A Typhoid Variant and a New Serological Variation in the Salmonella Group

Abstract

In confirmation of the report of Almon and Stovall it was found that typhoid strain T2 lacked part of the O-antigen. This lack did not affect antigen IX, as assumed by Almon and Stovall, but a part of the complex common antigen XII, which was divisible into 3 fractions, XIL1, XII2, and XII3. The antigen XII2 was lacking in strain T2. The XII2-antigen in various Salmonella types was subject to a "XII2-variation," in which forms occurred with a strongly or a weakly developed XIL-antigen. This corresponded in principle to the "I-variation." The writer discussed the serological form variations and phase variations in general, with particular reference to the newly demonstrated "O-variation.".