There is a growing need for rapid diagnostic methods to support stewardship of antibiotics. We describe an analytical platform for sample concentration to detect antimicrobial resistance (AMR) genes directly from human urine for the diagnosis of urinary tract infections (UTIs) that are resistant to antibiotics. A sample-processing unit concentrates plasmid DNA directly from urine using magnetic beads, followed by isothermal amplification of target genes. The sample preconcentration unit interfaces with a digital microfluidic platform (DMF) and scales the sample volume by 500-fold, preconcentrating DNA from 1 mL into a 2 μL droplet for downstream processing. Tests with a clinical strain of Klebsiella pneumoniae (NCTC 13443), spiked into human urine demonstrated a limit of detection of 104 cfu mL-1 and a "sample to answer" detection in approximately 30 minutes.
Bibliographical noteFunding Information:
The authors would like to thank Ben Hadwen, Chris J. Brown, and Jonathan Buse of Sharp Laboratories Europe for many useful discussions and the development of a measurement jig. This work has been supported by the National Institute for Health Research (NIHR) i4i Programme grant II-ES-0511-21002 “Rapid detection of infectious agents at point of triage (PoT)”. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research, Public Health England or the Department of Health. All data supporting this study are openly available from the University of Southampton repository at “https://doi.org/10.5258/SOTON/D0731”.
© The Royal Society of Chemistry 2019.