Ion mobility spectrometry for microbial volatile organic compounds: a new identification tool for human pathogenic bacteria

Abstract

Presently, 2 to 4 days elapse between sampling at infection suspicion and result of microbial diagnostics. This delay for the identification of pathogens causes quite often a late and/or inappropriate initiation of therapy for patients suffering from infections. Bad outcome and high hospitalization costs are the consequences of these currently existing limited pathogen identification possibilities. For this reason, we aimed to apply the innovative method multi-capillary column–ion mobility spectrometry (MCC-IMS) for a fast identification of human pathogenic bacteria by determination of their characteristic volatile metabolomes. We determined volatile organic compound (VOC) patterns in headspace of 15 human pathogenic bacteria, which were grown for 24 h on Columbia blood agar plates. Besides MCC-IMS determination, we also used thermal desorption–gas chromatography–mass spectrometry measurements to confirm and evaluate obtained MCC-IMS data and if possible to assign volatile compounds to unknown MCC-IMS signals. Up to 21 specific signals have been determined by MCC-IMS for Proteus mirabilis possessing the most VOCs of all investigated strains. Of particular importance is the result that all investigated strains showed different VOC patterns by MCC-IMS using positive and negative ion mode for every single strain. Thus, the discrimination of investigated bacteria is possible by detection of their volatile organic compounds in the chosen experimental setup with the fast and cost-effective method MCC-IMS. In a hospital routine, this method could enable the identification of pathogens already after 24 h with the consequence that a specific therapy could be initiated significantly earlier.

A Pilot Study of the Noninvasive Assessment of the Lung Microbiota as a Potential Tool for the Early Diagnosis of Ventilator-Associated Pneumonia

“…55,56 Other exhaled breath studies use short, minute-scale durations, increasing variability, and false-negative results. 57,58 Our study has several limitations. Th is study only examines HMEs from patients with clinically suspected VAP and thus does not provide any information regarding EBCF in patients without suspicion.…”

Clinical Application of Volatile Organic Compound Analysis for Detecting Infectious Diseases

“…The objective of this article is to review emerging studies focusing on the utility of VOC analysis as a diagnostic tool for detecting and monitoring infectious diseases in a clinical setting. The extensive literature concerning the use of VOC analysis for in vitro identification and classification of microorganisms, including pathogens, is already the subject of various review articles (2,12,(32)(33)(34)(35) and will not be addressed here. Thus, after a brief introduction to some of the newly developed analytical technologies used for VOC analysis in clinical matrices, we focus on findings of studies which have used these novel approaches for investigating the potential of disease-related VOC biomarkers or for generating marker profiles enabling detection of underlying infectious diseases.…”

Metabolomics in Biotechnology (Microbial Metabolomics)

“…Also for CE many successful applications show that various MS detector types can be used efficiently for this separation technology [19]. To analyze the metabolites present in the gas phase above microbial cultures ion-mobility MS has been successfully employed to statistically analyze characteristic metabolite pattern as well as targeted analysis of metabolic compounds [20].…”