CLONAL RELATIONSHIPS AMONG ESCHERICHIA-COLI STRAINS THAT CAUSE HEMORRHAGIC COLITIS AND INFANTILE DIARRHEA
CLONAL RELATIONSHIPS AMONG ESCHERICHIA-COLI STRAINS THAT CAUSE HEMORRHAGIC COLITIS AND INFANTILE DIARRHEA
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DOI：
10.1128/iai.61.5.1619-1629.1993
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发表时间：
1993-05-01
影响因子：
3.1
通讯作者：
WILSON, RA
中科院分区：
文献类型：
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作者：
WHITTAM, TS;WOLFE, ML;WILSON, RA
从出血性结肠炎和溶血性尿毒症综合征患者中分离的O157：H7菌株和O26：H11、O55：H6、O55：H7、O111：H2和O128：H2菌株等16个肠道疾病相关血清型的1,300株大肠杆菌之间的遗传关系，通过多位点酶电泳法检测到的20个酶编码基因的等位基因变异，估计了它们之间的遗传关系。在每种血清型的分离株之间观察到多种电泳型，同一O血清群的分离株平均有28%的酶座位不同。多位点酶谱比较表明，72%的菌株属于15种主要的电泳型，每种电泳型对应一个地理分布广泛的细菌克隆。在基因上，O157：H7克隆与055：H7菌株的克隆关系最密切，后者长期以来一直与全球婴儿腹泻暴发有关。我们认为，新的病原菌是当已经具有与肠道细胞黏附机制的055：H7样祖细胞，通过水平转移和重组获得次级毒力因子(志贺样细胞毒素和质粒编码的粘附素)时出现的。
The genetic relationships among 1,300 isolates of Escherichia coli representing 16 serotypes associated with enteric disease, including O157:H7 strains recovered from patients with hemorrhagic colitis and hemolytic uremic syndrome and O26:H11, O55:H6, O55:H7, O111:H2, and O128:H2 strains, many of which were isolated originally from infants with diarrhea, were estimated from allelic variation among 20 enzyme-encoding genes detected by multilocus enzyme electrophoresis. Multiple electrophoretic types were observed among isolates of each serotype, with isolates of the same O serogroup differing on average at 28% of the enzyme loci. Comparisons of the multilocus enzyme profiles revealed that 72% of the isolates belong to 15 major electrophoretic types, each of which corresponds to a bacterial clone with a wide geographic distribution. Genetically, the O157:H7 clone is most closely related to a clone of 055:H7 strains that has long been associated with worldwide outbreaks of infantile diarrhea. We propose that the new pathogen emerged when an 055:H7-like progenitor, already possessing a mechanism for adherence to intestinal cells, acquired secondary virulence factors (Shiga-like cytotoxins and plasmid-encoded adhesins) via horizontal transfer and recombination.