比较6种氟喹诺酮类药物对金黄色葡萄球菌的防耐药变异浓度

Comparison the mutant prevention concentration of 6 kinds of fluoroquinolones for Staphylococcus aureus

目的比较6种氟喹诺酮类药物对临床分离金黄色葡萄球菌耐药突变体的选择能力。方法用呼吸道标本,选择对苯唑西林、环丙沙星敏感的金黄色葡萄球菌36株,采用标准琼脂二倍稀释法、标准琼脂平板稀释法,测定6种氟喹诺酮类药物对金黄色葡萄球菌的MIC、MPC。结果 MPC值比较,莫西沙星最低;而环丙沙星最高。选择指数(MPC90/MIC90)较低有如下4种:莫西沙星、卡屈沙星、加替沙星和帕珠沙星,均为2。6种药物MPC90值与其体内药动学参数比较,莫西沙星和卡屈沙星小于其Cmax。结论莫西沙星、卡屈沙星和加替沙星对金葡菌的MPC值较低,突变选择窗范围相对较窄。

Objective To determine the mutant prevention concentration（MPC） of 6 kinds of fluoroquinolones for the clinical isolated Staphylococcus aureus,and to compare the capacity of the choosing on the resistant mutant strain of the 6 kinds of fluoroquinolones.Methods The minimal inhibitory concentrations（MIC） and MPC of ciprofloxacin,levofloxacin,gatifloxacin,caderofloxacin,mixifloxacin and pazufloxacin were determined on 36 strains of S.aureus isolated from clinic which were sensitive to oxacillin and ciprofloxacin by agar two-fold dilution method and ager plates dilution method.Results For MPC,mixifloxacin was the lowest,then caderofloxacin,gatifloxacin,pazufloxacin and levofloxacin,and ciprofloxacin was the highest among the 6 kinds of fluoroquinolones against Staphylococcus aureus.As for MIC90/MPC90,mixifloxacin,caderofloxacin,gatifloxacin and pazufloxacin were more lower,levofloxacin and ciprofloxacin were more higher.The comparison of the pharmacokinetic parameters in vivo to MPC90 for the 6 kinds of fluoroquinolones against the 36 strains of S.aureus showed that MPC90 was less than Cmaxfor moxifloxacin and caderofloxacin.Conclusion Moxifloxacin,caderofloxacin and gatifloxacin have the lower MPC and narrower mutant selective window with a high ability to restrict the selection of S.aureus resistant mutants among the 6 kinds of fluoroquinolones against the S.aureus.