Screening And Application Of Effective Components Of Traditional Chinese Medicine Sensitive To Staphylococcus Aureus In Dairy Cow Mastitis

The adverse consequences caused by antibiotic therapy have become a difficult problem for the prevention and control of dairy cow mastitis.It is of great significance to develop green,efficient and low toxicity antibiotic alternatives.The content of effective active components,antibacterial and anti-inflammatory effect in traditional Chinese medicine extract are relatively stable,and it has many advantages,such as low toxicity,low residue and not easy to produce drug resistance.Its development and application has become a research hotspot.In this study,the pathogenic bacteria of cow mastitis were isolated from four dairy farms in Handan area,and their drug resistance was analyzed to explore the therapeutic effect of effective components of traditional Chinese medicine on mastitis model mice,so as to provide a theoretical basis for the treatment of cow mastitis with effective components of traditional Chinese medicine.The main results are as follows:1.Isolation and identification of pathogenic bacteria of cow mastitis in four dairy farms in Handan area.38 dairy cow mastitis milk samples from 4 dairy farms in Handan area were collected.According to the bacterial culture characteristics,bacterial Gram staining microscopic examination characteristics,bacterial biochemical identification and 16S r DNA gene identification results,Staphylococcus aureus(15/49 strains),Streptococcus agalactiae(11/49 strains),Escherichia coli(12/49 strains)and Salmonella(11/49 strains)were isolated,The isolation rate of Staphylococcus aureus was the highest,30.61%,which was the dominant pathogen.2.Drug resistance analysis of Staphylococcus aureus and screening of effective components of traditional Chinese medicine.The drug resistance of 15 strains of Staphylococcus aureus to 14 commonly used antibiotics was detected and analyzed by disk method,The Oxford cup method was used to determine the effective components of 9 kinds of traditional Chinese medicine(hawthorn acid,paeoniflorin,andrographolide,baicalin,cinnamaldehyde,berberine,curcumin,Poria cocos acid,oregano oil)antibacterial effect in vitro.The results showed that 15 strains of Staphylococcus aureus were moderately sensitive to penicillin,chloramphenicol,cefuroxime,cefazoxime and other drugs;the results of antibacterial test in vitro showed that berberine,baicalin and cinnamaldehyde had the best antibacterial effect and their antibacterial activity The circle diameters(mm)were coptidine(39.06±0.69),baicalin(36.18±0.36)and cinnamaldehyde(33.38±0.45).3.Establishment of mouse mastitis model induced by Staphylococcus aureus.After injection of 20μL S.aureus solution with concentration of 1×10~7cfu/m L into mouse mammary gland tissue,the pathological changes of mouse mammary gland tissue had the pathological characteristics of mouse mastitis.4.Effect of effective components of traditional Chinese medicine on Mastitis Induced by Staphylococcus aureus in mice.The mouse mastitis infection model was treated with berberine,baicalin and cinnamaldehyde for 5 days.Compared with the model group,it was found that berberine,baicalin and cinnamaldehyde could reduce the proinflammatory factors(IL-1 and TNF-α)in mice in varying degrees.The relative expression of m RNA and significantly increased anti-inflammatory factor(IL-10)and immunoglobulin(Ig G1,Ig G2,Ig A and Ig M)The relative expression of m RNA showed that it had the best therapeutic effect on mastitis caused by Staphylococcus aureus infection in mice.By observing the pathological sections,the inflammatory infiltration in breast cells disappeared,the acini gradually tended to be complete,and the nuclear staining disappeared in coptidine group.