title: [Molecular epidemiology of enterohaemorrhagic Esacherichia coli O157 in some areas in China].
abstract: OBJECTIVE
  To understand the epidemiological characteristics of enterohaemorrhagic Escherichia coli (EHEC) O157 and to determine the degree of its genetic relations.
  
  
  METHODS
  Polymerase chain reaction (PCR) techniques and chromosomal DNA digested by restriction enzyme Xba I according to PulseNet directions by pulsed field gel electrophoresis (PFGE) method were applied to 300 E. coli O157 strains isolated from patients and animal sources from 1988 to 2005 from Henan, Jiangsu and Anhui provinces.
  
  
  RESULTS
  Very high prevalence of stx2 gene in EHEC O157:H7 strains isolated from some provinces of China was found and variation existed in some strains. We got 161 PFGE patterns from 300 strains. The stx2-producing strains could be clearly separated from stx2 variation-producing strains.
  
  
  CONCLUSIONS
  The variability of restriction enzyme-digestion patterns of O157 genomes suggested that the presence of some genomic diversity among the strains did exist.
authors.affiliation: National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Li-li
authors.initials: LL
authors.lastname: Wang
authors.forename: Sheng-li
authors.initials: SL
authors.lastname: Xia
authors.forename: Wan-fu
authors.initials: WF
authors.lastname: Hu
authors.forename: Ling
authors.initials: L
authors.lastname: Gu
authors.forename: Jin-chuan
authors.initials: JC
authors.lastname: Yang
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.forename: Zhi-gang
authors.initials: ZG
authors.lastname: Cui
authors.forename: Yan-mei
authors.initials: YM
authors.lastname: Xu
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Chang-yun
authors.initials: CY
authors.lastname: Ye
authors.forename: Huai-qi
authors.initials: HQ
authors.lastname: Jing
authors.forename: Jian-guo
authors.initials: JG
authors.lastname: Xu
mesh_terms: D002681:China / Q000453:epidemiology; D016521:Electrophoresis, Gel, Pulsed-Field; D019453:Escherichia coli O157 / Q000145:classification / Q000235:genetics*; D006801:Humans; D017720:Molecular Epidemiology; D016133:Polymerase Chain Reaction; D022641:Shiga Toxin 2 / Q000235:genetics
chemical_list: D022641:Shiga Toxin 2