肺炎克雷伯菌的耐药性和防耐药突变浓度的初步研究

目的了解临床分离的肺炎克雷伯菌对常用抗菌药物的耐药性,并测定氟喹诺酮类药物（FQNs）对肺炎克雷伯菌的防耐药突变浓度（MPC）能力进行分析。方法采用微量稀释法测定肺炎克雷伯菌的最低抑菌浓度（MIC）、琼脂稀释法测定MPC,K—B法测定常用抗菌药物的耐药性。结果30株临床分离的肺炎克雷伯菌中超广谱β-内酰胺酶（ESBLs）阳性15株,为阳性组;阴性15株,为阴性组。2组对临床常用抗菌药物的耐药性存在较大差异,ESBLs阳性组的耐药率明显高于ESBLs阴性组。左氧氟沙星和莫西沙星对ESBLs阳性和ESBLs阴性的肺炎克雷伯菌的MPC、MIC和耐药选择指数（sI）具有不同的分布特征。结论30株临床分离的肺炎克雷伯菌对常用抗菌药物的耐药性以ESBLs阳性株较为严重,且MPC明显高于ESBLs阴性株,ESBLs阴性株的细菌sI较高,临床应给予高度关注。

Preliminary study on drug resistance and mutant prevention concentration of Klebsiella pneumoniae

Objective To study the drug resistance of Klebsiella pneumoniae to common antibiotics, and to measure the mutant prevention concentration （MPC） of fluoroquinolone （FQNs） and analyze the anti-drug resistance mutation ability. Methods The minimum inhibition concentration （MIC） was determined by micro-dilution method, and MPC was determined by agar dilution method. The drug resistance to common antibiotics was measured by K-B method. Results A total of 30 clinical isolates of Klebsiella pneumoniae had extended-spectrum beta lactamases （ESBLs） positive （15 isolates, positive group） and negative （15 isolates, negative group）. The results showed that the drug resistance to common antibiotics had significant difference. The drug resistance rate of ESBLs positive group was higher than that of ESBLs negative group. The MPC, MIC and drug resistance selection index （SI） of levofloxacin and moxifloxacin for ESBLs positive and ESBLs negative Klebsiella pneumoniae showed different distribution characteristics. Conclusions For the 30 isolates of Klebsiella pneumoniae, the drug resistance to common antibiotics of ESBLs positive isolates is serious, and MPC and SI are significantly higher than those of ESBLs negative isolates.