滇产中草药体外抗产超广谱β-内酰胺酶耐药大肠埃希菌的筛选研究

Screen of Chinese herbal medicines originated in Yunnan province against drug resistant Escherichia coli producing ESBLs in vitro

目的：测定中草药提取物体外对产超广谱β-内酰胺酶（ESBLs）大肠埃希菌耐药菌的抗菌活性,比较10种滇产中草药对临床耐药大肠埃希菌的抑菌作用。方法：呼吸系统患者痰液标本按常规方法分离培养纯化得到3株耐药大肠埃希菌株,采用80%乙醇提取得到10种中草药提取物,用琼脂扩散法和试管二倍稀释法评价其抗菌活性。结果：10种滇产中草药提取物中,有9种提取物具有不同程度抗菌活性,其抑菌圈（IZD）在11.0-21.0 mm之间,最低抑菌浓度（MIC）为（0.78-12.50）mg/ml。其中,以博落回[Macleaya cordata（Willd.）R.Br.]的抑制作用为最大,其对耐药菌的IZD和MIC分别为16 mm和1.56 mg/ml,提取物对标准大肠埃希菌的抑制作用稍强于耐药菌产ESBLs大肠埃希菌。结论：10种抗大肠埃希菌的中草药中有9种对产超广谱β-内酰胺酶耐药大肠埃希菌具抑菌作用,对标准菌抗菌活性较大的提取物对耐药菌也具有较大的抗菌活性。

Objective：To assay the bacteriostatic activity of the extracts in vitro from ten Chinese herbal medicines against drug resistant Escherichia coli producing extended - spectrumβ - lactamase （ESBLs） and to compare their bacteriostasis on drug resistant Escherichia coli strains isolated clinically. Methods ：Three Escherichia coli strains were obtained by routine isolation, cultivation and purification of sputum specimens from patients with respiratory diseases. After the extracts from ten Chinese herbal medicines were obtained by using 80% ethanol,agar diffusion method, twofold dilution method were adopted to evaluate their antibacterial activity. Results： Among ten Chinese herbal medicines tested, nine extracts showed different bacteriostatic activity to some extent. Their inhibitory zone diameter （IZD） was 11.0 - 21.0 mm and their MIC ranged between 0. 78 and 12.50 mg/ml against Escherichia coli. The most active extract was from Macleaya cordata （WiUd. ） R. Br. with IZD at 16 mm and MIC at 1.56 mg/ml. The bacteriostasis of these extracts on standard Escherichia coli was slightly better than those on the drug resistant strain producing ESBLs. Conclusion：Nine of ten tested Chinese herbal medicines demonstrate the bacteriostasis. The extracts with higher bacteriostatic activity against standard Escherichia coli also show higher bacteriostatic activity against drug resistant one.