Department of Microbiology, Panjab University Department of Pathology, Government Medical College, Chandigarh, India.
Microbiol Immunol. 2011 May;55(5):295-303. doi: 10.1111/j.1348-0421.2011.00317.x.
In the present study, the course of acute pneumonia in normal BALB/c mice infected by intranasal inoculation of planktonic and preformed biofilm cells (3 days old) of Klebsiella pneumoniae B5055 was studied and compared. With both cell forms the peak of infection was observed on the third post infection day, as assessed on the basis of lung bacterial load and corresponding pathology. There was an intense neutrophil infiltration in bronchoalveolar lavage fluid. Tissue damage was assessed on the basis of increased amounts of nitrite, malondialdehyde and lactate dehydrogenase in lung homogenates. The phagocytic potential of alveolar macrophages was lower in biofilm cell-induced infection than in that induced by planktonic cells. Biofilm cell induced infection generated significantly greater production of tumor necrosis factor-α and interleukin-1β on the third and fifth days of infection, respectively. Production of interleukin-10 was, however, variable. There was no significant difference in the ability of planktonic and biofilm cell forms of K. pneumoniae to induce acute pneumonia in mice in terms of bacterial counts and histopathological changes. However, biofilm cell-induced infection showed delayed clearance as compared to infection induced with the planktonic form.
在本研究中，通过鼻内接种浮游和预形成生物膜细胞（3 天龄）对正常 BALB/c 小鼠的肺炎进行了研究，并将其与感染进行了比较。在感染后第 3 天，通过肺部细菌负荷和相应的病理学评估，观察到两种细胞形式的感染达到高峰。支气管肺泡灌洗液中有强烈的中性粒细胞浸润。通过测量肺匀浆中硝酸盐、丙二醛和乳酸脱氢酶的含量评估组织损伤。与浮游细胞诱导的感染相比，生物膜细胞诱导的感染中肺泡巨噬细胞的吞噬能力较低。生物膜细胞诱导的感染分别在第 3 天和第 5 天产生了显著更高水平的肿瘤坏死因子-α和白细胞介素-1β。然而，白细胞介素-10 的产生是可变的。就细菌计数和组织病理学变化而言，肺炎克雷伯菌的浮游和生物膜细胞形式均能在小鼠中诱发急性肺炎，其能力没有显著差异。然而，与浮游形式诱导的感染相比，生物膜细胞诱导的感染显示出清除延迟。
