Studies on the multiplication of a porcine parvovirus

A solid phase fluorescent immunoassay for the rapid detection of virus antigen or antibodies in fetuses infected with porcine parvovirus

A solid phase fluorescent immunoassay using polyacrylamide beads coated with rabbit anti-porcine parvovirus antibodies has been developed and utilized in the diagnosis of porcine parvovirus infection. The antibody-coated beads (immunobeads) were used both to detect virus in mummified fetal tissues and to demonstrate specific antibodies in serum and ovarian follicular fluid. The immunobeads assay (IBA) was as sensitive as ELISA but more sensitive than virus isolation using tissue culture and haemagglutination tests. Both mummified and normal fetuses were obtained after experimental infection of SPF pregnant gilts. Using immunobeads, porcine parvovirus antigen was found in all mummified fetuses, but was found in only 1 out of 17 normal fetuses.

Porcine parvovirus: virus purification and structural and antigenic properties of virion polypeptides

Porcine parvovirus (PPV) was extensively purified from infected swine fetal homogenates by CaCl2 precipitation followed by CsCl density centrifugation. Two species of particles possessing PPV-specific hemagglutinating activity were observed banding at densities of 1.39 and 1.30 g/ml, representing full and empty 20-nm virion particles, respectively. Both classes of particles contained three major polypeptides. A, B, and C, with respective molecular weights of 83,000, 64,000, and 60,000. The amount of polypeptide A was similar in both species (approximately 10%); however, the B protein was most abundant in the 1.30-g/ml particles, whereas the C protein was the major polypeptide found in the 1.39-g/ml particles. Antisera generated to each sodium dodecyl sulfate-polyacrylamide gel-purified virion structural protein had reactivities qualitatively similar to those of conventional antisera raised against intact PPV in a variety of standard serological assays. The antisera generated against the individual sodium dodecyl sulfate-denatured PPV polypeptides were able to react with native, intact PPV virions and were capable of neutralizing virus infectivity.