TABLE 3.
Infection of ticks with B. burgdorferi strains
| B. burgdorferi strain | No. of ticks infected with B. burgdorferi/total no. of ticks examineda
|
||
|---|---|---|---|
| Artificially infected larvae | Naturally infected larvae | Nymphal infectionb | |
| B31 A3 (wild type) | 6/6 | 9/9 | 8/10 |
| ΔD109 | 5/6 | 10/10 | 5/10 |
| ΔD117 | 1/2 | 15/15 | 3/6 |
a
Infection was assessed by IFA of tick midgut contents using polyclonal antiserum raised against B. burgdorferi. Ticks were artificially infected by immersion (42), allowed to feed on mice, and then examined. Naturally infected larvae acquired B. burgdorferi by feeding on infected mice and were examined within 3 days after detachment from the host.
b
Ticks were artificially infected as larvae, fed, and followed through the molt. Nymphs were assessed for infection after feeding.