| Title: | Identifying volatile in vitro biomarkers for oral bacteria with proton-transfer-reaction mass spectrometry and gas chromatography-mass spectrometry |
| Author(s): | Roslund K; Lehto M; Pussinen P; Hartonen K; Groop PH; Halonen L; Metsala M; |
| Address: | "Department of Chemistry, University of Helsinki, Helsinki, Finland. kajsa.roslund@helsinki.fi. Folkhalsan Institute of Genetics, Folkhalsan Research Center, Biomedicum Helsinki, Helsinki, Finland. Abdominal Center Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. Clinical and Molecular Metabolism, Faculty of Medicine Research Programs, University of Helsinki, Helsinki, Finland. Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. Department of Chemistry, University of Helsinki, Helsinki, Finland. Department of Diabetes, Central Clinical School, Monash University, Melbourne, VIC, Australia" |
| DOI: | 10.1038/s41598-021-96287-7 |
| ISSN/ISBN: | 2045-2322 (Electronic) 2045-2322 (Linking) |
| Abstract: | "We have measured the volatile fingerprints of four pathogenic oral bacteria connected to periodontal disease and dental abscess: Porphyromonas gingivalis (three separate strains), Prevotella intermedia, Prevotella nigrescens and Tannerella forsythia. Volatile fingerprints were measured in vitro from the headspace gas of the bacteria cultured on agar. Concrete identification of new and previously reported bacterial volatiles were performed by a combination of solid phase microextraction (SPME) and offline gas chromatography-mass spectrometry (GC-MS). We also studied the effect of the reduced electric field strength (E/N) on the fragmentation patterns of bacterial volatiles in online proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS). We aimed to discover possible new biomarkers for the studied oral bacteria, as well as to validate the combination of GC-MS and PTR-MS for volatile analysis. Some of the most promising compounds produced include: 1-Methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ), indole, and a cascade of sulphur compounds, such as methanethiol, dimethyl disulphide (DMDS) and dimethyl trisulphide (DMTS). We also found that several compounds, especially alcohols, aldehydes and esters, fragment significantly with the PTR-MS method, when high E/N values are used. We conclude that the studied oral bacteria can be separated by their volatile fingerprints in vitro, which could have importance in clinical and laboratory environments. In addition, using softer ionization conditions can improve the performance of the PTR-MS method in the volatile analysis of certain compounds" |
| Keywords: | Bacteria/*chemistry Biomarkers/*analysis *Gas Chromatography-Mass Spectrometry Mouth/*microbiology *Protons Volatile Organic Compounds/*analysis; |
| Notes: | "MedlineRoslund, Kajsa Lehto, Markku Pussinen, Pirkko Hartonen, Kari Groop, Per-Henrik Halonen, Lauri Metsala, Markus eng Research Support, Non-U.S. Gov't England 2021/08/21 Sci Rep. 2021 Aug 19; 11(1):16897. doi: 10.1038/s41598-021-96287-7" |
