Shigella Rio, A New Type of Shigella

Abstract

Three strains of similar antigenic and cultural behavior were isolated from cases of diarrhoeic infection. Their cultural properties suggest their inclusion in the genus Shigella. They have a characteristic major antigen different from any of the presently known Shigellæ; their secondary antigens are essentially similar to those found in phase B of Sh. paradysenteriæ type IV. The designation Shigella rio is suggested for these microorganisms.