Text Box: THE VERIFICATION OF THE COAGULASE-NEGATIVE STAPHYLOCOCCAL BACTERAEMIA – INFECTION OR CONTAMINATION Pawińska A,, Dzierżanowska D., Piegdoń G. The Children’s Memorial Health Institute, Warsaw, Poland Objective: of the study was to determine whether isolated from blood-culture coagulase-negative staphylococci were contamination or the case of the true bacteraemia. Methods: All coagulase-negative staphylococci (CoNS) isolated from blood and venous catheters between 01-01-2000 and 31-12-2000 was collected. For each patient with CoNS-positive blood culture and CoNS-positive catheter culture the following data were collected: age, sex, underlying disease, duration of hospitalisation, the signs of sepsis, the management of sepsis. The blood culture was done at least 3-times from each patient with suspected bacteraemia. All isolated CoNS were identified and susceptibility to antibiotics was checked. To type by pulsed field gel electrophoresis (PFGE) staphylococcal strains isolated from sequential blood culture (at least twice from one patient) or from blood culture and catheter’s culture of the same patient were selected (according to CDC criteria). Results: CoNS were isolated from 115 patients (54% of all positive blood cultures) with suspected bacteraemia. In 95 cases (83%) we obtained one CoNS-positive blood culture (without catheter culture or with negative catheter culture) and these patients were excluded from the farther analysis. The strains isolated from 20 patients were qualified to the genetic analysis. PFGE typing confirmed the true bacteraemia in 13 cases (11% of patients with CoNS – positive blood culture). 1444