title: Molecular epidemiological characteristics of Streptococcus pyogenes strains involved in an outbreak of scarlet fever in China, 2011.
abstract: OBJECTIVE
  To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011.
  
  
  METHODS
  Seventy-four Streptococcal pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011. Emm genotyping, pulsed-field gel electrophoresis (PFGE), superantigen (SAg) genes and antimicrobial susceptibility profiling were analyzed for these isolates.
  
  
  RESULTS
  A total of 4 different emm types were identified. Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles. Emm12 (79.7%) and emm1 (14.9%) accounted for approximately 94% of all the isolates. The speA gene was all negative in emm12 isolates and positive in emm1 isolates. All strains were resistant to erythromycin, and 89.4% of them were resistant to erythromycin, tracycline, and clindamycin simultaneously.
  
  
  CONCLUSIONS
  Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains, though no new emm type was found in this outbreak. The data provide a baseline for further surveillance of scarlet fever, which may contribute to the explanation of the outbreak and development of a GAS vaccine in China.
authors: Collabroative Innovation Center for Diagnosis Treatment of Infectious Disease, State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors: Yuan Hai
authors: YH
authors: You
authors: Yan Yan
authors: YY
authors: Song
authors: Xiao Mei
authors: XM
authors: Yan
authors: Hai Bin
authors: HB
authors: Wang
authors: Meng Han
authors: MH
authors: Zhang
authors: Xiao Xia
authors: XX
authors: Tao
authors: Lei Lei
authors: LL
authors: Li
authors: Yu Xin
authors: YX
authors: Zhang
authors: Xi Hong
authors: XH
authors: Jiang
authors: Bing Hua
authors: BH
authors: Zhang
authors: Hao
authors: H
authors: Zhou
authors: Di
authors: D
authors: Xiao
authors: Lian Mei
authors: LM
authors: Jin
authors: Zi Jian
authors: ZJ
authors: Feng
authors: Feng Ji
authors: FJ
authors: Luo
authors: Jian Zhong
authors: JZ
authors: Zhang
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D002648:Child; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D015994:Incidence; D017720:Molecular Epidemiology; D012541:Scarlet Fever / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents
keywords: Molecular epidemiology; Scarlet fever; Streptococcus pyogenes