鲍曼不动杆菌临床株多重药物外排泵AdeABC的研究

The multtdrug efflux pump AdeABC in clinical Acinetobacter baumannii isolates

目的研究鲍曼不动杆菌（Acinetobaeter baumannii）临床株外排泵AdeABC的表达与耐药的关系及表达调控。方法微量肉汤稀释法检测鲍曼不动杆菌临床株对抗菌药物的敏感性及泵抑制剂作用，RT—PCR检测泵基因adeB的mRNA表达水平，PCR扩增泵调控基因adeRS并测序分析。结果30株多重耐药的鲍曼不动杆菌临床株及5株敏感株均存在泵结构基因片段adeB和调控基因adeRS，随机选取15株多重耐药株中均检测到adeB的mRNA表达，而在5株敏感株中无表达。测定2株多重耐药株调控基因adeRS序列均出现基因突变，发生氨基酸替代及缺失。结论鲍曼不动杆菌临床株外排泵AdeABC的表达可能与耐药性有关，在多重耐药株中存在着调控基因adeRS的基因序列变化。

Objective To study the expression of active efflux pump AdeABC in clinical Acineto- bacter baumannii islates and whether this effiux pump confers resistance to antibiotics. Methods The antibiotic susceptibility and the function of efflux pump inhibitor were tested by micro-dilution broth method. The expression of adeB was examined by RT-PCR. The controlling gene adeRS was amplified by PCR and sequenced. Results Thirty muhidrug resistance Acinetobacter baumannii isolates and 5 sensitive isolates for PCR were both abtained the expected products of adeB and adeRS. The mRNA expression of adeB in 15 muhidrug resistance（MDR） isolates were positive, but there was no expression of adeB in 5 sensitive isolates. The mutations of adePtS existed in 2 MDR isolates. Conclusion The expression of AdeABC may involved in the resistant mechanisms of the clinical MDR Acinetobacter baumannii isolates.