2种喹诺酮药物单用及联合氨苄西林或卡那霉素对猪源沙门菌耐药突变选择窗的研究

Study on Mutant Selection Window of two Fluoroquinolones alone and combination with Ampicillin or Kanamycin against SalmonellaIsolated from Swine

为探讨联合用药对猪沙门菌耐药突变选择窗的影响,采用琼脂二倍稀释法测定环丙沙星、左氧沙星及其联合氨苄西林和卡那霉素对56株临床分离的猪源沙门菌的最低抑菌浓度(MIC)、耐药变异浓度(MPC)、耐药指数(SI),并进行统计学分析。结果显示,环丙沙星联合氨苄西林和卡那霉素后其耐药变异浓度(MPC)降低到2mg/L和1mg/L,SI分别下降了4倍和8倍;左氧沙星联合氨苄西林和卡那霉素MPC降低到1mg/L和0.5mg/L,SI分别下降了2倍和4倍;且两种药物与卡那霉素联合能完全关闭其突变选择窗(MSW)。本研究表明,环丙沙星、左氧沙星联合氨苄西林和卡那霉素能够缩小甚至关闭其单药的MSW,防止耐药的产生。

To study the effect of antibiotics combination on the mutant selection window （MSW） of salmonella isolated from swine. The MIC of ciprofloxacin （CIP）, levofloxacin （LVF）, ampicillin （AMP） and kanamycin（KAN） and the mutant prevention concentration （MPC） both sole and combined were de- termined by the method of agar plates dilution method, and the value of SI （selection index ： MPC/M IC） was acquired. SPSS statistics software was used to analyze the data. The results showed that after com- bined with ampicillin and kanamycin, the MPC of ciprofloxacin was reduced to 2 mg/and 1 mg/L, and the value of SI decreased by 4- and 8-fold respectively. The MPC of levofloxacin was reduced to 1 mg/L and 0. 5 mg/L and the SI decreased by 2- and 4-fold. Compared with sole treatment, CIP and LVF combined with other two antibiotics can decrease MPC and SI of antibiotics alone and restrain the drug-resistant mutants.