BACTERIAL INTERRELATIONSHIPS IN AN ANIMAL MODEL

这种啮齿类动物已经被用作研究的模型系统很多年了。 人类龋齿的产生。 (1)老鼠提供了一个 因为容易诱发龋齿，所以选择合适的模型，并且结果在 一般重现性（1、2、3）。 对致龋性的宝贵见解 已经获得了单个细菌物种（4，5）。 最近的 宿主免疫因子在龋病调控中的作用 已在大鼠和仓鼠中进行了广泛研究（2，3）， 表明口服或粘膜下免疫可以防止 龋齿（2，3，4）。 尽管这一领域的数据丰富， 关于细菌的相互关系， 定植和龋齿。 在体外龋齿模型中， 已经发现，当一种以上的 在该模型中使用了一种细菌（Heilman和克拉克森）。 它有 当S. mutans和A. viscossus是用蔗糖发酵的 在牙齿存在的情况下，釉质的亚表面病变发展为S. 变形杆菌和小得多或没有病变发展与A。粘肌 因为没有 检测pH值差异（两者均为pH 4.5）， 在相同的时间内，这些结果是 令人惊讶。 然而，在同一系统中，两种细菌产生的 根面损伤。 计划进一步调查：混合 用S.然后接种 与A.粘性（逆转这一点）;改变发酵条件; 并将免疫和非免疫因子引入到 系统 我们希望将体外工作扩展到合适的体内模型， 并能够研究唾液和宿主免疫的影响， 影响细菌定植和后续发展的因素 龋齿。 选择大鼠是因为这是目前最好的 研究了动物模型，并已被证明是可重复的。 研究 对于单个细菌物种，有必要使用gntobiotic单位。

The rodent has been used for a number of years as a model system for the production of human dental caries. (1) the rat has provided to be a suitable model since caries can be readily induced, and the results are in general reproducible (1,2,3). Valuable insights into the cariogenicity of individual bacterial species has been obtained (4,5). More recently the role of host immune factors in the modulation and control of dental caries has been extensively studied in the rat and in the hamster (2,3) and have revealed that either oral or submucosal immunization may protect against caries (2,3,4). In spite of the wealth of data in this field, little is known about the bacterial interrelationships in relation to bacterial colonization and dental caries. In the in vitro model of caries important differences in the production of caries have been found when more than one species of bacteria is used in the model (Heilman and Clarkson). It has been shown that when S. mutans and A. viscossus are fermented with sucrose in the presence of teeth, subsurface lesions in enamel developed with S. mutans and much smaller or no lesions developed with A. viscossus. As no pH differences were detected (both were at pH 4.5) and the teeth were suspended in the media for the same length of time, these results were surprising. However, in the same system both bacteria produced comparable lesions on the root surface. Further investigations are planned to: mix the bacterial strains; to monoinnoculate with S. mutans and then innoculate with the A. Viscossus (to reverse this); to vary the fermation conditions; and to introduce immunological and nonimmunological factors into the system. We wish to extend the in vitro work into a suitable model in vivo, and to be able to study the effects of saliva and host immunological factors on the colonization of bacteria, and on the subsequent development of caries. The rat was selected since this is currently the most well studied animal model and has been shown to be reproducible. For the study of individual bacterial species it is necessary to use a gntobiotic unit.