Subminimal inhibitory concentrations of the disinfectant benzalkonium chloride select for a tolerant subpopulation of Escherichia coli with inheritable characteristics.

ABSTRACT: Exposure of Escherichia coli to a subminimal inhibitory concentration (25% below MIC) of benzalkonium chloride (BC), an antimicrobial membrane-active agent commonly used in medical and food-processing environments, resulted in cell death and changes in cell morphology (filamentation). A small subpopulation (1-5% of the initial population) survived and regained similar morphology and growth rate as non-exposed cells. This subpopulation maintained tolerance to BC after serial transfers in medium without BC. To withstand BC during regrowth the cells up regulated a drug efflux associated gene (the acrB gene, member of the AcrAB-TolC efflux system) and changed expression of outer membrane porin genes (ompFW) and several genes involved in protecting the cell from the osmotic- and oxidative stres

SUBMITTER: Moen B 

PROVIDER: S-EPMC3344204 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature