Study on the "Streptococcus milleri" Adhesins Involved in Its Colonization to Human Bodies

在36株不同血清型的“米勒链球菌”中，只有26株g型、g相关或h型中间链球菌、4株星状链球菌和1株星状链球菌能在人全唾液滤液中产生细胞凝集。中间链霉菌1208-1(g型)的细胞具有长纤维，而星状链球菌NCTC 10708(B)的细胞不具有长纤维，纤维呈1微米或更长的卷曲单链，提示唾液诱导的细胞聚集因子(S)可能存在于富周附属物上。用超声法从细胞中分离出纤维，经50%硫酸铵沉淀和DEAE-SepharoseCL-6B柱层析纯化。纯化后的纤维由碳水化合物和蛋白质组成，质量比约为3：1。丝氨酸、半胱氨酸和赖氨酸的含量较高(10.0-7.9mol%)，非极性氨基酸的含量为38.1%。碳水化合物部分由甘露糖、半乳糖及其氨基衍生物组成，摩尔比约为4：2：1。纤维状物质可被木瓜酶、链霉蛋白酶-P和枯草杆菌酶部分降解，但不被所测试的任何糖苷酶所降解。纯化后的原纤维的相对分子质量大于250kd，建议由60kd的单元单体组成。细胞的热处理、抗原纤维免疫球蛋白Fab片段或纯化的原纤维制剂可抑制细胞聚集。然而，热敏感的细胞聚集中介部位被认为与纤毛分子的耐热抗原决定簇不同。在26株唾液诱导的聚集菌株(g、h或g相关)中，只有20株中间链霉菌、链球菌和链球菌不能产生与中间链霉菌1208-1(G)细胞所检测到的特殊类型的纤维。

Of the 36 "Streptpcoccus milleri" strains tested of various serotypes, only 26 serotype g, g-related or h Streptpcoccus intermedius, Streptococcus constellatus or Streptococcus constellatus strains (21,4 and 1 strains respectively) produced cellular agglutination in human whole saliva filtrate. Cells of S.intermedius 1208-1 (serotype g) but not of S.constellatus NCTC 10708 (b) carried long fibrils which extended radially from cell surface and assumed a curly single strand of 1 mum or longer, suggesting that saliva-indeced cell-aggregating factor (s) may exist on the peritrichous appendage. The fibrils were isolated from cells by sonication and purified by 50% ammonium sulfate precipitation followed by a DEAE-Sepharose CL-6B column chromatography. The purified fibrils were composed of carbohydrate and protein in an approximate weight ratio of 3 : 1. Serine, cysteine and lysine were contained in relatively high proportions (10.0-7.9 mol%) and nonpolar amino acids were detected 38.1 mol%. Carbohydrate moiety was composed of mannose, galactose and their amino derivatives at an approximate molar ratio of 4 : 2 : 1. The fibrillar materials were partially hydrolyzed by papain, pronase-P and subtilisin but not by any glycosidases tested. The purified fibrils possessed the molecular weightof higher than 250 kd and were suggested to be composed of unit monomer of 60kd. The cellular aggregation was inhibited by heat treatment of cells and by the presence of the anti-fibril immunoglobulin Fab fragment or the purified fibril preparation. However, the heat-sensitive cellular aggregation-mediating site was supposed not to be identical to the heat-resistant antigenic determinant of fiblillar molecules. Of the 26 saliva-induced aggregating strains (g, h or g-related), only 20 S.intermedius, S.costellatus or S.anginosus strains, but 6 S.intermedius or S.constellatus strains did not, produced the particular type of fibril detected with S.intermedius 1208-1 (g) cells.