GENETIC AND BIOCHEMICAL ANALYSES OF ADAPTIVE MUTATIONS IN SHIGELLA

志贺氏菌适应性突变的遗传和生化分析

• 批准号: 5200698
• 负责人: D J KOPECKO
• 金额: --
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/5200698
• 关键词: Shigella; bacterial genetics; biochemical evolution; carbohydrate metabolism; enteric bacteria; gene mutation; microorganism growth; microorganism metabolism; molecular genetics; nucleic acid sequence; virulence

Genetic and biochemical studies of Escherichia coli over the past 5 years have revealed novel mutations, termed adaptive mutational events, that occur at high frequency(i.e. generally 3 to 5 logs higher than mutations occurring during logarithmic growth), only under special adaptive conditions, and in the stationary phase of bacterial growth. Our recent studies of Shigella indicate that this organism also undergoes adaptive mutations in a large variety of oligosaccharide utilization pathways and in other metabolic and virulence gene regions. This project is aimed at characterizing genetically and biochemically adaptive mutational events in Shigella at various metabolic and virulence gene loci for frequency and chemical nature. Involved loci will be DNA sequenced to examine the precise nature of the mutational event, with an emphasis on understanding the mechanisms involved in stimulating these high frequency ( e.g. 10-3) mutational events in stationary phase cells. Similar studies of other related enteric bacteria will be conducted to determine if adaptive mutations are a cause of misidentification of pathogens, via altered biochemical pathways, or a method by which bacteria modulate their virulence.

过去5年大肠杆菌的遗传和生化研究 多年来已经揭示了新的突变，称为适应性突变事件， 其发生频率高（即，通常比 在对数生长期间发生的突变），仅在特殊情况下 适应条件，并在细菌生长的稳定期。我们 最近对志贺氏菌的研究表明，这种生物体也经历 适应性突变在各种寡糖的利用 途径和其他代谢和毒力基因区域。 该项目旨在从基因和生物化学方面 志贺菌在不同代谢和代谢水平的适应性突变事件 毒力基因位点的频率和化学性质。涉及的位点将 进行DNA测序以检查突变事件的确切性质， 重点是理解刺激大脑的机制， 这些在稳定期的高频率（例如10-3）突变事件 细胞其他相关肠道细菌的类似研究将在 以确定适应性突变是否是导致 病原体的错误识别，通过改变生化途径，或 细菌调节其毒力的方法。