自然感染途径建立肺炎链球菌感染性肺炎小鼠模型

目的探索自然感染途径制备肺炎链球菌感染性肺炎小鼠模型的方法,为肺炎链球菌性肺炎的相关研究提供实验基础。方法肺炎链球菌标准菌株(CMCC 31203)经血平板培养18 h后配成2麦氏浊度。小鼠浅麻醉状态下,破损鼻黏膜,滴注一定量肺炎链球菌菌液。于3、7、14和21 d分别处死小鼠,取肺脏进行组织病理学观察,确定肺炎小鼠模型制备的最佳方式。结果鼻黏膜破损组小鼠3 d时肺泡间隔内毛细血管扩张,肺泡腔内以红细胞和纤维素渗出为主;7 d时病变以纤维素和中性粒细胞浸润为主;14 d时肺泡腔内渗出减少,炎症开始减轻;21 d时肺脏外观趋于正常,肺泡腔内渗出物质基本溶解吸收。结论以3×107CFU的肺炎链球菌菌液通过破损的鼻黏膜感染7 d时可以制备出比较典型、稳定的肺炎小鼠模型。

Establishment of a pneumonia mice model infected with Streptococcus pneumoniae by natural infection route

Objective To establish a pneumonia mice model infected with Streptococcus pneumoniae by intranasal instillation to support researches on pneumonia caused by Streptococcus pneumoniae. Method Streptococcus pneumoniae standard strain （CMCC 31203） cultured 18 h in blood plate was prepared to 2 Maxwell turbidity, dripped 3 ×10^7 CFU into the nasal cavities of mice under light anesthesia. At Days 3, 7, 14 and 21 respectively, the mice were dissected and their lungs taken for histopathological observation to determine the typical pneumonia model. Result At Day 3, the capillaries in alveolar intervals expansed ; alveolar space were full of RBC and cellulose in the nasal mucosa damaged mice ; at Day 7 the congestive lungs were reducing and neutrophil infiltration appeared; at Days 14 and 21, the inflammation became reduced and tended to be normal. Conclusion Intranasal instillation to mice with 3×10^7 CFU of Streptococcus pneumoniae can establish a typical, stable pneumonia mice model at Day 7.