应用E-test法、肉汤微量稀释棋盘法检测泛耐药鲍曼不动杆菌的试验

Combined anfimicrobial susceptibility test against pan-drug-resistant Acinetobacter baumannii with E-test and microdilution checkerboard assay

目的比较E-test法和肉汤微量稀释棋盘法（CB法）检测体外联合药敏试验并与时间杀菌曲线对比的观察。方法选择31株泛耐药（PDR）鲍曼不动杆菌临床株进行体外试验，分为替加环素、可立其丁、亚胺培南、阿米卡星单用和两药组合，亚胺培南＋替加环素＋阿米卡星三药组合也由CB法测试。这些测试的结果与时间杀菌曲线进行比较。结果亚胺培南＋可立其丁、替加环素＋亚胺培南能检测到协同作用。培养基中加入抗菌药物的E—test法联合药敏试验与时间杀菌曲线更具有可比性。在三药组合中由CB法和时间杀菌曲线可以检测到协同作用。结论结果表明联合药敏试验中协同作用测试可以预测特定的抗生素组合对泛耐药鲍曼不动杆菌的作用。

Objective To evaluate the activity of antibiotics against pan-drug-resistant （PDR） Acinetobacter baumannii by combination antimicrobial susceptibility test in viro with epsilometric methods （ E- test method） and microdilution checkerboard （CB method）, and to detect a good correlation between time- kill curve with the above mentioned two assays. Methods Thirty-one clinical isolates of PDR Acinetobacter baumannii were selected for mono and combination antimicrobial susceptibility test in vitro by E-test and CB method, then a comparison was conducted between the test results and the time-kill curve. Mono drugs in- volved tigecycline, colistin, imipenem and amikacin, and combinations involved two of drugs above, and three drugs involved imipenem/tigecycline, plus amikacin combination. Results Synergistic effect was de- tected in imipenem plus colistin and tigecycline plus imipenem combination. A high comparability was re- vealed between the E-test method with antimicrubial drugs added into the culture medium and the time-kill curves. Synergy in the combination of imipenem/tigecyeline, plus amikacin was detected by the CB method and time-kill curves. Conclusion The results showed that the effect of specific combination of antibiotics against PDR Acinetobacter baumannii could be predicted by testing their synergistic effect with combination antimicrobial susceptibility test.