title: Genotype diversity of methicillin-resistant Staphylococcus aureus in Shenyang, China.
abstract: BACKGROUND
  The aim of this study was to better understand methicillin-resistant Staphylococcus aureus (MRSA) at the molecular level by investigating the genotypic characteristics and evolutionary patterns of MRSA clones in Shenyang, China.
  
  
  METHODS
  We analyzed the molecular epidemiology of 60 MRSA isolates in Shenyang, China, between 2002 and 2008, using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, and S. aureus protein A (spa) typing. They were examined for their antimicrobial susceptibilities.
  
  
  RESULTS
  Among the 60 isolates, ST239 was identified most frequently (34 isolates; 58%), followed by ST5 (20 isolates; 34%). Nine spa types were obtained and 4 PFGE strain families (A, B, C, and D) were resolved. Spa type t030, which corresponded to PFGE genotypes A1, A3, and A4, constituted 45% (27/60) of all isolates; spa type t037, which corresponded to PFGE type A2, accounted for 13% (8/60) of all isolates. These 2 spa genotypes belonged to ST239 and carried SCCmec type III. Isolates genotyped as spa type t002 comprised 27% (16/60) of the study set and included isolates typed as PFGE B1 and B2, ST5, and SCCmec II. Most of MRSA isolates belonging to ST239 were susceptible to trimethoprim-sulfamethoxazole. The minimum inhibitory concentration (MIC50) of vancomycin among MRSA isolates belonging to ST5 (2 mg/l) was higher than that for other isolates (1 mg/l).
  
  
  CONCLUSIONS
  These data document 2 major epidemic MRSA clones in Shenyang, China: ST239-MRSA-SCCmec type III-t037/t030 and ST5-MRSA-SCCmec type II-t002.
authors.affiliation: From the 1 Department of Laboratory Medicine, The First Affiliated Hospital of China Medical University.
authors.forename: Su Fei
authors.initials: SF
authors.lastname: Tian
authors.forename: Yun Zhuo
authors.initials: YZ
authors.lastname: Chu
authors.forename: Hua
authors.initials: H
authors.lastname: Nian
authors.forename: Fu Shun
authors.initials: FS
authors.lastname: Li
authors.forename: Ji Mei
authors.initials: JM
authors.lastname: Sun
authors.forename: Yan Ling
authors.initials: YL
authors.lastname: Wang
authors.forename: Li Wen
authors.initials: LW
authors.lastname: Liu
authors.forename: Hong
authors.initials: H
authors.lastname: Shang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002681:China / Q000453:epidemiology; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial