Purification of PO, Antigenic Subfraction of the Endotoxin Extracted from S. typhi O 901

Abstract

In studying toxicity we have demonstrated (1, 2) that the purified endotoxins extracted by the method of Boivin (3) or by sodium chloride-sodium citrate hypertonic solution (4) are more toxic than those obtained by the corresponding lipopolysaccharide phenol water procedure of Westphal et al. (5) or by the technique of Galanos (6). According to some authors, lipid A solubilized with bovine serum albumin exhibits equal endotoxic activity as the original LPS in lethal toxicity or pyrogenicity (Lüderitz et al., Intern. Symp. on toxic products of bacteria, Prague, September 1973). According to other authors, the content of lipid A from LPS is not related to the level of toxicity (D. Mlynarcik, same symposium). To try to solve this problem, we have previously proved (1, 2) that a Triton X100 treatment could reveal an antigenic subfraction enriched in nitrogen from the endotoxin extracted by the trichloracetic method of Boivin (3) or by the sodium chloride-sodium citrate procedure (4).