Figure 3.

Transmission of Ft from infected Dv and Aa ticks to naïve mice. Ft-infected Dv and Aa adult ticks were prepared as described for the 10⁷ CFU infection studies (Figure 2). After 14 weeks, Ft-infected Dv and Aa adult ticks, together with an uninfected adult male tick of the same species, were individually placed onto naïve C3H/HeN mice and ticks were allowed to take a blood meal until replete (7–12 days). Upon repletion (day 0), ticks were harvested, and a small volume of mouse blood was collected from each mouse via retro-orbital bleeding to enumerate bacterial burdens in mice. Mice were monitored daily for signs of disease and humanely euthanized when moribund (within 2 days of tick repletion). Upon euthanasia, mouse blood and the indicated tissues (skin at attachment site, lungs, livers, and spleens) were collected and plated to enumerate bacterial numbers. Student’s t-test was used to compare bacterial numbers in blood samples or indicated samples: n.s. indicates not significant.