Detecção herpesvírus bovino tipo 5 em cortes histológicos e fragmentos de encéfalo congelado pela reação em cadeia de polimerase
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Data
2007-11-29
Autores
Ferrari, Heitor Flávio [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Meningoencefalite não supurativa causada pelo Herpesvírus bovino tipo 5 (BoHV-5) ocorre de forma endêmica em algumas regiões do Brasil, com ênfase no Rio Grande do Sul. No entanto, outras regiões possuem poucos relatos da ocorrência da doença, como os estados de São Paulo e Mato Grosso do Sul. O presente trabalho objetivou realizar a classificação histológicas das lesões desenvolvidas durante a infecção aguda pelo BoHV-5, no encéfalo de 20 animais naturalmente acometidos pelo infecção. As principais lesões observadas, em 80% dos animais, foram de meningoencefalite não supurativa, caracterizadas por infiltrado linfo-histiocitária inflamatório. Em 20% dos animais as lesões encontradas foram não significativas, mas nestes casos todos os bovinos desenvolveram sintomatologia neurológica, e o diagnóstico da doença foi confirmado na reação em cadeia pela polimerase (PCR), com amplificação do DNA do BoHV-5. Esta classificação histológica permitiu observar alterações compatíveis com a doença, mas também mostrou que nem sempre nestes casos vai ocorrer o desenvolvimento de alterações histológicas. Todas as amostras frescas (n=20) foram submetidas ao isolamento viral e a técnica da técnica de PCR. Já os fragmentos fixados em formol e incluídos em parafina foram testados quanto à presença do vírus por meio da técnica de PCR. As vinte amostras congeladas foram consideradas positivas para o isolamento viral e para a amplificação do DNA viral na técnica de PCR, enquanto apenas 15 das 20 incluídas em parafina foram consideradas positivas para o vírus. Os fragmentos de tecidos que apresentaram alterações histopatológicas permitiram suspeitar de infecção viral por BoHV-5, mas nos casos em que estas alteração não estão presentes testes mais sensíveis são necessários.
Meningoencephalitis occasioned by Bovine Herpesvirus type 5 (BoHV-5) has been described as localized in some regions inside Brazil, like Rio Grande do Sul State and, also characterized as an endemic encephalitis disorder. However, the often description of its occurrence in São Paulo end Mato Grosso has being notice. The aim of this work was to first characterize the histologic lesions obtained from bovine brains suspected of suffering of neurological disorders. For this purpose, 20 brains were collected from acute cases of the disease, naturally infected by BoHV-5, confirmed by virus isolation and PCR. The most observed lesions were described as being: inflammatory cells, specially infiltrated lymphocytes (80%), necrosis (20%), and less focal gliosis and hemorrhage, in spite of these lesions have been characterized as no-specific. Brains were divided into two halves, one kept fresh for virus isolation and PCR assay, targeting the glycoprotein C gene from BoHV-5 genome. The other half brain, corresponding to cortex region, was submitted to formalin fixation and embedded into paraffin blocks for total DNA isolation. The 20 fresh samples were confirmed, by virus isolation and PCR assay, as having the BoHV-5 virus, while 15 of 20 formalin-fixed, paraffin-embedded samples were considered positive for the same analysis. Finally, the gross lesions and microscopic damage of the brain structure were sufficient for the virus infection suspicion, however it is necessary the complementary techniques to confirm the diagnosis in most of the cases.
Meningoencephalitis occasioned by Bovine Herpesvirus type 5 (BoHV-5) has been described as localized in some regions inside Brazil, like Rio Grande do Sul State and, also characterized as an endemic encephalitis disorder. However, the often description of its occurrence in São Paulo end Mato Grosso has being notice. The aim of this work was to first characterize the histologic lesions obtained from bovine brains suspected of suffering of neurological disorders. For this purpose, 20 brains were collected from acute cases of the disease, naturally infected by BoHV-5, confirmed by virus isolation and PCR. The most observed lesions were described as being: inflammatory cells, specially infiltrated lymphocytes (80%), necrosis (20%), and less focal gliosis and hemorrhage, in spite of these lesions have been characterized as no-specific. Brains were divided into two halves, one kept fresh for virus isolation and PCR assay, targeting the glycoprotein C gene from BoHV-5 genome. The other half brain, corresponding to cortex region, was submitted to formalin fixation and embedded into paraffin blocks for total DNA isolation. The 20 fresh samples were confirmed, by virus isolation and PCR assay, as having the BoHV-5 virus, while 15 of 20 formalin-fixed, paraffin-embedded samples were considered positive for the same analysis. Finally, the gross lesions and microscopic damage of the brain structure were sufficient for the virus infection suspicion, however it is necessary the complementary techniques to confirm the diagnosis in most of the cases.
Descrição
Palavras-chave
Meningoencefalite, Herpesvirus bovino, Meningoencephalitis, Herpesvirus 5, Bovine, Polymerase chain reaction
Como citar
FERRARI, Heitor Flávio. Detecção herpesvírus bovino tipo 5 em cortes histológicos e fragmentos de encéfalo congelado pela reação em cadeia de polimerase. 2007. 94 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Odontologia de Araçatuba, 2007.