ABSTRACT
Lipopolysaccharide (LPS) is a critical, if not essential, component of the cell wall of gram-negative bacteria. Through lipid A functioning as a bacterial endotoxin and the saccharide portion contacting host cell surfaces, LPS is responsible for many aspects of host-parasite interaction. The key role of LPS structure in membrane architecture and function makes it no surprise that LPS contributes to many aspects of host-pathogen interactions. In enteric bacteria, the polymerized sugar units of the O-antigen side chains impart to the cell surface relatively hydrophilic properties that facilitate resistance to bile salts and intestinal enzymes. The exact role of LPS during each stage of infection by any given bacterium has not been defined, but the LPS structure of H. influenzae has been shown to be important at each stage in the pathogenesis of systemic infections in the infant rat model of bacteremia and meningitis.
