Unité de Virologie Médicale et Moléculaire et EA-4303, UFR Médecine, Université Reims Champagne-Ardenne, F-51092 Reims, France.
Microbes Infect. 2011 Nov;13(12-13):1045-51. doi: 10.1016/j.micinf.2011.05.013. Epub 2011 Jun 30.
In the present study, we comparatively assessed the pathophysiological mechanisms developed during lung infection of BALB/C female mice infected by an original wild type Klebsiella pneumoniae subsp. ozaenae strain (CH137) or by a referent subspecies K. pneumoniae. subsp. pneumoniae strain (ATCC10031). The mice infected with 2.10⁶ CFU K. p. subsp. pneumoniae (n = 10) showed transient signs of infection and all of them recovered. All of those infected with 1.10⁶ CFU K. p. subsp. ozaenae (n = 10) developed pneumonia within 24 h and died between 48 and 72 h. Few macrophages, numerous polymorphonuclear cells and lymphocytes were observed in their lungs in opposite to K. p. subsp. pneumoniae. In bronchoalveolar lavage, a significant increase in MIP-2, IL-6, KC and MCP-1 levels was only observed in K. p. subsp. ozaenae infected mice whereas high levels of TNF-α were evidenced with the two subspecies. Our findings indicated a lethal effect of a wild type K. p. subsp. ozaenae strain by acute pneumonia reflecting an insufficient alveolar macrophage response. This model might be of a major interest to comparatively explore the pathogenicity of K. p. subsp ozaenae strains and to further explore the physiopathological mechanisms of gram-negative bacteria induced human pneumonia.
在本研究中，我们比较评估了 BALB/C 雌性小鼠肺部感染原始野生型肺炎克雷伯菌亚种（CH137）或参考亚种肺炎克雷伯菌（ATCC10031）时发展的病理生理机制。感染 2.10⁶ CFU 肺炎克雷伯菌亚种（n = 10）的小鼠表现出短暂的感染迹象，所有小鼠均恢复。感染 1.10⁶ CFU 肺炎克雷伯菌亚种（n = 10）的小鼠在 24 小时内均发展为肺炎，并在 48 至 72 小时内死亡。与肺炎克雷伯菌亚种相比，其肺部中观察到的巨噬细胞较少，多形核细胞和淋巴细胞较多。在支气管肺泡灌洗中，仅在感染肺炎克雷伯菌亚种的小鼠中观察到 MIP-2、IL-6、KC 和 MCP-1 水平显著增加，而两种亚种均显示出高水平的 TNF-α。我们的研究结果表明，野生型肺炎克雷伯菌亚种通过急性肺炎产生致死效应，反映出肺泡巨噬细胞反应不足。该模型可能对比较探索肺炎克雷伯菌亚种的致病性以及进一步探索革兰氏阴性菌引起的人类肺炎的生理病理机制具有重要意义。
