title: Gas signatures from Escherichia coli and Escherichia coli-inoculated human whole blood.
abstract: BACKGROUND
  The gaseous headspace above naïve Escherichia Coli (E. coli) cultures and whole human blood inoculated with E. coli were collected and analyzed for the presence of trace gases that may have the potential to be used as novel, non-invasive markers of infectious disease.
  
  
  METHODS
  The naïve E. coli culture, LB broth, and human whole blood or E. coli inoculated whole blood were incubated in hermetically sealable glass bioreactors at 37°C for 24 hrs. LB broth and whole human blood were used as controls for background volatile organic compounds (VOCs). The headspace gases were collected after incubation and analyzed using a gas chromatographic system with multiple column/detector combinations.
  
  
  RESULTS
  Six VOCs were observed to be produced by E. coli-infected whole blood while there existed nearly zero to relatively negligible amounts of these gases in the whole blood alone, LB broth, or E. coli-inoculated LB broth. These VOCs included dimethyl sulfide (DMS), carbon disulfide (CS2), ethanol, acetaldehyde, methyl butanoate, and an unidentified gas S. In contrast, there were several VOCs significantly elevated in the headspace above the E. coli in LB broth, but not present in the E. coli/blood mixture. These VOCs included dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), methyl propanoate, 1-propanol, methylcyclohexane, and unidentified gases R2 and Q.
  
  
  CONCLUSIONS
  This study demonstrates 1) that cultivated E. coli in LB broth produce distinct gas profiles, 2) for the first time, the ability to modify E. coli-specific gas profiles by the addition of whole human blood, and 3) that E. coli-human whole blood interactions present different gas emission profiles that have the potential to be used as non-invasive volatile biomarkers of E. coli infection.
authors.affiliation: Department of Chemistry, University of California, Irvine, CA 92697, USA.
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Umber
authors.affiliation: Department of Pediatrics, University of California, Irvine, CA 92697, USA ; Institute for Clinical and Translational Sciences, University of California, Irvine, CA 92697, USA.
authors.forename: Hye-Won
authors.initials: HW
authors.lastname: Shin
authors.affiliation: Department of Chemistry, University of California, Irvine, CA 92697, USA.
authors.forename: Simone
authors.initials: S
authors.lastname: Meinardi
authors.affiliation: Department of Pediatrics, University of California, Irvine, CA 92697, USA ; Institute for Clinical and Translational Sciences, University of California, Irvine, CA 92697, USA.
authors.forename: Szu-Yun
authors.initials: SY
authors.lastname: Leu
authors.affiliation: Department of Pediatrics, University of California, Irvine, CA 92697, USA ; Institute for Clinical and Translational Sciences, University of California, Irvine, CA 92697, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Zaldivar
authors.affiliation: Department of Pediatrics, University of California, Irvine, CA 92697, USA ; Institute for Clinical and Translational Sciences, University of California, Irvine, CA 92697, USA.
authors.forename: Dan M
authors.initials: DM
authors.lastname: Cooper
authors.affiliation: Department of Chemistry, University of California, Irvine, CA 92697, USA.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Blake
keywords: Acetaldehyde; Carbon disulfide (CS2); Cell culture; Dimethyl sulfide (DMS); Escherichia coli; Ethanol; Gas biomarker; Human whole blood culture; Methyl butanoate; Volatile organic compounds (VOCs)