FIG. 2.

Time of administration of PEN G (62.5 mg/kg i.m.) (A) or OFX (40 mg/kg i.p.) (B) for 7 days and rates of survival from B. anthracis Sterne challenge (7.8 × 10⁸ CFU i.t.) in ⁶⁰Co γ-irradiated (7 Gy) mice. Therapy was started 6, 24, 48, or 72 h after challenge. Significant comparisons were as follows: P < 0.01 for the control versus PEN G started at 6 h, OFX started at 6 h, PEN G started at 24 h, and OFX started at 24 h; P < 0.05 for the control versus OFX started at 48 h; P < 0.05 for PEN G started at 48 h versus PEN G started at 24 h, OFX started at 24 h versus OFX started at 6 h, OFX started at 48 h versus OFX started at 24 h, and OFX started at 72 h versus OFX started at 48 h.