变形链球菌葡聚糖结合蛋白D(gbpD)基因失活菌株体外黏附能力的实验研究

目的:体外观察gbpD基因失活菌株在羟基磷灰石表面的黏附能力,为明确GbpD在变形链球菌黏附过程中的作用提供实验依据。方法:荧光标记gbpD失活菌和野生菌,与唾液包被的羟基磷灰石粉末共同孵育后,测定羟基磷灰石沉淀的荧光值,比较粘附率的差异。结果:发现gbpD失活菌的黏附率(19.7%±0.91)低于野生菌(29.5%±2.9),差异有显著性(P<0.05);当加入抗GbpD抗体后,变形链球菌UA159的黏附率低于未加抗体组(P<0.05)。结论:GbpD的缺失严重影响了变形链球菌与唾液包被羟基磷灰石的粘附,抗GbpD抗体对这种粘附有一定的抑制作用,表明GbpD与变形链球菌的粘附能力有关。

In vitro investigation of the adhesion properties of glucan-binding protein D gene inactivated mutant of Strep tococcus mutans

Objective： To investigate the adhesion properties of gbpD mutant and wildtype strains in vitro. Method： The bacteria cells were labeled with a fluorescent indicator （BCECF / AM） and incubated with saliva-coated hydroxyapatite （SHA）. Bacteria adhered to the SHA were measured using a spectrofluorometer. Result： Significantly lower adherence percentage was observed in the gbpD mutant group （19.7%±0.91） as compared with the wild type strains （29.5%±2.9）. After the labeled wild type bacteria were co-incubated with anti-GbpI） antibody and SHA, the adherence percentage was decreased compared to the non-antibody controls （P 〈0.05）. Conclusion： The test indicated that GbpD played a role in the S. mutans adhesion to SHA, and the anti-GbpD antibody could inhibit this process.