Single-cell microfluidics facilitates the rapid quantification of antibiotic accumulation in Gram-negative bacteria (article)

This is the final version. Available on open access from the Royal Society of Chemistry via the DOI in this recordData availability: All the data is available in the main text or in the supplementary materials.The code associated with this article is located in ORE at: http://hdl.handle.net/10871/121661The double-membrane cell envelope of Gram-negative bacteria is a formidable barrier to intracellular antibiotic accumulation. A quantitative understanding of antibiotic transport in these cells is crucial for drug development, but this has proved elusive due to a dearth of suitable investigative techniques. Here we combine microfluidics and time-lapse auto-fluorescence microscopy to rapidly quantify antibiotic accumulation in hundreds of individual Escherichia coli cells. By serially manipulating the microfluidic environment, we demonstrated that stationary phase Escherichia coli, traditionally more refractory to antibiotics than growing cells, display reduced accumulation of the antibiotic ofloxacin compared to actively growing cells. Our novel microfluidic method facilitates the quantitative comparison of the role of the microenvironment versus various membrane transport pathways in cellular drug accumulation. Unlike traditional techniques, our assay is rapid, studying accumulation as the cells are dosed with the drug. This platform provides a powerful new tool for studying antibiotic accumulation in bacteria, which will be critical for the rational development of the next generation of antibiotics.European CommissionBiotechnology and Biological Sciences Research Council (BBSRC)Engineering and Physical Sciences Research Council (EPSRC)University of Exeter School of BiosciencesEuropean Union Horizon 2020Medical Research Council (MRC)Royal SocietyWellcome TrustGW4 Initiator awar