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| Author(s): |
Karen Linares Ferrari
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2012-09-03 |
| Examining board members: |
Leonardo José Richtzenhain;
Alessandra Marnie Martins Gomes de Castro;
Tais Fukuta da Cruz
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| Advisor: | Leonardo José Richtzenhain |
| Abstract | |
Porcine circovirus 2 (PCV2) associated disease (PCVAD) may manifest as systemic infection, enteritis, reproductive problems, dermatitis and nephropathy syndrome and porcine respiratory disease complex (PRDC). The occurrence of PRDC, which affects mainly the growing and finishing animals, characterized by slow growth, prolonged cough and dyspnea, as well as characteristic gross lesions in the lungs. PCV2 has three main regions denominated open reading frames (ORFs): ORF-1 encodes a protein involved in replication (Rep gene), ORF-2 encodes the capsid structural protein (Cap gene) and ORF-3 encodes a protein involved in the induction of cellular apoptosis. The Cap gene is the most variable region of PCV2, with evidence of association between the Cap protein and pathogenicity. According to an unified nomenclature proposed by Ségales et al., three different subtypes are currently recognized (PCV2a,-2b-2c). The increased incidence and severity of PCVAD was attributed to the rise of PCV2b becoming the most prevalent subtype in countries of North America, Europe, and Brazil. Given the damage that leads to PRDC, 200 samples of lungs with and without macroscopic pneumonic lesions were analyzed for PCV2 by PCR; 88.5% (177/200) were positive for PCV2 by PCR corroborating with studies in which PCV2 was found in a large number of samples and could develop a role in PRDC. However, there was no significant association between positive samples and the presence or absence of macroscopic pneumonic lesions (p=0.26). Phylogenetic analysis of the 27 samples PCV2 positive sequenced (22 complete genome and five complete ORF-2) were grouped in genotype PCV2b. Due to the high identity between the nucleotide and amino acid sequences obtained and retrieved from previous studies with presence and absence of PCVAD, there is no evidence of association between subtype and pathogenicity of PCV2 identified in this work (AU) | |
| FAPESP's process: | 10/03371-1 - Molecular diversity of cap gene (ORF-2) of porcine circovirus type 2 (PCV2) detected in samples of lung with and without macroscopic pneumonic lesions in pigs slaughtered in São Paulo State. |
| Grantee: | Karen Linares Ferrari |
| Support Opportunities: | Scholarships in Brazil - Master |