鲍曼不动杆菌多重耐药性与主动外排机制的相关性研究

目的 了解多重耐药鲍曼不动杆菌主动外排系统及双组分调节系统编码基因的携带情况,并观察外排泵抑制剂对多重耐药鲍曼不动杆菌耐药水平的影响程度,以探讨鲍曼不动杆菌多重耐药性与胞膜主动外排系统的关系.方法 PCR方法 扩增外排泵编码基因adeB及双组分调节系统编码基因adeR和adeS.采用琼脂稀释法测定50株多重耐药鲍曼不动杆菌对环丙沙星、阿米卡星、头孢噻肟和亚胺培南的最低抑菌浓度(MIC),并观察在含25μg/ml利血平条件下MIC值的变化程度.结果 50株多重耐药鲍曼不动杆菌adeB、adeR及adeS基因的携带率分别为94%、96%及92%.以环丙沙星、头孢噻肟、阿米卡星和亚胺培南作为底物,分别有49、50、50和46株菌在含25μg/ml利血平的条件下MIC值降低4倍或4倍以上,呈现明显的外排作用.结论 主动外排机制是本地区鲍曼不动杆菌多重耐药的重要原因之一.

Relationship between multiresistance and efflux system of Acinetobacter baumannii

Objective To detect the encoding gene of efflux pump and two-component system, and investigate the effect of efflux inhibition on the multiresistance of Acinetobacter baumarmii. Methods PCR was used to detect the adeB, adeR and aries gene. Agar dilution was used to determine the minimum inhibitory concentrations(MIC) of ciprofloxacin, cefotaxime, amikacin and imipenem of 50 multiresistance Acinetobacter baumannii, with or without 25 μg/ml reserpine. Results 94%, 96% and 92% of 50 muhiresistance of Acinetobacter baumannii were detected for adeB, adeR and aries gene,respectively. At least four fold decrease of MIC was observed in 49, 50, 50 and 46 isolates for ciprofioxacin, cefotaxime, amikacin and imipenem, respectively. Conclusion The multiresistance of Acinetobacter baumannii is related to the effect of the efflux system.