Complete genome sequence of enterohemorrhagic Escherichia coli O157:H7 and genomic comparison with a laboratory strain K-12
Complete genome sequence of enterohemorrhagic Escherichia coli O157:H7 and genomic comparison with a laboratory strain K-12
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DOI：
10.1093/dnares/8.1.11
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发表时间：
2001-02-28
期刊：
影响因子：
4.1
通讯作者：
Shinagawa, H
中科院分区：
文献类型：
--
作者：
Hayashi, T;Makino, K;Shinagawa, H
大肠杆菌O157:H7是一种主要的食源性感染性病原体，可引起腹泻、出血性结肠炎和溶血性尿毒症综合征。在这里，我们报告了从Sakai爆发分离的O157:H7菌株的完整染色体序列，以及与良性实验室菌株K-12 MG1655的基因组比较结果。染色体长5.5 Mb，比K-12大859 Kb。我们发现了一个4.1 mb的序列，在两个菌株之间高度保守，这可能代表了大肠杆菌染色体的基本骨干。其余1.4 mb序列由O157: h7特异性序列组成，大部分是水平转移的外源dna。噬菌体在O157:H7出现过程中的主要作用是由24个噬菌体和噬菌体样元件的存在所证明的，它们占据了O157:H7特异性序列的一半以上。O157:H7染色体编码1632种蛋白质和20种tR- NAs，这些在K-12中不存在。其中，至少有131种蛋白质被认为具有毒力相关的功能。全基因组密码子使用分析表明，O157: h7特异性trna参与了菌株特异性基因的有效表达。完整的O157:H7特异性基因为O157:H7的致病性和生理学提供了新的认识，并为全面了解O157:H7感染的分子机制开辟了一条途径。
Escherichia coli O157:H7 is a major food-borne infectious pathogen that causes diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Here we report the complete chromosome sequence of an O157:H7 strain isolated from the Sakai outbreak, and the results of genomic comparison with a benign laboratory strain, K-12 MG1655. The chromosome is 5.5 Mb in size, 859 Kb larger than that of K-12. We identified a 4.1-Mb sequence highly conserved between the two strains, which may represent the fundamental backbone of the E. coli chromosome. The remaining 1.4-Mb sequence comprises of O157:H7-specific sequences, most of which are horizontally transferred foreign DNAs. The predominant roles of bacteriophages in the emergence of O157:H7 is evident by the presence of 24 prophages and prophage-like elements that occupy more than half of the O157:H7-specific sequences. The O157:H7 chromosome encodes 1632 proteins and 20 tR- NAs that are not present in K-12. Among these, at least 131 proteins are assumed to have virulence-related functions. Genome-wide codon usage analysis suggested that the O157:H7-specific tRNAs are involved in the efficient expression of the strain-specific genes. A complete set of the genes specific to O157:H7 presented here sheds new insight into the pathogenicity and the physiology of O157:H7, and will open a way to fully understand the molecular mechanisms underlying the O157:H7 infection.