Mutational Activation of Antibiotic-Resistant Mechanisms in the Absence of Major Drug Efflux Systems of Escherichia coli.

ABSTRACT: Mutations are one of the common means by which bacteria acquire resistance to antibiotics. In an Escherichia coli mutant lacking major antibiotic efflux pumps AcrAB and AcrEF, mutations can activate alternative pathways that lead to increased antibiotic resistance. In this work, we isolated and characterized compensatory mutations of this nature mapping in four different regulatory genes, baeS, crp, hns, and rpoB. The gain-of-function mutations in baeS constitutively activated the BaeSR two-component regulatory system to increase the expression of the MdtABC efflux pump. Missense or insertion mutations in crp and hns caused derepression of an operon coding for the MdtEF efflux pump. Interestingly, despite the dependence of rpoB missen

SUBMITTER: Cho H 

PROVIDER: S-EPMC8223954 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature