Brucella abortus deficient in copper/zinc superoxide dismutase is virulent in BALB/c mice

• Published in: Microbial pathogenesis Vol. 12; no. 2; p. 105
• Main Authors: Latimer, E, Simmers, J, Sriranganathan, N, Roop, 2nd, R M, Schurig, G G, Boyle, S M
• Format: Journal Article
• Language: English
• Published: England 01-02-1992
• Subjects: Animals; Blotting, Southern; Blotting, Western; Brucella abortus - enzymology; Brucella abortus - genetics; Brucella abortus - pathogenicity; Brucellosis - microbiology; Cloning, Molecular; Mice; Mice, Inbred BALB C; Mutation; Superoxide Dismutase - deficiency; Superoxide Dismutase - genetics; Superoxide Dismutase - metabolism; Virulence - genetics
• ISSN: 0882-4010
• DOI: 10.1016/0882-4010(92)90113-3

The gene encoding the Cu/Zn superoxide dismutase (SOD) of Brucella abortus strain 2308 was identified in a Brucella genomic library utilizing a combination of Western blotting and native gel electrophoresis. The Cu/Zn SOD gene was inactivated in vitro by ligation of a kanamycin resistance gene into the open reading frame encoding SOD. The plasmid born construct was introduced back into B. abortus by electroporation. Replacement of the wild-type Cu/Zn SOD by recombination was demonstrated by showing that both the KnR gene and the Cu/Zn SOD gene hybridized to the same band in a Southern analysis of genomic DNA. In addition, KnR strains were deficient in Cu/Zn SOD activity as assessed by lack of Cu/Zn SOD activity on a native gel and by lack of reactivity with specific serum in a Western analysis. Either strain 2308 or the Cu/Zn SOD deficient mutant injected intraperitoneally into BALB/c mice, exhibited no differences in their ability to colonize the spleen at 7 and 28 days post-inoculation. Thus, the inability to produce Cu/Zn SOD by B. abortus does not significantly impair its virulence in mice.