Surface-disorganized, attenuated mutants of Aeromonas salmonicida as furunculosis live vaccines

• Published in: Microbial pathogenesis Vol. 11; no. 2; pp. 85 - 99
• Main Authors: Thornton, J.C., Garduño, R.A., Newman, S.G., Kay, W.W.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier India Pvt Ltd 01.08.1991; Elsevier
• Subjects: A. salmonicida; Aeromonas - chemistry; Aeromonas - pathogenicity; Aeromonas - physiology; Aeromonas salmonicida; Animals; Antigens, Surface - analysis; Antigens, Surface - immunology; attenuated vaccines; Bacterial Infections - immunology; Bacterial Vaccines; Bacteriology; Biological and medical sciences; Drug Resistance, Microbial - genetics; Fundamental and applied biological sciences. Psychology; furunculosis; Furunculosis - immunology; Furunculosis - microbiology; Microbiology; Mutation; Pisces; Salmon - immunology; Salmon - microbiology; Streptomycin - pharmacology; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Vaccines, Attenuated; Virulence - genetics; Virulence - immunology; furunculosis; A. salmonicida; attenuated vaccines; Immunoprotection; Oncorhynchus tshawytscha; Vaccination; Virulence; Furunculosis; Aeromonas salmonicida; Host agent relation; Vaccine; Infection; Vertebrata; Pisces; Bacteriosis; Bacteria; Vibrionaceae; Mutation; Attenuated strain
• ISSN: 0882-4010; 1096-1208
• DOI: 10.1016/0882-4010(91)90002-R

A slow-growing, aminoglycoside-resistant mutant and a rapidly-growing psuedorevertant 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 wildtype by the apparent loss of virtually all aerobic metabolism; the pseudorevertant 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 pseudorevertant, when administered either intraperitoneally or by immersion, effectively protected salmonid fish from challenge by a heterologous virulent strain suggesting its candidature as a live, attenuated furunculosis vaccine.