Wiklund Tom, Dalsgaard Inger
Fish Disease Laboratory, Danish Institute for Fisheries Research, Stigbøjlen 4, 1870 Frederiksberg C, Denmark.
Fish Shellfish Immunol. 2003 Nov;15(5):387-95. doi: 10.1016/s1050-4648(03)00009-3.
The capacity of virulent and non-virulent strains of Flavobacterium psychrophilum of different serotypes to associate with isolated rainbow trout (Oncorhynchus mykiss, 300-500 g) kidney phagocytes was evaluated in vitro. The results showed that F. psychrophilum was associated with the phagocytes but large differences in association were observed between the different bacterial strains examined. These differences in association with the phagocytes was not clearly related to the serotype or virulence of the bacteria, although all strains tested of the non-virulent serotype FpT showed strong association with the isolated phagocytes. A competitive association assay with treatment of the phagocytes with seven different carbohydrates, suggested a role for N-acetylneuraminic acid (sialic acid) in the binding of F. psychrophilum to phagocytes. A significant dose dependent inhibition of the association was observed with sialic acid. Treatment of F. psychrophilum with sodium-metaperiodate showed that carbohydrate components play a role in the adhesion of the bacteria to the phagocytes. The results indicate that the binding of F. psychrophilum to rainbow trout kidney phagocytes can be mediated by opsonin independent cell-receptor adhesion. All tested strains seemed to be non-cytotoxic for rainbow trout kidney phagocytes in vitro suggesting that a phagocyte toxin is not necessary for the virulence of F. psychrophilum
在体外评估了不同血清型的嗜冷黄杆菌的强毒株和无毒株与分离出的虹鳟（Oncorhynchus mykiss，300 - 500克）肾脏吞噬细胞结合的能力。结果表明，嗜冷黄杆菌与吞噬细胞有关联，但在所检测的不同细菌菌株之间观察到结合存在很大差异。尽管所有测试的无毒血清型FpT菌株都与分离出的吞噬细胞有很强的结合，但这种与吞噬细胞结合的差异与细菌的血清型或毒力并无明显关联。用七种不同碳水化合物处理吞噬细胞的竞争性结合试验表明，N - 乙酰神经氨酸（唾液酸）在嗜冷黄杆菌与吞噬细胞的结合中起作用。观察到唾液酸对结合有显著的剂量依赖性抑制。用偏高碘酸钠处理嗜冷黄杆菌表明，碳水化合物成分在细菌与吞噬细胞的黏附中起作用。结果表明，嗜冷黄杆菌与虹鳟肾脏吞噬细胞的结合可由不依赖调理素的细胞受体黏附介导。所有测试菌株在体外对虹鳟肾脏吞噬细胞似乎都无细胞毒性，这表明吞噬细胞毒素对于嗜冷黄杆菌的毒力并非必需。
