Genotypic and phenotypic changes in the emergence of Escherichia coli O157:H7
Genotypic and phenotypic changes in the emergence of Escherichia coli O157:H7
复制标题
DOI：
10.1086/517438
复制
发表时间：
1998-06-01
影响因子：
6.4
通讯作者：
Whittam, TS
中科院分区：
文献类型：
--
作者：
Feng, P;Lampel, KA;Whittam, TS
埃希氏菌O157:H7是一种食源性病原体，与典型的大肠杆菌不同，它产生志贺毒素（Stx），不能发酵山梨醇（SOR）和表达β -葡糖醛酸酶（GUD）活性。利用GUD基因的等位基因特异性探针和多位点酶电泳来阐明其进化出现的阶段。O157: H7大肠杆菌。仅在O157:H7及其非运动亲缘基因中发现了uidA +92点突变，包括与德国溶血性尿毒症综合征暴发有关的SOR+ O157:H-克隆。结果支持O157:H7从O55:H7祖先依次进化的模型，首先获得Stx2基因，然后分化成两个分支；一个变成了GUD(-) SOR-，导致O157:H7克隆在世界范围内传播，另一个失去了活力，导致O157:H-克隆，这是欧洲日益严重的公共卫生问题。
Escherichia toil O157:H7 is a foodborne pathogen distinguished from typical E. coli by the production of Shiga toxins (Stx) and the inability to ferment sorbitol (SOR) and to express beta-glucuronidase (GUD) activity. An allele-specific probe for the GUD gene (uidA) and multilocus enzyme electrophoresis were used to elucidate stages in the evolutionary emergence off. coli O157:H7. A point mutation at +92 in uidA was found only in O157:H7 and its nonmotile relatives, including a SOR+ O157:H- clone implicated in outbreaks of hemolytic-uremic syndrome in Germany. The results support a model in which O157:H7 evolved sequentially from an O55:H7 ancestor, first by acquiring the Stx2 gene and then by diverging into two branches; one became GUD(-) SOR-, resulting in the O157:H7 clone that spread worldwide, and the other lost motility, leading to the O157:H- clone that is an increasing public health problem in Europe.