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Bovine viral diarrhea (Bovine viral diarrhea, BVD) is caused by the bovine viral diarrhea virus (Bovine viral diarrhea virus, BVDV) multi-symptom, multi-homed characterized by an important infectious diseases. Latent infection of the disease, persistent infection and immune tolerance characteristics will be persistent carriers of the virus, detoxification, often the source of infection is caused widespread BVDV important factors. Cattle infected with homologous CP BVDV persistent infection can lead to mucosal disease, severe diarrhea, the fatality rate is almost 100%, not less than 5 million, according to the statistics around the world die each year from the disease infected cattle. With the cattle industry in Xinjiang have been expanding, BVDV infection upward trend, if not take the appropriate measures will cause serious economic losses. There is no application of egg yolk antibody (egg yolk antibodies, IgY) BVDV infections caused by passive immunotherapy research reports. Therefore, the study by cytopathic type (cytopathic CP) of BVDV standard poison and non-induced cytopathic type (ncytopathic, NCP) BVDV Xinjiang isolates Immunization, the preparation of anti-BVDV yolk antibody, and the yolk antibody in vivo, in vitro neutralizing activity studies, to provide new ideas and methods for the prevention and treatment of this disease. This experiment, proliferation of MDBK cells by BVDV, collection of viral cell culture was concentrated by using PEG method to obtain high purity virus, using the experimental method of immunoperoxidase monolayer, concentrated drug titer was measured. Then concentrated NCP BVDV (Xinjiang isolates) and CP-type BVDV (standard poison) as antigen immune health of laying hens, collect eggs, egg yolk antibody extracted by improved PEG6000. Agar diffusion method and indirect ELISA IgY titer obtained yolk antibody and virus titer Microtest. In clinical trials, the selected 12 BVDV recessive infected calves, prepared IgY treatment again after treatment in our laboratory to establish nested RT-PCR to detect, Statistics negative number of calves to calculate the elimination rate. The research results show that the agar diffusion method IgY after the last immunization titer of 14 days, the anti-the NCP type of BVDV and Type CP BVDV titers were 1:32, indirect ELISA anti-NCP BVDV titer of 1:40000 the CP BVDV titer of 1:32000, in vitro and NCP BVDV titer of 1 × 10-3, and again after three months of testing, yolk antibody titer did not significantly change; clinical trials showed that high titers of anti-BVDV the yolk antibody calves BVDV latent infection to eliminate 100% rate. BVDV (standard poison) the research concentrated CP and NCP BVDV (Xinjiang isolates) immunization of laying hens, the preparation of a high titer, good anti-BVDV neutralizing activity yolk antibody in vitro and NCP BVDV efficiency price of 1 × 10-3, the treatment of clinically detected latent infection BVDV calves, to eliminate the virus a significant effect. The resulting antibody economic, convenient, large-scale production, the study results show that the anti-BVDV yolk antibodies can be further developed for the antibody preparations for the prevention and treatment of the disease.
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