Lipopolysaccharides of Acinetobacter
Ralph A. Pantophlet
from: Acinetobacter Molecular Biology (Edited by: Ulrike Gerischer). Caister Academic Press, U.K. (2008)
Lipopolysaccharides (LPS) are the major constituent of the outer membrane of most Gram-negative bacteria. Early structural characterization of Acinetobacter LPS suggested that they may be devoid of an O-polysaccharide, i.e., comprised solely of a core oligosaccharide with a lipid A moiety. In recent years, however, it has become evident that most Acinetobacter LPS do contain an O-polysaccharide chain (O-antigen). Elucidation of the chemical structure of several O-polysaccharides has revealed that they generally are branched and contain amino sugars. Simultaneously, O-polysaccharide-specific monoclonal antibodies have allowed the chemical features of the polymers to be related to serotypes. As such, these antibodies may serve as tools to discriminate Acinetobacter strains based on their O-antigens and to track clinically important clonal groups. Analyses of Acinetobacter LPS core regions have shown that they are structurally different from core regions in most other Gram-negative bacteria, which suggests the possible occurrence of an atypical LPS biosynthetic pathway in Acinetobacter. In addition to enthusiasm for the immunochemical properties and biosynthesis of Acinetobacter LPS, interest in their biological activity has been rekindled recently due to the availability of chemically-defined preparations from clinical strains. Collectively, these studies provide new impulses for investigating the possible roles of LPS in Acinetobacter infection read more ...