Multiplex PCR Assay For Detecting Four Major Mastitis-causing Pathogens In Milk

Bovine mastitis(BM)is a kind of inflammatory change that occurs when the mammary gland of cow is stimulated by physics and chemistry,especially the invasion of microorganism.Which is also the most harmful disease to dairy production.The disease can not only lead to the decline of milk production and quality of dairy products,but also cause the loss of lactation function and elimination of the affected cows.Bovine mastitis is the most common infectious disease affecting the development of dairy industry in the world,among which Staphylococcus aureus,Streptococcus agalactiae,Streptococcus dysgalactiae,Escherichia coli and other pathogenic bacteria are the main pathogens causing bovine mastitis.According to the 23SrRNA gene of Staphylococcus aureus,the phoA gene of E.coli,the 16SrRNA Gene of Streptococcus agalactiae and Streptococcus dysgalactiae,a multiplex PCR system was constructed.The specificity,sensitivity and clinical practicability were verified.The multiplex PCR method established in this study has good specificity and sensitivity.The specific bands of Staphylococcus aureus,Streptococcus agalactiae,Streptococcus dysgalactiae and Escherichia coli are 895 bp,320 bp,575 bp,466 bp.The sensitivity is 1 pg/?L?1 pg/?L?100 fg/?L?1 pg/?L.This method can accurately diagno se clinical milk samples within 6 hours.Compared with the traditional method of bacteria isolation and culture,it can save a lot of time and has a good prospect of application.