Test of the virulence and live-vaccine efficacy of auxotrophic and galE derivatives of Salmonella choleraesuis.

Abstract

Aromatic compound-dependent (aro) derivatives of three mouse-virulent strains of Salmonella choleraesuis (Salmonella cholerae-suis) were constructed and shown to be nonvirulent for mice (intraperitoneal [i.p.] 50% lethal dose [LD50], greater than 5 X 10(6) CFU). A pur derivative, and a thy derivative, each of a different virulent parent, remained moderately virulent (i.p. LD50S for BALB/c mice, ca. 10(5) and 5 X 10(4) CFU, respectively). Tested as live vaccines i.p., the aro strains were ineffective in salmonella-susceptible BALB/c and C57BL/6 mice but were somewhat effective in salmonella-resistant CBA/J mice and in outbred CD-1 mice. The pur and thy strains were effective as live vaccines in BALB/c mice when given in sublethal doses. Two previously isolated nonvirulent galE derivatives of S. choleraesuis (i.p. LD50 in BALB/c mice, greater than 10(6) CFU) were also ineffective as live vaccines in BALB/c and C57BL/6 mice. The main antigenic difference between S. choleraesuis (O-6,7) and S. typhimurium (O-4,12) is in O-antigen character, thought to largely determine the specificity of protection in salmonellosis. Paired, nearly isogenic O-6,7 and O-4,12 derivatives were constructed from an aro S. typhimurium strain of proven efficacy as a live vaccine. Used as live vaccines, the O-4,12 member protected BALB/c mice against challenge with virulent S. typhimurium, whereas the O-6,7 member did not protect against virulent S. choleraesuis. However, BALB/c mice vaccinated with the O-6,7 member and mice vaccinated with an aro S. choleraesuis strain were protected against challenge with a moderately virulent (LD50, 5 X 10(4) CFU) O-6,7 derivative of an S. typhimurium strain.

• Authors: N A Nnalue, B A Stocker
• Journal: Infection and immunity (Infect Immun) Vol. 55 Issue 4 Pg. 955-62 (Apr 1987) ISSN: 0019-9567 [Print] United States
• PMID: 3104209 (Publication Type: Journal Article)

Chemical References

• Bacterial Vaccines
• Galactose

Topics

• Animals
• Bacterial Vaccines (immunology)
• Galactose (genetics)
• Mice
• Mice, Inbred Strains
• Mutation
• Paratyphoid Fever (immunology, microbiology)
• Salmonella (immunology, pathogenicity)
• Swine
• Swine Diseases (immunology, microbiology)