Detection Of Volatile Organic Compounds Emitted By Some Bacteria And Fungi

Objective:To study the characteristics of volatile organic compounds(VOCs)from some bacteria in bacteria and fungi in vitro culture, and therefore to explore its use in the diagnosis of the infectious diseases in lung.Methods:Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, enterococcus, Candida albicans, Candida glabrata were cultured.Air samples in the headspace of culture flasks were analyzed for VOCs with solid-phase micro-extraction and gas chromatography-mass spectroscopy technique (SPME-GC/MS).Results:Characteristic markers were found for certain microbial cultures:Escherichia coli、 Pseudomonas aeruginosa、Klebsiella pneumoniae and Candida albicans could be identified by unique markers compared with the other organisms,Indole、undecanol and Butylated Hydroxytoluene were detected in Escherichia coli、Pseudomonas aeruginosa and Klebsiella pneumonia respectively, C15H26O and C17H28O2were detected in Candida albicans.Indole and undecanol were detected in mixed microbial cultures of Escherichia coli and Pseudomonas aeruginosa.Candida albicans and Candida glabrata were distinguishable from each other,demonstrating the potential of this method to differentiate between even closely related microorganisms. Similar characteristic volatiles were seen from both cultures of individual bacteria and mixed microbial culture with A549cell strain.Conclusion:Characteristic VOCs can be detected from certain microbial cultures and mixed microbial cultures;There is no change when A549cell strain be added to A549cell strain;SPME/GC-MS is a non-invasive examination for suspected infection, and a method to differentiate between even closely related microorganisms.