In Vitro Volatile Metabolite Signatures of Common Pathogenic Mucorales

X. Yu1 , M. Al-Kateb1 , O. Aloum1 , L. R. Baden1 , F. M. Marty1 , S. Z. Manolakos2 , N. P. Wiederhold3 , A. Chowdhary4 , S. Koo1

Author address: 

1Brigham and Women's Hosp., Harvard Med. Sch., Boston, MA, 2Draper Lab., Cambridge, MA, 3Univ. of Texas Hlth.Sci. Ctr., San Antonio, TX, 4Vallabhbhai Patel Chest Inst., Univ. of Delhi, Delhi, India


Background: Members of the order Mucorales cause life-threatening, rapidly progressive infections. The diagnosis of mucormycosis is challenging.Methods: We characterized the in vitro volatile metabolite profiles of Rhizopus arrhizus var. arrhizus (n=8) and var. delemar (n=8), Rhizopus microsporus (n=4), and Mucor circinelloides (n=4), the most common species causing mucormycosis, using thermal desorption-gas chromatography (GC)/tandem mass spectrometry and, in parallel, GC-differential mobility spectrometry (DMS), a rapid, portable method of identifying specific volatile metabolite signatures in complex gas mixtures.Results: Each of these 4 species consistently emitted a distinctive profile of volatile sesquiterpene secondary metabolites, all distinct from volatile sesquiterpenes released by Aspergillus: longipinene, maaliene, gurjunene, selinene, and himachalene in R. arrhizus var. arrhizus; caryophyllene, isocaryophyllene, and gurjunene in R. arrhizus var. delemar (Figure: corresponding DMS metabolite plots); caryophyllene and cubebol in R. microsporus; and caryophyllene, cubebol, and guaiene in M. circinelloides.Conclusion: Volatile sesquiterpene secondary metabolite signatures of Mucorales are highly distinct from secondary metabolites released by Aspergillus spp. These distinctive metabolic features may be useful in the breathbased diagnosis of mucormycosis, particularly in helping distinguish mucormycosis from aspergillosis. DMS appears to be a useful technique for the rapid identification of these sesquiterpene metabolites.

abstract No: 


Full conference title: 

ASM Microbe 2016
    • ASM microbe 1st (2016)