[Molecular epidemiology of enterohaemorrhagic Esacherichia coli O157 in some areas in China].
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.
Wang
Li-li
LL
National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
Xia
Sheng-li
SL
Hu
Wan-fu
WF
Gu
Ling
L
Yang
Jin-chuan
JC
Chen
Qian
Q
Cui
Zhi-gang
ZG
Xu
Yan-mei
YM
Wang
Xin
X
Ye
Chang-yun
CY
Jing
Huai-qi
HQ
Xu
Jian-guo
JG
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
D022641:Shiga Toxin 2