BACTERIAL INTERRELATIONSHIPS IN AN ANIMAL MODEL

多年来，啮齿类动物一直被用作 人类龋齿的产生。(1)该老鼠已被规定为 合适的模型，因为很容易诱发龋齿，结果发表在 一般可重复性(1，2，3)。对人的致龋性有价值的见解 已获得单个细菌种(4，5)。最近， 宿主免疫因素在龋病调控中的作用 已经在大鼠和仓鼠(2，3)中进行了广泛的研究，并有 显示无论是口服免疫还是粘膜下免疫都可以预防 龋病(2，3，4)。尽管这一领域的数据非常丰富，但几乎没有 已知细菌与细菌的相互关系 移居和龋齿。在龋病的体外模型中 当不止一种情况下，就会发现龋齿的产生存在差异 模型中使用了细菌的种类(海尔曼和克拉克森)。它有 已经证明，当变形链球菌和粘性链球菌用蔗糖发酵时 在牙齿存在的情况下，牙釉质中的亚表面病变发生在S。 变形杆菌和小得多的或没有病变的粘性葡萄球菌。作为否 检测到PH值差异(两者都在PH4.5)，牙齿 在媒体上暂停了相同的时间，这些结果是 令人惊讶。然而，在同一系统中，这两种细菌产生的 根部表面的损伤。计划进行进一步调查：混合 细菌菌株；与变形链球菌单菌接菌，然后再接菌 用粘性曲霉(逆转这一点)；改变发酵条件； 并将免疫和非免疫因素引入到 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 影响细菌定植和随后发展的因素 有很多龋齿。这只老鼠被选中是因为这是目前最好的 研究了动物模型，并已证明是可重复性的。为了这项研究 对于单独的细菌种类，有必要使用固生菌单位。

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.