Production of volatile organic compounds by mycobacteria.
The need for improved rapid diagnostic tests for tuberculosis disease has prompted interest in the volatile organic compounds (VOCs) emitted by Mycobacterium tuberculosis complex bacteria. We have investigated VOCs emitted by Mycobacterium bovis BCG grown on Lowenstein-Jensen media using selected ion flow tube mass spectrometry and thermal desorption-gas chromatography-mass spectrometry. Compounds observed included dimethyl sulphide, 3-methyl-1-butanol, 2-methyl-1-propanol, butanone, 2-methyl-1-butanol, methyl 2-methylbutanoate, 2-phenylethanol and hydrogen sulphide. Changes in levels of acetaldehyde, methanol and ammonia were also observed. The compounds identified are not unique to M. bovis BCG, and further studies are needed to validate their diagnostic value. Investigations using an ultra-rapid gas chromatograph with a surface acoustic wave sensor (zNose) demonstrated the presence of 2-phenylethanol (PEA) in the headspace of cultures of M. bovis BCG and Mycobacterium smegmatis, when grown on Lowenstein-Jensen supplemented with glycerol. PEA is a reversible inhibitor of DNA synthesis. It is used during selective isolation of gram-positive bacteria and may also be used to inhibit mycobacterial growth. PEA production was observed to be dependent on growth of mycobacteria. Further study is required to elucidate the metabolic pathways involved and assess whether this compound is produced during in vivo growth of mycobacteria.
Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine, London, UK. ruth.mcnerney@lshtm.ac.uk
Ruth
R
McNerney
Kim
K
Mallard
Phyllis Ifeoma
PI
Okolo
Claire
C
Turner
D001431:Bacteriological Techniques; D015374:Biosensing Techniques; D000440:Butanols / Q000378:metabolism; D002074:Butanones / Q000378:metabolism; D003470:Culture Media / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006862:Hydrogen Sulfide / Q000378:metabolism; D000432:Methanol / Q000378:metabolism; D009163:Mycobacterium bovis / Q000254:growth & development / Q000378:metabolism*; D010626:Phenylethyl Alcohol / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism*; D055549:Volatile Organic Compounds / Q000302:isolation & purification* / Q000378:metabolism
D000440:Butanols; D002074:Butanones; D003470:Culture Media; D013440:Sulfides; D055549:Volatile Organic Compounds; C040507:isobutyl alcohol; D010626:Phenylethyl Alcohol; C004784:dimethyl sulfide; D000432:Methanol; D006862:Hydrogen Sulfide