Three Types of Small Oral Spirochetes

Thirty strains of human oral anaerobic spirochetes were isolated in three different media: veal heart infusion-ascitic fluid, Spirolate-Brain Heart Infusion-rabbit serum, and supplemented PPLO broth. The morphological and biochemical characteristics of the isolates permitted their differentiation into three distinct species: Trepoifema denticola, T. macrodentium, and T. oralis (proposed new species). These species could be differentiated as follows. Organisms of the T. denticola type had a "2-4-2" axial fibril relationship as determined by electron microscopy, required serum for growth, did not utilize glucose or lactate, and produced indole, ammonia, acetate, and lactate as end products. T. macrodentiwm had a "1-2-1" axial fibril relationship, did not require serum, utilized 1ucose but not lactate, did not produce indole