Handley P S, Hargreaves J, Harty D W
Department of Cell and Structural Biology, Manchester University, UK.
J Gen Microbiol. 1988 Dec;134(12):3165-72. doi: 10.1099/00221287-134-12-3165.
Ruthenium red staining revealed both the long and short classes of cell surface fibril in thin sections of Streptococcus salivarius HB, indicating that the fibrils contained polyanionic polymers, probably polysaccharides. Also visible was a 16.2 +/- 2.2 nm thick ruthenium red staining layer (RRL) outside the 16.7 +/- 2.2 nm thick cell wall. The fibrils could not be seen after conventional glutaraldehyde and osmium fixation. The RRL was protease resistant and was not involved in septum formation. Loss of the fibrils after protease treatment coincided with a decrease of 54% in cell surface hydrophobicity, indicating that cell surface hydrophobicity was due partly to fibrils and partly to the RRL. There was no correlation between the lengths of fibrils as measured on whole cells after negative staining and on thin sections of ruthenium red stained cells. The thickness of the RRL was the same in three adhesion deficient mutants--strains HB-7, HB-V5 and HB-V51--with various fibril lengths. However, a completely bald mutant, HB-B, had a significantly thicker RRL than S. salivarius HB, although it was unable to adhere to buccal epithelial cells, and it could not co-aggregate with Veillonella parvula V1. The RRL therefore did not contain adhesins.
钌红染色显示，在唾液链球菌HB的薄片中，长类和短类细胞表面纤丝均存在，这表明纤丝含有聚阴离子聚合物，可能是多糖。在16.7±2.2纳米厚的细胞壁外，还可见到一层16.2±2.2纳米厚的钌红染色层（RRL）。经过常规戊二醛和锇固定后，纤丝不可见。RRL对蛋白酶具有抗性，且不参与隔膜形成。蛋白酶处理后纤丝消失，同时细胞表面疏水性降低了54%，这表明细胞表面疏水性部分归因于纤丝，部分归因于RRL。负染色后在全细胞上测量的纤丝长度与钌红染色细胞薄片上测量的纤丝长度之间没有相关性。在三个具有不同纤丝长度的黏附缺陷突变体——HB - 7、HB - V5和HB - V51菌株中，RRL的厚度相同。然而，一个完全光秃的突变体HB - B，其RRL比唾液链球菌HB明显更厚，尽管它无法黏附于颊上皮细胞，也不能与小韦荣球菌V1共聚集。因此，RRL不包含黏附素。
