Platt M W
Department of Microbiology, University of New Mexico, School of Medicine, Albuquerque 87131, USA.
Curr Microbiol. 1995 Jul;31(1):5-9. doi: 10.1007/BF00294625.
Experiments were performed to determine the interaction between the hemolysin of group B streptococcus (GBS) and sheep erythrocytes. Growing GBS were shown to possess a potent hemolysin at a very early stage of the growth cycle. After separation of the cells from the growth medium, all the hemolytic activity remained with the bacterial cells, and no activity could be detected in the growth medium. When fetal calf serum was added to the media, some "soluble" activity was detected. This activity, however was completely removed by ultracentrifugation, the hemolytic activity being found solely in the pellet. After the hemolysin had formed, no new protein synthesis was needed to cause hemolysis because the addition of chloramphenicol to cells caused no difference in their hemolytic potential. For proof that no short-lived, soluble factors are produced by the bacteria, bacteria and sheep erythrocytes were incubated in contiguous media, separated by a 0.22-microns membrane. No hemolytic activity was detected on the erythrocyte side of the membrane, although high amounts of hemolysin could be extracted from the bacteria. Only when a detergent was added to the growth medium was hemolysis detected from the erythrocytes, showing that extracted hemolysin could indeed pass through the membrane. These results suggest that the hemolysin is attached to the surface of the cell and that contact is needed between the bacteria and erythrocyte to cause lysis. Where soluble activity was detected, it was connected to bacterial fragments.
进行了实验以确定B组链球菌（GBS）溶血素与绵羊红细胞之间的相互作用。结果显示，处于生长周期非常早期阶段的GBS具有一种强效溶血素。将细胞与生长培养基分离后，所有溶血活性都保留在细菌细胞中，在生长培养基中未检测到活性。当向培养基中添加胎牛血清时，检测到一些“可溶性”活性。然而，这种活性通过超速离心被完全去除，溶血活性仅存在于沉淀中。溶血素形成后，溶血不需要新的蛋白质合成，因为向细胞中添加氯霉素对其溶血潜力没有影响。为了证明细菌不会产生短暂存在的可溶性因子，将细菌和绵羊红细胞在相邻的培养基中孵育，中间隔着0.22微米的膜。在膜的红细胞一侧未检测到溶血活性，尽管可以从细菌中提取大量溶血素。只有当向生长培养基中添加去污剂时，才从红细胞中检测到溶血，这表明提取的溶血素确实可以穿过膜。这些结果表明，溶血素附着在细胞表面，细菌与红细胞之间需要接触才能导致裂解。在检测到可溶性活性的地方，它与细菌碎片有关。
