Rapid and accurate detection of urinary pathogens by mobile IMS-based electronic nose: a proof-of-principle study

PLoS One. 2014 Dec 19;9(12):e114279. doi: 10.1371/journal.pone.0114279. eCollection 2014.

Abstract

Urinary tract infection (UTI) is a common disease with significant morbidity and economic burden, accounting for a significant part of the workload in clinical microbiology laboratories. Current clinical chemisty point-of-care diagnostics rely on imperfect dipstick analysis which only provides indirect and insensitive evidence of urinary bacterial pathogens. An electronic nose (eNose) is a handheld device mimicking mammalian olfaction that potentially offers affordable and rapid analysis of samples without preparation at athmospheric pressure. In this study we demonstrate the applicability of ion mobility spectrometry (IMS) -based eNose to discriminate the most common UTI pathogens from gaseous headspace of culture plates rapidly and without sample preparation. We gathered a total of 101 culture samples containing four most common UTI bacteries: E. coli, S. saprophyticus, E. faecalis, Klebsiella spp and sterile culture plates. The samples were analyzed using ChemPro 100i device, consisting of IMS cell and six semiconductor sensors. Data analysis was conducted by linear discriminant analysis (LDA) and logistic regression (LR). The results were validated by leave-one-out and 5-fold cross validation analysis. In discrimination of sterile and bacterial samples sensitivity of 95% and specificity of 97% were achieved. The bacterial species were identified with sensitivity of 95% and specificity of 96% using eNose as compared to urine bacterial cultures.

In conclusion: These findings strongly demonstrate the ability of our eNose to discriminate bacterial cultures and provides a proof of principle to use this method in urinanalysis of UTI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Case-Control Studies
  • Electronic Nose*
  • Humans
  • Microbiota
  • Sensitivity and Specificity
  • Urinalysis / instrumentation
  • Urinalysis / methods*
  • Urinary Tract Infections / microbiology*

Associated data

  • Dryad/10.5061/dryad.V3G17

Grant support

This study was funded by the Competitive State Research Financing of the Expert Responsibility area of Tampere University Hospital (grants 9N035 and X51001 for TL) and Tekes – the Finnish Funding Agency for Innovation for project “DiagNOSE - from extrasensory olfactory cues to status of wellbeing” project number 1010/31/2013 for Tampere University of Technology and 564/31/2013 for University of Tampere. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.