Studies of Corynebacterium Isolated from Non-exposed Human Pulp Canals

¹ Department of Bacteriology and Pathology, College of Physicians and Surgeons, School of Dentistry, San Francisco, California

The pathogenicity of 14 strains of Corynebacterium isolated from non-exposed pulp canals was studied.

Of the mice inoculated intraperitoneally with the organisms, 23.3 per cent developed local lesions of the peritoneum at the site of injection, and 50.4 per cent showed gross and histopathologic changes in the liver.

Rabbit abdomens inoculated intracutaneously with the organisms developed localized lesions which healed spontaneously without draining.

Rabbit abdomens exposed to hard and soft roentgen rays before inoculation of the organisms developed fiery-red and sharply raised lesions. These lesions opened and drained spontaneously before healing. Histopathologically, they were shown to be poorly circumscribed and multiple.

Inoculation of heat-killed cells produced small lesions at the sites of inoculation.

Intracutaneous inoculations of saline suspensions of acetone-extracted cells and of filtrates from 1-, 2-, and 4-week cultures elicited slight reactions. These responses did not occur with any regularity.