 For the laboratorial detection of polymorphisms of TLR9 will be taken blood samples from the patients in the three first days of their nursing and will be sent in laboratory for analysis. For the laboratorial confirmation of bacteremia will be taken blood cultures or percutaneous or via intravenous catheters, which will be sent for analysis in the laboratory. Each result of blood culture will be also accompanied by the antibiogram according to which will be determined also the therapeutic form of antibiotics from the servant doctors. The reception of blood cultures will be realised in each change of central catheters and in the appearance of fever wave. 