Destruction of Diphtheria Toxin by Bacteria

Abstract

Donaldson 2 in a study of septic gunshot wounds noted that, in cases where the salt bag treatment failed, no foul, pungent odor was emitted. Further investigation showed an anaerobe, which Donaldson called the Reading Bacillus, to be the cause of the foul odor. This organism in pure culture was found capable of destroying diphtheria and tetanus toxins. Guinea-pigs were unharmed by 60 MLD of diphtheria toxin in which this organism had grown. Most workers consider the Reading a strain of Clostridium sporogenes. Dernby 3 and his coworkers conclude that diphtheria toxin is produced by the action of proteolytic enzymes on the albumoses and peptones present in the medium. They think some of the primary split products constitute the toxin. It is felt by them that further proteolysis will disintegrate the toxin. These workers found that . . Bacillus pyocyaneus, Bacillus proteus, and others, destroy the toxin very rapidly. The diphtheria toxin used in these experiments was made by the method recommended by Dernby and David 4 with only minor modifications. In their procedure a veal-yeast-peptone medium with a PH value of 7.2 to 7.3 is used. The familiar Park 8 strain of Corynebacterium diphtheriae was used by us. The sterile toxin-filtrate preparation was mixed with sterile beef infusion-2% peptone broth (PH 7.4) in the proportion of one part of toxin solution to four parts of the peptonebeef extract broth. Tubes of this mixture were inoculated with cultures of the bacteria tested, while other tubes of the toxin-broth mixture were retained sterile as controls. All tubes were then incubated at 37 C. for