A Microorganism Decomposing Group-Specific A Substances.

The use of bacteria to effect the degradation of serologically active carbohydrates was initiated by Avery and Dubos (1930; see also Dubos and Avery 1931) in studies on the capsular carbohydrate of Pneumococcus Type III; and other microorganisms capable of splitting polysaccharides of bacterial origin have since been found. The present report concerns the isolation and cultural characters of an apparently hitherto undescribed bacterium, having specialized food requirements and not growing on most common culture media, which is able to decompose actively the group-specific substance found in the saliva of human beings of blood group A and in various group A preparations obtained from animal materials, namely horse saliva (Landsteiner 1936) commercial pepsin and gastric mucin (Landsteiner and Chase 1936). From chemical investigations it has become probable that the substances underlying the serological differentiation of human blood groups are of polysaocbaride nature (for literature, see Landsteiner 1936, Landsteiner and Chase 1936). Apart from adding to the relatively small number of organisms known to attack "specific" polysaccharides-a property not as common as might have been supposed-the description of a new species with unusual characters may be of interest. Of bacteria which decompose serologically active complex polysaccharides, mention may be made of the following: the Myxococcus of Morgan and Thaysen which acts upon several specific polysaccharides of bacterial origin (Morgan and Thaysen 1933; Meyer and Morgan 1935) and also "group specific" A substances (Landsteiner and Chase 1935a); strains of bacteria,