title: Immunochemical characterization of surface antigens of Bacteroides melaninogenicus.
abstract: Major surface antigens of Bactmbrane complex by gentle methods, purified, and characterized immunochemically. A lipopolysaccharide (LPS) was found to be chemically distinct from the LPS of facultative gram-negative bacteria in that it lacked two core sugars, 2-keto-3-deoxyoctonate and heptose, as well as beta-hydroxymyristic acid, the predominant fatty acid in the lipid A moiety. The LPS was further atypical in that it had a very low level of biologic activity. A capsular polysaccharide was demonstrated morphologically by electron microscopy with ruthenium red staining and a ferritin-labeled antibody technique. This antigen was shown to be subspecies-specific by indirect immunofluorescence. Antibody to the capsular polysaccharide was measured by an enzyme-linked immunospecific assay. The presence of a relatively impotent LPS and a surface capsular antigen may partly explain the rarity of bacteremia and septic shock due to B. melaninogenicus subspecies asaccharolyticus and the common association of this organism with abscess formation.
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology / Q000302:isolation & purification*; D000954:Antigens, Surface / Q000276:immunology / Q000302:isolation & purification*; D001439:Bacteroides / Q000276:immunology*; D001442:Bacteroides Infections / Q000473:pathology; D004591:Electrophoresis, Polyacrylamide Gel; D005856:Germ-Free Life; D007120:Immunochemistry; D008854:Microscopy, Electron; D011135:Polysaccharides, Bacterial / Q000302:isolation & purification; D001443:Prevotella melaninogenica / Q000145:classification / Q000276:immunology* / Q000648:ultrastructure; D051381:Rats
chemical_list: D000942:Antigens, Bacterial; D000954:Antigens, Surface; D011135:Polysaccharides, Bacterial