Background: Scedosporium apiospermum, Scedosporium boydii, and Lomentospora (formerly Scedosporium) prolificans are ubiquitous molds that can cause severe, life-threatening fungal disease. Identification of scedosporiosis is important due to the resistance of these molds to many antifungal agents, but challenging due to the lack of specific diagnostic methods.
Methods: We examined the volatile organic metabolite profile of pathogenic Scedosporium species and L. prolificans in vitro, identifying key volatile organic metabolites using thermal desorption-gas chromatography (GC)/tandem mass spectrometry (MS), in parallel with GC-differential mobility spectrometry (DMS). DMS provides a rapid, portable method of identifying particular volatile metabolites in complex gas mixtures based on atmospheric pressure ionization followed by differential trajectories of these ion species across an asymmetric waveform electrical field.
Results: We identified a unique pattern of secondary sesquiterpene metabolites for each Scedosporium species and L. prolificans by GC-MS, with corresponding identification of these species-specific metabolite signatures by GC-DMS. S. prolificans (N = 6) emitted a signature of farnesene, alloaromadendrene, bisabolene, and germacrene (Fig 1: left panel: representative GC-MS total ion chromatogram segment of relative abundance vs. retention time), right panel: representative GC-DMS plot of metabolite intensity vs. VC (compensation voltage) vs. retention time). S. apiospermum produced cedrene, aromadendrene, selinene, and isogermacrene (Fig 2), and S. boydii produced cedrene, guaiene, gurjunene, sesquisabinene hydrate and cadinene (Fig 3).
and Lomentospora emit unique,
species-specific secondary metabolite volatile metabolite signatures, distinct
from the volatile metabolite signatures of Aspergillus
and Fusarium species, and pathogenic Mucorales. These distinctive fungal metabolite signatures
may be used as targets for rapid, species-specific, breath-based identification
infections and allow differentiation from other invasive mold infections.
Figure 1. L. prolificans.
Figure 2. S. apiospermum.
Figure 3. S. boydii.
O. Aloum, None
L. R. Baden, None
F. M. Marty, Alexion: Scientific Advisor , Consulting fee
Ansun: Investigator , Research support
Astellas: Consultant and Investigator , Consulting fee and Research support
Basilea: Conference speaker , Speaker honorarium
Chimerix: Consultant and Investigator , Consulting fee and Research support
Gilead: Consultant and Investigator , Consulting fee and Research support
GlaxoSmithKline: Consultant and Investigator , Consulting fee and Research grant
LFB, S.A.: Consultant , Consulting fee
Merck: Consultant and Investigator , Consulting fee and Research support
Shire: Consultant and Investigator , Consulting fee and Research support
WHISCON: Investigator , Research support
Pfizer: Course speaker , Speaker honorarium
Fate Therapeutics: Scientific Advisor , Consulting fee
N. Wiederhold, BioMerieux: Grant Investigator , Research support
S. Koo, Wako Diagnostics: Grant Investigator , Research support