Brucella abortus deficient in copper/zinc superoxide dismutase is virulent in BALB/c mice.
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.
Latimer
E
E
Department of Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg 24061.
Simmers
J
J
Sriranganathan
N
N
Roop
R M
RM
Schurig
G G
GG
Boyle
S M
SM
D000818:Animals; D015139:Blotting, Southern; D015153:Blotting, Western; D002003:Brucella abortus / Q000201:enzymology / Q000235:genetics / Q000472:pathogenicity*; D002006:Brucellosis / Q000382:microbiology; D003001:Cloning, Molecular; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D013482:Superoxide Dismutase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D014774:Virulence / Q000235:genetics
D013482:Superoxide Dismutase