中文摘要：

为合理应用恩诺沙星治疗猪大肠杆菌感染。本研究采用了体内药动和体外药效联合的方法,研究了恩诺沙星在血清和组织笼液中抗大肠杆菌的活性。体外测定结果显示,恩诺沙星在血清和组织笼液中对猪大肠杆菌的MIC均为0.4μg.mL-1。如果在血清和组织液中添加更多的细菌,则需要高于MIC药物浓度才能持续抑制细菌的生长。猪按5mg.kg-1的剂量肌内注射恩诺沙星后,血清中半效浓度（EC50）为77.67±31.12,即恩诺沙星血清药物浓度为1.29μg.mL-1时可产生50%最大效应;组织液中恩诺沙星的半效浓度（EC50）为15.78±4.99,即组织液药物浓度为0.26μg.mL-1时可产生50%最大效应。结果提示,临床应用恩诺沙星治疗大肠杆菌感染时,应适当提高给药的剂量,不应仅以高于MIC作为制定给药间隔的标准。

英文摘要：

The research was performed for the rational usage of enrofloxacin in treating pigs infected by Escherichia coli.The combined method of pharmacokinetics in vivo and pharmacodynamics in vitro was used to survey and evaluate the pharmacokinetics-pharmacodynamics relationship of enrofloxacin against Escherichia coli.The MICs of enrofloxacin against Escherichia coli in serum or tissue cage fluid were 0.4 μg·mL-1 in vitro.The concentration of enrofloxacin that is more than MIC in serum or tissue cage fluid will be needed to inhibit the bacteria if lots of Escherichia coli was added.EC50 were 77.67±31.12 and 15.78±4.99,respectively in serum and tissue cage fluid of pigs after intramuscular administration at 5 mg·kg-1 body weight.Enrofloxacin produces 50% of the maximal antibacterial effect,when the concentration of enrofloxacin is 1.29 and 0.26 μg·mL-1,respectively in serum and tissue cage fluid.These results indicated that the dosage of enrofloxacin should be increased when it was used to prevent the infection of Escherichia coli,and MIC shouldn＇t be the only standard that set interval of administration.