中文摘要：

从临床分离的20株鹿源耐氨基糖苷类药物大肠杆菌中选取2株高度耐药菌,4株中度耐药菌和1株低度耐药菌,利用实时荧光定量RT-PCR方法检测编码磷酸转移酶aphA基因mRNA的表达水平。结果表明,2株高度耐药株Ct值（Cycle threshold,即反应管内荧光信号到达设定域值时所经历的循环数）最小,平均为23.40,但这2株之间Ct值也存在着差异;4株中度耐药株之间差异不大,Ct值平均为27.20;而1株低度耐药株Ct值最大,为31.53。这说明不同耐药程度的7株菌在mRNA表达水平上存在差异,且aphA基因的转录、表达水平与耐药水平成正相关。

英文摘要：

Two higher drug-resistant stains, 4 midrange drug-resistant strains and one lower drug-resistant strains were selected from 20 clinical strains which were resistant to aminoglycosides antibiotics, to detect the expression of phosphotransferase A （aphA） gene by real-time RT-PCR. As result,the cycle thresholds of 2 higher drug-resistant stains were different,to be the small- est; That of 4 midrange drug-resistant strains were similar; And that of one lower drug resistant strain was the highest. It demonstrated that the more different levels of drug-resistant the more different quantification of cDNA,and that expressions of aphA gene were positive correlation with the level of drug-resistant.