肺炎链球菌假想蛋白SPD0414亚细胞定位及对细菌黏附侵袭的影响

目的 为研究肺炎链球菌假想蛋白SPD0414在肺炎链球菌（S.pn）的亚细胞定位,并初步研究其在S.pn黏附和定植中的作用.方法 通过分别在SPD0414的N端和C端融合绿色荧光蛋白（GFP）,共聚焦荧光显微镜观察定位情况.用203野生菌和203△spd0414缺陷菌对鼻咽癌细胞CNE和肺腺癌细胞A549细胞的黏附侵袭实验.体内实验中用203和203△spd0414滴鼻感染BALB/c,在6 h和12 h观察细菌在鼻腔和肺中的载量.结果 无论N端或C端融合的GFP都显示绿色荧光,且整个菌体都显示荧光.与203野生菌相比,203△spd0414缺陷菌对CNE和A549的黏附和侵袭能力均显著下降（P＜0.05）.滴鼻感染BALB/c小鼠,在6 h和12 h,203△spd0414在鼻腔和肺中的细菌载量也明显低于203野生菌（P＜0.05）.结论 肺炎链球菌假想蛋白SPD0414定位于细菌的胞质.该蛋白在细菌的定植和侵袭中发挥了重要的作用.

Subcellular Localization of Streptococcus Pneumonia Hypothetical Proteins SPD0414 and Its Effect on Adhesion and Invasion of S. pn

Objective To study the subcellular localization of streptococcus pneumonia hypo- thetical proteins SPD0414 and its effect on the adhesion and colonization of S. pn. Methods Two vector allowing C-and N-terminal GFP fusions for SPD0414 were used to construct recombinant pro- teins of SPD0414-GFP and GFP-SPD0414 in R6, and the fluorescence was observed under the con- focal microscopy. CNE and A549 were subjected to the adhesion and invasion assays with 203 and 203 A spd0414 stains. In the in vivo experiment, BALB/c mice were infected nasally, and the bacteria load in the nasal cavity and lung was determined after 6 h and 12 h. Results The whole bacteria had obvious fluorescence in mater C-or N-terminal GFP fusions for SPD0414. Besides, the adhe sion and invasion abilities of 203 Aspd0414 to CNE and A549 cells were significantly reduced as compared with that of 203 （P 〈 0.05） . As compared with 203 infection group, the bacteria load in 203 A spd0414 infection group was significantly reduced also in the nasal cavity and lung at 6 h and 12 h （ P 〈 0. 05 ） . Conclusion Streptococcus pneumonia hypothetical proteins SPD0414 locates in cytoplasm, and is associated with the adhesion and invasion of S. pn.