耐环丙沙星阴沟肠杆菌临床株泵出机制的探讨  

Study of active efflux in ciprofloxacin-resistant Enterobater cloacae isolates

作　　者：于树云[1] 毕玲[1] 葛庚芝[1] 

机构地区：[1]天津医科大学第二医院呼吸科,天津300211

出　　处：《天津医科大学学报》2009年第4期646-648,652,共4页Journal of Tianjin Medical University

摘　　要：目的:探讨耐环丙沙星阴沟肠杆菌临床株中是否存在主动泵出机制。方法:用荧光分光光度法测定5株耐环丙沙星阴沟肠杆菌及2株敏感菌细胞内环丙沙星的聚积动力,比较加入能量抑制剂碳酰氰间氯苯腙(CCCP)前后细菌细胞内环丙沙星稳态聚积量的变化。结果:5株耐环丙沙星阴沟肠杆菌临床株和2株敏感株对环丙沙星的摄取均在5min内达到稳态浓度,耐药菌株细胞内环丙沙星的稳态浓度低于敏感菌株(均P<0.05),加入CCCP后耐环丙沙星菌株细胞内的环丙沙星聚积浓度较未加CCCP时增加12%～46%(均P<0.05),敏感菌株加入CCCP前后环丙沙星聚积浓度无明显变化(均P>0.05)。测试菌株对环丙沙星的聚积浓度与MIC值间呈负相关。结论:耐环丙沙星阴沟肠杆菌临床株中可能存在对环丙沙星的主动泵出机制,该机制可能参与了阴沟肠杆菌对环丙沙星的耐药。Objective： To detect whether Enterobater cloacae （ E.cloaeae ） isolated from active efflux system is present in ciprofloxacin-resistant clinic. Methods：The accumulations of ciprofloxacin in E. cloacae isolates were measured by a fluorescence method and the effects of carbonyl cyanidem- chlorophenylhydrazone （CCCP）in the uptake of ciprofloxacin in E.cloaeae isolates were evaluated by comparing intracellular stable concentrations of ciprofloxacin with CCCP and without CCCP. Results：The accumulations of ciprofloxacin detected in E.cloacae isolates reached to stable concentrations within the first 5 rain, while the intracellular stable concentrations of ciprofloxacin showed lower in ciprofloxacinresistant isolates than in ciprofloxacin-sensitive isolates, the accumulations of ciprofloxacin in resistant isolates increased after incubated with CCCP. Conclusion：h maybe exist an energy-dependent active efflux system targeting ciprofloxacin in ciprofloxacin-resistant E.cloaeae isolates and the active effiux system may play a role in resistance to ciprofloxacin of E.cloacae isolates.

关 键 词：阴沟肠杆菌 环丙沙星 泵出机制 碳酰氰间氯苯腙 耐药 

分 类 号：R51[医药卫生—内科学] R37[医药卫生—临床医学]