Heterogeneous Distribution of Proton Motive Force in Nonheritable Antibiotic Resistance
Annie H. Lee, Rachit Gupta, Hong Nhi Nguyen, Isabella R. Schmitz, Deborah A. Siegele, Pushkar P. Lele
Abstract
Bacterial cells with low PMF may survive antibiotic stress due to dormancy, which favors nonheritable resistance without genetic mutations or acquisitions. On the other hand, cells with high PMF are less tolerant, as PMF helps in the uptake of certain antibiotics. Here, we quantified flagellar motility as an indirect measure of the PMF in cells of Escherichia coli that had adapted to ampicillin. Despite the disadvantage of maintaining a high PMF in the presence of antibiotics, we observed high PMF in ~30% of the cells, as evidenced by their ability to swim rapidly for several hours. These and other results were consistent with the idea that antibiotic tolerance can arise via different mechanisms in a clonal population.