Figure 2.

Desipramine bacteriostatically limits A. phagocytophilum infection in immunocompetent mice. (A, B) Twenty C57BL/6 (Wt) mice were intraperitoneally injected with 1 × 10⁸  A. phagocytophilum bacteria followed by the administration of desipramine or PBS on days 7 through 12 to 10 mice per group. Mice were tail bled on days 0 (pre-challenge), 4 and 8. The mice were euthanized and blood collected on day 12 via cardiac puncture. Peripheral blood smears were microscopically examined for neutrophils containing ApVs. (A, C) Heparin-treated blood from all desipramine- or PBS-treated mice was pooled. One hundred microliters of pooled blood was transferred to naïve C57BL/6 SCID mice such that 10 received blood from infected desipramine-treated mice and 10 received blood from infected PBS-treated mice. Infection was monitored by examination of smears from peripheral blood obtained from the SCID mice on days 0, 4, 8, 12, 16, 21 and 28 post-injection. Each symbol corresponds to the percentage of A. phagocytophilum-infected neutrophils as determined by examining at least 100 neutrophils per mouse. Data are the mean ± SD of the percentages determined for 10 mice per group. Error bars indicate SD among the samples per time point. Statistically significant values are indicated. ^****P < 0.0001.