' confinement favored the transmission of infectious agents, resulting in health challenges. Viruses are among the main challenges for maintaining the health of pig farms. One of the main, if not the main pathogenic agent in swine farming is the porcine circovirus 2 (PCV2). In 2015, a new circovirus was described in pigs with a clinical condition of circovirus associated disease, including multisystemic inflammation and reproductive failure. Due to the virion structure similarities and related disease, this agent was named porcine circovirus 3 (PCV3). Since then, several studies have demonstrated the pathogenic potential of this agent, as well as the worldwide distribution of this virus in domestic and wild pigs, including Brazil. Thereby, the objective of this study was to perform the molecular diagnosis of PCV3 in finishing swine of farms in Western Santa Catarina State. The samples were obtained through the collection of oral fluid (OF), a non-invasive process based on the natural behavior of swine. Samples from 110 finishing swine farms were accessed from clinically healthy animals. Using ropes, pools of FO from 110 farms (one pool per pen contain 12 animals each), contemplating a sampling of 1,320 swine. Together, the 110 farms housed approximately 74,805 pigs at the time of collection. The samples were processed and the viral genome was extracted and subjected to PCR. A total of 79 out of 110 pools (72%) were positive for PCV3 by PCR. The nucleotide sequence of the capsid gene (ORF2) from five samples was obtained and submitted to the GenBank database. When phylogenetic analysis was performed using sequences from Brazilian samples and from countries in Europe and Asia, the diversity between the sequences obtained in the present study was observed. The results of this study demonstrate that PCV3 is widely distributed in Western Santa Catarina, the largest pork producer in Brazil.

GENETIC VARIABILITY OF NEW BRAZILIAN PCV2D STRAINS AND THEIR RELATION TO COMMERCIAL VACCINES

No presente estudo 246 amostras clínicas oriundas de granjas de suínos comerciais nas regiões sul, sudeste e centr-oeste do Brasil, previamente vacinadas contra PCV2 e que apresentavam sinais clínicos compatíveis com PCVD foram submetidas para genotipagem de PCV2. O tipo de material enviado para diagnóstico foram amostras de fluido oral, soro e pool de órgãos linfoides. Das amostras analisadas, 106 (43.09% - 106/246) foram genotipadas, sendo 75.47% (80/106) identificadas como PCV2d e 22.64% (24/106) identificadas como PCV2b. Em 2/106 (1.89%) amostras foram verificadas co-infecção de PCV2b e PCV2d. Não houve detecção do genótipo PCV2a nas amostras analisadas. Dentre as amostras clínicas analisadas, o fluido oral obteve um maior número de amostras genotipadas (40/106-37.74%), seguido de pool de órgãos linfóides e soro, com o mesmo número de amostras genotipadas (33/106- 31.13%). Adicionalmente, 51 amostras clínicas brasileiras coletadas em 2019 foram enviadas para sequenciamento genético do gene ORF2, que codifica a proteína do capsídeo viral (Cap). Destas, 25 apresentaram boa qualidade para análise, sendo 8 genotipadas como PCV2b e 17 como PCV2d, confirmando que no Brasil, como descrito mundialmente, houve o aumento do genótipo PCV2d. Para analisar a distribuição temporal dos genótipos e flutuação mundial dos genótipos desde 1993 à 2019, 3,544 sequencias disponíveis no GenBank foram analisadas, demonstrando um considerável aumento do genótipo PCV2d a partir de 2006, sendo hoje, o genótipo mais prevalente no mundo. Para estimar a variabilidade da Cap protein de nossas sequencias de PCV2d, comparamos nossas amostras com outras 1,300 sequencias de PCV2d disponíveis no GenBank. Com o objetivo de avaliar a possível pressão vacinal sobre o o genótipo PCV2d, separamos as sequencias em 4 grupos: (1) Pre vacinação (PreVacD) - sequencias de amostras coletadas antes de 2006; (2) Pós vacinação (PosVacD) - sequencias de amostras coletadas entre 2007 e 2020; (3) sequencias de suínos selvagens ou de vida livre(WboarD) que não sofreram pressão vacinal; e (4) nossas sequencias de PCV2d (TestD), analisadas no presente estudo.. Devido às possíveis falhas vacinais observadas nas granjas de suínos comerciais no Brasil, as amostras de PCV2d sequenciadas no presente estudo foram comparadas com as sequencias da ORF2 disponíveis de três vacinas comercias utilizadas no Brasil, uma contendo o genótipo PCV2b e duas contendo o genótipo PCV2a. Grande parte dos resíduos de aminoácidos que se encontram dentro de regiões de epítopo são conservadas, sugerindo uma boa reação cruzada entre as amostras vacinais e as amostras de PCV2d analisadas. Contudo, em alguns resíduos de aminoácidos em sítios antigênicos, essencias para ligação de anticorpos e, consequentemente, neutralização viral, foram detectadas mutações entre as sequencias de PCV2d e as sequencias vacinais. Este resultado sugere que estas mutações possam ter importancia em relação à resposta. Porém, mais estudos devem ser realizados para elucidar essas questões, principalmente a implementação de processos de vigilância de genótipos de Circovirus suínos tipo 2 circulantes no Brasil.

