Journal List > Korean J Clin Microbiol > v.11(1) > 1038136

Korean J Clin Microbiol. 2008 Apr;11(1):11-17. Korean.
Published online April 30, 2008.  https://doi.org/10.5145/KJCM.2008.11.1.11
Copyright © 2008 The Korean Society of Clinical Microbiology
Characteristics of Microorganisms Isolated from Blood Cultures at a University Hospital Located in an Island Region During 2003~2007
Sung Ha Kang and Young Ree Kim
Department of Laboratory Medicine, College of Medicine, Cheju National University, Jeju, Korea.

Correspondence: Young Ree Kim, Department of Laboratory Medicine, College of Medicine, Cheju National University, 154, Samdo 2-dong, Jeju 690-716, Korea. (Tel) 82-64-750-1257, (Fax) 82-64-750-1257, Email: namu8790@empal.com
Received January 03, 2008; Accepted February 26, 2008.

Abstract

Background

The referral hospital is somewhat isolated from the mainland due to its island status; thus, microorganisms isolated from blood cultures might have a distinct pattern in their frequency and antibiogram. We attempted to uncover these characteristics.

Methods

The isolates from blood cultures at the Cheju University Hospital during 2003~2007 were analysed. After inoculation in aerobic and anaerobic bottles, blood specimens were cultured using BacT/Alert system, and the isolates were identifieded and antimicrobial susceptibilities were tested using Vitek II system.

Results

The overall positive rate of blood cultures was 9.6% and contamination rate was 3.6%. The most commonly isolated pathogens were Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae. Gram positive rod, gram negative cocci, and anaerobes were not isolated, but fungi were isolated in 0.6% of blood cultures. The prevalence of methicillin-resistant S. aureus (MRSA) was 68.0% in 2003, 41.4% in 2004, 48.1% in 2005, 54.5% in 2006, and 65.2% in 2007. The prevalence of vancomycin-resistant enterococcus (VRE) was 0% in 2003 and 2004, 16.7% in 2005, 10.0% in 2006, and 9.5% in 2007.

Conclusion

The most commonly isolated pathogens were similar to those from other hospitals, but the isolation rates of MRSA and VRE by year showed different patterns. Also, gram positive rods, gram negative cocci and anaerobes were not isolated. To help the choice of empirical antibiotic treatments, we need complementary measures to upgrade microorganism isolation systems and further studies including the monitoring of antibiotic use.

Keywords: Blood culture; Positive rate; Contamination; Antimicrobial susceptibility

Figures


Fig. 1
Trend of antimicrobial resistance of S. aureus, S. pneumoniae and E. faecalis by year. Abbreviations: OXS R SAU, oxacillin-resistant S. aureus; SXT SAU, trimethoprim-sulfamethoxazole-resistant S. aureus; TET R SPN, tetracycline-resistant S. pneumoniae; SXT R SPN, trimethoprim-sulfamethoxazole-resistant S. pneumoniae; TET R EFC, tetracycline-resistant E. faecalis; VAN R EFC, vancomycin-resistant E. faecalis.
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Fig. 2
Trend of antimicrobial resistance of E. coli and K. pneumoniae by year. Abbreviations: FOX R ECO, cefoxitin-resistant E. coli; TAX R ECO, cefotaxime-resistant E. coli; SXT R ECO, trimethoprim-sulfamethoxazole-resistant E. coli; FOX R KPN, cefoxitin-resistant K. pneumoniae; TAX R KPN, cefotaxime-resistant K. pneumoniae; SXT R KPN, trimethoprim-sulfamethoxazole-resistant K. pneumoniae.
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Fig. 3
Trend of antimicrobial resistance of A. baumannii and P. aeruginosa by year. Abbreviations: CIP R ABA, ciprofloxacin-resistant A. baumannii; IMI R ABA, imipenem-resistant A. baumannii; PIP R PAE, piperacillin-resistant P. aeruginosa; CIP R PAE, ciprofloxacin-resistant P. aeruginosa; IMI R PAE, imipenem-resistant P. aeruginosa; AZM R PAE, aztreonam-resistant P. aeruginosa.
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Tables


Table 1
Microorganisms isolated from blood in an island region during 2003~2007
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Table 2
Species of aerobic gram-positive cocci, bacilli and gram-negative cocci from blood in an island region during 2003~2007
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Table 3
Species of aerobic and facultative anaerobic gram-negative bacilli from blood in an island region during 2003~2007
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Table 4
Species of glucose-nonfermenting gram-negative bacilli isolated from blood in an island region during 2003~2007
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Table 5
Species of fungi isolated from blood in an island region during 2003~2007
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Table 6
Annual isolation rate of relatively common bacteria isolated from blood in an island region during 2003~2007
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Table 7
Distribution of relatively common bacteria isolated from blood in an island region by age group of patients
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Table 8
Association between the number of blood culture and blood culture-positive patients and CNS and BCP isolated from blood
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