| Title: | TD/GC-MS analysis of volatile markers emitted from mono- and co-cultures of Enterobacter cloacae and Pseudomonas aeruginosa in artificial sputum |
| Author(s): | Lawal O; Knobel H; Weda H; Nijsen TME; Goodacre R; Fowler SJ; BreathDx c; |
| Address: | "Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK. School of Chemistry, Manchester Institute of Biotechnology, University of Manchester, Manchester, UK. Philips Innovation Labs, Philips Lighting, Eindhoven, The Netherlands. Philips Research, Royal Philips B.V., Eindhoven, The Netherlands. Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK. stephen.fowler@manchester.ac.uk. Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Manchester, UK. stephen.fowler@manchester.ac.uk" |
| DOI: | 10.1007/s11306-018-1357-5 |
| ISSN/ISBN: | 1573-3882 (Print) 1573-3890 (Electronic) 1573-3882 (Linking) |
| Abstract: | "INTRODUCTION: Infections such as ventilator-associated pneumonia (VAP) can be caused by one or more pathogens. Current methods for identifying these pathogenic microbes often require invasive sampling, and can be time consuming, due to the requirement for prolonged cultural enrichment along with selective and differential plating steps. This results in delays in diagnosis which in such critically ill patients can have potentially life-threatening consequences. Therefore, a non-invasive and timely diagnostic method is required. Detection of microbial volatile organic compounds (VOCs) in exhaled breath is proposed as an alternative method for identifying these pathogens and may distinguish between mono- and poly-microbial infections. OBJECTIVES: To investigate volatile metabolites that discriminate between bacterial mono- and co-cultures. METHODS: VAP-associated pathogens Enterobacter cloacae and Pseudomonas aeruginosa were cultured individually and together in artificial sputum medium for 24 h and their headspace was analysed for potential discriminatory VOCs by thermal desorption gas chromatography-mass spectrometry. RESULTS: Of the 70 VOCs putatively identified, 23 were found to significantly increase during bacterial culture (i.e. likely to be released during metabolism) and 13 decreased (i.e. likely consumed during metabolism). The other VOCs showed no transformation (similar concentrations observed as in the medium). Bacteria-specific VOCs including 2-methyl-1-propanol, 2-phenylethanol, and 3-methyl-1-butanol were observed in the headspace of axenic cultures of E. cloacae, and methyl 2-ethylhexanoate in the headspace of P. aeruginosa cultures which is novel to this investigation. Previously reported VOCs 1-undecene and pyrrole were also detected. The metabolites 2-methylbutyl acetate and methyl 2-methylbutyrate, which are reported to exhibit antimicrobial activity, were elevated in co-culture only. CONCLUSION: The observed VOCs were able to differentiate axenic and co-cultures. Validation of these markers in exhaled breath specimens could prove useful for timely pathogen identification and infection type diagnosis" |
| Keywords: | Bacteria Enterobacter cloacae Gas Chromatography-Mass Spectrometry Infection Pseudomonas aeruginosa Volatile organic compounds; |
| Notes: | "PubMed-not-MEDLINELawal, Oluwasola Knobel, Hugo Weda, Hans Nijsen, Tamara M E Goodacre, Royston Fowler, Stephen J eng BB/M017702/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom II-LA-0214-20009/DH_/Department of Health/United Kingdom 2018/05/05 Metabolomics. 2018; 14(5):66. doi: 10.1007/s11306-018-1357-5. Epub 2018 Apr 26" |
