氟喹诺酮类药物浓度对预防肺炎链球菌耐药的影响研究

目的检测氟喹诺酮类药物对肺炎链球菌临床耐药的预防作用,并比较防突变浓度（MPC）与最低抑菌浓度（MIC）间的关系,为临床合理用药提供依据。方法采用琼脂二倍稀释法检测5种抗菌药物的MIC值,计算MIC50和MIC90值;采用新鲜制备的1010 CFU/mL菌液测定MPC值,测定MPC值,接种细菌浓度〉1010,计算MPC50和MPC90值,并比较MPC/MIC。结果在5种药物中,莫西沙星的MPC50和MPC90值最低,分别为1mg/L和2mg/L,环丙沙星最高,为16mg/L和32mg/L;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、左氧沙星抗菌谱广,而且MPC值较低,并可以防止肺炎链球菌突变的发生。

Study the effect of Fluoroquinolone drugs concentrations on preventing drug resistance of streptococcus pneumoniae

Objective To detect the prevention of fluoroquinolone drugs on resistance of streptococcus pneumoniae, and to compare the relations between the MPC and MIC in order to provide basis for clinical rational drug use. Meth- ods The MIC values of 5 kinds of antibacterial drug were detected by two-fold agar dilution method and MIC50 and MIC90 values were calculated. The MPC value was measured using 1010 cfu/mL bacteria liquid of fresh preparation. The bacteria inocula concentration was more than 1010, then MPC50 and MPC90 values were calculated and MPC/ MIC was compared. Results MPC50 and MPC90 values of moxifloxacin were 1 mg/L and 2 mg/L, which was the low- est among the 5 kinds of drugs. MPC50 and MPC90 values of Ciprofloxacin is the highest about 16 mg/L and 32 mg/L separately. The MPC/MIC ratio for moxifloxacin and levofloxacin was 8 to 16, for gatifloxacin and sparfloxacin was 16 to 32, for ciprofloxacin was mainly in 32 to 64. Conclusion Moxifloxacin and levofloxacin have not only broad an- tibacterial activity, but also advantage in mutant prevention.