Metabolite profiling of Clostridium difficile ribotypes using small molecular weight volatile organic compounds

Volatile organic compounds (VOCs) emitted by cultures of ten different Clostridium difficile ribotypes have been profiled using proton transfer reaction-time of flight-mass spectrometry. A total of 69 VOCs were identified and combinations of these VOCs were found to be characteristic for each of the ribotypes. The VOC patterns, with the aid of a statistical analysis, have been shown to be useful in distinguishing different ribotypes. A tentative assignment of different masses also shows that different ribotypes have markedly different emissions of methanol, p-cresol, dimethylamine and a range sulfur compounds (ethylene sulfide, dimethylsulfide and methyl thioacetate), which point to VOCs as potential indicators of different metabolic pathways in virulent and less-virulent strains. The results establish the potential of detecting emitted VOC metabolites to differentiate between closely related C. difficile ribotypes and in the longer term provide metabolic insight into virulence.