莫西沙星联合头孢哌酮/舒巴坦对耐碳青霉烯类鲍曼不动杆菌防耐药突变浓度的研究

摘要

Aim To study the change of mutant pre- vention concentration (MPC) in carbapenem-resistant Acinetobacter baumannii (CRAB) treated with moxi- floxacin ( MFX ) and/ or cefoperazone/ sulbactam (CFS) in vitro, and provide a theoretical support for preventing the bacterial resistance. Methods To cal- culate the fractional inhibitory concentration (FIC) in- dex, the minimum inhibitory concentration (MIC) of 20 clinical isolates of CRAB treated with MFX and/ or CFS was determined by checkerboard microdilution as- say. In addition, to calculate the selection index (SI), the MPC of 20 clinical isolates of CRAB treated with MFX and/ or CFS was determined by agar plate di- lution assay. Results Our study showed that there was synergistic/ addictive action, rather than antago- nism action against clinical isolates of CRAB when treated with MFX + CFS. The SI of the 20 isolates trea- ted with MFX or CFS alone was 4 ~128 and 8 ~64 re- spectively, but reduced to 1 ~8 and 4 ~16 when trea- ted with MFX + CFS, which decreased by 2 ~16 and 2 ~4 times respectively compared with the single treat- ment. Conclusion These results suggest that the combination treatment of MFX + CFS against clinical isolates of CRAB might lower the MPC of the isolates treated with MFX/ CFS alone, narrow the mutant selec- tion window, and prevent the generation of drug - re- sistant mutants.%目的：在体外探讨莫西沙星( MFX)、头孢哌酮/舒巴坦( CFS)单用及联合使用对耐碳青霉烯类鲍曼不动杆菌( CRAB)防耐药突变浓度( MPC)的影响,为防止细菌耐药的产生提供理论依据。方法采用棋盘法设计,微量肉汤稀释法测定抗菌药物对20株临床分离 CRAB的最低抑菌浓度( MIC),计算部分抑菌浓度( FIC)指数。用肉汤富集浓度为1013 CFU· L-1 CRAB,采用琼脂平板稀释法测定 MFX 和CFS单用及联合使用对20株临床分离CRAB的MPC,并计算相应的选择指数( SI)。结果 MFX联合CFS后,主要表现为协同和相加作用,无拮抗作用。 MFX和CFS单用对上述20株CRAB的选择指数分别为：4~128、8~64,两者联合后选择指数下降为：1~8、4~16,联合用药较单独用药选择指数分别下降2~16、2~4倍。结论 MFX与CFS联用后,均可降低其单用对CRAB的MPC,缩小耐药突变选择窗,防止耐药突变菌株的产生。