环丙沙星联合多西环素对金黄色葡萄球菌防耐药突变浓度的影响

Effects on Mutant Prevention Concentration of Staphylococcus Aureus by Combination of Ciprofloxacin and Doxycyline in vitro

目的探讨环丙沙星联用多西环素对金黄色葡萄球菌防耐药突变浓度(MPC)值的影响,为防止产生细菌耐药提供依据。方法应用肉汤法富集浓度为1010CFU/ml金黄色葡萄球菌ATCC29213菌株,采用琼脂平板二倍稀释法测定环丙沙星、多西环素单药以及2药以不同浓度联用时对金黄色葡萄球菌ATCC29213的防耐药突变浓度(MPC)和耐药突变选择窗(MSW)。结果环丙沙星、多西环素单药对金黄色葡萄球菌ATCC29213的MPC分别为3.00和20.16μg/ml,MSW分别为10和84。在联用多西环素浓度由0.12μg/ml至15.36μg/ml时,环丙沙星对ATCC29213的MPC由3.00μg/ml下降至0.30μg/ml。在联用环丙沙星浓度由0.30μg/ml至2.60μg/ml时,多西环素对ATCC29213的MPC由15.36μg/ml下降至0.24μg/ml。结论多西环素和环丙沙星联合用药可使各自单药对金黄色葡萄球菌ATCC29213的MPC下降,MSW减小。

Objective To examine the influence of combination of ciprofloxacin and doxycyline on mutant prevention concentration（MPC） of staphylococcus aureus in vitro,so as to provide evidence for new strategies of restricting the development of drug resistance.Methods The staphylococcus aureus strain ATCC29213 of 1010 CFU/ml was enriched by meat infusion culture-medium.The agar plates dilution method was used to determine the MPCs and mutant selection windows（MSWs） of ciprofloxacin,doxycyline,and the 2 drugs combination against the strain ATCC29213.Results The MPC of ciprofloxacin and doxycyline was 3.00 and 20.16 μg/ml,and the MSW was 10 and 84,respectively.The MPCs of the combination of ciprofloxacin and doxycyline from 0.12 μg/ml to 15.36 μg/ml was decreased from 3.00 μg/ml to 0.30 μg/ml.The MPCs doxycyline which combined with ciprofloxacin from 0.30 μg/ml to 2.60 μg/ml was decreased from 15.36 μg/ml to 0.24 μg/ml.Conclusion Combinations of ciprofloxacin and doxycyline can decrease the MPC of them to staphylococcus aureus strain ATCC29213 and narrow the MSW.