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

• Ano de defesa: 2021
• Autor(a) principal: Assao, Viviane Sisdelli
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Suíno - Doenças - Diagnóstico; Proteínas recombinantes; Porcine circovirus; Medicina Veterinária Preventiva
• Link de acesso: https://locus.ufv.br//handle/123456789/28161

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. Keywords: Porcine circovirus 3. Genetic diversity. Real-time PCR. Nested PCR. Capsid protein.