Addition of new serogroups and improvement of the antigenic designs ofYersinia pseudotuberculosis

Eight strains ofYersinia pseudotuberculosis, untypable for any established serogroups, were studied. They were isolated from humans (three), dogs (two), cat (one), and rats (two), and the general characteristics of the strains were identical with those ofY. pseudotuberculosis. On the basis of results of O-agglutinin absorption tests, these strains were classified into three new serogroups. The new serogroups proposed were serogroups IIC, VII, and VIII, and a new O-antigenic scheme ofY. pseudotuberculosis was designed.