The Isolation of an Actinomycetes-like Organism from Root Canals'

The actinomycetes are a group of fungi, usually classified as hypomycetes, probably bearing a relationship to the acid fast and diphtheroid groups of bacteria. The organisms are commonly found in the soil, and certain types may produce lesions in animals and man. In man the type most often isolated from lesions is Actinomycetes bovis with primary lesions about the head and neck in approximately half the cases studied. The infection in man is commonly called "lumpy jaw," characterized by a purulent discharge containing "sulfur granules" and the formation of sinuses and granulation tissue. At the periphery of the lobulated granules are radiating clubs, composed of mycelia slightly thicker at the tip, surrounded by sheaths which take the acid rather than basic dyes. The name "ray fungus" has been given to the actinomycetes because of the appearance of the granules, when examined under the microscope. The club forms are usually seen in tissues, although a few workers have reported formation of clubs in artificial media (1, 2). The granules when crushed and stained are seen to be made up of extremely fine, branching gram positive filaments. When first isolated, the organisms grow best under anaerobic or partially anaerobic conditions: but upon further cultivation most strains will grow aerobically on suitable media. The mode of infection of the disease is not exactly clear. It is more common among farmers and those who handle grains, straw, etc. For this reason it is thought that the organisms are carried on grains and other vegetable matter to the mouth. The infection in cattle and in man is believed to be caused by the same organism. Wright (3) suggested that Actinomycetes bovis was a normal inhabitant of the secretions of the buccal cavity and intestinal tract, both