Ohnishi Makoto, Hayashi Tetsuya
Department of Microbiology, Miyazaki Medical College.
Nihon Rinsho. 2002 Jun;60(6):1077-82.
Enterohemorrhagic Escherichia coli(EHEC) causes diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Genomic comparison of an EHEC O157: H7 strain isolated from the Sakai outbreak and a benign laboratory strain K-12 revealed that acquisition of a large amount of foreign DNA has promoted the genetic diversification of E. coli strains. In the emergence of O157: H7, bacteriophages, in particular, played an important role. EHEC are a group of strains with several serotypes, each belonging to different E. coli lineages. Even in an O157 lineage, significant phenotypic and genetic heterogeneities are observed. Recent knowledge on the significance and the generating mechanism of such heterogeneity in EHEC strains are summarized.
肠出血性大肠杆菌（EHEC）可引起腹泻、出血性结肠炎和溶血尿毒综合征。对从阪崎疫情中分离出的一株EHEC O157:H7菌株和一株良性实验室菌株K-12进行基因组比较发现，大量外源DNA的获得促进了大肠杆菌菌株的遗传多样化。在O157:H7的出现过程中，噬菌体尤其发挥了重要作用。EHEC是一组具有多种血清型的菌株，每种血清型都属于不同的大肠杆菌谱系。即使在O157谱系中，也观察到明显的表型和遗传异质性。本文总结了关于EHEC菌株中这种异质性的意义和产生机制的最新知识。
