title: Capsulated cells of Aeromonas salmonicida grown in vitro have different functional properties than capsulated cells grown in vivo.
abstract: When grown in vivo in the peritoneal cavity of rainbow trout, Aeromonas salmonicida produces a clearly defined capsule with virulence-related functions. Aeromonas salmonicida grown in vitro in a glucose-rich medium (GRM) has also been reported to reproduce capsular material. Because in vitro mimicry of in vivo induced traits is highly desirable in vaccine design, the extent to which growth in GRM mimicked in vivo growth was examined. Antibodies specific to in vivo grown cells partially labeled the surface of GRM-grown cells, as well as two distinct proteins (81,700 and 41,000 Mr) in immunoblots of mutants with S-layer or lipopolysaccharide defects. GRM-grown strains showed an increased sensitivity to trout serum in contradistinction to the complete serum resistance of in vivo grown cells; as well, GRM-grown cells were more adherent to trout macrophages. Thus in spite of possessing some surface antigens normally expressed in vivo, cells grown on solid GRM did not possess all functional properties of in vivo grown cells.
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, BC, Canada.
authors.forename: R A
authors.initials: RA
authors.lastname: Garduño
authors.forename: W W
authors.initials: WW
authors.lastname: Kay
mesh_terms: D000333:Aeromonas / Q000254:growth & development* / Q000276:immunology / Q000502:physiology; D000818:Animals; D001422:Bacterial Adhesion; D016667:Bacterial Capsules / Q000096:biosynthesis / Q000276:immunology / Q000502:physiology*; D001770:Blood Bactericidal Activity; D003470:Culture Media; D015151:Immunoblotting; D007150:Immunohistochemistry; D008264:Macrophages / Q000382:microbiology; D017686:Oncorhynchus mykiss / Q000097:blood / Q000382:microbiology
chemical_list: D003470:Culture Media