Figure 1.
Infection, persistence, and replication of Francisella tularensis (Ft) in ticks after feeding on mice infected with 105 CFU. Nymphal Dermacentor variabilis (Dv), Amblyomma americanum (Aa), and Haemaphysalis longicornis (Hl) ticks were placed onto non-infected C3H/HeN mice (day 5), the ticks fed for 3 days, mice were i.v. infected with 105 CFU of Ft LVS (day 2), and replete ticks were harvested 2–3 days later (day 0; 5–6 day total blood meal). Following tick harvest (day 0 ticks), blood was collected and plated from infected mice (day 0 mouse blood; n = 6–9/tick species/experiment) to enumerate bacterial numbers (CFU/mL blood). At the indicated time points, individual ticks (n = 6–9/tick species/experiment) were homogenized and plated to enumerate bacterial numbers (CFU/tick). Two independent experiments were performed to confirm reproducibility, with combined data shown. One-way ANOVA was used to compare groups of mice or ticks at each time point: n.s. indicates not significant; * indicates p < 0.05; **** indicates p < 0.0001.