Fig. 4.

ID₅₀ analysis of B. burgdorferi clones. Probit regression on adjusted spirochete doses was used to estimate the ID₅₀ of B. burgdorferi clones. The plot represents the probability of infection versus the base 10 logarithm of the adjusted dose. Mouse infection data from both the ID₅₀ and single dose experiments were included. Actual doses of the different inocula were adjusted for both the observed colony-forming units following plating on solid medium and the proportion of the B. burgdorferi population harbouring both lp25 and lp28-1. The point size is proportional to the number of mice inoculated at different target doses.