title: Surface-disorganized, attenuated mutants of Aeromonas salmonicida as furunculosis live vaccines.
abstract: A slow-growing, aminoglycoside-resistant mutant and a rapidly-growing pseudo-revertant were isolated from Aeromonas salmonicida, the causative agent of salmonid furunculosis. These mutants continued to elicit a variety of classical virulence factors associated with A. salmonicida pathogenesis. They differed morphologically from the wild-type and from one another with respect to A-layer organization, membrane antagonist sensitivity and particularly to aerobic metabolism. Both mutants were drastically altered in the architecture of the 2D crystalline surface array (A-layer), although both were similar to wild-type with respect to cell surface composition. The slow-growing, antibiotic-resistant mutant differed significantly from the wild-type by the apparent loss of virtually all aerobic metabolism; the pseudo-revertant had partially recovered the ability to aerobically metabolize certain carbon sources. Both mutants were avirulent and incapable of tissue persistence. The rapidly-growing, antibiotic-sensitive pseudo-revertant, when administered either intraperitoneally or by immersion, effectively protected salmonid fish from challenge by a heterologous virulent stain suggesting its candidature as a live, attenuated furunculosis vaccine.
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada.
authors.forename: J C
authors.initials: JC
authors.lastname: Thornton
authors.forename: R A
authors.initials: RA
authors.lastname: Garduño
authors.forename: S G
authors.initials: SG
authors.lastname: Newman
authors.forename: W W
authors.initials: WW
authors.lastname: Kay
mesh_terms: D000333:Aeromonas / Q000737:chemistry / Q000472:pathogenicity / Q000502:physiology*; D000818:Animals; D000954:Antigens, Surface / Q000032:analysis / Q000276:immunology; D001424:Bacterial Infections / Q000276:immunology; D001428:Bacterial Vaccines; D004352:Drug Resistance, Microbial / Q000235:genetics; D005667:Furunculosis / Q000276:immunology* / Q000382:microbiology; D009154:Mutation; D012474:Salmon / Q000276:immunology* / Q000382:microbiology; D013307:Streptomycin / Q000494:pharmacology; D014613:Vaccines, Attenuated; D014774:Virulence / Q000235:genetics* / Q000276:immunology
chemical_list: D000954:Antigens, Surface; D001428:Bacterial Vaccines; D014613:Vaccines, Attenuated; D013307:Streptomycin