The Inhibition Of Tea Saponin In Biofilm Formation Mechanism Of Dairy Cow Source Resistant Staphylococcus Aureus

Mastitis caused huge economic losses in dairy farming,A common pathogenic bacteria of dairy cow mastitis is Staphylococcus aureus,Streptococcu sagalactiae and Escherichia coli(E.coli)etc,especially the most common is Staphylococcus aureus,the most important pathogenic factors in Staphylococcus aureus lead to dairy cow mastitis infection is it can form biofilms in infection group.The ica loci in Staphylococcus aureus is formed by operon icaADBC,which is the necessary structure gene in synthesis of PIA.The most commonly current treatment of dairy cow mastitis is antibiotics therapy,but along with a large number use of antibiotics,a lot of multiple drug-resistant strains began to appear,So it's have great significance to choose new treatment ideas and alternative medicine.Relative to the antibiotics,tea saponin from natural,theaceae plants extracts,low cost,less side effects,and have low residual,And tea saponin inhibition of multiple drug resistance of Staphylococcus aureus biofilm formation mechanism research has not been reported.This paper explored the effect of tea saponin on staphylococcus aureus biofilm formation,and further study in its regulatory mechanism of film-forming icaA gene expression.The further study could provide new biofilm drug targets treatment methods and experimental evidence for the prevention of dairy cow mastitis in pathogenic SA.1.In order to detect the antibiotic resistance of the clinical S.aureu strain isolated from a dairy cow with mastitis,the study used double dilution method to detect various antibiotic resistance of the clinical SA2 mastitis.The results showed that minimum inhibitory concentrations of erythromycin,streptomycin and penicillinG were 1 mg/mL,160 ?g/mL and 640 ?g/mL,And erythromycin belongs to large ring lactone class antibiotic,streptomycin belongs to aminoglycoside antibiotics,penicillin G as part of the beta lactam antibiotics.And detect the mecA drug-resistant genes,So it is concluded that the clinical isolates of dairy cow mastitis staphylococcus aureus SA2 is not only MRSA but also multiple drug resistant strains.2.Get Staphylococcus aureus film-forming gene icaA by PCR technology.3.Different concentrations of tea saponin on Staphylococcus aureus isolates SA2 into the influence of the biofilm,results showed that tea saponin restrain SA2 to form the lowest concentration of biofilm is 100 ?g/mL.4.Do not add tea saponin and tea saponin concentrations of 100 ?g/mL,tested for growth curve of tea saponin on Staphylococcus aureus isolates SA2 growth,results show that the concentration of tea saponin is 100 ?g/mL have not to inhibit the action of the growth to SA2.5.Staphylococcus aureus isolates SA2 electricity into green fluorescent plasmid,use laser scanning confocal microscope to observe,the situation of the biofilm before and after dosing to SA2.Results shows that SA2 is difficult to form biofilm in the 100 ?g/mL concentration of tea saponin.6.By real time fluorescence quantitative PCR(RT-qPCR)technology to detect the transcription of icaA film-forming gene in and out 100 ?g/mL tea saponin.Results showed that when tea saponin is 100 ?g/mL,the transcription of icaA level lower than normal.To sum up,this study using PCR amplification techniques and RT-qPCR proved theaceae plant extracts of tea saponin can reduce the cow mastitis staphylococcus aureus icaA gene transcription level,thereby inhibiting Staphylococcus aureus biofilm formation.Therefore,this research for further research on plant extracts treatment for multiple drug resistance caused by Staphylococcus aureus and provides an experimental basis for effective dairy cow mastitis.