Partially Defined Medium for the Cultivation of Borrelia vifcentii

The recognition and evaluation of the physio-logical activities of Borrelia vincentii are de-pendent upon the formulation of a more re-producible medium for its cultivation. A defined medium, developed by Steinman et al. (1952) was adequate for the growth of the Reiter treponeme, but would not support the growth of several other varieties of spirochetes (Hampp, 1957). More recently, B. vincentii has been cultivated in a veal heart infusion medium wherein five coenzymes and glucose-i-phosphate were sub-stituted for the ascitic fluid enrichment (Hampp and Nevin, 1959). The infusion medium could not be used for more definitive studies, however, since erratic, submaximal growth occurred frequently when any one of the required factors was omitted. Thus a simple reproducible basal medium has been devised which, although requiring an ascitic fluid enrichment, is suitable for further experimentation. Moreover, require-ments for several nutrilites have been established. MATERIALS AND METHODS The medium consisted of 1 per cent "Vitamin Free " Casamino acids (Difco),2 10 mg per cent L-tryptophan, 0.5 per cent K2HP04, and 0.25 per cent glucose. A mineral supplement included MgS04 *7H20, 8 mg; FeS04- 7H20, 0.4 mg; and MnCl2, 0.12 mg; per L of complete medium. Added also was a mixture of known vitamins containing riboflavin, biotin, thiamin-HCl, folic acid, niacin, niacinamide, calcium pantothenate, pyridoxine, pyridoxamine, and pyridoxal. Each was supplied at 1,ug per ml final concentration. These materials were com-bined, adjusted to pH 7.5, and brought to 2 the desired final volume. Ten-ml samples wer