Abstract:A multiplex PCR diagnostic method was established.The live vaccine of resurrected ovine Streptococcus septicus disease was used as the research object.According to the universal primers of bacterial 16S rRNA gene and the speciesspecific sodA gene of ovine streptococcus septicus,the primers were designed and synthesized and amplified by PCR.The results showed as follows:(1)The vaccine were inoculated with BHI medium, the growth of bacteria was slow,and the BHI medium became cloudy after 24 h; On the blood plate, shiny, transparent, moist, viscous, smooth surface,neat edges, small dew drops, gray and white colonies were formed, and there was obvious beta hemolysis around the colonies.(2)The microscopic examination results of the bacteria of the ovine septicemia streptococci vaccine strain showed that the microscopic examination showed gram staining positive, often in pairs or 3 to 5 short chain arranged spherical or oval coccus, with capsules.(3)The results of nucleic acid extraction showed that the extracted nucleic acid was stable and could be used for subsequent experimental studies.(4)PCR amplification results showed that the method had good specificity and sensitivity, and could provide technical support for laboratory diagnostic detection and molecular epidemiological investigation of sheep septicemia streptococcus disease.The study concluded that the multiplex PCR detection method is simple,rapid,sensitive and specific,easy to master,and generally suitable for grassroots units to use,can quickly obtain diagnostic results,identify the pathogen,and provide scientific basis for clinical rational drug use.
