Ogunnariwo J A, Schryvers A B
Department of Microbiology and Infectious Diseases, Faculty of Medicine, University of Calgary, Alberta, Canada.
Avian Dis. 1992 Jul-Sep;36(3):655-63.
To investigate the mechanisms of iron acquisition in avian haemophili, strains of Haemophilus paragallinarum and H. avium were tested for siderophore production and utilization of transferrin iron for growth. No evidence of siderophore production was detected in either of these species using a functional screening assay. H. paragallinarum, but not strains of H. avium, was able to acquire iron from 30% saturated chicken and turkey transferrins but not from human, porcine, or bovine transferrins. In response to iron limitation, H. paragallinarum expressed four iron-regulated outer-membrane proteins of 53, 62, 66, and 94 kilodaltons (kDa). Only the 53- and 94-kDa proteins were detected in the H. avium strains. Using affinity methods, the 94- and 53-kDa proteins were isolated specifically by chicken or turkey transferrin, indicating that they may be equivalent to transferrin binding proteins (TBP1 and TBP2, respectively) isolated from other bacterial species. The isolation of the 62- and 66-kDa proteins in association with TBP1 and TBP2 under less stringent washing conditions only in H. paragallinarum implicates these proteins in the iron acquisition process.
为了研究禽嗜血杆菌中铁摄取的机制，对副鸡嗜血杆菌和鸟嗜血杆菌菌株进行了铁载体产生及利用运铁蛋白铁进行生长的测试。使用功能筛选试验在这两个物种中均未检测到铁载体产生的证据。副鸡嗜血杆菌能够从30%饱和的鸡和火鸡运铁蛋白中获取铁，但不能从人、猪或牛运铁蛋白中获取铁，而鸟嗜血杆菌菌株则不能。在铁限制条件下，副鸡嗜血杆菌表达了四种铁调节外膜蛋白，分子量分别为53、62、66和94千道尔顿（kDa）。在鸟嗜血杆菌菌株中仅检测到了53-kDa和94-kDa的蛋白。使用亲和方法，94-kDa和53-kDa的蛋白分别被鸡或火鸡运铁蛋白特异性分离，这表明它们可能分别等同于从其他细菌物种中分离出的运铁蛋白结合蛋白（TBP1和TBP2）。仅在副鸡嗜血杆菌中，在不太严格的洗涤条件下，62-kDa和66-kDa的蛋白与TBP1和TBP2一起被分离出来，这表明这些蛋白参与了铁摄取过程。
