Korean J Clin Microbiol.  2011 Jun;14(2):48-54. 10.5145/KJCM.2011.14.2.48.

Characteristics of Microorganisms Isolated from Blood Cultures at Nine University Hospitals in Korea during 2009

• Kim HJ
• Lee NY
• Kim S
• Shin JH
• Kim MN
• Kim EC
• Koo SH
• Ryoo NH
• Kim JS
• Cho JH

• KMID: 2089814
• DOI: http://doi.org/10.5145/KJCM.2011.14.2.48

Abstract

BACKGROUND
Blood culture is important for determining the etiologic agents of bacteremia and fungemia. Analyses of blood culture results and antimicrobial susceptibility can provide clinicians with relevant information for the empirical treatment of patients. The present study was conducted to assess the frequencies and antimicrobial resistance patterns of clinically important microorganisms from nine hospitals.
METHODS
Data including microbiological isolates and corresponding antimicrobial susceptibility test results were collected during 2009 from nine and five university hospitals, respectively. Microorganism identification was based on conventional methods. Antimicrobial susceptibility was tested using the VITEK II system or the Clinical and Laboratory Standards Institute disk diffusion method.
RESULTS
Of 397,602 blood specimens cultured from nine hospitals, 34,708 (8.7%) were positive for microorganisms. Excluding coagulase-negative Staphylococci (CoNS), Escherichia coli was the most common isolate (13.5%), followed by Staphylococcus aureus (11.5%), Klebsiella pneumoniae (6.5%) and Enterococcus faecium (3.4%). The isolation rate of CoNS was 23.6%, while that of ceftazidime-resistant E. coli showed geographic differences ranging from 11% to 28%. Among the Gram-negative isolates, A. baumannii displayed the highest levels of resistance. The total isolation rate of the Candida species increased compared to the previous reported rate in Korea.
CONCLUSION
Among the isolates, CoNS was the most common, followed by E. coli and S. aureus. The gradual increase in the prevalence of extended-spectrum beta-lactamase (ESBL) producers has contributed to the increase in multi-drug resistance among bacterial isolates from bloodstream infections.

Keyword

Blood culture; Bacteremia; Antimicrobial susceptibility; Fungemia

MeSH Terms

Bacteremia
beta-Lactamases
Candida
Diffusion
Drug Resistance, Multiple
Enterococcus faecium
Escherichia coli
Fungemia
Hospitals, University
Humans
Klebsiella pneumoniae
Korea
Prevalence
Staphylococcus aureus
beta-Lactamases

Figure

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  Fig. 1. The isolation frequencies of common bacteria from 9 hospitals. A, Asan Medical Center; B, Samsung Medical Center; C, Seoul National University Hospital; D, Gyeongsang National University Hospital; E, Inje University Paik Hospital; F, Chungnam National University Hospital; G, Dongsan Medical Hospital; H, Wonkwang University Hospital; I, Kangdong Sacred Heart Hospital.

• 

  Fig. 2. The isolation frequencies of common yeasts from 9 hospitals. See Fig. 2 for designations for each hospital (A∼H).

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