A New Way of Sensing: Need-Based Activation of Antibiotic Resistance by a Flux-Sensing Mechanism

Abstract

Bacteria have to be able to accurately perceive their environment to allow adaptation to changing conditions. This is usually accomplished by sensing the concentrations of beneficial or harmful substances or by measuring the effect of the prevailing conditions on the cell. Here we show the existence of a new way of sensing the environment, where the bacteria monitor the activity of an antibiotic resistance transporter. Such a "flux-sensing" mechanism allows the cell to detect its current capacity to deal with the antibiotic challenge and thus precisely respond to the need for more transporters. We propose that this is a cost-efficient way of regulating antibiotic resistance on demand.