金黄色葡萄球菌isdb基因的克隆表达及其小鼠免疫试验

为了研究金黄色葡萄球菌表面Isdb蛋白的免疫原性，应用PCR方法扩增出金黄色葡萄球菌Wood46株的isdb 基因并进行序列分析，再将isdb 基因插入到pET32-a(+) 载体上，构建了pET32-a(+)-isdb重组质粒，将重组质粒转化到宿主菌大肠埃希菌BL21中并诱导表达和纯化Isdb蛋白。用纯化的Isdb蛋白免疫小鼠，检测小鼠血清中抗体水平；在二次免疫之后的第2周，用金黄色葡萄球菌Wood46、HLJ23-1株对小鼠攻毒，每组8只小鼠。研究结果发现：isdb基因在不同菌株中高度保守；Isdb蛋

Cloning and expression of Staphylococcus aureus surface protein Isdb and its immune experiment in mice

In order to characterize the immunogenicity and immunoprotection of the Staphylococcus aureus (S. aureus) surface Isdb, we amplified isdb gene from S. aureus Wood46 strain. The isdb gene was subsequently inserted into pET32a(+) vector and the recombinant plasmid was transformed into E. coli strain BL21. The recombinant Isdb was expressed and purified. Then, we immunized mice with the purified recombinant protein. The antibody level was measured by enzyme-linked immunosorbent assay. Finally, immunized mice were challenged with S. aureus strains Wood46 and HLJ23-1. These results showed that isdb gene sequences were highly conserved, and the recombinant Isdb was successfully expressed. The antibody titer in the immunized groups was increased significantly (P<0.05) compared with the control, the protective rate of Isdb protein inducted by challenge with the two S. aureus stains Wood46 and HLJ23-1 was 62.5% and 75%, respectively. These results showed that the Isdb protein had high immunogenicity and immunoprotective capacity.