Background: Blood culture is an important procedure for the determination of the etiologic agent of septicemia. Analysis of the blood culture results can provide clinicians with very important information for the empirical treatment of patients.

Methods: In this study the blood cuture results at Chosun University Hospital during the years 2002 to 2005 were analysed to determine the species and antimicrobial susceptibility of the isolates. Blood culture bottles were incubated in BACTEC 9240 blood culture system; the isolates were identified by VitekⅡ, and antimicrobial susceptibility was tested by VitekⅡ system or the NCCLS disk diffusion method.

Results: Positive blood cultures were obtained from 1,520 (18.5%) patients. Among the microorganisms isolated from blood culture, 97.0% were aerobic and facultative anaerobic bacteria and 2.8% were fungi. Frequently isolated organisms in decreasing order were coagulase-negative staphylococci (CNS), Escherichia coli, Staphylococus aureus, Stenotrophomonas maltophilia, Serratia marcescens, and Klebsiella pneumoniae. The proportion of Pseudomonas aeruginosa isolates resistant to ceftazidime and imipenem was increased during the study period.

Conclusion: E. coli was the most frequent etiologic agent of bacteremia except CNS, common contaminants of skin, at Chosun University Hospital. It seems to be necessary to enhance infection control measures to cope with an increasing number of the resistant bacteria to various antibiotics. (Korean J Clin Microbiol 2006;9(1):42-50)