Mack D, Siemssen N, Laufs R
Institute for Medical Microbiology and Immunology, University Hospital Eppendorf, Hamburg, Germany.
Infect Immun. 1992 May;60(5):2048-57. doi: 10.1128/iai.60.5.2048-2057.1992.
The initial attachment and the accumulation of Staphylococcus epidermidis on polymer surfaces in multilayered cell clusters embedded in amorphous slime, which together lead to the plastic-adherent phenotype detected by the adherence assay used in this study, have been proposed to be major virulence factors of these bacteria. An antigen specific for plastic-adherent S. epidermidis strains was detected by an indirect immunofluorescence test using absorbed antiserum raised against the strongly plastic-adherent S. epidermidis 1457. A coagglutination assay was established, which allowed the quantitation of the antigen in bacterial extracts under different physiologic growth conditions. Expression of the antigen and of plastic adherence depended significantly on the presence of glucose in the growth medium. Parallel to increased plastic adherence, a 32- to 64-fold increase in the amount of the antigen was detected in bacterial extracts of cells grown in tryptone soya broth (TSB) compared with that in extracts of cells grown in TSB lacking glucose. A parallel time-dependent increase of plastic adherence and expression of the antigen was observed after stimulation by glucose of stationary-phase cultures of plastic-adherent S. epidermidis strains grown in TSB lacking glucose. The antigen consisted most probably of polysaccharide, because its immunologic reactivity was completely abolished by periodate oxidation but was resistant to protease digestion. A significant proportion of cells of plastic-adherent as compared with nonadherent S. epidermidis strains grown in TSB were located in large cell clusters exceeding 50 cells, which completely disintegrated after periodate oxidation of the cell preparations. Periodate oxidation of adherent bacterial films in situ led to release of the adherent cells from the plastic surface. These results strongly indicate a functional relation of the antigen to adherence of S. epidermidis to polymer surfaces, most probably by mediating intercellular adhesion of cells leading to accumulation in multilayered cell clusters.
表皮葡萄球菌在嵌入无定形黏液的多层细胞簇中在聚合物表面的初始附着和积累，共同导致了本研究中使用的黏附试验所检测到的塑料黏附表型，这些已被认为是这些细菌的主要毒力因子。通过使用针对强塑料黏附性表皮葡萄球菌1457产生的吸收抗血清进行间接免疫荧光试验，检测到了一种针对塑料黏附性表皮葡萄球菌菌株的抗原。建立了一种协同凝集试验，该试验能够在不同生理生长条件下对细菌提取物中的抗原进行定量。抗原的表达和塑料黏附性在很大程度上取决于生长培养基中葡萄糖的存在。与塑料黏附性增加平行的是，与在不含葡萄糖的胰蛋白胨大豆肉汤（TSB）中生长的细胞提取物相比，在TSB中生长的细胞的细菌提取物中检测到抗原量增加了32至64倍。在用葡萄糖刺激在不含葡萄糖的TSB中生长的塑料黏附性表皮葡萄球菌菌株的稳定期培养物后，观察到塑料黏附性和抗原表达随时间的平行增加。该抗原很可能由多糖组成，因为其免疫反应性被高碘酸盐氧化完全消除，但对蛋白酶消化具有抗性。与在TSB中生长的非黏附性表皮葡萄球菌菌株相比，很大比例的塑料黏附性表皮葡萄球菌细胞位于超过50个细胞的大细胞簇中，细胞制剂经高碘酸盐氧化后这些细胞簇完全解体。原位对黏附细菌膜进行高碘酸盐氧化导致黏附细胞从塑料表面释放。这些结果有力地表明该抗原与表皮葡萄球菌对聚合物表面的黏附之间存在功能关系，很可能是通过介导细胞间黏附导致细胞在多层细胞簇中积累。
