title: Rapid and accurate detection of urinary pathogens by mobile IMS-based electronic nose: a proof-of-principle study.
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.
  
  
  
  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.
authors.affiliation: School of Medicine, University of Tampere, Tampere, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Roine
authors.affiliation: School of Medicine, University of Tampere, Tampere, Finland.
authors.forename: Taavi
authors.initials: T
authors.lastname: Saviauk
authors.affiliation: Department of Automation Science and Engineering, Tampere University of Technology, Tampere, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Kumpulainen
authors.affiliation: Department of Automation Science and Engineering, Tampere University of Technology, Tampere, Finland.
authors.forename: Markus
authors.initials: M
authors.lastname: Karjalainen
authors.affiliation: School of Medicine, University of Tampere, Tampere, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Tuokko
authors.affiliation: Department of Clinical Microbiology, Fimlab Laboratories, Tampere, Finland.
authors.forename: Janne
authors.initials: J
authors.lastname: Aittoniemi
authors.affiliation: Department of Clinical Microbiology, Fimlab Laboratories, Tampere, Finland.
authors.forename: Risto
authors.initials: R
authors.lastname: Vuento
authors.affiliation: Department of Automation Science and Engineering, Tampere University of Technology, Tampere, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Lekkala
authors.affiliation: Department of Clinical Chemistry, Fimlab Laboratories and University of Tampere, School of Medicine, Tampere, Finland.
authors.forename: Terho
authors.initials: T
authors.lastname: Lehtimäki
authors.affiliation: Department of Surgery, School of Medicine, University of Tampere and Department of Urology, Tampere University Hospital, Tampere, Finland.
authors.forename: Teuvo L
authors.initials: TL
authors.lastname: Tammela
authors.affiliation: Department of Surgery, School of Medicine, University of Tampere and Department of Vascular Surgery, Tampere University Hospital, Tampere, Finland.
authors.forename: Niku K J
authors.initials: NK
authors.lastname: Oksala
mesh_terms: D016022:Case-Control Studies; D062609:Electronic Nose; D006801:Humans; D064307:Microbiota; D012680:Sensitivity and Specificity; D016482:Urinalysis / Q000295:instrumentation / Q000379:methods*; D014552:Urinary Tract Infections / Q000382:microbiology*