Vegetative Cell and Spore Proteomes ofClostridioides difficileshow finite differences and reveal potential biomarkers.

Clostridioides difficile -associated infection (CDI) is a health-care-associated infection mainly transmitted via highly resistant endospores from one person to the other. In vivo , the spores need to germinate in to cells prior to establishing an infection. Bile acids and glycine, both available in sufficient amounts inside the human host intestinal tract, serve as efficient germinants for the spores. It is therefore, for better understanding of Clostridioides difficile virulence, crucial to study both the cell and spore states with respect to their genetic, metabolic and proteomic composition. In the present study, mass spectrometric relative protein quantification, based on the 14 N/ 15 N peptide isotopic ratios, has led to quantification of over 700 proteins from combined spore and cell samples. The analysis has revealed that the proteome turnover between a vegetative cell and a spore for this organism is moderate. Additionally, specific cell and spore surface proteins, vegetative cell proteins CD1228, CD3301 and spore proteins CD2487, CD2434 and CD0684 are identified as potential biomarkers for C. difficile infection.