Molecular pathogenesis and development of a genetically engineered vaccine for type-2 porcine circovirus [electronic resource] /
Porcine circovirus type 2 (PCV2) is the primary causative agent of postweaning multisystemic wasting syndrome (PMWS), whereas the ubiquitous porcine circovirus type 1 (PCV1) is nonpathogenic for pigs. Since its initial detection in a Canadian commercial swine herd in 1991, PMWS has been detected in all swine producing regions of the world and is now a serious economic problem to the swine industry. The objectives of this dissertation were to biologically, genetically and experimentally characterize both PCV1 and PCV2, to identify the genetic determinant(s) for virulence and replication, and to develop an effective genetically-engineered vaccine against PCV2 infection and PMWS. The genetic heterogeneity of PCV2 and PCV1 isolates from different geographic origins were determined. We found that, although PCV1 and PCV2 genomes were very conserved, some minor genomic variation exists among PCV1 isolates and PCV2 isolates. The nonpathogenic PCV1 and pathogenic PCV2 share only about 76% nucleotide sequence identity but have similar genomic organization. The highest sequence variability among PCV isolates is found in the immunogenic ORF2 capsid gene. Based on the sequence data in this dissertation, a universal polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was developed that is capable of detecting all known PCV isolates and differentiating between infections by nonpathogenic PCV1 and pathogenic PCV2.
School:Virginia Polytechnic Institute and State University
School Location:USA - Virginia
Source Type:Master's Thesis
Keywords:postweaning multisystemic wasting syndrome s pcv1 chimeric vaccine keywords and abbreviations porcine circovirus recombinant molecular biology virology pmws pcv2
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