Fig. 4.

lp6.6 mutant B. burgdorferi displays no defects in its ability to enter and persist in ticks. Mice were infected with B. burgdorferi (two mice per group) and following 12 days of infection, naïve I. scapularis larvae or nymphs (25 ticks per group) were allowed to feed on mice, and B. burgdorferi burdens in ticks were analysed at the indicated time intervals following feeding by measuring copies of the B. burgdorferi flaB RNA. Amounts of tick β-actin mRNA were determined in each sample and used to normalize the quantities of spirochete RNA. The bars represent the mean values and the error bars represent the SEM values from two independent experiments. Burdens of wild type and lp6.6 mutant are similar at all time points (P > 0.05).