A survey of community-associated methicillin-resistant Staphylococcus aureus in Korea.
OBJECTIVE
Methicillin-resistant Staphylococcus aureus (MRSA), originally restricted to hospitals, has emerged as a significant pathogen in the community. Although MRSA accounts for over 60% of S. aureus in tertiary hospitals in Korea, little is known about the epidemiology of community-associated MRSA (CA-MRSA).


METHODS
From January to July 2005, a hospital laboratory-based survey was conducted in seven community-based or tertiary hospitals. The medical records and Health Insurance Review Agency databases were reviewed and MRSA isolated from patients without apparent risk factors was defined as CA-MRSA. Susceptibilities to 12 antibiotics were tested by the disc diffusion method. SCCmec typing, Panton-Valentine leucocidin (PVL) gene detection and multilocus sequence typing (MLST) were performed according to published protocols.


RESULTS
Of 3,251 S. aureus, 1,900 (58.4%) were MRSA. CA-MRSA accounted for 112 (5.9%) of the MRSA. Of the 112 CA-MRSA isolates, 27 and 33 were found to be pathogens and colonizers, respectively. Fifty-two isolates from the patients with chronic otitis media were classified as 'undetermined'. Most of the 27 CA-MRSA patients had skin and soft tissue infections or acute ear infections. None of the patients died during the study period. Among 72 isolates tested, 64% were multidrug-resistant. SCCmec type IVa was the most common type among the colonizers and pathogens. On MLST analysis, ST72 was predominant, but ST5 and ST239 were prevalent in the 'undetermined' group. None possessed the PVL gene.


CONCLUSIONS
Despite MRSA-endemic hospital settings, CA-MRSA infections are not common in Korea. A new clone of CA-MRSA, ST72-SCCmec type IVa without the PVL gene, is the most common form.
Kim
Eu Suk
ES
Department of Internal Medicine, Dongguk University College of Medicine, Goyang, Republic of Korea.
Song
Jin Su
JS
Lee
Hye Jin
HJ
Choe
Pyoeng Gyun
PG
Park
Kyung Hwa
KH
Cho
Jae Hyun
JH
Park
Wan Beom
WB
Kim
Sung-Han
SH
Bang
Ji-Hwan
JH
Kim
Dong-Min
DM
Park
Kyoung Un
KU
Shin
Sue
S
Lee
Mi Suk
MS
Choi
Hee Jung
HJ
Kim
Nam Joong
NJ
Kim
Eui-Chong
EC
Oh
Myoung-Don
MD
Kim
Hong Bin
HB
Choe
Kang Won
KW
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007723:Korea / Q000453:epidemiology; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects*