FIG 1.

Experimental approach to assay host superinfection by homologous and heterologous B. burgdorferi. (A) Schematic for the general two-step approach to assay for host superinfection by B. burgdorferi. First, groups of mice were needle inoculated with either the B31 or 297 wild-type strain. The establishment of infection was confirmed by culturing blood taken at day 7 postinfection and ear skin tissues sampled weekly afterwards. At day 6, 13, 21, or 28 postinfection, mice were superinfected with either homologous or heterologous B. burgdorferi via needle inoculation or tissue transplantation. Blood, ear, heart, bladder, and tibiotarsal joint tissues were collected at the indicated time points and cultured in the presence of the appropriate antibiotic to assess the outcome of superinfection. (B and C) Flow chart of superinfection experiments involving homologous (B) or heterologous (C) B. burgdorferi. T, T cell; B, B cell; comp, host complement; ha, host adapted.