TABLE 2.
Experimental mouse/tick/mouse infection cyclea
| Strain | No. positive for infection/total no. (%)
|
|||||
|---|---|---|---|---|---|---|
| Larvaec
|
Molted nymphsd
|
Micee | ||||
| 1 wk | 2 wk | 3 wk | Unfed | Fed | ||
| B31-A3 or B31-C1b | 104/108 (96.3) | 76/82 (92.7) | 70/71 (98.6) | 27/27 (100) | 28/29 (96.6) | 3/3 (100) |
| A3-pB | 0/93 (0)* | 0/41 (0)* | ND | 0/54 (0)* | 0/59 (0)* | 0/4 (0) |
| A3-pB22 | 121/135 (89.6)* | 72/93 (77.4)* | 21/35 (60)* | 3/51 (5.9)* | 6/53 (11.3)* | 0/4 (0) |
a
Data are pooled from three separate experiments. ND, not determined. *, tick infection mean was significantly different than the infection mean of ticks that fed on B31-A3-injected or B31-C1-injected mice for each column (P < 0.05, Fisher's exact test).
b
B31-A3 was used in the first and third repeats of the experiment, while B31-C1 was used in the second repeat of the experiment.
c
Larvae were tested for infection at 1, 2, and 3 wk after placement on needle-inoculated mice.
d
Nymphs were tested for infection 1 wk after molt as unfed nymphs, as well as 2 wk after molt after feeding to repletion on naïve mice.
e
Mice were sacrificed and tested for infection 3 wk after being fed on by molted nymphs.