The investigation suggests that Mar phenotype of Escherichia coli be determined by the levels of active efflux system acrAB gene expression, and the expression of acrAB gene should be regulated by mar operon.

• 本研究表明大肠杆菌acrAB表达水平决定了大肠杆菌多重耐药表型，mar可能调控acrAB的表达。