Research And Application Of HI Antibody Detection Method For Peste Des Petits Ruminants Virus

PPRV can cause fever,mucosal ulcers,diarrhea,increased eye secretions,miscarriage,cough and difficulty breathing.It is mainly infected with small ruminants,especially goats.The sheep farming industry has caused huge economic losses.Because of its high cure rate and high mortality rate,the International Organization for Animal Health has listed it as an animal disease that must be reported.China has classified it as a type of animal disease.At present,there is no effective treatment for this disease,mainly by vaccination for prevention and control.The detection of antibody levels after immunization includes virus neutralization test(VNT)and enzyme-linked immunosorbent assay(ELISA),but these two methods are more effective,complex,costly,and long test time.The hemagglutination inhibition(HI)test is an effective method for clinical detection of hemagglutinating virus antibody detection,and the operation method is simple,low in cost,and short in test time.According to the characteristics of hemagglutination(HA)of some strains of PPRV,we have prepared qualified blood coagulation antigen by virus proliferation culture.The serum samples of goats immunized with the small ruminant attenuated vaccine were tested by VNT,ELISA and HI antibody detection methods,and the coincidence rates of the three methods were analyzed.The test results are as follows:1.The results of HA test with 1%sheep red blood cell suspension showed that there were differences in blood coagulation between the two strains of PPRV vaccine strains from different sources in the laboratory.The strain named"PPRV Nigeria75/1-a"has a blood coagulation phenomenon,and the strain named"PPRV Nigeria75/1-b"has no blood coagulation.The results of gene sequencing analysis showed that the similarity between the H gene of Nigeria75/1-a strain and the H gene of Nigeria75/1-b strain was 100%,and there was no difference in gene sequence.The F gene of Nigeria75/1-a strain and the gene of Nigeria75/1-b strain were 99.9%similar,the 333 locus of Nigeria75/1-b F gene was A,and the 333 locus of Nigeria75/1-a F gene was G.2.Different animal red blood cells were collected to prepare a 1%red blood cell suspension.The results of HA test showed that PPRV Nigeria75/1-a strain could agglutinate red blood cells of sheep,goats and cocks.Among them,sheep red blood cells were stable and the results of agglutination were clear.In addition,When the p H of PBS is 6.6,the blood coagulation titer is higher than when the p H is 7.0,and the blood coagulation titer was higher at 4°C than in 32℃.Vero cells were monolayerly inoculated with PPRV Nigeria75/1-a strain,and the blood coagulation titer was up to 2~8after 96 hours of culture.3.The VRT,ELISA and HI test methods were used to detect the antibodies of the goat anti-veterinary vaccine-immunized goat serum samples,and the coincidence rates of the three methods were compared.The results showed that when the HI antibody titer≥2~3was positive,The total coincidence rate of HI and VNT results was 96%,and the total coincidence rate of HI and ELISA results was 88%.