The structure of the lipopolysaccharide O-antigen produced by Flavobacterium psychrophilum (259-93)

Flavobacterium psychrophilum, a Gram-negative bacterium, is the etiological agent of rainbow trout fry syndrome and bacterial cold water disease, sept icemic infections in reared salmonids. In humans Flavobacterium spp. have b een associated with neonatal meningitis and septicemia, catheter-associated bacteremia, and pneumonia. Recently, several F. psychrophilum surface mole cules, including lipopolysaccharide (LPS), have been implicated in its path ogenesis and identified as potential vaccine and diagnostic candidate macro molecules. Studies on the LPS produced by the bacterium are reported herein . The structure of the antigenic O-polysaccharide contained in the LPS of F . psychrophilum was deduced by the application of analytical NMR spectrosco py, mass spectrometry, glycose and methylation analysis, and partial hydrol ysis degradations, and was found to be an unbranched polymer of trisacchari de repeating units composed of L-rhamnose (L-Rhap), 2-acetamido-2-deoxy-L-f ucose (L-FucpNAc) and 2-acetamido-4-((3S,5S)-3,5-dihydroxyhexanamido)-2,4-d ideoxy-D-quinovose (D-Quip2NAc4NR, 2-N-acetyl-4-N-((3S,5S)-3,5-dihydroxyhex anoyl)-D-bacillosamine) (1 : 1 : 1) and having the structure: -->4)-alpha -L-FucpNAc-(1-->3)-alpha -D-Quip2NAc4NR-(1-->2)- alpha -L-Rhap- (1--> where R is (3S,5S)-CH3CH(OH)CH2CH(OH)CH2CO-.