Immunochemical studies on the serotype of Shigella flexneri and its recombinant

Chemical and serologic analysis of polysaccharides of Shigella flexneri 2b and its recombinant revealed complete defect of the gene responsible for type II specificity as a result of recombination. At the same time, function of the gene in the same locus responsible for 7,8 group specificity was partially inhibited. Attenuation of group antigen 7,8, associated with partial uncovering of the structure of the basic chain, causes appearance of a distinct 3,4 group antigen. Changes of this type in Shigella flexneri have not been described hitherto.