| The application studies of the rapid diagnosis strips for the detection of IBDv and antibodies against IBDv were conducted in experiment I in this paper.In order to learn the property of the rapid diagnosis strips in the detection of IBDv and its antibodies compared with other detection methods, the sandwich ELISA was established. The results indicated that the sensitivity of rapid diagnosis strips was higher than that of sandwich ELISA and AGPT.Both the titers and immunity of different vaccine strains and the existence and distribution of vaccine viruses in vaccinated chickens were detected by sandwich ELISA and rapid diagnosis strips. Among 9 IBDv vaccine strains, the titers from the highest to the lowest were B87, D78, NEW I, V877,France vaccine strain, NF8.W2512, MB and 228E. The existence time of 5 vaccine viruses (MB, 228E, NF8,V877, NEW I) in tissues were 9, 9, 8, 7 and 4 days respectively. The results implied that the existence time of the vaccine viruses in tissues appears to be not coincident with the titers of vaccine viruses used and this finding has significant importance for the evaluation and using of IBDv vaccines.In 5 detected organs of chickens, the titer of IBDv vaccine viruses from the highest to the lowest were in order bursa, spleen, liver, blindgut antiades and thymus. But in all experimental chickens, the vaccine viruses were absent in kidney.The change of the maternal anti-IBDv antibodies and its effect on the humoral immunity were monitored by the rapid diagnosis strips. The maternal antibody against IBDv were not present in the sera of chickens at the age of one day monitored both by rapid diagnosis strips and AGPT. At 3 days of age, the maternal antibody rise up to the peak , and disappeared at 10 days of age. Compared with lower titer maternal antibody ( with a strip titer of 1:5 and an AGPT positive rate of 39.4%), the higher titer maternal antibody (strip titer >1:10, positive rate of AGPT over 46.1%) showed more powerful ability to neutralize the vaccine viruses.The result of the experimental challenge to chickens with virulent IBDv strains showed that vaccine strain B87 provided well protection against both vvlBDv strain H4 and standard strain BC6/85.Imported vaccine strain D78 provided higher protection against BC6/85 than against H4, on the contrary, the inactivation vaccine only provided well protection against H4. The protection provided by imported vaccine strain W2512 against both virulent IBDv strains above was the lowest. So, the maternal anti-IBDv antibodies should be monitored pre-vaccination and the optimum time of the first vaccination against IBD should be chose when the strips titer of maternal antibodies were lower than 1:5, and the optimal vaccine strains should be chose as well.The liters of yolk antibodies were also detected by rapid diagnosis strips and AGPT, and the result indicated that they had a very significant linear regression relation (r=0.898). All the results gained in the experiment I verified that the rapid diagnosis strips could not only be applied in the detection of virulent or vaccine viruses but also be used to detect the maternal antibodies, immune antibodies and yolk antibodies. The application of rapid diagnosis strips will provide important instructions for the clinical diagnosis and vaccination of IBD.In experiment II, the Balb/c mice were vaccinated by rabbit IgG and the hybridoma cell strain, named 2E5Ai0, was established by cell fusion of splenocytes of vaccinated Balb/c mice with mouse myelomas cells strain NSO . The monoclonal antibody secreted by hybridoma cell strain 2EsAio had no cross reaction with neither rabbit IgM nor IgG or IgM of human beings, pigs and chickens. The AGPT and ELISA liters of cell culture media and ascitic fluid were 1:8,1:320 and 1:16,1:3200 respectively.The establishment of anti-rabbit IgG not only provided a new hybridoma cell srain for the monoclonal antbody pool of our laboratory but also could meet the demand of other laboratories.
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