Chronic intestinalMycobacteriainfection: discrimination via VOC analysis in exhaled breath and headspace of feces using differential ion mobility spectrometry

Abstract

Differential ion mobility spectrometry (DMS) is a method to detect volatile organic compounds (VOC) in the ppt range. This study assessed whether VOC analysis using DMS could discriminate subjects with an experimentally induced chronic intestinal infection caused by Mycobacteria from non-infected controls. The animal model consisted of two groups of goats orally infected with two different doses of Mycobacterium avium subspecies paratuberculosis (MAP) and one group of non-infected healthy controls (each group: n = 6). Using DMS, exhaled breath and headspace of feces were analyzed on-line on an individual basis 9 months after inoculation of MAP. Data analysis included peak detection, cluster analysis, selection of discriminating VOC features (Mann-Whitney U test), and classification using a support-vector-machine. Taking the background of ambient air conditions into account, VOC analysis of exhaled breath as well as of feces revealed significant differences between chronically infected animals and non-infected controls. In both specimens, increasing as well as decreasing VOC features could be attributed to infection. Discrimination between infected and non-infected animals was sharper analyzing exhaled breath compared to headspace of feces. In exhaled breath, at least two VOC features were found to increase in a dose-dependent manner with increasing doses of MAP inoculated. Results of this study provide strong evidence that DMS analysis of exhaled breath has the potential to become a valuable tool for non-invasive assessment of VOC specifically related to certain diseases or infections.

Use of fecal volatile organic compound analysis to discriminate between non-vaccinated and BCG—Vaccinated cattle prior to and after Mycobacterium bovis challenge

“…Evaluation of volatile organic compounds (VOCs) present in breath, biofluids such as urine and blood, and feces have been conducted in an effort to develop a diagnostic modality for identifying disease (including tuberculosis) in humans [16–27]. In cattle, VOC analysis of breath samples has been explored as a method for diagnosis of bovine respiratory disease [28], brucellosis [29], bTB [30–32], Johne’s disease [29, 33], and ketoacidosis [34, 35]. Fecal VOC analysis has been used experimentally to identify goats [33, 36] and cattle [37] infected with Mycobacterium avium paratuberculosis (MAP; Johne’s disease).…”

Physiological variability in volatile organic compounds (VOCs) in exhaled breath and released from faeces due to nutrition and somatic growth in a standardized caprine animal model

“…Therefore, the clinical application of VOC analysis may be a promising tool for the non-invasive diagnosis of metabolic, inflammatory, or infectious diseases in humans (Spanel and Smith 2011, Buszewski et al 2013, Wang and Wang 2013 and animals (Dobbelaar et al 1996, Knobloch et al 2010, Purkhart et al 2011, Peled et al 2012, Ellis et al 2014.…”

Volatile Emissions from Mycobacterium avium subsp. paratuberculosis Mirror Bacterial Growth and Enable Distinction of Different Strains

“…Based on the knowledge that bacteria emit volatile organic compounds (VOCs) [11,12] a number of studies has been undertaken to identify potential volatile biomarkers for mycobacterial infections [13–22]. Differences between VOC patterns of infected and not infected animals were described in first pilot experiments applying less specific techniques such as electronic noses [13] and IMS [18]. Although these first results are promising, any detailed knowledge on potential marker compounds concerning their biochemical origin and their physico-chemical properties is lacking [18].…”

“…Differences between VOC patterns of infected and not infected animals were described in first pilot experiments applying less specific techniques such as electronic noses [13] and IMS [18]. Although these first results are promising, any detailed knowledge on potential marker compounds concerning their biochemical origin and their physico-chemical properties is lacking [18]. …”