GENETICS AND PHYSIOLOGY OF ORAL BIOFILMS

口腔生物膜的遗传学和生理学

• 批准号: 2849038
• 负责人: Robert A Burne
• 金额: $ 32.15万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2849038
• 关键词: acidity /alkalinity; bacterial genetics; confocal scanning microscopy; dental plaque; fusion gene; gene environment interaction; gene expression; microorganism culture; microorganism growth; microorganism interaction; microorganism metabolism; molecular film; mutant; oral bacteria; phenotype; recombinant DNA; species difference; virulence

Oral microbial biofilms coat the hard and soft tissues of the mouth. Although the composition of the biofilms is heterogeneous and varies considerably by site, populations at a given site remain fairly stable and are usually compatible with the maintenance of the integrity of the colonized tissue. However, changes in the environment can perturb the balance in biofilms, leading to shifts in the proportions of particular species and alterations in the spectrum of metabolic activities, which can lead to oral diseases. For example, sustained low pH favors the growth of mutans streptococci in caries development, and as yet uncharacterized changes in the periodontium leading to increases in the populations of proteolytic, Gram-negative anaerobic bacteria appear necessary for periodontal diseases. Among the environmental factors known i) to affect the expression of known virulence attributes of oral bacteria, and ii) to induce dramatic changes in the composition and activity of oral biofilms, pH, carbohydrate source and availability, and oxygen have perhaps the most profound influences. This proposal describes a collaborative, multidisciplinary research effort by three investigators that addresses central hypotheses about homeostasis in biofilms, gene expression by adherent bacteria and the role of the environment in the development of pathogenic biofilms. Coupling recombinant DNA techniques to construct defined mutants and gene fusions, with physiologic manipulations, cultivation of mono-species and defined consortia, and scanning confocal laser microscopy, the effects of, and responses to, environmental pH, carbohydrate availability, and oxygen by individual species in biofilms and by complex populations will be explored. The results obtained will provide much needed, fundamental knowledge about the phenotypic capacities of oral bacteria in biofilms and yield new insights into potential mechanisms for modulating plaque physiology and ecology to inhibit the development of oral diseases.

口服微生物生物膜覆盖口腔的硬组织和软组织。 尽管生物膜的组成是异质的，并且因位置而异，但给定位点的种群仍然相当稳定，通常与维持定殖组织的完整性兼容。 但是，环境的变化会扰动生物膜的平衡，从而导致特定物种比例的变化以及代谢活动范围的变化，这可能导致口腔疾病。 例如，持续较低的pH有利于龋齿发育中链球菌链球菌的生长，并且在牙周上尚未表征变化，从而导致蛋白水解，革兰氏阴性厌氧细菌的种群增加似乎是牙周疾病所必需的。 在已知的环境因素中，i）影响了口腔细菌的已知毒力特性的表达，ii）诱导口服生物膜，pH，碳水化合物来源和可用性的组成和活性发生巨大变化，氧气可能具有最深刻的影响。 该提案描述了三名研究者的合作，多学科研究工作，该研究涉及有关生物膜中稳态的中心假设，依从细菌的基因表达以及环境在致病生物膜发展中的作用。耦合重组DNA技术以构建定义的突变体和基因融合，并与生理操纵，培养一单形物种和定义的财团以及扫描共焦激光显微镜，对环境pH，碳水化合物的可用性和氧气的效果和响应是由碳水化合物的可用性和氧化物在碳水化合物中和氧气中的复杂物质和复杂的种类所探索的。 获得的结果将提供有关生物膜中口腔细菌表型能力的急需的基本知识，并为调节牙菌斑生理学和生态学的潜在机制提供新的见解，以抑制口腔疾病的发展。