Supported by grants by the Hellenic Institute for the Study of Sepsis and by bioMérieux. Procalcitonin assays, material for detection of fecal colonization and laboratory training were provided by bioMérieux. Contribution of authors EJGB conceptualized the study design, participated in data analysis and drafting the manuscript, had full access to all of the study data and takes responsibility for their integrity and the accuracy of the analysis. EK participated in data analysis, drafted the manuscript, had full access to all of the study data and takes responsibility for their integrity and the accuracy of the analysis. MK performed data analysis and