Composition of O‐Antigenic Lipopolysaccharides from Enterobacter cloacae

Abstract

Abstract Analyses have been carried out on lipopolysaccharides (LPS) from 14 strains of Enterobacter cloacae representing different O serotypes. All of the products appeared to have a composition and architecture typical of enterobacterial LPS, but points of interest include the absence of phosphate residues from the core oligosaccharide, the presence of both L‐glycero‐D‐mannoheptose and D‐glycero‐D‐mannoheptose (ratio usually about 4: 1), and the presence in lipid A of small amounts of fatty acids with odd numbers of carbon atoms (mainly C 13 ) in addition to tetradecanoic acid and 3‐hydroxytetradecanoic acid. Monosaccharides identified as components of polymeric fractions from the LPS were glucose, galactose, mannose, rhamnose, glucosamine, galactosamine, fucosamine, and galacturonic acid. Most polymeric fractions also probably contained an O ‐acetyl substituent. Closely similar chemotypes found for the polymeric fractions from the LPS of cross‐reacting serotypes support the view that these fractions contain the O‐antigenic determinants and represent the side chains of the LPS.