据美国物理学家组织网7月21日（北京时间）报道，德国明斯特大学和美国生命技术公司的研究人员刚刚公布了肠出血性大肠杆菌(EHEC)的基因组草图。研究人员称，该草图的公布不但有助于人们对近几个月来在德国等多个国家暴发的EHEC疫情进行监控，还可能带来更为有效的治疗方法。相关研究成果7月20日发表在《公共科学图书馆—综合》（PLoS One）杂志在线版上。
明斯特大学卫生研究所溶血性尿毒综合征实验室博士亚历山大·迈尔曼说，通过将引发此次疫情的O104：H4型肠出血性大肠杆菌与2001年采集自一名溶血性尿毒症（HUS）体内的O104：H4型肠出血性大肠杆菌进行基因对比后，他们发现，两种菌株并非同源，引起此次德国EHEC暴发的O104:H4菌株来自一种肠聚集性大肠杆菌EAEC O104:H4 55989菌株的变异，其中还掺杂了一种目前未知的由志贺毒素产生的O104：H4菌株。
论文作者、明斯特大学卫生研究所教授赫希·卡赫说，这项研究再次强调了积累的重要作用。从1996年起他们就开始了溶血性尿毒症症候群等疾病的研究和生物样本的采集工作，此前的研究对发现高致病性EHEC菌株的变异非常重要。
负责该研究的明斯特大学微生物学家达格·哈马舍尔教授说：“多亏有了离子流个人化操作基因组测序仪(PGM)和新一代测序技术(NGS)的帮助，测序工作才能进行得如此迅速。虽然此前已有不少研究采用了新一代测序技术，但将其用于突发疫情的实时研究还尚属首次。”
明斯特大学医学院院长威廉·施密茨说，如此快速的测序完全可以被称为一个“技术杰作”，其成果不但有助于对疫情的监测和诊断，还极有可能导致新疗法的产生。(生物谷 Bioon.com)
生物谷推荐原文出处：
PLoS ONE doi:10.1371/journal.pone.0022751
Prospective Genomic Characterization of the German Enterohemorrhagic Escherichia coli O104:H4 Outbreak by Rapid Next Generation Sequencing Technology
Alexander Mellmann, Dag Harmsen2, Craig A. Cummings, Emily B. Zentz, Shana R. Leopold, Alain Rico, Karola Prior, Rafael Szczepanowski, Yongmei Ji, Wenlan Zhang, Stephen F. McLaughlin, John K. Henkhaus, Benjamin Leopold, Martina Bielaszewska, Rita Prager, Pius M. Brzoska, Richard L. Moore, Simone Guenther, Jonathan M. Rothberg, Helge Karch
An ongoing outbreak of exceptionally virulent Shiga toxin (Stx)-producing Escherichia coli O104:H4 centered in Germany, has caused over 830 cases of hemolytic uremic syndrome (HUS) and 46 deaths since May 2011. Serotype O104:H4, which has not been detected in animals, has rarely been associated with HUS in the past. To prospectively elucidate the unique characteristics of this strain in the early stages of this outbreak, we applied whole genome sequencing on the Life Technologies Ion Torrent PGM? sequencer and Optical Mapping to characterize one outbreak isolate (LB226692) and a historic O104:H4 HUS isolate from 2001 (01-09591). Reference guided draft assemblies of both strains were completed with the newly introduced PGM? within 62 hours. The HUS-associated strains both carried genes typically found in two types of pathogenic E. coli, enteroaggregative E. coli (EAEC) and enterohemorrhagic E. coli (EHEC). Phylogenetic analyses of 1,144 core E. coli genes indicate that the HUS-causing O104:H4 strains and the previously published sequence of the EAEC strain 55989 show a close relationship but are only distantly related to common EHEC serotypes. Though closely related, the outbreak strain differs from the 2001 strain in plasmid content and fimbrial genes. We propose a model in which EAEC 55989 and EHEC O104:H4 strains evolved from a common EHEC O104:H4 progenitor, and suggest that by stepwise gain and loss of chromosomal and plasmid-encoded virulence factors, a highly pathogenic hybrid of EAEC and EHEC emerged as the current outbreak clone. In conclusion, rapid next-generation technologies facilitated prospective whole genome characterization in the early stages of an outbreak.
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