In the present study, 246 clinical samples from commercial pig farms located in the south, southeast and central-west regions of Brazil previously vaccinated against PCV2 and showing clinical signs compatible with PCVD were submitted for PCV2 genotyping. The type of material sent for diagnosis were samples of oral fluid, serum and lymphoid organs pool. Of the analyzed samples, 106 (43.09% - 106/246) were genotyped, with 75.47% (80/106) identified as PCV2d and 22.64% (24/106) as PCV2b. In 2/106 (1.89%) samples, coinfection of PCV2b and PCV2d was observed. There was no detection of the PCV2a genotype in the analyzed samples. Among the analyzed clinical samples, oral fluid obtained the greater number of genotyped samples (40/106- 37.74%), followed by pool of lymphoid organs and serum, with the same number of genotyped samples (33/106-31.13%) . Additionally, 51 Brazilian clinical samples collected in 2019 were sent for genetic sequencing of the ORF2 gene, widely used for genomic/protein analysis, which encodes for the viral capsid protein (Cap). Of these, 25 had good quality for analysis, and 8 were genotyped as PCV2b and 17 as PCV2d, corroborating many other publications around the world that demonstrated the increase of the PCV2d genotype. To analyze the temporal distribution of genotypes and fluctuation of genotypes from 1993 to 2019 worldwide, 3,544 sequences available in GenBank were analyzed, demonstrating a considerable increase in the PCV2d genotype since 2006, today the most prevalent genotype in the world. To estimate the Cap protein variability of our PCV2d sequences, our results were compared to other 1,300 PCV2d sequences available in GenBank. In order to assess the possible pressure of the vaccine against the PCV2d genotype population infection, four groups of samples were defined: (1) Prevaccination (PreVacD) - sequences from samples collected before 2006; (2) Post-vaccination (PosVacD) - sequences of samples collected between 2007 and 2020; (3) sequences from wild or feral pigs (WboarD) that were not vaccinated, and (4) our PCV2d sequences (TestD) analyzed in the present study. Due to possible vaccine failures observed in commercial pig farms in Brazil, the PCV2d sequenced samples in the present study were compared to the ORF2 amino acid sequences available from three commercial vaccines used in Brazil, one containing the PCV2b genotype and 2 containing the PCV2a genotype. Most of the amino acid residues found within epitope regions were conserved, suggesting a good cross-reaction between vaccines and the analyzed PCV2d samples. However, in some amino acid residues in antigenic sites essential for antibody binding and consequently viral neutralization, mutations were detected in PCV2d sequences and in vaccine sequences. This result may suggest that these mutations might be involved in the vaccine immune response. However, further studies must be carried out to elucidate these aspects, especially the implementation of surveillance processes of Porcine Circovirus type 2 genotypes circulating in Brazil.

A double-antibody sandwich ELISA based on the porcine circovirus type 2 (PCV2) propagated in cell culture for antibody detection / Sandwich ELISA com duplo anticorpo baseado no circovirus suíno tipo 2 (PCV2) produzido em cultivo celular para detecção de anticorpos

Few studies have described enzyme-linked immunosorbent assays (ELISAs) for the detection of antibodies against porcine circovirus type 2 (PCV2) based on antigens produced in cell culture. Furthermore, few articles have described viral purification techniques for members of the family Circoviridae. This occurs because circoviruses are difficult to isolate, noncytopathogenic, and produce low viral titres in cell culture. Thus, for overcoming these difficulties in the cultivation of PCV2, this study aimed to develop a double-antibody sandwich ELISA based on the cell culture antigen PCV2b for the quantification of anti-PCV2 antibodies. A 20% and 50% discontinuous sucrose cushion was used for viral purification, which enabled the separation of cell culture proteins in the 20% sucrose cushion and a greater viral concentration in the 50% sucrose cushion. Following isopycnic centrifugation, PCV2 was concentrated in the band with density values from 1.330 to 1.395g/cm3. Viral purification was assessed using SDS-PAGE, indirect ELISA and electron microscopy. The standardised ELISA revealed a strong linear correlation (r= 0.826, p<0.001) when compared with a commercial ELISA kit. The assay exhibited low variability (inter-assay coefficient of variation of 4.24% and intra-assay of 1.80%) and excellent analytical specificity conferred by the capture antibody produced in rabbit. Thus, this ELISA is a rapid, specific and convenient method for the detection of antibodies against PCV2 in studies of experimental and natural infection, and in monitoring the response to vaccination on commercial farms.(AU)

