Some properties of the pili of Corynebacterium renale.

Some properties of the pili of the gram-positive bacteria Corynebacterium renale were described. A relationship was found between the morphological features of pili and the types of C. renale. Strains of types I and III usually possessed a small number of pili, whereas those of type II possessed numerous pili. Thick and long bundles of pili characteristic of C. renale were frequently observable in type II strains. Piliation of C. renale was stable under various cultural conditions. No ability to agglutinate red blood cells was demonstrated by piliated strains of C. renale. Pili were isolated from the cells of C. renale and studied serologically by immunodiffusion. The pili of a type II strain were serologically identical with the pili of another type II strain but not with those of the strains belonging to types I and III. The pili were serologically distinct from the cell wall. The pili were broken into short pieces by boiling, but their antigenicity was increased after boiling.