FIG. 5.

Histological examination of joints from C3H/HeN mice infected intradermally with 10³ spirochetes per mouse. The tibiotarsal joints were collected 62 days postinfection, processed as described in Materials and Methods, and stained with hematoxylin and eosin. The joint-tissue samples are from mice inoculated with phosphate-buffered saline (mock), the wt (ML23/pBBE22; n = 3), or the mt (MM4/pBBE22; n = 3). Note the presence of increased levels of infiltration in joint tissue of mice (samples 1 and 2) inoculated with the mt compared to that of mice inoculated with the wt, as indicated by arrows.