Patent ID: 8337831

Claim:
Salmonella typhi Ty21a comprising core-linked Shigella dysenteriae serotype 1 O-specific polysaccharide (O-Ps) and DNA encoding O antigen biosynthesis, said DNA selected from the group consisting of: a) the DNA sequence set out in any one of SEQ ID NOs: 1 and 2; and b) DNA encoding: i) Shigella dysenteriae serotype 1 biosynthesis polypeptides encoded by any one of SEQ ID NOs: 1 and 2, or ii) variants thereof, wherein the variants comprise O antigen biosynthesis polypeptide analogs, wherein one or more of the specified amino acids is deleted or replaced, or wherein one or more non-specified amino acids are added without loss of biosynthesis of Shigella dysenteriae serotype 1 O antigen or protective immunological activity of the O antigen biosynthesis gene product.