Empirical antimicrobial therapy is usually started in febrile neutropenic patients without having culture results. The aim of this study was to help determine the policies of empirical antibiotic usage in febrile neutropenic patients by detecting the antimicrobial susceptibility profile in this group of patients. In this study 3342 blood cultures taken from neutropenic patients hospitalized at the Departments of Hematology and Oncology of Gulhane Military Medical Academy between January 1, 2001 and December 31, 2005 were retrospectively evaluated. Positive blood cultures were entered in the study if the same bacteria was isolated from both the Bact/ALERT and the BACTEC blood culture systems. Six hundred and twenty five pathogens accepted as pathogen were identified by conventional methods and their antimicrobial susceptibilities were determined by disc diffusion method according to the criteria of Clinical Laboratory Standarts Institute. Of 625 isolates analyzed, 430 (69%) were gram positive cocci, 194 (31%) were gram negative bacilli and one was gram negative diplococcus (Neisseria sp.). Among gram positive cocci 84% of the coagulase negative staphylococci isolates and 63% of the Staphylococcus aureus isolates were resistant to oxacillin, and penicillin resistance rates were 96% and 91%, respectively. Ampicillin (78%), trimethoprim-sulfamethoxazole (62%), ampicillin-sulbactam (60%) and amoxicillin-clavulonic acid (54%) were the most resistant antimicrobial agents in gram negative bacilli. No resistance to imipenem was detected in enteric bacteriae. To know the antimicrobial susceptibility profile of the pathogens frequently isolated from febrile neutropenic patients and to consider this profile before starting an empirical antibiotic therapy would help the clinics which have any role in the treatment of these patients to determine the empirical antibiotic usage policies.

Keywords: Antimicrobial susceptibility, febrile neutropenia, blood culture