Next Article in Journal
Internet of Things Platform for Smart Farming: Experiences and Lessons Learnt
Previous Article in Journal
Label-Free Fluorescent Detection of Trypsin Activity Based on DNA-Stabilized Silver Nanocluster-Peptide Conjugates
Previous Article in Special Issue
Biomimetic Precapillary Flow Patterns for Enhancing Blood Plasma Separation: A Preliminary Study
Article Menu

Export Article

Open AccessArticle
Sensors 2016, 16(11), 1879;

Fast and Inexpensive Detection of Bacterial Viability and Drug Effectiveness through Metabolic Monitoring

School of Biomedical Engineering, McMaster University, Hamilton, ON L8S 4K1, Canada
Department of Mechanical Engineering, McMaster University, Hamilton, ON L8S 4L7, Canada
Author to whom correspondence should be addressed.
Academic Editors: Fan-Gang Tseng and Tuhin Subhra Santra
Received: 5 August 2016 / Revised: 19 October 2016 / Accepted: 26 October 2016 / Published: 9 November 2016
(This article belongs to the Special Issue Biomicrofluidics)
Full-Text   |   PDF [3888 KB, uploaded 9 November 2016]   |  


Conventional methods for the detection of bacterial infection such as DNA or immunoassays are expensive, time consuming, or not definitive and thus may not provide all the information sought by medical professionals. In particular, it is difficult to obtain information about viability or drug effectiveness, which is crucial to formulate a treatment. Bacterial culture tests are the “gold standard” because they are inexpensive and do not require extensive sample preparation, and most importantly, provide all the necessary information sought by healthcare professionals, such as bacterial presence, viability and drug effectiveness. These conventional culture methods, however, have a long turnaround time, anywhere between 1 day and 4 weeks. Here, we solve this problem by monitoring the growth of bacteria in thousands of nanowells simultaneously to more quickly identify their presence in the sample and their viability. The segmentation of a sample with low bacterial concentration into thousands of nanoliter wells digitizes the samples and increases the effective concentration in those wells that contain bacteria. We monitor the metabolism of aerobic bacteria by using an oxygen-sensitive fluorophore, ruthenium tris (2,2’-diprydl) dichloride hexahydrate (RTDP), which allows us to monitor the dissolved oxygen concentration in the nanowells. Using E. coli K12 as a model pathogen, we demonstrate that the detection time of E. coli can be as fast as 35–60 min with sample concentrations varying from 104 (62 min for detection), 106 (42 min) and 108 cells/mL (38 min). More importantly, we also demonstrate that reducing the well size can reduce the detection time. Finally we show that drug effectiveness information can be obtained in this format by loading the wells with the drug and monitoring the metabolism of the bacteria. The method that we have developed is low cost, simple, requires minimal sample preparation and can potentially be used with a wide variety of samples in a resource-poor setting to detect bacterial infections such as tuberculosis. View Full-Text
Keywords: bacterial culture; microfluidics; sample segmentation; metabolic monitoring; rapid analysis bacterial culture; microfluidics; sample segmentation; metabolic monitoring; rapid analysis

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Ayyash, S.; Wu, W.-I.; Selvaganapathy, P.R. Fast and Inexpensive Detection of Bacterial Viability and Drug Effectiveness through Metabolic Monitoring. Sensors 2016, 16, 1879.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top