Yamane K, Yamanaka T, Yamamoto N, Furukawa T, Fukushima H, Walker C B, Leung K-P
Department of Bacteriology, Osaka Dental University, Osaka, Japan.
Oral Microbiol Immunol. 2005 Feb;20(1):1-9. doi: 10.1111/j.1399-302X.2004.00178.x.
Prevotella nigrescens, a gram-negative black-pigmented anaerobic rod, has frequently been isolated from periodontitis and periapical periodontitis lesions. We have isolated an exopolysaccharide-producing P. nigrescens, strain 22, from a chronic periodontitis lesion. The purpose of this study was to determine the chemical composition and function of the exopolysaccharide associated with this clinical isolate. The chemical composition and structure of the purified exopolysaccharide from strain 22 were determined by high performance liquid chromatography and methylation analysis. To define the biological function of this exopolysaccharide, a chemically induced exopolysaccharide nonproducing mutant, strain 328, which was derived from strain 22, was established. The biological effects of exopolysaccharide were determined by comparing the ability of strain 22, strain 328 or heat-killed strain 22 to form abscesses in mice and to interfere with the phagocytic activity of peripheral blood polymorphonuclear leukocytes. Chemical analysis showed that isolated exopolysaccharide consisted of mannose (521.6 microg/mg), glucose (25.6 microg/mg), fructose (65.8 microg/mg), galactose (12.5 microg/mg), arabinose (6.2 microg/mg), xylose (3.2 microg/mg), rhamnose (6.1 microg/mg), and ribose (0.6 microg/mg). Methylation analysis of exopolysaccharide indicated that the linkages of mannose were primarily (1-->2, 1-->6) (1-->2) (1-->6), and (1-->3). Strain 22 and, to a lesser extent, its heat-killed counterpart induced greater abscess formation in mice than strain 328, even though the enzymatic profile of strain 22 was similar to that of strain 328. The ability of strain 328 to induce abscess formation was restored by adding the purified exopolysaccharide isolated from strain 22 to the cell suspension of strain 328. Exopolysaccharide alone failed to induce abscess formation in mice. Further, strain 328 but not the untreated or heat-killed strain 22, was phagocytosed by polymorphonuclear leukocytes both in the presence and in the absence of opsonic factors. The results suggest that these polysaccharides isolated from strain 22, which primarily consisted of mannose, may play a key role in the development of the chronic inflammatory lesion from which this strain was isolated.
变黑普雷沃菌是一种革兰氏阴性、产黑色色素的厌氧杆菌，常从牙周炎和根尖周炎病变中分离得到。我们从一例慢性牙周炎病变中分离出一株产胞外多糖的变黑普雷沃菌，菌株22。本研究的目的是确定与该临床分离株相关的胞外多糖的化学组成和功能。通过高效液相色谱和甲基化分析确定了菌株22纯化胞外多糖的化学组成和结构。为了确定这种胞外多糖的生物学功能，建立了一株化学诱导的不产胞外多糖的突变株，菌株328，它源自菌株22。通过比较菌株22、菌株328或热灭活的菌株22在小鼠体内形成脓肿以及干扰外周血多形核白细胞吞噬活性的能力，确定了胞外多糖的生物学效应。化学分析表明，分离得到的胞外多糖由甘露糖（521.6微克/毫克）、葡萄糖（25.6微克/毫克）、果糖（65.8微克/毫克）、半乳糖（12.5微克/毫克）、阿拉伯糖（6.2微克/毫克）、木糖（3.2微克/毫克）、鼠李糖（6.1微克/毫克）和核糖（0.6微克/毫克）组成。胞外多糖的甲基化分析表明，甘露糖的连接主要为（1→2，1→6）（1→2）（1→6）和（1→3）。菌株22及其热灭活对应物在小鼠体内诱导脓肿形成的能力比菌株328更强，尽管菌株22的酶谱与菌株328相似。通过将从菌株22中分离得到的纯化胞外多糖添加到菌株328的细胞悬液中，菌株328诱导脓肿形成的能力得以恢复。单独的胞外多糖未能在小鼠体内诱导脓肿形成。此外，在有或没有调理素因子的情况下，菌株328均被多形核白细胞吞噬，而未处理的或热灭活的菌株22则未被吞噬。结果表明，从菌株22中分离得到的这些主要由甘露糖组成的多糖，可能在分离出该菌株的慢性炎症病变的发展中起关键作用。
