Korean J Clin Microbiol.  2006 Oct;9(2):84-89.

Multilocus Sequence Typing of Clonal Changes of Methicillin-resistant Staphylococcus aureus Isolated from Intensive Care Unit Patients: 1996 versus 2004

• Huh JY
• Yi J
• Hong KH
• Kim EC

Abstract

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) accounts for more than 70% of S. aureus isolates from tertiary-care hospitals in Korea. Recently, a multilocus sequence typing (MLST) scheme has been used to study the local and global epidemiologies of MRSA. The aim of this study is to compare the genetic background of MRSA strains isolated in the same ward during two different periods.
METHODS
To investigate clonal changes of endemic MRSA isolates between 1996 and 2004, we studied a total of 33 MRSA strains (16 from 1996 and 17 from 2004) isolated in the intensive care units of a tertiary-care hospital in Korea. The isolates were analyzed for their sequence types by MLST and for their antimicrobial susceptibilities by the disk diffusion method.
RESULTS
ST5 was the most frequent type (n=11, 68.7%) in 1996, followed by ST254 (n=3, 18.8%) and ST1 (n=2, 12.5%). In 2004, ST239 was the most frequent type (n=10, 58.8%), followed by ST5 (n=6, 35.3%).
CONCLUSION
The major clone type of MRSA isolates from intensive care unit patients changed from ST5 in 1996 to ST239 in 2004.

Keyword

Methicillin-resistant Staphylococcus aureus; Multilocus sequence typing; ST5; ST239

MeSH Terms

Clone Cells
Diffusion
Humans
Intensive Care Units*
Critical Care*
Korea
Methicillin Resistance*
Methicillin-Resistant Staphylococcus aureus*
Multilocus Sequence Typing*