Isolation,Identification And Fluorescence Quantitative Real-Time PCR Of Duck-Derived New Goose Parvovirus

Research status and significance:since March 2015,infectious diseases characterized by hypoplasia of beak,tongue,growth retardation,tongue exposure,dilation and paralysis have appeared in duck farms in Jiangsu,Anhui and Shandong provinces,which are called"short beak and dwarfism syndrome".The mortality rate of the infected duck farm is 2%~6%,the infection rate is 10%~30%,and the serious duck farm can even reach 50%.The weight of ducks with SBDS disease can be 20%~30%less than the weight for normal ducks,which caused great economic losses to meat duck breeding industry.Research methods and results:in this study,a novel goose parvovirus-related virus was isolated from a diseased duck farm in Tai'an by the methods of agar diffusion test,PCR amplification test and sequencing.The homology between the gene sequences and the fifteen GPV reference strains at home and abroad were 79.6%-98.5%.The results of the hemagglutination inhibition test showed that the virus could not agglutinate red blood cells of chickens,ducks and geese.In order to improve the detection accuracy and detection efficiency,this study selected novel goose parvovirus-related virus N-GPV gene as the target gene,and used the positive recombinant plasmid as the standard curve to establish a fluorescent quantitative real-time PCR detection method for novel goose parvovirus-related virus.The results showed that the melting curve of the real-time PCR showed a narrow and sharp single peak,indicating that the primer has specificity and can be used for amplification of real-time PCR.N-GPV showed a good linear relationship,the correlation coefficient was R~2=0.993,and the amplification curve showed a good S-shaped curve.It was found to be specific by the specificity test of real-time PCR,and only the N-GPV gene could be amplified.The artificially infected ducklings test was used to evaluate the pathological changes of various tissues infected with novel goose parvovirus-related virus and to study the application effect of fluorescent quantitative real-time PCR.The study found that the novel goose parvovirus-related virus mainly caused damage to the intestinal villi,which may be related to the duck's diarrhea.In addition,the study also found that the novel goose parvovirus-related virus can cause liver cell deformation and necrosis,renal tubules,cuolation.Conclusion and application prospects:using the fluorescence quantitative PCR method established in this study,can quickly and accurately detect novel goose parvovirus-related virus,which can be applied to clinical detection.