title: Molecular and phenotypic evidence for the spread of three major methicillin-resistant Staphylococcus aureus clones associated with two characteristic antimicrobial resistance profiles in China.
abstract: OBJECTIVE
  The distribution of methicillin-resistant Staphylococcus aureus (MRSA) clones is dynamic and geographically unique. To understand the changing epidemiology of MRSA infections in China, we performed a prospective, multicity surveillance study with molecular typing and phenotypic analysis to determine the association of major prevalent clones with their antimicrobial resistance profiles.
  
  
  METHODS
  A total of 517 S. aureus isolates collected between January 2009 and March 2012 from six cities in China were subjected to antibiogram analysis and molecular typing, including staphylococcal cassette chromosome mec typing, multilocus sequence typing, staphylococcal protein A gene typing and PFGE typing.
  
  
  RESULTS
  Among the isolates collected, 309 were characterized as MRSA, with a prevalence of 59.8%. Three major clones were found to be prevalent in China: ST239-MRSA-III-t030, ST239-MRSA-III-t037 and ST5-MRSA-II-t002. These three clones were associated with two characteristic resistance profiles, namely, gentamicin/ciprofloxacin/rifampicin/levofloxacin for the first clone and gentamicin/ciprofloxacin/clindamycin/erythromycin/tetracycline/levofloxacin/trimethoprim/sulfamethoxazole for the latter two. Several geographically unique minor clones were also identified.
  
  
  CONCLUSIONS
  The predominant MRSA clones in China were associated with characteristic antimicrobial resistance profiles. Antibiotics for treating patients with MRSA infections can be selected based on the strain typing data.
authors.affiliation: Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Cheng
authors.forename: Wenchang
authors.initials: W
authors.lastname: Yuan
authors.forename: Fangyin
authors.initials: F
authors.lastname: Zeng
authors.forename: Qiwen
authors.initials: Q
authors.lastname: Hu
authors.forename: Weilong
authors.initials: W
authors.lastname: Shang
authors.forename: Dahai
authors.initials: D
authors.lastname: Tang
authors.forename: Wencheng
authors.initials: W
authors.lastname: Xue
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Fu
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Nan
authors.initials: N
authors.lastname: Liu
authors.forename: Junmin
authors.initials: J
authors.lastname: Zhu
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Hu
authors.forename: Jizhen
authors.initials: J
authors.lastname: Yuan
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.forename: Shu
authors.initials: S
authors.lastname: Li
authors.forename: Zhijin
authors.initials: Z
authors.lastname: Chen
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Hu
authors.forename: Xiancai
authors.initials: X
authors.lastname: Rao
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002681:China / Q000453:epidemiology; D024881:Drug Resistance, Bacterial; D005838:Genotype; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058889:Molecular Typing; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents
keywords: antibiogram analysis; clonal complexes; drug resistance profiles; molecular typing