Vaccination with Live Escherichia coli Expressing Brucella abortus Cu/Zn Superoxide Dismutase Protects Mice against Virulent B. abortus

Vaccination of mice with Escherichia coli expressing Brucella Cu/Zn superoxide dismutase (SOD) [E. coli(pBSSOD)] induced a significant level of protection against virulent Brucella abortus challenge, although this level was not as high as the one reached with B. abortus vaccine strain RB51. In addition, vaccination with E. coli(pBSSOD) induced antibodies to Cu/Zn SOD and a strong proliferative response of splenocytes when stimulated in vitro with a thioredoxin-Cu/Zn SOD fusion protein.