Suitability of silica hydride stationary phase, aqueous normal phase chromatography for untargeted metabolomic profiling of Enterococcus faecium and Staphylococcus aureus

Abstract

We report the robustness of silica hydride stationary phase, aqueous normal phase (ANP) chromatography to the chemical complexity of the intracellular metabolomes of Staphylococcus aureus and Enterococcus faecium. We specifically demonstrate that the chromatographic behavior of known metabolites is unaffected by the intracellular chemical matrix of these microbes and that this method enable untargeted profiling of their intracellular metabolites using accurate mass-retention time (AMRT) identifiers. We further demonstrate the ability of AMRT-based metabolite profiling to differentiate bacteria along genetic and phenotypic lines. Overall, these data commend the utility of ANP-based chromatography for untargeted metabolomics-based studies of microbial physiology and antibiotic resistance.

Accurate mass–time tag library for LC/MS-based metabolite profiling of medicinal plants

“…Hydrophilic interaction chromatography has been used successfully for the untargeted separation of polar metabolites for several years (reviewed in Cubbon et al, 2010). An emerging alternative is the use of silica hydride-based stationary phases (Pesek et al, 2008; 2011), which has been employed successfully for polar metabolome analyses to differentiate microbial strains (Weisenberg et al, 2009), study microbial metabolism of specific carbon substrates (de Carvalho et al, 2010a), profile enzyme function (de Carvalho et al, 2010b), discover biomarkers to indicate human cancer progression (Putluri et al, 2011), and enable the broad-spectrum profiling of biological extracts (Callahan et al, 2009). The expansion of the AMT tag database to include polar metabolites would enable the tentative identification of a much broader range of metabolites, which would be another significant contribution to improving peak annotation in LC/MS-based metabolomics.…”

Hierarchical expression of genes controlled by theBacillus subtilisglobal regulatory protein CodY

“…Sample preparation and metabolite analyses were performed as described in SI Materials and Methods using methods similar to those of Weisenberg et al (64). …”

Liquid chromatography/mass spectrometry compatible approaches for the quantitation of folic acid in fortified juices and cereals using aqueous normal phase conditions

“…In this manner, the columns can be used for retention of both hydrophilic and hydrophobic analytes depending on the mobile phase composition. Under ANP conditions, they have been found to be especially useful in metabolomics applications [28][29][30], since a given metabolome often contains a variety of polar species which are difficult to retain and separate by conventional RP techniques.…”