金黄色葡萄球菌不同菌株黏附和侵袭293细胞的比较

目的对金葡菌不同菌株侵袭力进行比较。方法将金葡菌各菌株与293细胞共孵育，使细菌侵袭细胞（细菌与细胞的比例为15：1），2h后，用溶葡萄球菌素杀死细胞外的细菌，用胰酶和Triton—X100消化裂解细胞并收集裂解液计数侵入细胞内的细菌克隆形成单位CFU，比较不同菌株的侵袭力。结果临床分离株04018具有较强的侵袭力。结论金葡菌的侵袭力主要由其表达的纤连蛋白结合蛋白FnBP介导。不同菌株由于FnBP表达水平的差异具有不同的侵袭力。但在细菌的侵袭过程中，除了FnBP蛋白的参与外，可能还有其他因素的参与。

Comparison of the ability of Staphylococcus aureus strains to adhere to and invade 293 cells

Objective To test the invasion ability of different Staphylococcus aureus （S.aureus） strains. Methods S.aureus strains were incubated with 293 cells at 37℃ to infect the 293 cells. Two hours after infection, the medium was replaced with DMEM containing 10 μg/mL lysostaphin to kill the S. aureus strains in extra-cellular cells. The cells were trypsinized and lysed with trypsin EDTA and Triton X-100 solution. Cell lysate and supernatant were appropriately diluted and plated on LB agar plates, and colony forming units （CFU） were quantified. Results Clinical isolates of S.aureus 04018 strain had a strong ability to invade 293 cells. Conclusion The ability of S. aureus strains to invade 293 cells by mediating expression of fibronectin-binding protein- FnBP. Different strains have different expression levels and invasion abilities. However, in addition to FnBP protein, other factors may be involved in the invasion of 293 cells.