Há poucos relatos na literatura de métodos de ELISA (Enzyme-linked immunosorbent assay), para a detecção de anticorpos contra o circovírus suíno tipo 2 (PCV2), baseados em antígenos produzidos em cultivo celular, bem como uma escassez de trabalhos descrevendo técnicas de purificação viral para os membros da família Circoviridae. Isso ocorre, pois os circovírus são de difícil isolamento, não causam efeito citopático e produzem um baixo título viral em cultivo celular. Assim, para superar essas dificuldades encontradas no cultivo do PCV2, este estudo objetivou desenvolver um sandwich ELISA com duplo anticorpo, baseado no antígeno de PCV2 produzido em cultivo celular, para a quantificação de anticorpos anti-PCV2. Um colchão de sacarose descontínuo a 20% e 50% foi utilizado para a purificação viral, o qual possibilitou a separação das proteínas oriundas do cultivo celular no colchão de sacarose a 20% e uma maior concentração viral no colchão de sacarose a 50%. Com a ultracentrifugação isopícnica, o PCV2 ficou mais concentrado na banda com valores de densidade de 1,330 a 1,395g/cm3. A purificação viral foi avaliada pelas técnicas de SDS-PAGE, ELISA indireto e microscopia eletrônica. Assim, o método de ELISA padronizado revelou uma forte correlação linear (r = 0,826, p <0,001) quando comparado com um kit de ELISA comercial. O ensaio demonstrou baixa variabilidade (coeficientes de variação inter-teste de 4,24% e intra-teste de 1,80%) e uma excelente especificidade analítica conferida pelo anticorpo de captura produzido em coelho. Portanto, o método de ELISA demonstrou ser rápido, específico e conveniente para a detecção de anticorpos contra o PCV2 em estudos de infecção natural e experimental, além da monitoria da resposta à vacinação contra o PCV2 em granjas comerciais.(AU)

A double-antibody sandwich ELISA based on the porcine circovirus type 2 (PCV2) propagated in cell culture for antibody detection / Sandwich ELISA com duplo anticorpo baseado no circovirus suíno tipo 2 (PCV2) produzido em cultivo celular para detecção de anticorpos

Few studies have described enzyme-linked immunosorbent assays (ELISAs) for the detection of antibodies against porcine circovirus type 2 (PCV2) based on antigens produced in cell culture. Furthermore, few articles have described viral purification techniques for members of the family Circoviridae. This occurs because circoviruses are difficult to isolate, noncytopathogenic, and produce low viral titres in cell culture. Thus, for overcoming these difficulties in the cultivation of PCV2, this study aimed to develop a double-antibody sandwich ELISA based on the cell culture antigen PCV2b for the quantification of anti-PCV2 antibodies. A 20% and 50% discontinuous sucrose cushion was used for viral purification, which enabled the separation of cell culture proteins in the 20% sucrose cushion and a greater viral concentration in the 50% sucrose cushion. Following isopycnic centrifugation, PCV2 was concentrated in the band with density values from 1.330 to 1.395g/cm3. Viral purification was assessed using SDS-PAGE, indirect ELISA and electron microscopy. The standardised ELISA revealed a strong linear correlation (r= 0.826, p < 0.001) when compared with a commercial ELISA kit. The assay exhibited low variability (inter-assay coefficient of variation of 4.24% and intra-assay of 1.80%) and excellent analytical specificity conferred by the capture antibody produced in rabbit. Thus, this ELISA is a rapid, specific and convenient method for the detection of antibodies against PCV2 in studies of experimental and natural infection, and in monitoring the response to vaccination on commercial farms.(AU)

