| Title: | Analysis of volatile metabolites from in vitro biofilms of Pseudomonas aeruginosa with thin-film microextraction by thermal desorption gas chromatography-mass spectrometry |
| Author(s): | Koehler T; Ackermann I; Brecht D; Uteschil F; Wingender J; Telgheder U; Schmitz OJ; |
| Address: | "Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141, Essen, Germany. Teaching and Research Center for Separation, University of Duisburg-Essen, Universitaetsstr. 5, 45141, Essen, Germany. Aquatic Microbiology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Universitaetsstr. 5, 45141, Essen, Germany. Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141, Essen, Germany. ursula.telgheder@uni-due.de. Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141, Essen, Germany. oliver.schmitz@uni-due.de. Teaching and Research Center for Separation, University of Duisburg-Essen, Universitaetsstr. 5, 45141, Essen, Germany. oliver.schmitz@uni-due.de" |
| DOI: | 10.1007/s00216-020-02529-4 |
| ISSN/ISBN: | 1618-2650 (Electronic) 1618-2642 (Print) 1618-2642 (Linking) |
| Abstract: | "Cystic fibrosis (CF) is an autosomal recessive inherited disease which leads to a production of thickened mucus in the airways. These conditions are conducive to poly-microbial infections, like chronic lung infection, in which Pseudomonas aeruginosa (P. aeruginosa) is the major pathogenic bacterium colonizing CF lungs at the end of the lifetime of CF patients. This in vitro study uses a P. aeruginosa biofilm model under partly cystic fibrosis conditions, with a sampling of volatile extracellular metabolites. The gas sampling was done with thin-film microextraction (TFME) and commercial polydimethylsiloxane (PDMS) films, whereas the analysis of loaded films was done by gas chromatography coupled to quadrupole mass spectrometry and thermodesorption (TD-GC-qMS). For this purpose, two commercially available films were characterized by means of thermogravimetry coupled to a qMS with atmospheric pressure photo ionization (TG-APPI-qMS), regarding homogeneity and temperature stability. The selected film was cleaned using a method developed in this study. The TD-GC-qMS method was successfully used for standards of volatile metabolites which were known to be produced by P. aeruginosa. Limits of detection and quantification of the method for middle and less polar compounds in low nanomolar range (0.5 nM and 1.5 nM) were achieved. The developed method was finally applied to investigate the extracellular volatile metabolites produced by biofilms of the strain P. aeruginosa DSM 50071 under aerobic and anaerobic conditions. In sum, eleven metabolites could be found under both conditions. Furthermore, it was shown in this study that different oxygen conditions (aerobic and anaerobic) resulted in emitting different extracellular volatile metabolites. Specific metabolites, like 1-undecene (aerobic) and 2-undecanone (anaerobic), could be identified. The results are promising, in that the biofilm model may be applicable for the identification of P. aeruginosa under clinical conditions. Furthermore, the model could be the basis for studying extracellular volatile metabolites from different mono- or co-cultures of various bacteria, as well as the implementation of pulmonary conditions, like these in CF lungs. This possibility allows the development of a non-invasive 'at-bedside' breath analysis method for CF patients in focus of various bacterial infections. Graphical abstract" |
| Keywords: | Biofilms/*growth & development Gas Chromatography-Mass Spectrometry/*methods Humans In Vitro Techniques Pseudomonas Infections/*diagnosis/metabolism/microbiology Pseudomonas aeruginosa/*isolation & purification Solid Phase Microextraction/*methods Volatil; |
| Notes: | "MedlineKoehler, Timo Ackermann, Imke Brecht, Dominik Uteschil, Florian Wingender, Jost Telgheder, Ursula Schmitz, Oliver J eng project number: 352241003/Deutsche Forschungsgemeinschaft/ Germany 2020/03/22 Anal Bioanal Chem. 2020 May; 412(12):2881-2892. doi: 10.1007/s00216-020-02529-4. Epub 2020 Mar 20" |
