YBX1 and infection: As previously observed [31], [34], [44], the kinetics of colonization by B. burgdorferi producing DbpA and DbpB varied with tissue: the bladder and joints were colonized by day 7 post-infection whereas the heart and ear were detectably colonized only at the 14 and 21-day time point, respectively (Figs. 3, 5 and Fig. S5; for comprehensive summary of bacterial loads at all times points, see Table S1).