Figure 1. Lethality and Systemic B. anthracis Sterne Dissemination in A/J Mice.
A. A/J mice were orally gavaged with 105, 107, or 109 spores of the Sterne strain of B. anthracis. Lethal infection was established within 3 days in A/J mice receiving 109 spores; n = 10 mice/group (105 and 107), n = 20 mice/group (109). Experiments were performed a minimum of three times. Statistical significance was calculated using the log-rank test. After 3 days of infection, A/J mice were sacrificed; both spores and vegetative bacilli (marked with *) were observed in the colon (B), MLNs (C), spleen (D, E), liver (F), kidneys (G), lungs (H), and in bronchoalveolar lavage (BAL) fluid (I). Bar = .