EVOLUTION OF VIRULENCE BY GENE ACQUISITION

描述(改编自申请者摘要)：基因获取是 对病原菌的进化和出现至关重要。习得的特征 病原体使它们能够在水库中生存，并定居和 伤害他们感染的宿主。产志贺毒素大肠杆菌(STEC)，如 作为大肠杆菌0157：H7和选定的不产生0157：H7毒素的大肠杆菌，提供 研究收购的进化方面的独特机会 毒力特征。 含有志贺毒素编码基因的大肠杆菌在系统发育上是多样化的， 但毒力强的菌株几乎总是在两个明确的系统发育中被发现 集群(STEC 1和STEC 2组)。调查人员提议研究 系统地，使用比较基因组分析，这些病原体的特征 ，以确定推测的毒力基因座的分布，并 辨别获得这些特征的顺序。他们还将评估 这些病原体在牛和人类体内基因表达的克隆性。 该项目产生的数据将阐明威力病毒使用的机制 生物体积累成功所需的遗传成分 病原体。

DESCRIPTION (Adapted from the Applicant's Abstract): Gene acquisition is crucial for the evolution and emergence of pathogenic bacteria. Traits acquired by pathogens enable them to survive in their reservoirs, and colonize and injure the hosts that they infect. Shiga toxin-producing E. coli (STEC), such as E. coli 0157:H7 and selected non-0157:H7 toxin-producing E. coli, provide a unique opportunity to study the evolutionary aspect of the acquisition of virulence traits. E. coli containing genes encoding Shiga toxins are phylogenetically diverse, but virulent strains are almost always found in two well defined phylogenetic clusters (STEC 1 and STEC 2 groups). The investigators propose to study systematically, using comparative genome analysis, the traits these pathogens have acquired, to determine the distribution of putative virulence loci, and to discern the sequence of acquisition of these traits. They will also assess the clonal nature of gene expression of these pathogens in bovids and humans. Data generated by this project will elucidate the mechanisms used by virulent organisms to accumulate the necessary genetic components to be successful pathogens.