MICROBIOLOGIC STUDIES OF HUMAN ORAL STREPTOCOCCI

人类口腔链球菌的微生物学研究

• 批准号: 3218826
• 负责人: BURTON ROSAN
• 金额: $ 15.34万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-07-01 至 1991-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3218826
• 关键词: Escherichia coli; Streptococcus; Streptococcus mitis; Streptococcus mutans; Streptococcus sanguis; bacterial antigens; bacterial polysaccharides; bacterial proteins; dental caries; dental plaque; ecology; gel electrophoresis; immunochemistry; immunoelectrophoresis; immunofluorescence technique; laboratory rabbit; membrane activity; monoclonal antibody; oral bacteria; periodontium disorder; polymers; radioassay; saliva; serotyping; surface antigens

Although Streptoccus sanguis is among the earliest colonizers of dental plaque, the molecular basis for its affinity for tooth surfaces is still not well understood. A number of laboratories have shown that this species as a high affinity for salivary glycoproteins which form the primary coating on the tooth surface. In addition, other studies indicate that S. sanguis can aggregate with salivary glycoproteins. These aggregates are believed to play a major role in controlling the numbers of bacteria in the oral cavity. Although both kinds of interactions appear to be specific, the molecular basis of these reactions is not known. We have been attempting to dissect the surface of S. sanguis and determine the specific molecules involved in each phenomenon. An adhesion assay which utilizes saliva coated hydroxyapatite has been shown to mimic the adhesion of S. sanguis to salivary pellicles. The saliva mediated aggregation assay employs both turbidimetric and sucrose gradients to determine the degree of bacterial aggregation. The surface of S. sanguis is much more complex than generally assumed. More than nine surface proteins always appear to be present in autoradiographs of iodinated cells. The surface antigenic composition also shows a complex surface. Attempts have been made to define the surface adhesions using chemostat cultures and a non-adherent mutant to determine if particular surface antigens were associated with adhesion. Although the results suggest such relationshps were present, the complexity of the surface made it difficult to isolate the antigens involved. Shotgun cloning methods will be used to introduce genes for specific surface antigens into E. coli; the antigens will be isolated and purified. Using these antigens, it will be possible to establish their relationship to adhesion and aggregation more directly. Monoclonal antibodies will also be produced to use both as markers for these antigens and as reagents which can help to purify them. The results of these studies could provide the basis for the preparation of chemotherapeutic agents or vaccines which could prevent plaque formation.

尽管血链球菌是最早的牙科定植者之一 牙菌斑，其与牙齿表面亲和力的分子基础仍然是 不太理解。 许多实验室表明该物种 作为对形成主要唾液糖蛋白的高亲和力 牙齿表面的涂层。 此外，其他研究表明 S. 血血可以与唾液糖蛋白聚集。 这些聚合体是 据信在控制细菌数量方面发挥着重要作用 口腔。 尽管这两种相互作用看起来都是特定的， 这些反应的分子基础尚不清楚。 我们曾经 试图解剖 S. sanguis 的表面并确定具体的 参与每种现象的分子。 一种粘附测定法，利用 唾液涂覆的羟基磷灰石已被证明可以模仿金黄色葡萄球菌的粘附力。 血液到唾液膜。 唾液介导的聚集测定 采用比浊法和蔗糖梯度来确定 细菌聚集。 S. sanguis 的表面比 S. sanguis 复杂得多 一般假设。 超过九种表面蛋白似乎总是 存在于碘化细胞的放射自显影照片中。 表面抗原 组成也显示出复杂的表面。 已做出尝试 使用恒化器培养物和非粘附物定义表面粘附 突变体以确定特定表面抗原是否与相关 附着力。 尽管结果表明存在这种关系， 表面的复杂性使得分离抗原变得困难 涉及。 鸟枪克隆方法将用于引入基因 特异性表面抗原进入大肠杆菌；抗原将被分离并且 纯化的。 使用这些抗原，将有可能建立它们的 与粘附和聚集的关系更直接。 单克隆 还将生产抗体以用作这些抗原的标记 并作为有助于纯化它们的试剂。 这些结果 研究可为化疗药物的制备提供依据 可以预防斑块形成的药物或疫苗。