中药复方对猪源多重耐药大肠埃希氏菌的耐药性消除研究

Drug Resistance Elimination Effect of Traditional Chinese MedicineCompounds on Multi-drug Resistant Escherichia coli Derived from Swine

为研究中药复方对多重耐药大肠埃希氏菌的耐药性消除效果,以从仔猪腹泻病例分离的1株多重耐药大肠埃希氏菌为研究对象,测定杨树花-地榆、杨树花-地锦草、杨树花-马齿苋和地榆-马齿苋4个中药复方的最小抑菌浓度,通过扫描电镜和透射电镜观察该菌株在中药复方作用后微观结构的变化,采用影印法和RT-PCR法测定各中药复方对该菌株耐药表型和耐药基因表达量的影响。结果显示,4个中药复方MIC值为62.50 mg/mL~250 mg/mL,各中药复方作用后菌株的细胞膜和细胞壁均发生不同程度的损伤;4个组中药复方的耐药消除率均在10.00%以上,杨树花-马齿苋可以极显著的下调aac(3)-Ⅱ、aacC2、aph(3′)-Ⅱ这3种耐药基因的表达量。结果说明中药复方对猪源多重耐药大肠埃希氏菌的耐药性具有一定的消除效果。

The drug resistance elimination effect of traditional Chinese medicine(TCM)compounds on multi-drug resistant E.coli isolated from piglet diarrhea was studied.The minimum inhibitory concentrations(MIC)of four groups of TCM compounds(Flos populi-Sanguisorbae Radix,Flos populi-Euphorbia humifuse,Flos populi-Portulaca oleracea and Sanguisorbae Radix-Portulaca oleracea)on this isolated E.coli were determined,and the microstructure changes of the strain after four TCM compounds action were observed by scanning electron microscope and transmission electron microscope.Furtherly,the effect of four different TCM compounds on the drug resistance phenotype of E.coli and the influence of them on the expressional amount of drug resistance genes were studied by photolithography and RT-PCR.The results showed that the MIC value ranges of four TCM compounds on E.coli were 62.50 mg/mL-250 mg/mL.The cell membrane and cell wall of E.coli were damaged at different degrees after administrated by four TCM compounds.The elimination rate of all four TCM compounds on bacterial resistance was above 10.00%.Flos populi-Portulaca oleracea can extremely significantly reduce the expressional amounts of aac(3)-Ⅱ,aacC2 and aph(3′)-Ⅱ.The results indicated that all four TCM compounds had certain resistance elimination effect on of the isolated multi-drug resistant E.coli.