Detection of Staphylococcus aureus in cystic fibrosis patients using breath VOC profiles

Abstract

Staphylococcus aureus (S. aureus) is a common bacterium infecting children with cystic fibrosis (CF). Since current detection methods are difficult to perform in children, there is need for an alternative. This proof of concept study investigates whether breath profiles can discriminate between S. aureus infected and non-infected CF patients based on volatile organic compounds (VOCs). We collected exhaled breath of CF patients with and without S. aureus airways infections in which VOCs were identified using gas chromatography-mass spectrometry. We classified these VOC profiles with sparse partial least squares discriminant analysis. Multivariate breath VOC profiles discriminated infected from non-infected CF patients with high sensitivity (100%) and specificity (80%). We identified the nine compounds most important for this discrimination. We successfully detected S. aureus infection in CF patients, using breath VOC profiles. Nine highlighted compounds can be used as a focus point in further biomarker identification research. The results show considerable potential for non-invasive diagnosis of airway infections.

Volatile organic compound breath signatures of children with cystic fibrosis by real-time SESI-HRMS

“…In almost all previous studies, breath was collected in bags and then analysed either directly by selected ion flow tube mass spectrometry (SIFT-MS) or by thermal desorption and subsequent gas chromatography mass spectrometry (GC-MS). Two small pilot studies showed distinct patterns of a range of exhaled features in patients with CF compared to healthy controls [10,11] detected by GC-MS. Other studies found molecules predictive for airway colonisation with various respiratory pathogens [12,13] including Pseudomonas aeruginosa [14,15]. Similar approaches reported exhaled molecules associated with CF and airway obstruction [16], acute exacerbations [17] and steroid treatment [18].…”

Volatile organic compound detection as a potential means of diagnosing cutaneous wound infections

“…It is controversial whether an organism can be identified by its VOC profile as these are influenced by environmental factors, co‐cultures, and species strains . However, recent studies on mono‐ and co‐cultures of species in different growth conditions associated with infections in cystic fibrosis patients have yielded patterns of VOCs that allowed species identification . Also, Kunze et al found no difference between VOC patterns of different strains of a single species and concluded that VOC patterns of a bacterial strain can be transferred to other strains of the same species .…”

“…62 However, recent studies on mono-and co-cultures of species in different growth conditions associated with infections in cystic fibrosis patients have yielded patterns of VOCs that allowed species identification. 93,150,151 Also, Kunze et al found no difference between VOC patterns of different strains of a single species and concluded that VOC patterns of a bacterial strain can be transferred to other strains of the same species. 91 VOCs also provide information about hostinfection interactions and the types of metabolic processes occurring.…”

Integrating exhaled breath diagnostics by disease-sniffing dogs with instrumental laboratory analysis

“…More recently, dogs have been trained to detect a variety of diagnosed medical conditions in humans (Sonoda et al 2011, Ehman et al 2012, Jezierski et al 2015, Hackner et al 2016, Neerincx et al 2016). The focus here is to explore a strategy of reaching pre-clinical (very early) instrumental detection of cancer based on breath analysis by taking advantage of the dog’s superior odor detection capabilities (Buszewski et al 2012, Ehman et al 2012).…”