Immunochemical studies on Salmonella. 13. Chemical changes appearing on the specific polysaccharide of S. cholerae suis (6-2,7) after its conversion by phage 14(6,7).

Abstract

A comparative study has been made of two polysaccharides extracted from the wild and phage-converted strains of S. cholerae suis 5210. The wild strain lacks factor 14, while in the converted strain factor 14 is present. Partial hydrolysis of the two polysaccharides gave oligosaccharides which fell into four classes. The first class contained di-, tri-, and tetramannoses common to both strains. The second class consisted of an oligosaccharide Gle1 3 Man Man found only in the wild strain. The third class comprised those oligosaccharides built up from one or more mannose residues bound 1:3 to a terminal reducing N-acetylglucosamine. These were found in both strains. Lastly, class four embraced 4 oligosaccharides with the formula where n varied from 0 to 3. This class was found only in the converted strain. Using these oligosaccharides, an attempt has been made to reconstruct the complete repeat unit on the side chains of both wild and converted strains from which they derived. In both strains the repeat units comprised at least 4 mannose residues linked probably 1:4 with each other and linked 1:3 with a terminal reducing N-acetylglucosamine. One of the mannose residues carried a glucose residue on carbon 3. It has been found that conversion by phage 14 consists of a simple displacement of glucose from one mannose residue, to the mannose residue that immediately precedes N-acetylglucosamine: