A single-cell drug efflux assay in bacteria by using a directly accessible femtoliter droplet array.
Active efflux of drugs, such as antibiotics, from a cell is one of the major mechanisms that cause multi-drug resistance in bacteria. Here we report a method to assess drug efflux activity in individual Escherichia coli cells enclosed and isolated in a directly accessible femtoliter droplet array with a fluorogenic compound. The inhibitory effect of a chemical compound on an exogenously expressed efflux pump system from pathogenic bacteria was easily detected at the single-cell level. We also present a proof-of-principle experiment to screen for the gene encoding a drug efflux pump by collecting individual droplets containing single cells in which the drug efflux activity was restored after introduction of the exogenous gene from pathogenic bacteria. Our approach will be a useful tool to screen novel pump inhibitors and efflux pump genes, and to overcome infectious diseases caused by multi-drug-resistant bacteria.
Department of Applied Chemistry, University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656, Japan. iino@appchem.t.u-tokyo.ac.jp
Ryota
R
Iino
Kohei
K
Hayama
Hiromi
H
Amezawa
Shouichi
S
Sakakihara
Soo Hyeon
SH
Kim
Yoshimi
Y
Matsumono
Kunihiko
K
Nishino
Akihito
A
Yamaguchi
Hiroyuki
H
Noji
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001681:Biological Assay / Q000295:instrumentation / Q000379:methods; D024901:Drug Resistance, Multiple, Bacterial / Q000502:physiology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000494:pharmacology; D008826:Microbial Sensitivity Tests / Q000295:instrumentation / Q000379:methods; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods
D000900:Anti-Bacterial Agents; D005456:Fluorescent Dyes