Starch Reaction as Aid in Identification of Causative Agent of "European Blastomycosis."

Abstract

A non-fermenting yeast may be classified as Torulopis neoformans if it produces extracellular starch on the medium described below and grows well between 37[degree] and 40[degree]C. Yeasts isolated from cases suspected of blastomycosis are transferred to a synthetic medium composed as follows: (NH4)2SO4 0.1%, MgSO4 0.05%, KH2PO4 0.1%, glucose 1%, thiamin 0.2 mcg. per ml., agar 2.5%. After several days of incubation the plate is flooded with Lugol''s iodine soln. In positive cases the whole streak of growth turns blue.