Há poucos relatos na literatura de métodos de ELISA (Enzyme-linked immunosorbent assay), para a detecção de anticorpos contra o circovírus suíno tipo 2 (PCV2), baseados em antígenos produzidos em cultivo celular, bem como uma escassez de trabalhos descrevendo técnicas de purificação viral para os membros da família Circoviridae. Isso ocorre, pois os circovírus são de difícil isolamento, não causam efeito citopático e produzem um baixo título viral em cultivo celular. Assim, para superar essas dificuldades encontradas no cultivo do PCV2, este estudo objetivou desenvolver um sandwich ELISA com duplo anticorpo, baseado no antígeno de PCV2 produzido em cultivo celular, para a quantificação de anticorpos anti-PCV2. Um colchão de sacarose descontínuo a 20% e 50% foi utilizado para a purificação viral, o qual possibilitou a separação das proteínas oriundas do cultivo celular no colchão de sacarose a 20% e uma maior concentração viral no colchão de sacarose a 50%. Com a ultracentrifugação isopícnica, o PCV2 ficou mais concentrado na banda com valores de densidade de 1,330 a 1,395g/cm3. A purificação viral foi avaliada pelas técnicas de SDS-PAGE, ELISA indireto e microscopia eletrônica. Assim, o método de ELISA padronizado revelou uma forte correlação linear (r = 0,826, p < 0,001) quando comparado com um kit de ELISA comercial. O ensaio demonstrou baixa variabilidade (coeficientes de variação inter-teste de 4,24% e intra-teste de 1,80%) e uma excelente especificidade analítica conferida pelo anticorpo de captura produzido em coelho. Portanto, o método de ELISA demonstrou ser rápido, específico e conveniente para a detecção de anticorpos contra o PCV2 em estudos de infecção natural e experimental, além da monitoria da resposta à vacinação contra o PCV2 em granjas comerciais.(AU)

Detection and evaluation of genetic diversity of Porcine circovirus 3 in Brazilian swine farms, expression and purification of the capsid protein.

Porcine circovirus 3 (PCV3) é um vírus que foi descoberto recentemente. PCV3 tem sido associado a diversos sintomas, mas a sua patogenicidade ainda está sendo discutida. PCV3 tem sido detectado circulando na população suína em todo o mundo. Devido ao fato de que existem poucos estudos sobre PCV3 no rebanho suíno brasileiro, esse trabalho teve como objetivo estudar a presença de PCV3 no Brasil. Neste trabalho nós investigamos a diversidade genética de PCV3 em fazendas de suínos localizadas em Minas Gerais. Os resultados mostraram que pelo menos duas linhagens de cepas de PCV3 estão circulando no Brasil. Pela primeira vez, um estudo relata a detecção de duas cepas diferentes de PCV3 no mesmo suíno. Nós avaliamos duas técnicas de diagnóstico molecular (real-time PCR e Nested PCR) para a detecção de PCV3, e a técnica de real-time PCR obteve resultados superiores em comparação com a técnica de Nested PCR usada neste estudo. Nós investigamos a presença de PCV3 em fazendas de suínos que relatavam problemas sanitários no Paraná, o segundo maior estado produtor de carne suína. Nossos resultados mostraram que 36,88% dos suínos eram positivos para PCV3. O DNA de PCV3 foi detectado em suínos com diversos problemas de saúde, incluindo suínos com lesões vesiculares o que não foi descrito em trabalhos anteriores. Além disso, nós expressamos a proteína truncada do capsídeo viral de PCV3 usando um sistema de expressão procarioto e purificamos parcialmente a proteína usando um protocolo de purificação em duas etapas para ser utilizada no futuro para o desenvolvimento de vacinas e testes de diagnóstico.

Porcine circovirus 3 (PCV3) is a recently discovered virus. PCV3 has been associated with several signs, but its pathogenicity is still being debated. PCV3 has been detected and circulating in the swine population worldwide. Due to the fact that there are a few studies of PCV3 in Brazilian swine herds, this work aimed to investigat PCV3 in Brazil. We evaluated two molecular diagnostic tests (real-time PCR and Nested PCR) for PCV3 detection, and the real-time PCR assay had better results than the Nested PCR assay used in this study. We investigated the genetic diversity of PCV3 in swine farms from Minas Gerais, the fourth largest pork producing state in Brazil. Our results revealed the presence of at least two PCV3 main lineages circulating in Brazil. Furthermore, for the first time, we reported the detection of two different PCV3 strains in the same pig. We also surveyed PCV3 in swine farms affected by several health problems in Paraná, the second-largest pork producing state in Brazil. Our results showed that 36.88% of the swine were PCV3 positive. PCV3 DNA was detected in swine with different health problems, including animals with vesicular lesions that had not been previously documented. Finally, we expressed the truncated PCV3 capsid protein using a prokaryotic expression system and partially purified it using a two-steps purification with the goal for future development of vaccines and diagnostic tests.

