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目的探讨5种氟喹诺酮抗菌药物浓度(MPC)对肺炎链球菌耐药的预防作用,并比较MPC与MIC间的关系,为临床合理用药提供依据。方法首先采用标准琼脂二倍稀释法,测定肺炎链球菌对5种氟喹诺酮药物的MIC值,计算MIC50和MIC90值;采用混菌法,测定MPC值,接种细菌浓度>1010,计算MPC50和MPC90值,并比较MPC/MIC。结果(1)在5种药物中,莫西沙星的MPC50和MPC90值最低,分别为1mg/L和2mg/L,以后依次为加替沙星2mg/L和4mg/L、司巴沙星4mg/L和8mg/L、左氧沙星8mg/L和8mg/L,而环丙沙星最高,为16mg/L和32mg/L;(2)测定菌株对莫西沙星、左氧沙星的MPC/MIC范围主要在8～16,对加替沙星、司巴沙星的MPC/MIC范围主要在16～32,对环丙沙星的MPC/MIC范围主要在32～64。结论莫西沙星、加替沙星和左氧沙星这些氟喹诺酮药物中比较新的品种,不仅抗菌谱广,而且MPC值较低,“突变选择窗”范围较窄,这些药物在预防细菌产生耐药突变方面有着明显的优势。
Objective To investigate the preventive effect of five fluoroquinolone antibiotics (MPC) on the drug resistance of Streptococcus pneumoniae and to compare the relationship between MPC and MIC, so as to provide a basis for clinical rational drug use. Methods The standard agar double dilution method was used to determine the MIC value of Streptococcus pneumoniae to five kinds of fluoroquinolones, and the MIC50 and MIC90 values were calculated. The MPC value and the bacterial concentration> 1010 were determined by the mixed method. The MPC50 and MPC90 values , And compare MPC / MIC. Results (1) Among the five drugs, moxifloxacin had the lowest MPC50 and MPC90 values of 1 mg / L and 2 mg / L respectively, followed by gatifloxacin 2 mg / L and 4 mg / L, and sparfloxacin 4 mg / L and 8mg / L, levofloxacin 8mg / L and 8mg / L, while ciprofloxacin was the highest, 16mg / L and 32mg / L; (2) The strains were tested for moxifloxacin, levofloxacin The range of MPC / MIC is mainly 8-16. The range of MPC / MIC for gatifloxacin and sparfloxacin is mainly 16-32, and the range of MPC / MIC for ciprofloxacin is 32-64. Conclusion The newer fluoroquinolones in moxifloxacin, gatifloxacin and levofloxacin are not only broad antibacterial spectrum, but also have low MPC value and narrower range of “mutation selection window”. These drugs are effective in preventing bacterial growth Drug resistance mutations have obvious advantages.