Microbial volatiles as diagnostic biomarkers of bacterial lung infection in mechanically ventilated patients.



Ahmed, Waqar M, Fenn, Dominic, White, Iain R, Dixon, Breanna, Nijsen, Tamara ME, Knobel, Hugo H, Brinkman, Paul, Van Oort, Pouline MP, Schultz, Marcus J, Dark, Paul
et al (show 5 more authors) (2022) Microbial volatiles as diagnostic biomarkers of bacterial lung infection in mechanically ventilated patients. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 76 (6). ciac859-ciac859.

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Abstract

<h4>Background</h4>Early and accurate recognition of respiratory pathogens is crucial to prevent increased risk of mortality in critically ill patients. Microbial-derived volatile organic compounds (mVOCs) in exhaled breath could be used as non-invasive biomarkers of infection to support clinical diagnosis.<h4>Methods</h4>In this study, we investigated the diagnostic potential of in vitro confirmed mVOCs in the exhaled breath of patients under mechanically ventilation from the BreathDx study. Samples were analysed by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS).<h4>Results</h4>Pathogens from bronchoalveolar lavage (BAL) cultures were identified in 45/89 patients and S. aureus was the most commonly identified pathogen (n = 15). Out of 19 mVOCs detected in the in vitro culture headspace of four common respiratory pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli), 14 were found in exhaled breath samples. Higher concentrations of two mVOCs were found in the exhaled breath of patients infected with S. aureus compared to those without (3-methylbutanal p < 0.01. AUROC = 0.81-0.87 and 3-methylbutanoic acid p = 0.01. AUROC = 0.79-0.80). In addition, bacteria identified from BAL cultures which are known to metabolise tryptophan (Escherichia coli, Klebsiella oxytoca and Haemophilus influenzae) were grouped and found to produce higher concentrations of indole compared to breath samples with culture-negative (p = 0.034) and other pathogen-positive (p = 0.049) samples.<h4>Conclusions</h4>This study demonstrates the capability of using mVOCs to detect the presence of specific pathogen groups with potential to support clinical diagnosis. Although not all mVOCs were found in patient samples within this small pilot study, further targeted and qualitative investigation is warranted using multi-centre clinical studies.

Item Type: Article
Uncontrolled Keywords: BreathDx Consortium
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Systems, Molecular and Integrative Biology
Depositing User: Symplectic Admin
Date Deposited: 11 Nov 2022 11:32
Last Modified: 31 Mar 2023 00:42
DOI: 10.1093/cid/ciac859
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3166162