Evaluation of the live vaccine efficacy of virulence plasmid-cured, and phoP- or aroA-deficient Salmonella enterica serovar Typhimurium in mice

• Published in: Journal of Veterinary Medical Science Vol. 77; no. 2; pp. 181 - 186
• Main Authors: MATSUI, Hidenori, ISSHIKI, Yasunori, EGUCHI, Masahiro, OGAWA, Yohsuke, SHIMOJI, Yoshihiro
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 01.01.2015; Japan Science and Technology Agency; The Japanese Society of Veterinary Science
• Subjects: Administration, Oral; Animals; aroA; Bacterial Proteins - immunology; Bacteriology; BALB/c mouse; Gene Deletion; Immunoglobulin A - blood; Immunoglobulin G - blood; Mice; Mice, Inbred BALB C; oral vaccine; phoP; Plasmids - genetics; Plasmids - metabolism; Salmonella enterica; Salmonella enterica serovar Typhimurium; Salmonella Infections, Animal - blood; Salmonella Infections, Animal - prevention & control; Salmonella typhimurium; Salmonella typhimurium - genetics; Salmonella Vaccines - immunology
• ISSN: 0916-7250; 1347-7439
• DOI: 10.1292/jvms.14-0013

We evaluated the protective efficacy of 94-kb virulence plasmid-cured, and phoP- or aroA-deficient strains of Salmonella enterica serovar Typhimurium (ΔphoP or ΔaroA S. Typhimurium) as oral vaccine candidates in BALB/c mice. Two weeks after the completion of 3 oral immunizations with 1 × 108 colony-forming units (CFU) of virulence plasmid-cured, and ΔphoP or ΔaroA S. Typhimurium at 10-day intervals, S. Typhimurium lipopolysaccharide (LPS)-specific mucosal secretory immunoglobulin A (s-IgA) antibody titers were detected in the cecal homogenate, bile and lung lavage fluid, but not in the intestinal lavage fluid. In addition, the increases in S. Typhimurium LPS-specific immunoglobulin G (IgG) and IgA antibody titers in the serum were also observed 2 weeks after completing 3 oral immunizations with virulence plasmid-cured, and ΔphoP or ΔaroA S. Typhimurium. The series of 3 oral immunizations protected the mice against an oral challenge with 5 × 108 CFU of the virulent strain of S. Typhimurium, suggesting that both the virulence plasmid-cured, and ΔphoP and ΔaroA S. Typhimurium strains are promising candidates for safe and effective live S. Typhimurium vaccines.