Okusu H, Ma D, Nikaido H
Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
J Bacteriol. 1996 Jan;178(1):306-8. doi: 10.1128/jb.178.1.306-308.1996.
Multiple-antibiotic-resistance (Mar) mutants of Escherichia coli are resistant to a wide variety of antibiotics, and increased active efflux is known to be responsible for the resistance to some drugs. The identity of the efflux system, however, has remained unknown. By constructing an isogenic set of E. coli K-12 strains, we showed that the marR1 mutation was incapable of increasing the resistance level in the absence of the AcrAB efflux system. This experiment identified the AcrAB system as the major pump responsible for making the Mar mutants resistant to many agents, including tetracycline, chloramphenicol, ampicillin, nalidixic acid, and rifampin.
大肠杆菌的多重抗生素耐药(Mar)突变体对多种抗生素具有抗性,已知活性外排增加是对某些药物产生抗性的原因。然而,外排系统的身份仍然未知。通过构建一组大肠杆菌K-12的同基因菌株,我们发现marR1突变在没有AcrAB外排系统的情况下无法提高抗性水平。该实验确定AcrAB系统是使Mar突变体对许多药物产生抗性的主要泵,这些药物包括四环素、氯霉素、氨苄青霉素、萘啶酸和利福平。