FIGURE 3.

The effect of ciprofloxacin, CFI or DRCFI prophylaxis on bacterial burden in a mouse model of inhalational Y. pestis infection. BALB/c mice (n = 5/group) were challenged via the aerosol route with approximately 1 × 10⁴ CFU Y. pestis CO92 and treated 24 h post-challenge with a single dose of 30 mg/kg intraperitoneal (IP) ciprofloxacin, 300 μl IP PBS, aerosolized empty liposomes (2.8 mg/kg lipid), 1 mg/kg lung dose of aerosolized CFI or DRCFI (2.7 and 3.2 mg/kg lipid, respectively). Graphs show bacterial burden in lung and spleen at onset of clinical signs in control groups (approximately 2.5 days post-challenge). Lines connect spleen and lung loads from the same animal. LOD indicates samples which were below the limit of detection. Asterisks indicate significant differences in bacterial burden compared to the relevant control (i.e., CFI compared to empty liposomes, IP ciprofloxacin compared to IP PBS), ^∗for P < 0.05.