鼠疫耶尔森菌与表面抗体相互作用的原子力显微镜观测研究

目的 以原子力显微镜(atomic force microscopy,AFM)观察比较鼠疫耶尔森菌EV76株与正常兔血清以及兔抗F1抗体反应后微观形态变化,探讨以原子力显微镜为工具的鼠疫耶尔森菌的免疫检测方法.方法 用兔抗F1抗体及正常兔血清处理鼠疫耶尔森菌菌液,并与对照菌一起制样后在原子力显微镜下观察鼠疫耶尔森菌的表面结构的改变,并对其主要指标,包括Ra、Rq改变进行测量比较.结果 正常菌体组细胞呈椭圆形,两端钝圆,长为1.1～1.3 μm,宽为0.8～1.0 μm,阶高为0.04～0.06 μm,细胞形状规则,表面相对比较光滑;对照抗体及F1抗体加入组,细菌阶高均明显增高;F1抗体结合株菌体形状不规则,表面粗糙度明显增加.结论 获得原子力显微镜下的鼠疫耶尔森菌形态特征;表面抗体与鼠疫耶尔森菌结合后,对鼠疫耶尔森菌的表面超微结构有显著的影响,其中粗糙度可以作为原子力显微镜免疫检测的指标.

Imaging study of interaction between Yersinia pestis and its surface antibody by atomic force microscopy

Objective To observe and compare the atomic force microscopy (AFM) images of Yersinia pestis EV76 and the changes in the morphology of the bacteria treated with normal serum and F1 antibody from rabbit,and to explore the immunoassay method to detect Yersinia pestis by AFM. Methods The Yersinia pestis were treated with normal serum and F1 antibody from rabbit and control buffer. All the prepared samples were observed and analyzed by AFM. The changes in the cell surface structures were probed and characterized through sectional analysis,especially the changes of Ra and Rq value. Results The normal morphology of Yersinia pestis was oval in shape with a relatively smooth surface, the size dimension of which was about 1.1-1.3 μm in length with a section profile of 0.8-1.0 μm in width and 0.04-0.06 μm in step height. The step height of the bacteria treated with the normal serum and F1 antibody was obviously enlarged. The shape of the bacteria treated with F1 antibody changed irregularly. Furthermore, the surface of the bacteria was more roughened. Conclusion The morphological characters of Yersinia pestis has been acquired through its AFM images. The morphology of Yersinia pestis treated with F1 antibody has changed greatly, and the index of roughness can be regarded as the distinguished index to detect Yersinia pestis by AFM.