1984-1993년의 혈액배양 성적

Abstract

Background : Blood culture is an important procedure for the determination of the etiologic agent of bacteremia. Analysis of blood culture results and antimicrobial susceptibility trend can provide the clinicians with relevant informations for the empirical antimicrobial treatment. Methods : The species and antimicrobial susceptibility of the isolates from blood cultures at the Severance Hospital during the years from 1984 to 1993 were analysed. Blood specimens were cultured using Brewer thioglycollate medium (BTM) and Tryptic soy broth (TSB) for 7 days. Indentification of organism was based on conventional method or commercial kit systems. Antimicrobial susceptibility was tested by disk diffusion method. Results : A total of 207,877 blood specimens were cultured, and 17,807 positive specimens were obtained from 10,344 patients. Among the isolates 92.2% were aerobic and facultative anaerobic bacteria, 5.8% anaerobes, and 1.9% fungi. E. coli was isolated most frequently, followed by S. aureus, ?-hemolytic Streptococcus, Enterococcus, K. pneumoniae, Enterobacter, S. typhi and P. aeruginosa. The proportion of patients with Enterococcus increased from 5.1% in 1984 to 10.6% I 1993, while that of S. typhi decreased from 13.7% in 1984 to 3.4% in 1993. There was no significant change in isolation freguency for other species of Enterobacteriaceae. ?-hemolytic Streptococcus was frequently isolated from the age group of less than 2 years, Enterobacteriaceae and glucose- nonfermenting gram-negative bacilli from more than 50 years, and S. typhi from 20~59 years. The isolation rate of S. typhi was higher from November to January, but no obvious seasonal trend was observed for most of the other organisms. Polymicrobial bacteremia was found in 3.8% of patients with positive blood culture. Isolation rate of methicillin-resistant S. aureus, ampicillin-resistant Enterococcus and cofotaxime-resistant K. pneumoniae increased significantly during the study period. Conclusion We conclude that E. coli is the most common cause of bacteremia and that S. aureus, ?-hemolytic Streptococcus and K. pneumoniae remain to be frequently isolated pathogens. While the isolation of S. typhi has decreased over the study period, the bacateremia due o Enterococcus has increased. Anaerobic bacateremia and fungemia has increased. Therefore, increased resistance of S. aureus, Enterococcus and K. pneumoniae should be considered in the empirical selection of antimicrobial agents.