FIG. 1.

ΔlysA ΔpanCD mutant of M. tuberculosis (mc²6020) is severely attenuated in immunocompromised and immunocompetent mice. (A) Southern blot demonstrating the loss of the panCD loci from an unmarked ΔlysA mutant of M. tuberculosis. Lane 1 represents the genomic DNA from an unmarked ΔlysA auxotroph of M. tuberculosis, and lanes 2 and 3 represent the genomic DNAs from two independent lysine-pantothenate double auxotrophs of M. tuberculosis. The sizes of the expected hybridization products are shown on the right of the blot. (B) Survival of immunocompetent BALB/c mice (n = 17) infected intravenously with H37Rv (○) or mc²6020 (•). (C) Growth of mc²6020 in the spleens (Sp) and lungs of immunocompetent C57BL/6 mice during the early phase of infection. (D) Survival of SCID mice (n = 10) infected intravenously with H37Rv (○) or mc²6020 (•). (E) Survival of GKO C57BL/6 mice (n = 10) infected intravenously with H37Rv (○), the mc²6020 mutant (•), or M. bovis BCG-P (▴).