CARBOHYDRATE CONTAINING ANTIGEN FROM THE BACTERIAL AND L FORMS OF PROTEUS'

It has been reported that L forms of several strains of group A streptococci were completely lacking the group specific polysaccharide, an important constituent of the bacterial cell wall (Sharp et al., 1957). In that study, the evidence obtained did not permit distinguishing between total loss of the cell wall and the isolated loss of the polysaccharide. Nevertheless, the specu-lation was advanced that in either case loss of the polysaccharide might be responsible for the altered morphology and the increased pliability and fragility of the L forms of streptococci. It was also proposed that this alteration might be a manifestation of pencillin effect. Since unusual plasticity and fragility (Dienes and Weinberger, 1951) and penicillin resistance (Ward et al., 1958; Robinson et al., 1952) are general characteristics of all L forms of bacteria, the study has now been extended to another bacterial species to determine whether the bac-terial mural polysaccharides are retained in its L form. Since Tulasne (1951) has previously re-ported that L forms of Proteus retain some somatic antigens and since the somatic antigens of a number of gram-negative organisms have been demonstrated to depend upon a poly-saccharide component for antigenic specificity (Morgan, 1937) a Proteus bacterium and its L form were chosen for the studies reported here. Antisera, prepared against the intact bacterium and demonstrating somatic type agglutination, were tested against various extracts of whole bacteria, separated bacterial cell walls, and L forms. An immunologically active extract, ob