Fig. 7.

Immunofluorescence assays (IFAs) of immersed larval ticks 7 days postfeeding. Spirochetes were detected in the wild-type, plzA mutant, and complemented plzA⁺ strains; however, this is the only tick in which several B. burgdorferi plzA mutant cells were detected. In nearly all ticks infected with plzA mutant spirochetes by immersion, no spirochetes were detected by IFA 7 days postfeeding (n = 15).