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.

A Winogradsky-based culture system shows an association between microbial fermentation and cystic fibrosis exacerbation

“…A modified bioreactor and analytical gas chromatography and mass spectrometry system was used for headspace gas collection (Umber et al, 2013), where replicates of six individual tubes were placed directly inside three separate glass collection containers (triplicate) and incubated at 37 1C for 24 h to collect headspace gas. Headspace gas was directly injected into a gas chromatography and mass spectrometry system and analyzed as described in , Shin et al (2009), Umber et al (2013) and Colman et al (2001). The area under the curve of selected volatile organic compounds was called manually and converted to partsper-trillion where possible for the quantification of gases.…”

A Compendium of Volatile Organic Compounds (VOCs) Released By Human Cell Lines

“…Frequently underestimated sources of volatile compounds in breath gas are inter alia (i) nutrition and medication uptake [42-45], (ii) physiology (hemo-dynamics, distribution in body compartments) [46, 47] and (iii) metabolism of intestinal bacteria [48, 49]. Detection of VOCs in general, but also their further identification, may be additionally complicated by the fact that their concentration levels are affected by metabolic processes, which may undergo large fluctua-tions, e.g .…”

Estimating Common Parameters of Lognormally Distributed Environmental and Biomonitoring Data: Harmonizing Disparate Statistics from Publications

“…DMDS is ubiquitous in human urinary headspace and likely a product of the human microbiome. In addition to the association with enteric bacterial colonization and systemic blood infections, DMDS is also an end product of methionine metabolism in liver mitochondria, and a bioindicator for chronic kidney disease (CKD) that finds its way into all biological media including urine Sehnert et al, 2002;Umber et al, 2013).…”