FIG 5.

Loss of bbk13 results in deficient spirochete expansion at the skin inoculation site during early infection. Spirochete load kinetics at the skin inoculation site were determined by qPCR at different time points after intradermal inoculation of groups of 6 C3H/HeN mice with 10⁴ spirochetes of the WT, Δbbk13, or Δbbk13/bbk13⁺ clone, as described in the legend to Fig. 2. The data are presented as the number of flaB copies per 10⁶ nid copies. Early kinetics were determined by quantitating the spirochete loads in the skin inoculation sites on days 0, 1, 3, 5, and 7 postinoculation. Columns and error bars represent the mean ± standard deviation. Two-way ANOVA and Tukey’s multiple-comparison test were used to test for statistical significance compared to the results for the WT (**, P < 0.001).