Factors affecting the course and severity of transnasally induced Staphylococcus aureus pneumonia in mice
Factors affecting the course and severity of transnasally induced Staphylococcus aureus pneumonia in mice
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DOI：
10.1099/00222615-48-11-1005
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发表时间：
1999-11-01
影响因子：
3
通讯作者：
Yamaguchi, K
中科院分区：
文献类型：
--
作者：
Kimura, K;Miyazaki, S;Yamaguchi, K
为了检查可能影响小鼠经鼻诱导的金黄色葡萄球菌肺炎的过程和严重程度的几个因素，将细菌制备在游离悬浮液中或与胎鼠细胞结合。用环磷酰胺（200 mg/kg体重）诱导ICR、C57 BL/6、BALB/c、C3 H/He和CBA/J五种小鼠免疫抑制，并以福尔马林滴鼻诱导粘膜纤毛清除功能障碍。虽然两种接种物之间没有观察到显著差异，但用福尔马林加环磷酰胺预处理与肺细菌计数显著增加相关。特别是，环磷酰胺治疗与感染几种S.金黄色葡萄球菌，而不管它们的毒素生产概况。组织学检查表明，在用福尔马林加环磷酰胺处理的小鼠中，在肺实质中观察到细菌簇，与第2天炎性细胞的轻度积聚和第7天的广泛细胞浸润相关。CBA/J小鼠是受检小鼠中最敏感的品系，在第3天和第5天肺中的细菌计数分别高出10（4）倍和10（2）倍。这些结果表明，中性粒细胞减少和粘膜纤毛清除功能受损是影响小鼠金黄色葡萄球菌肺炎严重程度的主要因素。在未来的研究中，需要分析遗传背景在增强感染易感性中的作用。
In order to examine several factors that may affect the course and severity of transnasally induced Staphylococcus aureus pneumonia in mice, bacteria were prepared in a free suspension or bound to fetal mouse cells. Immunosuppression was induced in five strains of mice (ICR, C57BL/6, BALB/c, C3H/He and CBA/J) by injection of cyclophosphamide (200 mg/kg body weight), 2 days before infection, Impairment of mucociliary clearance was induced by intranasal instillation of formalin, Mice were then infected with various doses and strains of the organism. Although no significant differences were observed between either form of inoculum, pretreatment with formalin plus cyclophosphamide was associated with a significant increase in lung bacterial counts. In particular, cyclophosphamide treatment was associated with a high mortality in mice infected with several strains of S. aureus irrespective of their toxin production profiles. Histopathological examination demonstrated that in mice treated with formalin plus cyclophosphamide, clusters of bacteria were observed in lung parenchyma, associated with a mild accumulation of inflammatory cells at day 2 and extensive cell infiltration at day 7. CBA/J mice represented the most susceptible strain among those examined, with 10(4)- and 10(2)-fold higher bacterial counts in the lungs at days 3 and 5, respectively. These results indicate that neutropenia and impaired mucociliary clearance are major factors that influence the severity of S, aureus pneumonia in mice. Analysis of the role of genetic background in enhancement of vulnerability to infection is warranted in future studies.