In our ICU the decision to draw cultures will be taken according to the guidelines recommending a sampling by signs and symptoms of infections as a new onset of fever, chills, hypothermia, leukocytosis, PCT (demonstrated by the high levels in bc+/- patients at the sampling day) or a raise in CRP, neutropenia or left shift in differential blood count. This evidence concerns the gene CRP and Increased total leukocyte count.