Changing molecular epidemiology of Staphylococcus aureus in Korea over a ten-year period
Abstract number: P1437
Kim E.S., Kim H.B., Lee H.J., Jung K.T., Lee Y.S., Shin D.H., Jung S.I., Park K.U., Park W.B., Kim N.J., Oh M.D., Kim E.C., Choe K.W.
Objectives: Most studies of molecular epidemiology on Staphylococcus aureus in Korea have been limited to meticillin-resistant S. aureus (MRSA) isolated in tertiary hospitals. This study was performed to evaluate the changes of molecular characteristics of S. aureus isolated both in the community and in hospitals over a 10-year period.
Methods: Antibiotic susceptibility tests, staphylococcal cassette chromosome mec (SCCmec) typing, multilocus sequence typing (MLST), and toxin gene analyses by multiplex polymerase chain reactions were performed on S. aureus isolates collected from clinical specimens from 1996 through 2005.
Results: Four-hundred thirty-three S. aureus isolates were tested, which included 148 meticillin-susceptible S. aureus (MSSA) and 285 MRSA. The clonal complex 1 strain, including the sequence type 1 (ST1) strain, was prevalent (29%, 28/96) in MSSA until 2003, but MLST profiles of MSSA showed a great diversity. While ST72, the most common strain (ST72-MRSA-SCCmec IV/IVa) of community-associated MRSA (CA-MRSA) in Korea as previously reported (J Antimicrob Chemother 2007;60:110814), was found in only one MSSA isolate till 2003, it has been increasing not only in MSSA (5/31) but also in MRSA (9/15) from the anterior nares of healthy people since 2005. Moreover, ST239-MRSA-SCCmec III/IIIa has surpassed ST5-MRSA-SCCmec II/IIa, the most prevalent strain till 2003, among MRSA isolates from the hospitals since 2005. Toxin gene profiles also showed a diverse distribution, but certain profiles were associated with meticillin resistance and the SCCmec types. Pvl genes were detected in only 7.4% of the total MSSA and 1.1% of MRSA during the study period.
Conclusion: The epidemiology of S. aureus in the community and hospital settings has changed gradually during the past 10 years in Korea. ST72-MRSA-SCCmec IV/IVa emerged recently in the community, even if it is uncertain whether this is a new clone or from the hospitals.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
|Back to top|