MOLECULAR BIOLOGICAL CHARACTERIZATION OF ORAL BACTERIA

口腔细菌的分子生物学特征

• 批准号: 3917059
• 负责人: B M CHASSY
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
• 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/3917059
• 关键词: Bacillus subtilis; Escherichia coli; Lactobacillaceae; Lactobacillus casei; Salmonella typhimurium; Staphylococcus aureus; Streptococcus lactis; bacterial DNA; bacterial genetics; bacterial proteins; electroporation; gene expression; gene therapy; genetic manipulation; genetic regulation; host organism interaction; lac operon; molecular cloning; mutant; nucleic acid sequence; oral bacteria; plasmids; virulence

This project seeks to use genetic, biochemical and physiological approaches to investigate the pathogenicity of oral bacteria. The two specific areas of investigation are: 1) characterization of plasmid-coded and chromosomal metabolic genes from oral bacteria and 2) development of systems for genetic exchange in oral bacteria. The nucleotide sequence of the EnzymeIIlac gene of Lactobacillus casei was completed. It displayed high homology to the same genes isolated from staphylococcus aureus and Streptococcus lactis. Little homology was observed in comparison with other EnzymeII found in Escherichia coli, Salmonella typhimurium or Bacillus subtilis. The genes encoding the EnzymeIIlac, P-beta-gal and Factor IIlac were found to comprise an operon-like structure. Site-directed mutagenesis has been used to prepare mutant EnzymeII proteins with altered catalytic activity. The sequence of the plasmid-coded beta-galactosidase of Lactobacillus casei has been completed: the adjacent lac permease gene has been cloned and its sequence is being determined. L. casei has been utilized for the cloning and expression of heterologous genes such as alpha-amylase, subtilisin and beta-gal. Expression and secretion of foreign proteins has been observed; improved vectors and promoters have been identified. Using electroporation, L. bulgaricus and L. acidophilus have been transformed. The feasibility of use of these food related bacteria that colonize the gastrointestinal system as vectors for gene delivery to humans is being examined.

该项目试图使用遗传，生化和生理学 研究口腔细菌致病性的方法。 调查的两个特定领域是：1）表征 口服细菌的质粒编码和染色体代谢基因 2）开发口服遗传交换的系统 细菌。 酶基因的核苷酸序列 乳杆菌酪蛋白已完成。 它表现出很高的同源性 从金黄色葡萄球菌和 乳酸链球菌。 比较观察到很少的同源性 与在大肠杆菌中发现的其他酶，沙门氏菌 伤寒或枯草芽孢杆菌。 编码的基因 发现酶，p-beta-gal和因子IILAC包括一个 类似操纵子的结构。 定点诱变已用于 制备具有改变催化活性的突变酶蛋白。 质粒编码的β-半乳糖苷酶的序列 乳酸乳杆菌已经完成：相邻的lac渗透率 基因已被克隆，并确定其序列。 L. Casei已用于克隆和表达 异源基因，例如α-淀粉酶，枯草菌素和β-gal。 已经观察到异物的表达和分泌。 已经确定了改进的向量和启动子。 使用 电穿孔，保加利亚和嗜酸乳杆菌已是 转变。 使用这些与食物相关的细菌的可行性 将胃肠道系统定居为基因的载体 正在研究向人类交付。