| Title: | Detection of mycobacteria by volatile organic compound analysis of invitro cultures using differential ion mobility spectrometry |
| Author(s): | Purkhart R; Becher G; Reinhold P; Kohler HU; |
| Address: | "IfU Diagnostic Systems GmbH, Gottfried-Schenker-Strasse 18, 09244 Lichtenau, Germany. BecherConsult GmbH, Froebelweg 33, 16321 Bernau, Germany. Institute of Molecular Pathogenesis, Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), Naumburger Str. 96a, 07743 Jena, Germany" |
| ISSN/ISBN: | 1473-5644 (Electronic) 0022-2615 (Linking) |
| Abstract: | "PURPOSE: Differential ion mobility spectrometry (DMS) is an analytical technique used to detect volatile organic compounds (VOCs) in gaseous samples at very low concentration ranges from ppb to ppt. The aim of this study was to investigate whether VOC analysis by DMS is capable of detecting Mycobacterium avium subsp. paratuberculosis (MAP). METHODOLOGY: Headspaces of in vitro cultures of two different MAP strains at 1, 2, 3, 4 and 6 weeks after inoculation (each at two dilutions) were analysed with DMS in comparison to control samples without viable bacteria [(i) blank medium, (ii) medium inoculated with heat-inactivated MAP and (iii) sterile-filtered MAP culture broth]. Furthermore, VOC patterns in the headspace over cultures of six non-tuberculous mycobacterial species were compared to MAP-derived VOC patterns. Data analysis included peak detection, cluster analysis, identification of discriminating VOC features (Mann-Whitney U test) and different cross-validated discriminant analyses. RESULTS: VOC analysis resulted in up to 127 clusters and revealed highly significant differences between MAP strains and controls at all time points. In addition, few clusters allowed differentiation between MAP and other non-tuberculous mycobacteria and even between different MAP strains. Compounds have not been characterized. VOC analysis by DMS was able to identify MAP-positive samples after 1 week of in vitro growth. CONCLUSIONS: This study provides strong evidence that VOC analysis of headspace over mycobacterial cultures in combination with appropriate data analysis has the potential to become a valuable method to identify positive samples much earlier than with current standard procedures" |
| Keywords: | Animals Culture Media/chemistry Feces/microbiology Mycobacterium avium subsp.paratuberculosis/*chemistry/growth & development/*isolation & purification/metabolism Paratuberculosis/diagnosis Principal Component Analysis Tandem Mass Spectrometry/methods Vo; |
| Notes: | "MedlinePurkhart, Roman Becher, Gunther Reinhold, Petra Kohler, Heike U eng England 2016/12/21 J Med Microbiol. 2017 Mar; 66(3):276-285. doi: 10.1099/jmm.0.000410. Epub 2017 Mar 23" |
