Biological Studies on Free Endotoxin and a Non-toxic Material from Culture Supernatant fluids of Escherichia coli 078 K 80

Abstract

The biological properties of 2 substances produced extracellularly by a strain of E. coli 078 K80 grown in aerated liquid culture are described. One of the materials of high molecular weight possesses the properties of endotoxin extracted from whole organisms by chemical methods. This material is toxic, in mice induces non-specific resistance to infection with Salmonella typhi, necrotizes Sacroma-180 and elicits the local and general Shwartzman reactions. It is strongly pyrogenic, dermonecrotic and induced formation of precipitating antibodies in rabbits. Heat, chemicals and enzymes do not affect its toxicity, but acid hydrolysis render it non-toxic. This substance is called "free endotoxin''. The other material of lower molecular weight had none of the properties of the endotoxin apart from inducing non-specific resistance to infection with S. typhi in mice.