LaFrentz Benjamin R, Lindstrom Nicole M, LaPatra Scott E, Call Douglas R, Cain Kenneth D
Department of Fish and Wildlife Resources and the Aquaculture Research Institute, University of Idaho, Moscow, ID 83844-1136, USA.
Fish Shellfish Immunol. 2007 Oct;23(4):770-80. doi: 10.1016/j.fsi.2007.02.005. Epub 2007 Feb 25.
Flavobacterium psychrophilum is the aetiological agent of bacterial coldwater disease (CWD) and rainbow trout fry syndrome (RTFS) and it has emerged as one of the most significant bacterial pathogens in salmonid aquaculture worldwide. Previous studies have suggested that the O-polysaccharide (O-PS) component of the lipopolysaccharide (LPS) of F. psychrophilum is highly immunogenic and may be involved in eliciting a protective immune response in rainbow trout (Oncorhynchus mykiss Walbaum). In the present study, SDS-PAGE and Western blotting techniques were used to analyse the carbohydrate antigens of F. psychrophilum. Our analysis identified two distinct carbohydrate-banding patterns. One banding pattern corresponds with LPS, and we hypothesise that the other carbohydrate-banding pattern is that of the loosely associated glycocalyx of F. psychrophilum. Electron microscopy of F. psychrophilum cells immunogold labelled with a monoclonal antibody specific for this banding pattern supports this hypothesis as the outermost layer of the bacterium was heavily labelled. This is a significant finding because the immunogenic antigens that have been referred to as the O-PS of LPS, and implicated as potential vaccine candidate antigens, appear to be components of the glycocalyx of F. psychrophilum. This research suggests that the glycocalyx of F. psychrophilum may be an important antigen to consider for the development of a vaccine to control CWD and RTFS.
嗜冷黄杆菌是细菌性冷水病（CWD）和虹鳟鱼苗综合征（RTFS）的病原体，已成为全球鲑鱼养殖中最重要的细菌病原体之一。先前的研究表明，嗜冷黄杆菌脂多糖（LPS）的O-多糖（O-PS）成分具有高度免疫原性，可能参与引发虹鳟（Oncorhynchus mykiss Walbaum）的保护性免疫反应。在本研究中，采用SDS-PAGE和Western印迹技术分析嗜冷黄杆菌的碳水化合物抗原。我们的分析确定了两种不同的碳水化合物条带模式。一种条带模式与LPS相对应，我们推测另一种碳水化合物条带模式是嗜冷黄杆菌松散结合的糖萼的条带模式。用针对这种条带模式的单克隆抗体进行免疫金标记的嗜冷黄杆菌细胞的电子显微镜检查支持了这一假设，因为细菌的最外层被大量标记。这是一个重要发现，因为被称为LPS的O-PS且被认为是潜在疫苗候选抗原的免疫原性抗原似乎是嗜冷黄杆菌糖萼的成分。这项研究表明，嗜冷黄杆菌的糖萼可能是开发控制CWD和RTFS疫苗时需要考虑的重要抗原。
