Construction of Recombinant Baculovirus Containing Peste des Petits Ruminants Virus N Gene and Establishment of Indirect ELISA for Detecting Serum Antibodies

This experiment was conducted to diagnose Peste des Petits Ruminants based on the eukaryotically-expressed PPRV nucleoprotein through an indirect ELISA. The full-length PPRV nucleoprotein gene was obtained from viral genome RNA by RT-PCR. The amplified fragments were cloned into baculovirus donor vectors pFastHTA of the Bac-to-Bac system. These recombinant plasmids, pFastHTA-PPRV-N, were transformed into DH10Bac host bacteria to obtain recombinant shuttle plasmids, pBacmid-PPRV-N. Recombinant baculovirus, Bacmid-PPRV-N, was generated for expression of the PPRV nucleoprotein by transfecting recombinant pBacmid-PPRV-N with Lipofectamine 2000 into Sf21 insect cells. The efficient expression of PPRV Nucleoprotein by baculovirus in Sf21 cells was verified by SDS-PAGE and Western blot. An indirect ELISA was developed using recombinant PPRV nucleoprotein as the coating antigen. 37 goat sera from an epidemic area in Tibet and 92 goat sera from a non-infected area in Qinghai Province were simultaneously detected by the indirect ELISA, developed here, and the international standard cELISA kit. The sensitivity and specificity of the indirect ELISA was 100% and 96.2% compared with the cELISA kit. The coincidence rate of the two methods was 96.9%. The results demonstrated that the indirect ELISA established in this study works well for diagnosis of PPR.

This experiment was conducted to diagnose Peste des Petits Ruminants based on the eukaryotically-expressed PPRV nucleoprotein through an indirect ELISA. The full-length PPRV nucleoprotein gene was obtained from viral genome RNA by RT-PCR. The amplified fragments were cloned into baculovirus donor vectors pFast HTA of the Bac-to-Bac system. These recombinant plasmids, oFastHTA-PPRV-N, were transformed into DH10Bac host bacteria to obtain recombinant shuttle Dlasmids.pBacmid-PPRV-N. Recombinant baculovirus, Bacmid-PPRV-N, was generated for expression of the PPRV nucleoprotein by transfecting recombinant pBacmid-PPRV-N with Lipofectamine 2000 into Sf21 insect cells. The efficient expression of PPRV Nucleoprotein by baculovirus in Sf21 cells was verified by SDS-PAGE and Western blot. An indirect ELISA was developed using recombinant PPRV nucleoproteinas the coating antigen. 37 goat sera from an epidemic area in Tibet and 92 goat sera from a non-infected area in Qinghai Province were simultaneously detected by the indirect ELISA, developed here, and the international standard cELISA kit. The sensitivity and specificity of the indirect ELISA was 100% and 96.2% compared with the cELISA kit. The coincidence rate of the two methods was 96.9%. The results demonstrated that the indirect ELISA established in this study works well for diagnosis of PPR.