There is an urgent need to develop simple and fast antimicrobial susceptibility tests (ASTs) that allow informed prescribing of antibiotics. Here, we describe a label-free AST that can deliver results within an hour, using an actively dividing culture as starting material. The bacteria are incubated in the presence of an antibiotic for 30 min, and then approximately 105 cells are analysed one-by-one with microfluidic impedance cytometry for 2–3 min. The measured electrical characteristics reflect the phenotypic response of the bacteria to the mode of action of a particular antibiotic, in a 30-minute incubation window. The results are consistent with those obtained by classical broth microdilution assays for a range of antibiotics and bacterial species.
Bibliographical noteFunding Information:
We would like to thank Ying Tran for fabricating the micro-cytometer chips. H.M. would like to thank the Royal Society for funding. T.J.J.I. and D.C.S. acknowledge travel funding from the University of Western Australia.
© 2020, The Author(s).