title: Comparative proteomic analysis of virulent and rifampicin-attenuated Flavobacterium psychrophilum.
abstract: Flavobacterium psychrophilum is the aetiologic agent of bacterial coldwater disease and rainbow trout fry syndrome. In this study, we compared a wild-type strain (CSF 259-93) with a rifampicin-resistant strain and virulence-attenuated strain of F. psychrophilum (CSF 259-93B.17). The attenuated strain harboured a mutation in the rpoB gene consistent with resistance to rifampicin. Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry demonstrated an altered proteome with eight proteins characteristic for the parent strain and six that were unique to the attenuated strain. Immunoblotting with a diagnostic monoclonal antibody (FL-43) identified a putative antigen (FP1493) that was subsequently cloned, expressed as a recombinant protein and confirmed as recognized by FL-43. 2D-PAGE, immunoblotting with rainbow trout, Oncorhynchus mykiss (Walbaum), convalescent antisera and mass spectrometry of bacterial whole-cell lysates revealed several uniquely expressed immunoreactive proteins including FP1493. An FP1493 recombinant subunit vaccine was tested, but did not provide protection against challenge with the CSF259-93 strain. While the exact mechanism responsible for altered protein synthesis and attenuation of CSF 259-93B.17 is still unknown, the differentially expressed immunoreactive proteins are a valuable resource to develop subunit vaccines and to identify proteins that are potentially involved in disease.
authors.affiliation: Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA.
authors.forename: K
authors.initials: K
authors.lastname: Gliniewicz
authors.forename: K P
authors.initials: KP
authors.lastname: Plant
authors.forename: S E
authors.initials: SE
authors.lastname: LaPatra
authors.forename: B R
authors.initials: BR
authors.lastname: LaFrentz
authors.forename: K
authors.initials: K
authors.lastname: Cain
authors.forename: K R
authors.initials: KR
authors.lastname: Snekvik
authors.forename: D R
authors.initials: DR
authors.lastname: Call
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology; D024881:Drug Resistance, Bacterial; D005393:Fish Diseases / Q000276:immunology / Q000401:mortality; D045826:Flavobacteriaceae Infections / Q000276:immunology / Q000401:mortality / Q000662:veterinary; D005417:Flavobacterium / Q000235:genetics* / Q000276:immunology*; D015964:Gene Expression Regulation, Bacterial; D007114:Immunization / Q000662:veterinary; D020543:Proteome; D012293:Rifampin / Q000378:metabolism; D014774:Virulence / Q000235:genetics*
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D020543:Proteome; D012293:Rifampin