猪链球菌脑膜炎小鼠模型的构建及特征性炎性细胞因子的检测  

Establishment of Streptococcus suis infected meningitic mouse model and detection of its characteristic inflammatory cytokines

作　　者：吴桐 孙莹莹 刘洪涛 雷连成 WU Tong;SUN Yingying;LIU Hongtao;LEI Liancheng(College of Veterinary Medicine,Jilin University,Changchun 130062,China)

机构地区：[1]吉林大学动物医学学院,吉林长春130062

出　　处：《中国兽医学报》2021年第6期1094-1104,共11页Chinese Journal of Veterinary Science

基　　金：国家重点研发计划资助项目(2017YFD0500204)。

摘　　要：猪链球菌2型(Streptococcus suis serotype 2,SS2)属革兰阳性菌,是一种常见猪共生菌,在特殊情况下会成为入侵病原菌感染仔猪,导致仔猪的脑膜炎、败血症、心内膜炎、关节炎和肺炎等。由于仔猪感染模型成本高、病理特征差别大、试验条件要求高以及猪源免疫细胞鉴别抗体非常少,限制了对SS2的免疫学致病机制的深入研究。本研究以ICR小鼠为对象,通过腹腔注射方式分别感染脑膜炎型和非脑膜炎型SS2,从临床症状、细菌定植、免疫学指标、组织病理学变化等方面全面比较,评价脑膜炎小鼠的发病特征。结果显示,与非脑膜炎型SS2感染的小鼠相比,感染脑膜炎型SS2的小鼠呈现明显的运动失调、转圈、头颈扭转等神经症状;脑组织病变明显,且有细菌定殖;血清中IL-6、IL-8、IL-17在感染后表达水平明显升高,且脑膜炎型SS2感染组显著高于非脑膜炎型SS2感染组;脑膜炎型SS2感染小鼠脑组织中高水平的髓过氧化物酶(myeloperoxidase,MPO)与IL-6,反映了脑部中性粒细胞的大量浸润和剧烈的炎症反应。结果表明,ICR小鼠可以用于SS2引起的脑膜炎研究,IL-6在外周血和脑组织中的表达具有一致性,可作为成功感染的评价指标。Streptococcus suis serotype 2(SS2),a Gram-positive zoonotic pathogen,it is one of the common symbiotic bacteria of pig.However,in exceptional cases,it can also become an invasive pathogen that can infect piglets,leading to meningitis,septicaemia,endocarditis,arthritis and pneumonia.The research on immunological pathogenic mechanism of SS2is limited by the high cost of piglet infection model,the great difference in pathological characteristics,the high requirement of experimental conditions,and the very few differential antibodies of porcine immune cells.In this study,ICR mice were intraperitoneally injected with meningitic SS2and non-meningitic SS2,respectively.The characteristics of meningitis in mice were evaluated by comprehensive comparison of clinical symptoms,bacterial colonization,immunological indexes,and histopathological changes.The results showed that compared with the non-meningitic infection,mice infected with meningitic SS2showed significant neurological symptoms,such as intermittent turning and upward torsion of head and neck.The lesions of brain tissue were obvious and there were bacteria colonization.Expression level of IL-6,IL-8and IL-17in serum was significantly increased after infection,and the level of cytokines in mice infected with meningitic SS2was significantly higher than that in mice infected with non-meningitic SS2at early stage.The levels of myeloperoxidase(MPO)and IL-6in the brain tissues of mice infected with meningitic SS2were significantly higher than those in the non-meningitic group.The results indicated that ICR mice can be used in the study of meningitis caused by SS2,and the expression of IL-6in peripheral blood and brain tissue is consistent,which can be used as an evaluation index of successful infection.

关 键 词：猪链球菌2型 ICR小鼠 脑膜炎 细胞因子 IL-6 IL-8 IL-17 

分 类 号：S852.61[农业科学—基础兽医学] S858.28[农业科学—兽医学]