Generation, characterization, and application in serodiagnosis of recombinant swine vesicular disease virus-like particles

Swine vesicular disease (SVD) is a highly contagious viral disease that causes vesicular disease in pigs. The importance of the disease is due to its indistinguishable clinical signs from those of foot-and-mouth disease, which prevents international trade of swine and related products. SVD-specific antibody detection via an enzyme-linked immunosorbent assay (ELISA) is the most versatile and commonly used method for SVD surveillance and export certification. Inactivated SVD virus is the commonly used antigen in SVD-related ELISA. A recombinant SVD virus-like particle (VLP) was generated by using a Bac-to-Bac baculovirus expression system. Results of SVD-VLP analyses from electron microscopy, western blotting, immunofluorescent assay, and mass spectrometry showed that the recombinant SVD-VLP morphologically resemble authentic SVD viruses. The SVD-VLP was evaluated as a replacement for inactivated whole SVD virus in competitive and isotype-specific ELISAs for the detection of antibodies against SVD virus. The recombinant SVD-VLP assay produced results similar to those from inactivated whole virus antigen ELISA. The VLP-based ELISA results were comparable to those from the virus neutralization test for antibody detection in pigs experimentally inoculated with SVD virus. Use of the recombinant SVD-VLP is a safe and valuable alternative to using SVD virus antigen in diagnostic assays.

Establishment of RT- LAMP for rapid detection of foot-and-mouth disease virus / 病毒学报

A rapid detection of foot-and-mouth disease virus (FMDV) was established by using reverse transcription loop-mediated isothermal amplification (RT-LAMP) method, meanwhile its specificity and sensitivity were assessed. The results showed that the FMDV RNA could be amplified by incubation at 65degrees C for only 1h using six primers designed based on FMDV polyprotein gene and the amplification products could be detected easily by naked-eye. There is no cross reaction with other virus such as SVDV, SFV and PPV by detecting their RNA samples. The detection limit of this method was found to be 10(-5) dilution of RNA sample which was 100-fold higher than that of PCR and 10-fold higher than real-time PCR.