title: Molecular characterization of methicillin-resistant Staphylococcus aureus obtained from the anterior nares of healthy Korean children attending daycare centers.
abstract: OBJECTIVE
  This study was performed to investigate the molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolated from the anterior nares of Korean children attending daycare centers.
  
  
  METHODS
  During September and October 2008, a survey of nasal carriage of MRSA was conducted among healthy children who were attending daycare centers in Seoul, Korea. Nasal swab samples were cultured to isolate S. aureus, and antimicrobial susceptibility was assessed using a disk diffusion test. All MRSA isolates were archived for subsequent molecular tests, including multilocus sequence typing, Panton-Valentine leukocidin (PVL) genes polymerase chain reaction (PCR), and staphylococcal cassette chromosome mec (SCCmec) typing.
  
  
  RESULTS
  Among 428 preschool-aged children enrolled, 9.3% (40/428) were colonized with MRSA. Among the 40 MRSA isolates, antibiotic susceptibilities to clindamycin and erythromycin were 97.5% (39/40) and 45% (18/40), respectively. All of the 21 strains susceptible to clindamycin and resistant to erythromycin had MLS(B)-inducible phenotypes. Sequence type (ST) 72-SCCmec type IV was the predominant clone (n=23; 57.5%), followed by ST72-SCCmec type II (n=6; 15%), ST1765-SCCmec type IV (n=4; 10%), ST1765-SCCmec type II (n=2; 5%), and ST1-SCCmec type IV (n=2; 5%). No clone was positive for PVL genes.
  
  
  CONCLUSIONS
  ST72 strains, which were previously found in hospital-associated MRSA, are now widely distributed in healthy Korean children. In addition, the prevalence of inducible resistance of clindamycin should be considered when selecting empirical antibiotics for community-associated MRSA infections in Korea.
authors.affiliation: Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Jina
authors.initials: J
authors.lastname: Lee
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Sung
authors.forename: Young Min
authors.initials: YM
authors.lastname: Kim
authors.forename: Chi Eun
authors.initials: CE
authors.lastname: Oh
authors.forename: Hong Bin
authors.initials: HB
authors.lastname: Kim
authors.forename: Eun Hwa
authors.initials: EH
authors.lastname: Choi
authors.forename: Hoan Jong
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D001427:Bacterial Toxins / Q000235:genetics; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology*; D002648:Child; D002656:Child Day Care Centers; D002675:Child, Preschool; D024901:Drug Resistance, Multiple, Bacterial; D005098:Exotoxins / Q000235:genetics; D005838:Genotype; D006801:Humans; D007223:Infant; D007956:Leukocidins / Q000235:genetics; D016106:Methicillin Resistance; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D009297:Nasal Mucosa / Q000378:metabolism / Q000382:microbiology*; D010641:Phenotype; D016133:Polymerase Chain Reaction; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*
chemical_list: D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin