Porcine reproductive and respiratory syndrome virus(PRRSV)0, porcine circovirus type 2(PCV-2) and porcine parvovirus (PPV)0 infections were investigated as possible causes of the postweaning multisystemic wasting syndrome(PMWS). Specific primers for RT-PCR and PCR were designed for the differential detection of PRRSV, PCV-2 and PPV. Using PCR, these viruses were detected in homogenized tissue samples from pigs that had respiratory of reproductive problems in the time period between 1998 and 2000; the overall prevalences were: PRRSV 31.4%, PCV-2 46.5%, and PPV 8.1%. PCV-2 was also detected in aborted fetal tissues.
Aborted Fetus/virology ; Animals ; Base Sequence ; Circoviridae Infections/diagnosis/epidemiology/*veterinary ; Circovirus/genetics/isolation&purification ; DNA Primers ; Diagnosis, Differential ; Korea/epidemiology ; Parvoviridae Infections/diagnosis/epidemiology/*veterinary ; Parvovirus, Porcine/genetics/isolation&purification ; Polymerase Chain Reaction/methods/veterinary ; Porcine Reproductive and Respiratory Syndrome/diagnosis/*epidemiology ; Porcine respiratory and reproductive syndrome virus/genetics/isolation & purification ; Prevalence ; Respiratory Tract Infections/veterinary/virology ; Reverse Transcriptase Polymerase Chain Reaction/methods/veterinary ; Sequence Homology ; Swine ; Swine Diseases/diagnosis/*epidemiology ; Wasting Syndrome/*veterinary/virology

To construct secretory expression vector of PPV NS1 gene, the fragment of PPV NS1 gene coding for major antigen region of the NS1 protein was amplified by PCR and inserted into multiple clone site of eukaryotic expression vector pPICZalpha-A. The recombinant pPICZalpha-A-NS1 plasmid was transferred into P. pastoris strain GS115 mediated by electro transform. Recombinant P. pastoris strain GS115 was induced to express the fusion protein by methanol. The expressed and purified protein was analyzed by SDS-PAGE and Western Blot. The recombinant protein was highly-expressed and showed a good immunoreactivity. The indirect ELISA method was developed for detecting antibodies against PPV by checkerboard titration assay. The result showed that the optimal concentration of coated antigen was 3.2 microg/mL and the best dilution of serum was 1 : 80. The positive cut-off value of the ELISA assay was OD450 > 0.4 and OD450 positive serum/OD450 negative serum > 2.0. Compared with HI and commercial ELISA kits, the assay revealed 94.2% and 92.1% agreement respectively. The assay demonstrates good specificity and sensitivity, and can be applied in the detection of porcine parvovirus.
Animals ; Antibodies, Viral ; immunology ; Antigens, Viral ; genetics ; immunology ; Enzyme-Linked Immunosorbent Assay ; methods ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Parvoviridae Infections ; diagnosis ; immunology ; veterinary ; virology ; Parvovirus, Porcine ; genetics ; immunology ; isolation & purification ; Recombinant Proteins ; genetics ; immunology ; Swine ; Swine Diseases ; diagnosis ; immunology ; virology ; Viral Nonstructural Proteins ; genetics ; immunology