Biased partitioning of the multidrug efflux pump AcrAB-TolC underlies long-lived phenotypic heterogeneity

Abstract

Drug efflux machinery inherited asymmetrically In dividing bacterial cells, asymmetric distribution of cell wall constituents occurs between mother cells and their progeny. Asymmetric distribution of efflux machinery in a growing population of bacterial cells results in heterogeneity in antibiotic resistance. One consequence is that in the presence of low levels of antibiotic, older cells tend to live longer than younger cells. Using a microfluidic device to trap and measure dividing cells, Bergmiller et al. showed that AcrAB-TolC, the main multidrug efflux pump of Escherichia coli , clusters at the pole of older cells (see the Perspective by Barrett et al. ). As cell division proceeds and daughter cells age, they too gradually accumulate polar efflux pumps. Science , this issue p. 311 ; see also p. 247