Establishment Of Multiplex PCR Diagnostic Method For Main Infectious Pathogens Of Bovine Diarrhea

With the increasing scale and intensity of cattle industry,a variety of epidemic diseases have become a major problem in cattle production.Bovine diarrhoeal disease(BED),caused by multiple pathogens,is the most common and harmful disease in the cattle industry,resulting in significant economic losses,charcherized by severe impaired production performance of dairy cows and beef cattle and increased mortality of calves.Various pathogens were the most important factors asscociated with bovine diarrhea.Due to the increasing incident and complicatd causative pathogenic factors,it is urgent to generat a rapid and efficient diagnosis method for BED prevention and control.In this study,based on the epidemic data of BED in milk/beef cattle in Hebei Province,a triple PCR method for main viral pathogen BVDV/BRV/BCo V detection and a dual PCR method for main bacterial pathogen Escherichia coli/Salmonella of BED were established,respectively,and these method were demonstrated effective by the clinical application.The main research contents are as follows:1.A triple PCR method was established targeting for BVDV,BCo V and BRV,the main viral pathogens of BED.The amplified fragments of BVDV,BCo V and BRV were 240bp,597bp and 383bp,respectively,and the detection sensitivity was2.47×10~8copies/uL,9.9×10~3copies/u L and 2.0×10~4copies/u L,respectively.2.A double PCR method targeting for Ecoli and Salmonella,the main bacterial pathogens of BED was established.The amplified fragments were 200bp and 400bp,and the detection sensitivities were 9.12×10~3copies/uL and 1.27×10~5copies/uL,respectively.