title: Electrophoretic and Western blot analyses of the lipopolysaccharide and glycocalyx of Flavobacterium psychrophilum.
abstract: 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.
authors.affiliation: Department of Fish and Wildlife Resources and the Aquaculture Research Institute, University of Idaho, Moscow, ID 83844-1136, USA.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: LaFrentz
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Lindstrom
authors.forename: Scott E
authors.initials: SE
authors.lastname: LaPatra
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Call
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Cain
mesh_terms: D000907:Antibodies, Bacterial / Q000378:metabolism; D000942:Antigens, Bacterial / Q000378:metabolism*; D015153:Blotting, Western / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005417:Flavobacterium / Q000378:metabolism* / Q000648:ultrastructure; D019276:Glycocalyx / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D008070:Lipopolysaccharides