小鼠急性肺炎链球菌中耳炎模型建立及肺炎链球菌荚膜多糖在中耳炎中的作用研究

发布时间：2018-01-19 06:13

本文关键词： 急性中耳炎小鼠肺炎链球菌动物模型荚膜多糖　出处：《重庆医科大学》2013年硕士论文　论文类型：学位论文

【摘要】：目的肺炎链球菌是一种常见的革兰阳性条件致病菌，是引起中耳炎的主要致病菌之一。中耳炎是儿童常见病，反复发作易引起患儿听力障碍甚至缺失，延迟患儿的语言及智力发育。但肺炎链球菌中耳炎的分子病理机制至今尚不十分清楚。因此，本研究拟建立小鼠急性肺炎链球菌中耳炎模型，并观察肺炎链球菌主要致病因子荚膜多糖在中耳炎中的作用。方法 1．不同浓度的4型肺炎链球菌（TIGR4）悬液经鼓膜穿刺接种于C57BL/6J小鼠中耳腔中，建立小鼠急性肺炎链球菌中耳炎模型。观察小鼠体重变化及发病情况，取心脏血及中耳灌洗液进行细菌培养，中耳灌洗液进行细胞计数、流式细胞分类计数和细胞涂片瑞氏染色，，并测定中耳灌洗液上清和血清中细胞因子含量，小鼠的中耳组织进行组织切片HE染色。 2．TIGR4和荚膜缺陷菌TIGR4Δcps分别经鼓膜穿刺接种于中耳腔中，通过观察小鼠体重变化及发病情况、小鼠中耳灌洗液细菌培养、细胞计数、细胞涂片瑞氏染色和流式分类计数及细胞因子水平的差异来研究肺炎链球菌荚膜多糖在中耳炎中的作用。结果 1．小鼠中耳腔接种肺炎链球菌后，小鼠体重下降，呈剂量依赖。中耳粘膜上皮细胞坏死脱落，粘膜增厚，中耳腔内大量炎症细胞浸润，中耳骨壁骨质破坏。中耳腔内中性粒细胞的募集时相与细菌的清除时相呈相关性，中耳灌洗液上清中IL-6和TNF-α显著升高。 2．与野生型TIGR4相比，TIGR4Δcps在中耳腔中的定植显著减少，清除加快，募集的炎症细胞数量以及IL-6和TNF-α水平显著低于野生组。结论本研究成功建立了小鼠急性肺炎链球菌中耳炎模型，中耳微环境中炎症细胞和炎症因子的募集增加。同时，研究发现在肺炎链球菌中耳炎中，荚膜多糖具有促进细菌定植、募集炎症细胞和诱导炎症因子释放等重要作用。
[Abstract]:Purpose Streptococcus pneumoniae is a common gram-positive conditional pathogen, which is one of the main pathogens causing otitis media. Otitis media is a common disease in children. The molecular pathological mechanism of Streptococcus pneumoniae otitis media is still unclear. Therefore, this study intends to establish a mouse model of acute streptococcus pneumoniae otitis media. To observe the role of capsular polysaccharide, the main pathogenic factor of Streptococcus pneumoniae, in otitis media. Method 1. Different concentrations of Streptococcus pneumoniae TIGR4 suspension were inoculated into the middle ear cavity of C57BL / 6J mice by tympanic membrane puncture. A mouse model of acute streptococcus pneumoniae otitis media was established. The changes of body weight and the incidence of the disease were observed. The heart blood and the middle ear lavage fluid were taken for bacterial culture and the middle ear lavage fluid was counted. The levels of cytokines in the supernatant of middle ear lavage fluid and serum were determined. The middle ear tissue of mice was stained with HE in tissue sections. 2. TIGR4 and TIGR4 螖 cps were inoculated into the middle ear cavity by tympanic membrane puncture. To study the role of streptococcus pneumoniae capsule polysaccharides in otitis media, cell count, cell smear staining, flow classification count and cytokine level were different in order to study the role of streptococcus pneumoniae capsule polysaccharides in otitis media. Results 1. After inoculation of Streptococcus pneumoniae in the middle ear cavity of mice, the weight of the mice decreased in a dose-dependent manner. The epithelial cells of the middle ear were necrotic, the mucosa thickened, and a large number of inflammatory cells infiltrated in the middle ear cavity. There was a correlation between the recruitment phase of neutrophils and the clearance of bacteria in the middle ear cavity. The IL-6 and TNF- 伪 in the supernatant of the middle ear lavage fluid increased significantly. 2. Compared with wild-type TIGR4, the colonization of TIGR4 螖 cps in the middle ear cavity was significantly reduced and the clearance was accelerated. The number of inflammatory cells recruited and the levels of IL-6 and TNF- 伪 were significantly lower than those in the wild group. Conclusion In this study, the mouse model of acute streptococcus pneumoniae otitis media was successfully established, and the recruitment of inflammatory cells and inflammatory factors in the middle ear microenvironment was increased. At the same time, it was found that in Streptococcus pneumoniae otitis media. Capsule polysaccharide plays an important role in promoting bacterial colonization, recruiting inflammatory cells and inducing the release of inflammatory factors.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R764.21;R-332

【参考文献】