The effects of sow viremia and maternal antibodies in porcine circovirus 2 on viral infection and weight of piglets / Efeito da viremia da porca e de anticorpos maternos para circovírus suíno 2 na infecção e no peso da leitegada

The aim of this study was to characterize the porcine circovirus 2 (PCV2) infections in farrowing sows and to evaluate an association with piglet viremia and weight. Twenty sows and 100 newborn piglets were studied. Colostrum and serum of the sows were obtained on the day of parturition. Milk samples were collected on day 20 postpartum. Blood samples were taken and the piglets were weighed on days 1, 20, 42, 63 and 84 postpartum. Colostrum, milk and serum were evaluated for PCV2 DNA load. Serum was evaluated for neutralizing antibodies. PCV2 DNA was found in 17/20 serum samples, 14/20 colostrum samples and 11/20 milk samples. On day 1 postpartum 29% of piglets were viremic. PCV2 viral load ranged from 3.02 to 6.75 log10 copies/mL considering all sampled days. There was no correlation between sow viremia, antibody levels or PCV2 load in colostrum and piglet viremia on day 1 postpartum. The PCV2 load in colostrum and milk was associated with viremia in piglets from weaning to 84 days postpartum. Piglets' PCV2 viremia and viral load could not be associated with weight throughout this study.(AU)

O objetivo deste estudo foi caracterizar o efeito do infecção pelo circovírus suíno 2 (PCV2) em porcas gestantes na viremia e no peso da leitegada. Vinte porcas e 100 leitões recém-nascidos foram acompanhados. Amostras de colostro e soro das porcas foram obtidas no dia do parto. Amostras de leite foram coletadas no dia pós-parto 20. Os leitões foram pesados e tiveram amostras de soro coletadas nos dias um, 20, 42, 63 e 84 pós-parto. Soro, colostro e leite foram testados para carga viral do PCV2. Soro foi avaliado para presença de anticorpos neutralizantes. O DNA do PCV2 foi encontrado em 14 de 20 amostras de colostro e em 11 de 20 amostras de leite. No dia pós-parto 1, 29% dos leitões foram virêmicos. A carga viral do PCV2 variou 3,02-6,75 log10 cópias / mL, considerando todos os dias amostrados. Não houve correlação entre viremia das porcas e os níveis de anticorpos no soro ou na carga de PCV2 no colostro e na viremia dos leitões com um dia de vida. A carga de PCV2 no colostro e no leite foi associada à viremia em leitões do desmame até 84 dias pós-parto. A carga viral do PCV2 em leitões não foi associada com o peso ao longo deste estudo.(AU)

Concomitant zearalenone ingestion and Porcine Circovirus-2 infection / Concomitant zearalenone ingestion and Porcine Circovirus-2 infection

Background: Researches have suggested that mycotoxins could corroborate the pathogenesis of porcine viral diseases. Zearalenone (ZEA), one of the most import mycotoxicosis in pigs result significant reproductive disorders. The circovirosis syndromes in pigs have been associated with multifactorial or predisposing conditions. No previous data have correlated ZEA with viral syndromes in Sus scrofa. In this report are described anamnesis, clinical and histological findings with zearalenone ingestion and PCV-2 infection in a Brazilian livestock. Case: Feeding ration was mixed and produced at the farm with low quality corn that was stored in barn with cement floor. During ten months, 28 farrowing occurred. Fifteen of them were normal and produced 145 animals, mean of 9.66 piglets per litter. Thirteen sows presented reproductive disorders, and one died. Eight of them had the delayed farrowing and three aborted. These animals produced 57 mummified fetuses (10-16cm crown-rump length), 23 aborted fetuses (60-72 days of gestation), four stillborn, two teratogenic fetuses and only 16 normal piglets. Skin pustules, hemorrhagic spots and petechiae, as well as coughing were observed in 88% of the animals and four piglets died. Diarrhea outbreaks frequently occurred in this period. Twenty five of 34 gilts (75%) showed longer estrous cycle, estrus returning, vulvae volume and mammary glands en

