To investigate multiple-antibiotic-resistance mechanism in Escherichia coli, the distribution of active efflux pump gene, acrAB, were determined by PCR, Southern bolt, and its expressions by RT-PCR, in clinical strains of Escherichia coli.

• 为了研究临床分离多重耐药大肠杆菌的耐药机制，我们采用PCR和Southernblot检测大肠杆菌主动外排系统AcrAB结构基因acrAB在临床分离菌株中的分布并用RT－PCR测定其mRNA表达水平。