Nutrient and environmental growth factors for nine oral small-sized spirochete strains containing one endoflagellum...

The present investigation was carried out in order to obtain better information about the growth requirements of small-sized spirochetes containing one endoflagellum from each cell end. Nine strains of such spirochetes were isolated from subgingival plaque in patients suffering from advanced marginal periodontitis. The strains were maintained in fluid NOS medium with 0.07% Noble Agar. The following environmental factors were studied: Oxygen in the incubation atmosphere and the pH value of the medium. The following nutrient factors were studied: Rabbit serum, heart infusion and trypticase, bovine albumin, human globulin, long-chain fatty acids, volatile fatty acids, steroids, amino acids, carbohydrates, and Na-bicarbonate. Growth was normally determined after 3 days' incubation at 35 degrees C by counting numbers of spirochete cells in a Petroff-Hausser counting chamber. All strains tolerated 3% oxygen in the atmosphere and the pH-optimum was 7.5. Rabbit serum was found not to be an essential nutrient factor. Human globulin stimulated growth, while bovine albumin inhibited growth. Heart infusion and trypticase influenced growth moderately. Of the remaining nutrient factors the long-chain fatty acids inhibited growth and the volatile fatty acids did not affect growth, while certain carbohydrates, especially glucose, stimulated growth. Na-bicarbonate in low concentrations stimulated growth, while higher concentrations inhibited growth.