头孢噻呋体外抗菌活性及其对实验性感染鸡大肠杆菌病的疗效

Antimicrobial Activity in vitro and Therapeutic Effect of Ceftiofur on Experimentally Infected Chickens with Colibacillosis

采用肉汤微量稀释法测定头孢噻呋对大肠杆菌、沙门菌、溶血性巴氏杆菌、金黄色葡萄球菌、链球菌等病原菌的最小抑菌浓度,采用棋盘稀释法测定头孢噻呋与氧氟沙星、甲氧苄啶(TMP)的联合抑菌浓度指数。结果表明,头孢噻呋、氧氟沙星对5种病原菌都具有很强的抗菌活性;头孢噻呋与氧氟沙星联合使用时,对大肠杆菌、沙门菌、链球菌可产生协同作用,对溶血性巴氏杆菌和金黄色葡萄球菌表现为无关作用;头孢噻呋与TMP联合用药时,对上述5种病原菌均具有协同作用。对实验性感染鸡大肠杆菌病的药效学试验结果表明,头孢噻呋高(100mg/L)、中(50mg/L)剂量对感染鸡的有效率明显高于对照药物庆大霉素(P<0.05),极显著高于感染对照组(P<0.01);头孢噻呋高剂量组(100mg/L)感染鸡的增重率与健康对照组相比差异不显著(P>0.05)。建议临床应用头孢噻呋治疗鸡大肠杆菌病时,可采用饮水给药,剂量为100mg/L。

The minimal inhibitory concentrations of Cefitiofur against E.coli,Salmonella,P.haemolyticus,Stophylococcus aureus and Streptococcus were determined by broth mierodilution assay,and the fractional inhibitory concentration was tested using checkerboard dilution method. The results showed that the above 5 kinds of pathogenic bacteria were high sensitive to Cefitiofur and Ofloxacin, When Cefitiofur was used combining with Ofloxacin,the synergistic action would existed against E.coli,SalmoneUa and Streptococcus except to P.haemolyticus and Staphylococcus aureus. While drug combination of Cefitiofur with TMP was used,the synergistic action would exist against 5 kinds of pathogenic bacteria,The results of curative effect of Ceftiofur against experimentally colibacillosis showed that effective rate of Cefitiofur for high dosage group（100mg/L）and middle dosage group（50 mg/L）was significantly superior to Gentamicin group（P〈0.05） and infection control group （P〈0.01）. The growth rate of Cefitiofur for high dosage group （100 mg/L）had not significant difference between health control group （P〉0.05）. We suggested that Cefitiofur should be given by water to treat colibacillosis in chickens,and the suitable dosage was 100 mg/L.