Study On Inhibition In Vitro And Drug Resistance Elimination Of Clinical Mastitis Escherichia Coli By Chinese Medicine

Dairy cow mastitis,a common and frequently encountered disease in cows,is an inflammatory reaction stimulated by physical,chemical and bacterial infection.What's more,a variety of pathogenic microorganisms mixed infection is the main cause of dairy cow mastitis which severely restricted to the current development of milk cows industry.Our study focus on four kind of Chinese traditional medicines in vitro and the effect on drug sensitivity to Escherichia coli(E.coli)isolated from milk of dairy cow mastitis.Prevention of dairy cow mastitis mainly relies on antimicrobial agents in the past few years.However,as a long-term and extensive using of antimicrobial agents lead to enhanced bacterial resistance,drug residues,dairy safety and environmental pollution,which has caused the wide attention from the whole society.Traditional Chinese medicine(TCM)have many distinguishing features,such as the natural characteristics,pluripotency,non-talerance,non-residue,small side effects and no pollution,which draw more attention on the prevention and treatment of mastitis.Limited publications are available about the application of Scutellaria baicalensis,Rhizoma Coptidis and Double Coptidis in antibacterial mechanism.Therefore,the purpose of this study was to study and analyze from the antibacterial activity in vitro,bacterial resistance and effect of drug resistance gene.We hope the research can provide scientific basis for TCM in prevention and treatment of mastitis in dairy cows.Escherichia coli was isolated suffering from clinical mastitis milk samples from parts of Shaanxi province.The determination of antibacterial activity of 4 group of TCM were evaluated by determining the minimum inhibitory concentrations(MICs)by two-fold serial dilutions of TCM.The morphology of Escherichia coli cell surface was observed by scanning electron microscope.Content changes of the alkaline phosphatase in the Escherichia coli supernatant was mensurated by enzyme labeled plate method,which was cultured by added huangqin decoction and Double Coptidis lyophilized Powder for injection.Drug resistance of Escherichia coli was detected by drug sensitive paper method.Drug resistance genes was detected by molecular biology.The isolated strains were cultured by the medium added 4groups of traditional Chinese medicine extracts.By comparing the resistance and the expression of resistance gene of the isolated bacteria before and after culture,the effect of Chinese medicine on the antibiotic sensitivity and resistance gene of Escherichia coli wasanalyzed.Fifteen E.coli isolates were cultured from 95 mastitis milk samples.The MIC50 of the Scutellaria baicalensis to these strains is 7.81 mg/mL.The MIC50 of the Rhizoma Coptidis to these strains is from 15.625 mg/mL.The MIC50 of the Scutellaria baicalensis and Rhizoma Coptidis(1:1)to these strains is from 15.625 mg/mL.The MIC50 of the Double Coptidis to these strains is from 3.91 mg/mL.Electron microscope observations illustrated the ultrastructural damage of E.coli after treatment with the Scutellaria baicalensis and Double Coptidis,and the apperance with Scutellaria baicalensis treated was collapse and distortion,while the apperance with Double Coptidis treated was broken and fragmented.The differences in absorbance between pre-and post-treatment of the control,Scutellaria baicalensis,or Double Coptidis were indicated that Double Coptidis and Scutellaria baicalensis have broken the bacteria cell wall permeability and the degree of damage to bacteria from Double Coptidis was higher than that from Scutellaria baicalensis.Fifteen isolates of E.coli showed resistance to at least three antimicrobials,and the most frequent resistances were for clindamycin,erythromycin and penicillin(100%),while most of the strains were susceptible to cefoxitin and cefotaxime(100%).With 4 group of TCM cultivation,the test showed that the drug resistance was weakened compared with control.What's more,compared with the others the reduction on resistance of Scutellaria baicalensis was the most significant.For example on vancomycin,the most reduction of drug resistance was Scutellaria baicalensis and the next was Double Coptidis.The blaTEM and blaSHV genes(Extended spectrum ?-lactamase,ESBLs)were detected in 40% and 33.3%,respectively.While the qnrB,qnrD and qnrS genes(Plasmid-mediated quinolone resistance,PMQR)were detected in 13.3% of the isolates,respectively.This study is to explore the inhibition of 4 group of TCM on Escherichia coli in vitro.what's more the reduction on drug resistance of Scutellaria baicalensis was significant compared with the other 3 groups.In conclusion,these medicines may be a rich source to combat pathogenic bacteria and reduce development of drug resistance in dairy industry.TCM could inhibit Escherichia coli and destroy the integrity of E.coli cells in vitro.In this study 4 group of TCM exhibited inhibition and elimination resistance of bacteria properties.