C3H/HeN mice were inoculated retro-orbitally with infectious B. burgdorferi strain B31-A3 with the vector pBSV2G (“B31-A3/Vector”), B31-A3ΔospC with the vector (“Vector”), or B31-A3ΔospC producing OspC from B31-A3 (“B31”), B. burgdorferi strain N40 clone D10/E9 (“N40-D10/E9”), or B. garinii strain PBr (“PBr”). After 1 hr, perfused tissues were collected and bacterial burdens were quantified by qPCR. Data are shown as the geometric mean ± 95% confidence interval. Statistical significance was determined using ANOVA with the Kruskal-Wallis test followed by the two-stage step-up method of Benjamini, Krieger and Yekutieli. * = P < 0.05, ** = P < 0.01, *** = P < 0.001. N = 10 or 15 mice per B. burgdorferi strain.