Background: Researches have suggested that mycotoxins could corroborate the pathogenesis of porcine viral diseases. Zearalenone (ZEA), one of the most import mycotoxicosis in pigs result significant reproductive disorders. The circovirosis syndromes in pigs have been associated with multifactorial or predisposing conditions. No previous data have correlated ZEA with viral syndromes in Sus scrofa. In this report are described anamnesis, clinical and histological findings with zearalenone ingestion and PCV-2 infection in a Brazilian livestock. Case: Feeding ration was mixed and produced at the farm with low quality corn that was stored in barn with cement floor. During ten months, 28 farrowing occurred. Fifteen of them were normal and produced 145 animals, mean of 9.66 piglets per litter. Thirteen sows presented reproductive disorders, and one died. Eight of them had the delayed farrowing and three aborted. These animals produced 57 mummified fetuses (10-16cm crown-rump length), 23 aborted fetuses (60-72 days of gestation), four stillborn, two teratogenic fetuses and only 16 normal piglets. Skin pustules, hemorrhagic spots and petechiae, as well as coughing were observed in 88% of the animals and four piglets died. Diarrhea outbreaks frequently occurred in this period. Twenty five of 34 gilts (75%) showed longer estrous cycle, estrus returning, vulvae volume and mammary glands en

Concomitant zearalenone ingestion and porcine circovirus-2 infection

Background: Researches have suggested that mycotoxins could corroborate the pathogenesis of porcine viral diseases. Zearalenone (ZEA), one of the most import mycotoxicosis in pigs result significant reproductive disorders. The circovirosis syndromes in pigs have been associated with multifactorial or predisposing conditions. No previous data have correlated ZEA with viral syndromes in Sus scrofa. In this report are described anamnesis, clinical and histological findings with zearalenone ingestion and PCV-2 infection in a Brazilian livestock. Case: Feeding ration was mixed and produced at the farm with low quality corn that was stored in barn with cement floor. During ten months, 28 farrowing occurred. Fifteen of them were normal and produced 145 animals, mean of 9.66 piglets per litter. Thirteen sows presented reproductive disorders, and one died. Eight of them had the delayed farrowing and three aborted. These animals produced 57 mummified fetuses (10-16cm crown-rump length), 23 aborted fetuses (60-72 days of gestation), four stillborn, two teratogenic fetuses and only 16 normal piglets. Skin pustules, hemorrhagic spots and petechiae, as well as coughing were observed in 88% of the animals and four piglets died. Diarrhea outbreaks frequently occurred in this period. Twenty five of 34 gilts (75%) showed longer estrous cycle, estrus returning, vulvae volume and mammary glands enlargement. Necropsies showed enlarged lymphatic nodes and kidneys. Histopathological and immunohistochemical analysis indicated the presence of Porcine Circovirus type 2 (PCV-2) in analyzed tissues. Toxicological tests demonstrated the presence of zearalenone (ZEA) in stomach contents with average of 8.75 µg/g and pesticides and aflatoxins were not detected. Discussion: The history, the clinical signs, the necropsy and histological findings suggested a mix of zearalenone mycotoxicosis and PVC-2 syndrome that was confirmed by PVC-2 tissue detection in immunohistochemical assay, and by food toxicological analysis. The ZEA average founded in stomach contents (8.75 µg/g could produce the reproductive disorders and could has exacerbated the circovirosis. The most frequent reproductive alteration observed in the farrowing was mummified fetuses that corresponded 66.7% of its products. The several reproductive disorders as abortion, stillborn, mummified fetuses, estrus returning, vulvae volume and mammary glands enlargement in gilts are frequently related to zearalenone mycotoxicosis. Appetite loss, apathy, wasting, cough and diarrhea and increased mortality and withdrawal rate in growth and post-weaning phases observed in this study are liked as the several descriptions in the Post-Weaning Multisystemic Wasting Syndrome. The hemorrhagic skin spots and increased kidneys, with multifocal glomerulonephritis, lymphohistiocytic interstitial nephritis to remember the several alterations in Porcine Dermatitis and Nephropathy Syndrome. Both syndromes by PCV-2 could be simultaneity occurring in this herd and could have a co-participation of the ZEA ingestion as aggravated factor. After contaminated corn to sorghum free of ZEA exchange at ration, the reproduction returned to normal level and no PCV-2 lesions were observed, suggesting the ZEA ingestion as one initial or aggravating factor for the PCV-2 syndromes. For the first time, this report describes historical, anamnesis, clinical and histological findings possibly associated with zearalenone contamination and PCV-2 infection in pigs.

