Abstract
Two cultures of Clostridium botulinum were sent to this laboratory in March, 1936, by Dr. L. Bier of the Bacteriologic Institute at Dniepropetrowsk, Ukraina, U.S.S.R. Toxin-neutralization tests had suggested a new type. The original cultures were toxic for mice in doses of 0.001 cc. and antitoxin of types A, B, C and D failed to protect against the the toxin.
The organism is a Gram positive, motile, granular, pleomorphic rod and forms oval, subterminal spores which swell the rods very slightly. In liver-agar shake-cultures small, disc-like colonies with or without small polar fluffs are formed. Colonies on the surface of glucose blood plates are non-hemolytic, greyish, translucent, smooth and flat with a marked tendency toward confluence.
These cultures are not ovolytic and do not liquefy coagulated egg-white even after a month's growth. In beef heart medium there is slight reddening of the meat and a large volume of gas is evolved. Brain is not blackened or digested. In milk, slight acid is produced but the casein is not attacked. Slight liquefaction of gelatin occurred after 23 days. The peptolytic properties are extremely low and the Sörenson figure was 2.00 after 21 days' growth.
Dextrose, levulose, maltose, sucrose, arabinose, xylose and adonite are fermented with little or no gas production in a medium composed of 0.3% Liebig's extract, 0.5% Difco peptone, and 1% carbohydrate. Lactose, rhamnose, galactose, dextrin, raffinose, glycerin, salicin, mannite, inulin and dulcite are not fermented.
The thermal resistance of the spores is extremely low. Spores were destroyed in a suspension in buffer solution (pH 7.4) containing 5 million spores per cc. after heating at 100°C. for 2 minutes or 80° C. for 6 minutes. A suspension containing 50 million spores per cc. failed to show growth after 5 minutes at 100°C. or after 40 minutes at 80°C.
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