title: Molecular characterization of Staphylococcus aureus from surgical site infections in orthopedic patients in an orthopedic trauma clinical medical center in Shanghai.
abstract: BACKGROUND
  Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of surgical site infections (SSIs). The aim of our study was to characterize molecularly S. aureus isolates from SSIs in orthopedic patients in Shanghai, China.
  
  
  METHODS
  Eighty-two S. aureus isolates (46 methicillin-susceptible Staphylococcus aureus [MSSA] and 36 MRSA) were collected from SSIs in orthopedic patients. Antimicrobial susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines and a variety of clinically important toxin genes were detected. The sequence type, spa type, and agr group were determined to analyze the genotypes of all the isolates collected. In addition, MRSA isolates were characterized by staphylococcal cassette chromosome mec (SCCmec) type as well.
  
  
  RESULTS
  The strains showed susceptibility to antibiotics such as teicoplanin, minocycline, quinupristin-dalfopristin, linezolid, mupirocin, and vancomycin. Ten pvl-positive isolates (three MRSA and seven MSSA) were found among all isolates. Eight community-associated MRSA (CA-MRSA) isolates were found, six of which belonged to ST59-MRSA-IV but most MRSA isolates (20/36, 55.6%) belonged to ST239-MRSA-III-t030/t037 with a wide range of antibiotic resistance. By contrast, MSSA isolates were more diverse in both molecular characterizations and virulence factors, with eight MSSA isolates harboring more than six toxin genes detected.
  
  
  CONCLUSIONS
  ST239-MRSA-III-t030/t037 was the epidemic clone, and healthcare-associated MRSA (HA-MRSA) strains might be the major pathogen causing S. aureus SSIs in orthopedic patients.
authors.affiliation: 1 Department of Clinical Microbiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai, China .
authors.forename: Fei-Fei
authors.initials: FF
authors.lastname: Gu
authors.forename: Li-Zhong
authors.initials: LZ
authors.lastname: Han
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
authors.forename: Yan-Chun
authors.initials: YC
authors.lastname: Wang
authors.forename: Hao
authors.initials: H
authors.lastname: Shen
authors.forename: Jian-Qiang
authors.initials: JQ
authors.lastname: Wang
authors.forename: Jin
authors.initials: J
authors.lastname: Tang
authors.forename: Ji
authors.initials: J
authors.lastname: Zhang
authors.forename: Yu-Xing
authors.initials: YX
authors.lastname: Ni
mesh_terms: D000046:Academic Medical Centers; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002681:China / Q000453:epidemiology; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D017720:Molecular Epidemiology; D058889:Molecular Typing; D019637:Orthopedic Procedures / Q000009:adverse effects*; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D013530:Surgical Wound Infection / Q000453:epidemiology / Q000382:microbiology*; D055815:Young Adult