Doenças infecciosas em suínos nas fases de crescimento e terminação na região Sul do Brasil

A suinocultura brasileira representa uma importante atividade econômica para o país, o qual ocupa lugar de destaque na produção e exportação de carne suína no mundo. O destaque do país na produção de suínos, deve-se a melhorias na sanidade, manejo, produção integrada e, principalmente, no aprimoramento gerencial dos produtores. O primeiro artigo consistiu em determinar a frequência e a distribuição das doenças infecciosas (DI) diagnosticadas através de exame de necropsia e histopatologia em suínos nas fases de crescimento e terminação ao longo de 12 anos (2005-2016) no sul do Brasil. Foram avaliados 1906 laudos anatomopatológicos de suínos nas fases de crescimento/terminação, dos quais as DI corresponderam a 75,6% (1441 casos) do total. As infecções por circovírus suíno tipo 2 (PCV2) foram as mais frequentes, contabilizando 51,3% (739/1441) dos casos, seguidas por DI que afetam o sistema respiratório (30,1% dos casos). Dentre essas, destacam-se a influenza suína A (15,1%; 218/1441) e pneumonias bacterianas (15%; 216/1441). O diagnóstico de influenza exibiu uma frequência elevada entre os anos de 2010 a 2013, totalizando 43,1% (167/387) dos casos. Após este período, ambas DI respiratórias exibiram caráter endêmico. As DI que afetam o sistema digestório totalizaram 10,5% (151/1441) dos diagnósticos, com as seguintes condições: enterocolite por Salmonella spp. (43,7%; 66/151), enteropatia proliferativa por Lawsonia spp. (41,7%; 63/151) e colite por Brachyspira spp. (14,6%; 22/151). Além dessas, as polisserosites e meningites bacterianas representaram 5,8% (84/1441) e 2,3% (33/1441) dos casos diagnosticados, respectivamente. O segundo artigo descreve três surtos de doença por circovírus suíno tipo-2 (PCVD) com lesões envolvendo musculatura esquelética. Em um curso clínico de 7 a 10 dias, 92 suínos apresentaram apatia, emagrecimento e diarreia. Ainda, cerca de 30 dos suínos afetados, apresentavam dificuldade de locomoção, fraqueza muscular, paresia de membros pélvicos e decúbito permanente. Quatro suínos exibiram palidez em músculos esqueléticos dos membros pélvicos, torácicos e dorso-lombares. As lesões microscópicas observadas consistiam de miosite necrótica granulomatosa, predominantemente, em membros pélvicos e torácicos, e em menor intensidade nos músculos dorso-lombares. No exame imuno-histoquímico para PCV2 observou-se marcação multifocal acentuada, predominantemente, no citoplasma e núcleos de macrófagos, linfócitos e células gigantes multinucleadas, além de marcação discreta no citoplasma no citoplasma de fibras necróticas da musculatura esquelética. As amostras de músculo esquelético foram positivas na reação em cadeia de polimerase para PCV2 e a ampliação exibiu 99% de identidade com sequências pertencentes ao genótipo PCV2b.

Brazilian pig farms represent an important economic activity for the country, which occupies a prominent place in the production and export of pork in the world. The country's prominence in pork production is due to improvements in sanitation, management, integrated production and, mainly, in the managerial improvement of the producers. The first study aimed to determine the frequency and distribution of infectious diseases (ID) diagnosed through necropsy and histopathology examination in growing-finishing swine along 12 years (2005-2016) in Southern Brazil. A total of 1906 anatomopathological exams performed in growing-finishing swine were evaluated, of which ID accounted for 75.6% (1441 cases) of the total. Porcine circovirus type 2 (PCV2) infections were the most frequent, accounting for 51.3% of the cases (739/1441), followed by respiratory system ID (30.1% of the cases). Among these, the main conditions were swine influenza (15.1%; 218/1441) and bacterial pneumonia (15%; 216/1441). Influenza diagnosis had a higher frequency between 2010 and 2013, accounting for 43,1% (167/387) of the cases. After this period, both respiratory ID had an endemic occurrence. Digestive system ID accounted for 10.5% (151/1441) of the diagnosis, with the main conditions diagnosed: Salmonella spp. enterocolitis (43.7%; 66/151), Lawsonia spp. proliferative enteropathy (41.7%; 63/151) and Brachyspira spp. colitis (14.6%; 22/151). Besides these, polyserositis and bacterial meningitis represented, respectively, 5.8% (84/1441) and 2.3% (33/1441) of the cases diagnosed. The second study describes three outbreak of porcine circovirus disease (PCVD) with the involvement of skeletal muscle. In a clinical course of 7 to 10 days, 92 pigs had apathy, weight loss and diarrhea. Approximately 30 of these 92 pigs had stiff gait, muscle weakness, hind limb paresis, and recumbency. 4 pigs necropsied presented pale discoloration from hind and thoracic limbs, as well from dorsal lumbar skeletal muscles. The microscopical lesions consisted of granulomatous necrotizing myositis mainly of hind and thoracic limbs, and mildly from dorsal lumbar muscles. Immunohistochemistry exam for PCV2 revealed marked multifocal intracytoplasmic and intranuclear staining predominantly in macrophages, lymphocytes and multinucleated giant cells, with a lower amount in the cytoplasm of necrotic fibers of the skeletal muscle. Affected muscle samples were polymerase chain reaction positive for PCV2 and the amplicon exhibited 99% identity with sequences belonging to the PCV2b genotype.

Detection of Genetic characterization of Porcine circovirus 2 (PCV2) in Brazilian wildlife boars

A semi-intensive wildlife boars farm presented a clinical history of high mortality in 70 - 90 days-old pigs (> 50 %). Two 90 days-old animals with weight loss and wasting were necropsied and the samples tested for PCV2 by polymerase chain reaction (PCR). The genetic material of PCV2 was sequenced and classified into the PCV2a genotype together with PCV2 sequences obtained from samples of Poland, Brazil, Slovenia and Greece wild boars.

Detection of Genetic characterization of Porcine circovirus 2 (PCV2) in Brazilian wildlife boars

A semi-intensive wildlife boars farm presented a clinical history of high mortality in 70 - 90 days-old pigs (> 50 %). Two 90 days-old animals with weight loss and wasting were necropsied and the samples tested for PCV2 by polymerase chain reaction (PCR). The genetic material of PCV2 was sequenced and classified into the PCV2a genotype together with PCV2 sequences obtained from samples of Poland, Brazil, Slovenia and Greece wild boars.

Interstitial nephritis of slaughtered pigs in the State of Mato Grosso, Brazil / Nefrite intersticial em suínos abatidos no Estado de Mato Grosso

This study evaluated histological lesions in kidney samples from pigs with nephritis in two slaughterhouses in the State of Mato Grosso, Brazil. Four hundred samples were subjected to histology, anti-porcine circovirus type 2 (PCV2) immunohistochemistry (IHC), anti-Leptospira sp. immunofluorescence (IF), and polymerase chain reaction (PCR) for PCV2, porcine parvovirus (PPV), and Torque teno virus type 1 and 2 (TTV1, TTV2) detection. Histological lesions were found in 81% of the samples, and mononuclear interstitial nephritis was the most frequent lesion (77.50%). A follicular pattern was observed in 40.97% of the interstitial nephritis lesions. PCV2, PPV, TTV1, and TTV2 were identified in the kidneys by PCR in 27.25%, 28.50%, 94%, and 87.5% of the samples, respectively. Leptospira sp. was not detected through IF. Infection by PCV2 (PCR) and the presence of histological lesions (P=0.008) and giant cells (P=0.0016) were significantly associated. An association was observed between the TTV2-TTV1 co-infection (P<0.0001) and the risk for pathogenesis. These findings indicated that PCV2, PPV, TTV1, and TTV2 were widely distributed among pigs in the local farms and that the presence of these agents should be considered in the differential diagnosis of kidneys with interstitial nephritis in pigs.(AU)

O propósito desse estudo foi avaliar as lesões histológicas observadas em rins condenados por nefrite pelo Serviço de Inspeção Federal, em dois frigoríficos de Mato Grosso, Brasil. Foram coletados 400 rins condenados por nefrite e submetidos aos exames de histologia, imuno-histoquímica (IHC) para Circovirus suíno Tipo 2 (PCV2), imunofluorescência direta (IF) para Leptospira sp. e reação em cadeia pela polimerase (PCR) para detecção de PCV2, Parvovirus suíno (PPV) e Torque teno vírus Tipo 1 e 2 (TTV1 e TTV2). Foram observadas lesões histológicas em 81% das amostras, sendo nefrite intersticial mononuclear a mais freqüente (77,50%). Das lesões de nefrite intersticial encontradas, 40,97% apresentaram padrão folicular. Através da PCR foi observada ampla distribuição dos agentes (PCV2, PPV, TTV1 e TTV2) nas propriedades e municípios, com ocorrência de 27,25%, 28,50%, 94% e 87,50%, respectivamente. Leptospira sp. não foi detectada através da IF. Houve associação significativa da infecção do PCV2 com presença de lesão histológica (P=0,008) e de células gigantes (P=0,0016). Também houve associação entre a co-infecção TTV2 e TTV1 (P<0,0001). Esses achados indicam que os vírus PCV2, PPV, TTV1 e TTV2 devem ser considerados no diagnóstico diferencial de rins com nefrite intersticial em suínos.(AU)