FIG. 2.

Macroscopic motility test in dense medium. (A) Plate after 3 days of incubation. A liquid culture (0.1 μl) of each sample was spotted on a 0.5% agarose–NOS plate and incubated at 36°C. 1, T. denticola wild type; 2, T. denticola CfpA-deficient mutant; 3, T. denticola fliK flagellar filament-less mutant (30). (B) T. denticola wild-type from a 3-day plated culture spread in agarose and propagated. Vertical section of the plate with side illumination. Bar, 1.5 mm. (C) Plate after 7 days of incubation, same strains as in panel A. (D) Vertical section of the plate with side illumination. Bar, 1 mm. T. denticola CfpA-deficient mutant from a 7-day plated culture does spread in the agarose but in a more limited volume. (E) Vertical section of the plate with side illumination. Bar, 1 mm. T. denticola fliK flagellar filament-less mutant from a 7-day plated culture was nonmotile and did not spread in the agarose. The vertical section photographs of the plate with side illumination were obtained using an SZ40 stereo microscope with a 35-mm camera mounted on a PM-20 exposure control unit (Olympus, Melville, N.Y.).