RobA-Induced Multiple Antibiotic Resistance Largely Depends on the Activation of the AcrAB Efflux
RobA is a member of the XylS/AraC subfamily of DNA binding proteins, and when overexpressed, it induces multiple antibiotic resistance in <i>Escherichia coli</i>. In this study, we introduced a multicopy <i>robA</i> plasmid (pMEP1) and its derivative into OmpF mutants and an AcrAB-deficient mutant. We found that a decrease in susceptibility to multiple antibiotics in these OmpF mutants when pMEP1 was introduced did not depend on OmpF porin expression. Interestingly, a <i>ΔompF</i> mutant (TK007) became more sensitive when pMEP1 was introduced. Moreover, no effect of RobA on the induction of multiple antibiotic resistance in an <i>acrA1</i><sup>-</sup> mutant was observed. Therefore, we conclude that the multiple antibiotic resistance induced by the overexpression of RobA largely depends on the activation of the AcrAB efflux, as well as the activation of <i>micF</i>.
- Microbiology and immunology
Microbiology and immunology 41(9), 697-702, 1997-09-20
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