Endotoxin
Endotoxin is the lipopolysaccharide complexes that are part of the outer membrane of the cell wall of Gram-negative bacteria such as E. coli, Salmonella, Shigella, Pseudomonas, Neisseria, Haemophilus, and other leading pathogens. Upon bacterial infections, the lipid component (Lipid A) of endotoxin contributes to its toxicity, while the polysaccharide components contribute to immunogenicity.