Strains that produce atypical results from these tests require additional analysis before they can be classified as B . cereus . Tests for differentiating members of the B . The following tests are useful for differentiating typical strains of B . Motility test . Inoculate BC motility medium by stabbing down the center with 3 mm loopful of 24 h culture suspension.
Motile organisms produce diffuse growth out into the medium away from the stab.
Nonmotile organisms produce growth only in and along stab. Alternatively, add 0.2 ml sterile distilled water to surface of nutrient agar slant and inoculate slant with 3 mm loopful of culture suspension. Apply cover glass and examine immediately with microscope for motility. Report whether or not isolates tested were motile. Most strains of B .