Retrospective Detection and Genetic Characterization of <i>Porcine circovirus</i> 3 (PCV3) Strains Identified between 2006 and 2007 in Brazil
Giuliana Loreto Saraiva,
Pedro Marcus Pereira Vidigal,
Viviane Sisdelli Assao,
Murilo Leone Miranda Fajardo,
Alerrandra Nunes Saraiva Loreto,
Juliana Lopes Rangel Fietto,
Gustavo Costa Bressan,
Zélia Inês Portela Lobato,
Márcia Rogéria de Almeida,
Abelardo Silva-Júnior
Affiliations
Giuliana Loreto Saraiva
Laboratório de Infectologia Molecular Animal, Instituto de Biotecnologia Aplicada à Agropecuária, Universidade Federal de Viçosa (UFV), Viçosa, Minas Gerais 36570-900, Brazil
Pedro Marcus Pereira Vidigal
Núcleo de Análise de Biomoléculas (NuBioMol), Centro de Ciências Biológicas (CCB), Universidade Federal de Viçosa (UFV), Viçosa, Minas Gerais 36570-900, Brazil
Viviane Sisdelli Assao
Laboratório de Imunobiológicos e Virologia Animal, Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, Minas Gerais 36570-900, Brazil
Murilo Leone Miranda Fajardo
Laboratório de Imunobiológicos e Virologia Animal, Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, Minas Gerais 36570-900, Brazil
Alerrandra Nunes Saraiva Loreto
Laboratório de Imunobiológicos e Virologia Animal, Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, Minas Gerais 36570-900, Brazil
Juliana Lopes Rangel Fietto
Laboratório de Infectologia Molecular Animal, Instituto de Biotecnologia Aplicada à Agropecuária, Universidade Federal de Viçosa (UFV), Viçosa, Minas Gerais 36570-900, Brazil
Gustavo Costa Bressan
Laboratório de Infectologia Molecular Animal, Instituto de Biotecnologia Aplicada à Agropecuária, Universidade Federal de Viçosa (UFV), Viçosa, Minas Gerais 36570-900, Brazil
Zélia Inês Portela Lobato
Escola de Veterinária, Departamento de Medicina Veterinária Preventiva, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais 36570-900, Brazil
Márcia Rogéria de Almeida
Laboratório de Infectologia Molecular Animal, Instituto de Biotecnologia Aplicada à Agropecuária, Universidade Federal de Viçosa (UFV), Viçosa, Minas Gerais 36570-900, Brazil
Abelardo Silva-Júnior
Laboratório de Infectologia Molecular Animal, Instituto de Biotecnologia Aplicada à Agropecuária, Universidade Federal de Viçosa (UFV), Viçosa, Minas Gerais 36570-900, Brazil
Porcine circovirus 3 (PCV3) is an emerging virus that was first identified in the United States in 2016. Since its first detection, PCV3 has already been found in America, Asia, and Europe. Although PCV3 has already been described in Brazil, knowledge of its detection and sequence variation before 2016 is limited, as well as its distribution in the main swine producing regions of Brazil. In this study, 67 porcine clinical samples collected from nine states in Brazil between 2006 and 2007 were analyzed for PCV3 infection by PCR. Results showed that 47.8% of the samples were PCV3 positive, across all nine states. Of the PCV3-positive samples, 37.5% were also positive for PCV2. Interestingly, no clinical signs were associated with samples that were detected singularly with PCV3 infection. Moreover, the positive PCV3 rate in healthy pigs was higher (29.8%) than that found in unhealthy pigs (17.9%), suggesting that most pigs could live with PCV3 infection without any clinical sign in the analyzed samples. Nucleotide sequence analysis showed that PCV3 strains obtained in this study shared 94.44% to 99.83% sequence identity at the open reading frame 2 (ORF2) gene level with available strains from different countries. PCV3 Brazilian sequences collected in 2006 and 2007 shared 97.94% to 99.62% identity with the strains obtained in 2016. The results of neutrality and selective pressure tests indicated that the PCV3 Cap protein seems unable to tolerate high levels of variation on its sequence. Phylogenetic analysis grouped the Brazilian strains in PCV3a and PCV3b genotypes clusters, both including strains collected in America, Asia, and Europe. Taking the results together, multiple events of introduction of PCV3 may have occurred in Brazil, and Brazilian PCV3 strains may show genetic stability over the past 10 years.
