不同抗菌药物对肺炎克雷伯菌耐药突变选择窗的影响分析

Analysis on influence of different antibacterial agents against Klebsiella pneumoniae drug resistant mutant selection window

目的 探讨不同抗菌药物对肺炎克雷伯菌耐药突变选择窗（MSW）的影响。方法 收集该院2013年4月至2014年4月分离的30株肺炎克雷伯菌的相关资料,采用琼脂倍比稀释法测定单一左氧氟沙星及左氧氟沙星联合阿米卡星的防突变浓度（MPC）及最低抑菌浓度（MIC）,比较单一左氧氟沙星及左氧氟沙星联合阿米卡星对肺炎克雷伯菌的选择指数（SI）。结果 左氧氟沙星联合阿米卡星的MIC为0.03~1.00 mg/L,为单一左氧氟沙星（0.01~1.00 mg/L）的50.0%,二者比较,差异有统计学意义（P〈0.05）;左氧氟沙星联合阿米卡星的MIC_（90）为0.250 mg/L,显著低于单一左氧氟沙星的0.500 mg/L,差异有统计学意义（P〈0.05）;2种抗菌药物的MIC_（50）比较,差异无统计学意义（P〉0.05）。左氧氟沙星联合阿米卡星的MPC为1~8 mg/L,MPC_（50）为1 mg/L、MPC_（90）为2 mg/L,显著低于单一左氧氟沙星的MPC（2~16 mg/L）及MPC_（50）、MPC_（90）（2、8 mg/L）,差异均有统计学意义（P〈0.05）;单一左氧氟沙星与左氧氟沙星联合阿米卡星对肺炎克雷伯菌的SI均在2~64,其不同SI菌株的分布比较,差异均无统计学意义（P〉0.05）。结论 左氧氟沙星联合阿米卡星能够降低肺炎克雷伯菌的MPC,引起左氧氟沙星对肺炎克雷伯菌的MSW变窄。

Objective To study the influence of different antibacterial drugs on Klebsiella pneumoniae drug resistant mu- tant selection window （MSW）. Methods The related data in 30 strains of Klebsiella pneumoniae in our hospital from April 2013 to April 2014 were collected. The mutant prevention concentration （MPC） and minimum inhibitory concentration （MIC） of single lev- ofloxacin and levofloxacin combined with amikacin were detected by adopting the agar double ratio dilution method. Then their se- lection indexes （SI） on Klebsiella pneumoniae were compared. Results MIC of levofloxacin combined with amikacin was 0.03- 1.00 mg/L, which was 50.0% of single levofloxacin （0.01-1.00 mg/L）, the difference was statistically significant （P〈0.05） ; MIC90 of levofloxacin combined with amikacin was 0.250 mg/L,which was significantly lower than 0.500 mg/L of single levofloxacin,the difference was statistically significant （P〈0.05） ; MICs0 had no statistical difference between the two kinds of antibacterial drug （P〉 0.05 ）. MPC of levofloxaein combined with amikacin was 1-8 mg/L, MPCso was 1 mg/L, MPCgo was 2 rag/L, which were significantly lower than 2-16 mg/L, 2,8 mg/L of single levofloxaein, the differences were statistically significant （P〈0.05） ;SI of single levofloxaein and levofloxacin combined with amikacin against Klebsiella pneumoniae was 2-64,the difference was not statistically significant （P〉O.05）. Conclusion Levofloxaein combined with amikacin can reduce MPC to Klebsiella pneumoniae and can cause lev- ofloxacin to narrow MSW to Klebsiella pneumoniae.