In spirillary rat-bite fever, diagnosis can be made by examining blood or a sample of tissue from the wound for evidence of Spirillum minus.
Bacillus subtilis, Cohn, and Spirillum undula, Ehrenb.
Spirillum containing many spores (a), which are liberated at b by the breaking up of the parent cells.
If the sinuosity is slight we have the Vibrio form; if pronounced, and the spiral winding well marked, the forms are known as Spirillum, Spirochaete, &c. These and similar terms have been applied partly to individual cells, but more often to filaments consisting of several cells; and much confusion has arisen form the difficulty of defining the terms themselves.
Divisions perpendicular to the long axis: - Vibrio (Muller-Ldffler), commashaped, motile, monotrichous; Spirillum (Ehrenb.), more strongly curved in open spirals, motile, lopho trichous; Spirochaete (Ehrenb.), spirally coiled in numerous close turns, motile, but apparently owing to flexile movements, as no cilia are found.