Abstract
Two filamentous organisms were screened from bacterial plaque by the use of propionate medium containing propionic acid in a concentration of 0.5% in common nutrient agar adjusted to pH7.0. The first one, which grew in a spider form colony, stained gram positive and showed characteristic granular growth and produced a mucinous precipitate in broth. Soluble starch was quickly hydrolized to produce acid. In spite of colonial similarity to Bacterionema matruchotti, their biological characteristics would be close to Odontomyces viscosus. This was conveniently called“ Granular organism” by this department. The heat killed cells were capable of producing skin lesions, by either Schwartzman or Arthus procedure, in rabbits, guinea pigs, and rats. Another colony, having a hair-pencil appearance, stained gram negative and developed long straight filaments. These should be idenifiable to Leptotrichia species, but extreme difficulty in producing pure stock cultures prohibited obtaining enough descriptive information for their taxonomy.
