碳青霉烯类抗生素耐药铜绿假单胞菌的体外联合药敏研究

Combined drug sensitivity test of carbapenem-resistant Pseudomonas aeruginosa in vitro

目的评价环丙沙星(CIP)分别与头孢哌酮/舒巴坦(CFS)、哌拉西林/三唑巴坦(TZP)联合用药对临床分离获得的碳青霉烯类抗生素耐药的铜绿假单胞菌(CRPA)的体外抑菌作用。方法采用棋盘法设计,琼脂平板稀释法测定抗菌药物对38株临床分离的CRPA的最低抑菌浓度(MIC),并计算抑菌指数(FIC指数)判断联合抑菌效应。结果 CIP与CFS联用后,5.3%为协同作用,81.5%为相加作用,13.2%为无关作用,没有拮抗作用;CIP与TZP联用后,7.9%为协同作用,73.7%为相加作用,18.4%为无关作用,没有拮抗作用。上述药物联用后,各药MIC50均明显降低,浓度-累积抑菌率曲线均表现为左移。结论 CIP分别与CFS、TZP联用对CRPA体外联合抗菌效应主要表现为协同和相加作用。

Objective To evaluate the combined inhibitory effect of ciprofloxacin（CIP） and cefoperazone/ sulbactam（CFS）, ciprofloxacin（CIP） and piperacillin/tazobactam （TZP） respectively on clinically isolated carbapenem- resistant Pseudomonas aeruginosa （CRPA） strains in vitro. Methods This test used chessboard method. Combined inhibitory effect of CIP and CFS, CIP and TZP in vitro was assayed by detecting the minimum inhibitory concentration and calculating the fractional inhibitory concentration （FIC） index for 38 CRPA strains with the agar dilution method. Results Combined CIP and CFS showed 5.3% synergic effect, 81.5% additive effect, 13.2% indifferent effect and no antagonistic effect on CRPA strains. Combined CIP and TZP displayed 7.9% synergic effect, 73.7% additive effect, 18.4% indifferent effect and no antagonistic effect on CRPA strains. The MIC50 of these drugs was significantly lower when they were used in combination with their concentration-accumulative curves shifted to the left. Conclusion Combined CIP and CFS, combined CIP and TZP show a combined synergic and additive inhibitory effect on CRPA strains in vitro.