Pfeifer C G, Campos M, Beskorwayne T, Babiuk L A, Potter A A
Canadian Bacterial Disease Network, Saskatoon, Saskatchewan.
Microb Pathog. 1992 Sep;13(3):191-202. doi: 10.1016/0882-4010(92)90020-o.
The interactions between bovine polymorphonuclear leukocytes (PMNs) and the bacterium Haemophilus somnus are known to be complex. In this paper, we evaluated the effect of H. somnus on PMN function using a flow cytometric (FC) technique that simultaneously determined the extent of phagocytosis and hydrogen peroxide production by PMNs, as well as using conventional techniques, such as the nitroblue tetrazolium (NBT) and chemiluminescence assays, to analyse the PMN respiratory burst. Results from the FC and chemiluminescence assays demonstrated that in vitro exposure of PMNs to logarithmically growing H. somnus reduced the respiratory burst of PMNs obtained from healthy calves. However, this reduction was not detected by the NBT assay. A decrease in phagocytosis by PMNs could also be shown using the FC assay. In addition, PMNs from calves with acute Hemophilosis (i.e. exposed to H. somnus in vivo) showed reduced activity when compared to PMNs from healthy calves. These in vitro and in vivo observations indicate that the modulation of bovine PMN function by H. somnus may contribute significantly towards the pathogenesis of the disease.
已知牛多形核白细胞（PMN）与睡眠嗜血杆菌之间的相互作用很复杂。在本文中，我们使用流式细胞术（FC）技术评估了睡眠嗜血杆菌对PMN功能的影响，该技术可同时测定PMN的吞噬作用程度和过氧化氢生成量，此外还使用了传统技术，如硝基蓝四氮唑（NBT）和化学发光测定法，来分析PMN的呼吸爆发。FC和化学发光测定法的结果表明，在体外将PMN暴露于对数生长期的睡眠嗜血杆菌会降低从健康犊牛获得的PMN的呼吸爆发。然而，NBT测定法未检测到这种降低。使用FC测定法也可显示PMN的吞噬作用降低。此外，与健康犊牛的PMN相比，患有急性嗜血杆菌病（即在体内暴露于睡眠嗜血杆菌）的犊牛的PMN活性降低。这些体外和体内观察结果表明，睡眠嗜血杆菌对牛PMN功能的调节可能对该疾病的发病机制有显著贡献。
