title: Asynchronous magnetic bead rotation (AMBR) biosensor in microfluidic droplets for rapid bacterial growth and susceptibility measurements.
abstract: Inappropriate antibiotic use is a major factor contributing to the emergence and spread of antimicrobial resistance. The long turnaround time (over 24 hours) required for clinical antimicrobial susceptibility testing (AST) often results in patients being prescribed empiric therapies, which may be inadequate, inappropriate, or overly broad-spectrum. A reduction in the AST time may enable more appropriate therapies to be prescribed earlier. Here we report on a new diagnostic asynchronous magnetic bead rotation (AMBR) biosensor droplet microfluidic platform that enables single cell and small cell population growth measurements for applications aimed at rapid AST. We demonstrate the ability to rapidly measure bacterial growth, susceptibility, and the minimum inhibitory concentration (MIC) of a small uropathogenic Escherichia coli population that was confined in microfluidic droplets and exposed to concentrations above and below the MIC of gentamicin. Growth was observed below the MIC, and no growth was observed above the MIC. A 52% change in the sensor signal (i.e. rotational period) was observed within 15 minutes, thus allowing AST measurements to be performed potentially within minutes.
authors.affiliation: Department of Chemistry, University of Michigan, 930 North University, Ann Arbor, MI 48109-1055, USA.
authors.forename: Irene
authors.initials: I
authors.lastname: Sinn
authors.forename: Paivo
authors.initials: P
authors.lastname: Kinnunen
authors.forename: Theodore
authors.initials: T
authors.lastname: Albertson
authors.forename: Brandon H
authors.initials: BH
authors.lastname: McNaughton
authors.forename: Duane W
authors.initials: DW
authors.lastname: Newton
authors.forename: Mark A
authors.initials: MA
authors.lastname: Burns
authors.forename: Raoul
authors.initials: R
authors.lastname: Kopelman
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D005839:Gentamicins / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000295:instrumentation / Q000379:methods; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D013997:Time Factors; D056689:Uropathogenic Escherichia coli / Q000254:growth & development*
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins