Twelve per cent dextrose media for prolonged anerobe growth.

Abstract

The following easily prepared media permits the vigorous growth of several strains of a typical anerobe, the bacillus of symptomatic anthrax (B. gangraenae emphysematosae, or B. chauvei) for 30 or more days.

Composition of media:

water 7000 cc.

liver, hog 2500 gm.

peptone 80 gm.

Ringer salt 40 gm.

chalk 350 gm.

dextrose 1000 gm.

The above quantities are for one 12 liter flask. It is essential that the liver be not more than 24 hours old, and should be obtained at the abbatoir. The media is sterilized by placing the flasks or jars in the autoclave, bringing the steam pressure up to 15 lbs., and maintaining it at 15 lbs. for 45 minutes. The media is not injured by this severe heat treatment. Several lots were autoclaved three times without interfering with the ability of the media to start and maintain the growth of the bacillus of symptomatic anthrax.

After autoclaving let the media cool, incubate for 24 to 48 hours, and the media is ready for inoculation. No titration or pH adjustment is necessary. The media keeps well; small jars containing a deep layer of it were good after having been kept at room temperature for several months.