BIOLOGICAL CHARACTERIZATION OF CAMPYLOBACTER-FETUS LIPOPOLYSACCHARIDES

Lipopolysaccharides (LPS) of three strains of Campylobacter fetus (sub spp. fetus and venerealis, and serotypes A and B), a bacterium of vete rinary importance but also a cause of various infections in humans, we re assessed for their ability to induce mitogenicity, gelation of Limu lus amebocyte lysate, lethal toxicity in mice, and pyrogenicity in rab bits. All C. fetus LPS exhibited activities lower than those of Salmon ella typhimurium LPS. LPS of C. fetus subsp. fetus serotype A had the lowest activity in all assays. Since the majority of C. fetus subsp. f etus isolates from humans are serotype A, the lower biological activit ies of this LPS may aid the pathogenesis of such strains, The lower ac tivities of C. fetus LPS compared with those of S. typhimurium LPS may reflect the presence of longer fatty acid chains in the lipid A of C. fetus LPS, whereas interstrain differences in C. fetus LPS bioactivit ies may be related to some property influenced by composition of the s accharide moiety.