CELL SURFACE INTERACTIONS OF ORAL PLAQUE BACTERIA

尽管它的临床表现表明牙菌斑是一种无定形的 细菌积累，最近的研究表明，不仅是结构性的 特定细菌的组织，但成熟是一个有序的过程。 链球菌的早期堆积，尤其是血链球菌 其次是革兰氏阳性和革兰氏阴性 细丝。与这些现象的出现有关的主要因素之一 细丝是特定表面成分之间的相互作用 具有类似细丝成分的链球菌。一种形式的 这种相互作用产生的集合体被称为“玉米芯”。 因为它们长得像一只玉米穗。这些单位是 通常观察到的浅层斑块最初被认为 为血链球菌和细菌线虫形成的聚集体所独有 Matruchotii，一种革兰氏阳性需氧菌。我们最近发现， 血链球菌和核梭杆菌之间也形成了玉米芯。 革兰氏阴性厌氧菌。这些厌氧细菌是世界上 在龈下菌斑和与牙菌斑有关的菌斑中发现大量微生物 某些类型的牙周病。因此，这些集合体可以提供 作为连接牙周上下菌斑的纽带。的目的 建议的研究是为了描述S。 Sanguis，B.matruchotii和F.nuatum，并确定其分子基础 玉米芯的形成。这将使用以下方法来完成 方法：1.解剖细胞表面并测定其各组分的含量 受体活性，II。比较应变表面的组成 它们不会与玉米棒形成玉米棒，III。两个版本的比较 玉米芯阴性突变体与阳性亲本菌株的表面，iv。 环境对玉米芯形成及其表面的影响 还将对变化进行分析。除了生物活性之外， 萃取物的化学和免疫化学特征将使用 分析电泳法、同位素标记的组合 技术、柱层析和分析化学。结果是 这些研究可以提供对表面聚合物的理解 与玉米芯形成有关的口腔细菌，并提示 可用于抑制斑块成熟的策略。

Although its clinical appearance suggest dental plaque is an amorphous bacterial accumulation, recent studies suggest not only structural organization of specific bacteria but an ordered process of maturation. The early accumulation of streptococci, particularly Streptococcus sanguis is followed by the appearance of Gram-positive and Gram-negative filaments. One of the major factors related to the appearance of these filaments is the interaction between specific surface components of the streptococci with analogous components of the filaments. One form of aggregate which results from this interaction has been termed "corncobs" because of their resemblance to an ear of corn. These units which are often observed in the superficial layers of plaque were originally thought to be unique to aggregates formed by S. sanguis and Bacterionema matruchotii, a Gram-positive aerobic rod. We have recently found that corncobs are also formed between S. sanguis and Fusobacterium nucleatum, a Gram-negative, anaerobic rod. These anaerobic rods are among the most numerous organisms found in subgingival plaque and plaque associated with certain types of periodontal disease. Thus, these aggregates could serve as a connecting link between supra and subgingival plaque. The object of the proposed studies is to characterize the interactions between S. sanguis, B. matruchotii and F. nucleatum and determine the molecular basis of corncob formation. This will be accomplished using the following methods: i. dissecting the cell surface and assaying the fractions for receptor activity, ii. comparing the composition of the surfaces of strains which do not form corncobs with those that do, iii. comparison of the surface of corncob negative mutants with the positive parent strains, iv. the effects of environment on corncob formation and resulting surface changes will also be assayed. In addition to biological activity the extracts will be characterized chemically and immunochemically using combinations of analytical electrophoretic methods, isotopic labeling techniques, column chromatography and analytical chemistry. The results of these studies could provide an understanding of the surface polymers of oral bacteria which are associated with corncob formation and suggest strategies which could be employed to inhibit plaque maturation.