中文摘要：

为探明内蒙古牧区自然发酵乳制品中乳酸球菌对氟喹诺酮类药物的耐药情况,对采自内蒙古四子王旗和达尔罕茂明安联合旗牧区的自然发酵乳制品中的乳酸菌进行分离纯化,并用二倍稀释法测定其最小抑菌浓度（MIC）,选取4株耐药和1株中介的乳酸球菌进行生理生化鉴定及16S rRNA同源性分析.MIC的测定结果显示,18株试验菌株对3种氟喹诺酮类药物均呈现不同程度的耐药,对左氧氟沙星、诺氟沙星、环丙沙星的耐药率均为88.9％.鉴定结果表明,选取的5株试验菌株中,SB4、SB26、DM41为屎肠球菌（Enterococcus faecium）,DM22、DM33为坚强肠球菌（Enterococcus durans）.

英文摘要：

The purpose of this study was to understand the drug resistance to fluoroquinolone of Lactococcus separated from natural fermented dairy in Inner Mongolia. The lactic acid bacteria collected from natural fermented dairy products of Inner Mongolia （including Siziwang banner and Darhan muminggan united banner） was isolated and purified, and double dilution method was used to determine the minimum inhibitory concentration （MIC）. The test analyzed the 16S rRNA homology and identified the physiological and biochemical characteristic of 4 resistant strains and 1 intermediate strain of lactic acid bacteria. According to the results of the MIC, the 18 tested strains were resistant to 3 kinds of fluoroquinolone drugs, and the resistance rate to levofloxacin, norfloxacin and ciprofloxacin were all 88.9%. Identification results showed that SB4, SB26 and DM41 were Enterococcus faecium, and DM22, DM33 were Enterococcus durans.