环丙沙星联用磷霉素抗尿路感染耐药铜绿假单胞菌的协同作用体外研究

On the In Vitro Synergistic Effect of Ciprofloxacin Combined with Fosfomycin against Drug-Resistant Pseudomonas Aeruginosa Isolates from Urinary Tract Infections

目的观察环丙沙星和磷霉素联合应用抗尿路感染耐药铜绿假单胞菌的体外协同作用。方法采用常规方法进行细菌分离和菌种鉴定。最低抑菌浓度(MIC)测定采用微量肉汤稀释法,联合抑菌浓度指数(FICI)测定采用棋盘法。结果 82株耐环丙沙星铜绿假单胞菌中,环丙沙星和磷霉素联合应用对22株细菌有协同抗菌作用,占26.83%。急性杀菌作用中,选取环丙沙星和磷霉素联合应用后协同抗菌作用和环丙沙星MIC降低均最明显的铜绿假单胞菌P34和P58作为研究对象,结果在药物处理8 h时,环丙沙星和磷霉素联合处理组的细菌数明显低于两种药物单独处理组。浊度试验结果显示,药物处理3 h后,联合用药组与单独用药组细菌浊度出现明显差异。结论环丙沙星和磷霉素联合应用不但具有抗耐环丙沙星铜绿假单胞菌的协同作用,且具有较强的杀菌效果和溶菌作用。

Objective To investigate the in vitro synergistic effect of eiprofloxacin combined with fosfomycin on ciprofloxacin-resistant Pseudomonas aeruginosa clinical isolates from urinary tract infections. Methods The isolation and identification of Pseudomonas aeruginosa were performed by using the traditional procedures. The minimum inhibitory concentration（MIC） testing was determined by using the mierodilution broth method. The fractional inhibitory concentration index（FICI） was tested by using the checkerboard method. Results Among the 82 ciprofloxacin-resistant Pseudomonas aeruginosa isolates, the synergistic effect of eiprofloxacin combined with fosfomycin was observed in 22 strains（26.83% ）. In the acute bactericidal effect experiments, Pseudomonas aeruginosa isolates P34 and P58 as the most obvious synergistic effect and the reduced MIC of ciprofloxacin were selected as the research subjects. The results showed that the viable c, ell count at 8 h after medication treatment in the ciprolloxacin and fosfomycin combination treatment group was significantly fewer than that of the single drug treatment group. The turbidity test results showed that the significant difference at 3 h after medica- tion treatment was observed between the ciprofloxacin and fosfomycin combination treatment group and the single drug treatment group. Conclusion The combination of ciprofloxacin and fosfomycin not only induces a synergistic eftect on ciprofloxacin-resistant Pseu- domonas aeruginosa strains, but also has a strong bactericidal effect and bacteriolytic effect.