Structural and immunochemical studies of the lipopolysaccharides of Salmonella strains with both antigen O4 and antigen O9.
Two Salmonella hybrid strains, SL5313 (Salmonella typhimurium with a D.rfb+ gene cluster) and SL5396 (S. enteritidis with a B.rfb+ gene cluster), each expressing both O-antigen 4 (of serogroup B) and O-antigen 9 (of serogroup D) were studied by immunofluorescence using a mixture of O4-specific mouse monoclonal and O9-specific rabbit polyclonal antibodies. Bound antibodies, detected by anti-mouse antibody labelled with fluorescein isothiocyanate and anti-rabbit antibody labelled with tetramethylrhodamine isothiocyanate showed that more than 98% of the bacteria expressed both the O4 and O9 epitopes. Phenol-water-extracted lipopolysaccharide from batch-grown cultures subjected to sugar and methylation analyses by gas-liquid chromatography and mass spectrometry were shown to contain abequose (of the O4 epitope) and tyvelose (of the O9 epitope) in ratios of 1:1.5 and 1:2.5 for SL5313 and SL5396, respectively. Isolated polysaccharide chains, obtained by weak-acid hydrolysis of the lipopolysaccharides, were found to contain both O4 and O9 specificities in the same molecule, since polysaccharide bound to O4 antibody attached to a solid-phase-adsorbed O9-specific antibody and vice versa. This demonstrates that in strains SL5313 and SL5396 O chains containing both O4 repeating units (from S. typhimurium) and O9 units (from S. enteritidis) are present.
Department of Clinical Bacteriology, Huddinge Hospital, Karolinska Institute, Sweden.
A
A
Weintraub
B N
BN
Johnson
B A
BA
Stocker
A A
AA
Lindberg
D000907:Antibodies, Bacterial / Q000276:immunology; D015153:Blotting, Western; D005455:Fluorescent Antibody Technique; D008070:Lipopolysaccharides / Q000737:chemistry / Q000276:immunology*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D019081:O Antigens; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000276:immunology; D012477:Salmonella enteritidis / Q000737:chemistry / Q000276:immunology*; D012486:Salmonella typhimurium / Q000737:chemistry / Q000276:immunology*
D000907:Antibodies, Bacterial; D008070:Lipopolysaccharides; D019081:O Antigens; D011135:Polysaccharides, Bacterial