Table 3. Borrelia burgdorferi strains used in this study.

B. burgdorferi strain	Description	Source or reference
A3	B31 isolate with all infection-associated plasmids capable of transformation	[50], [71]
MSK5	B31 isolate with all infection-associated plasmids	[49]
ML23	B31 isolate lacking lp-25; non-infectious	[49]
TR1	ML23 transformed with pTR1	This study