RAPID METHODS FOR THE DETECTION OF MOTILITY

When small tubes (75 by 10 mm), containing 1 or 2 ml of SIM medium (Difco) or Trypticase Agar Base (semisolid) (BBL), are preheated to 37 C, "stabinoculated" from a young agar slant culture, and incubated in a water bath at 37 C, motility may be observed in a fraction of the time required by the methods usually employed with these media. In a series of cultures which were studied, motility could be determined usually within 90 to 120 minutes. When small tubes (75 by 10 mm), containing 1 ml of nutrient broth, are preheated to 37 C and heavily inoculated from young nutrient agar slants or from colonies growing on agar plates, motility can be observed in hanging drop preparations within 15 to 30 minutes. In some cases, the freshly inoculated tubes may show motility.