Structures of the two polymers present in the lipopolysaccharide of Burkholderia (Pseudomonas) cepacia serogroup O4.

Like several other strains of Burkholderia (Pseudomonas) cepacia, the reference strain for serogroup O4 in the French typing scheme [Heidt, A., Monteil, H. & Richard, C. (1983) J. Clin. Microbiol. 18, 738-740] produces a lipopolysaccharide containing two distinct polymers. Attempts to separate the polymers chromatographically were unsuccessful, but the periodate-resistant major polymer could be isolated by application of the Smith degradation technique to the mixture. By means of chemical and NMR spectroscopic analysis, the following structure could be assigned to the repeating unit of the major polymer: -->3)-alpha-D-Galp-(1-->3)-beta-D-Galp-(1-->3)-beta-D-GalpNAc-(1-->. The following structure of the repeating unit of the minor polymer was established from similar studies of its degradation product, resulting from the oxidation of L-rhamnose (Rha), and of the original mixture: -->3)-alpha-D-GalpNAc-(1-->3)-beta-D-GalpNAc-(1-->4)-alpha-L-Rhap- (1-->. Individually, the polymers have recently been found in related strains of B. cepacia. The minor polymer was identified as the O-antigen in serotype A of a Canadian typing scheme [Beynon, L. M. & Perry, M. B. (1993) Biochem. Cell Biol. 71, 417-420], and the major polymer in serotype C of a Japanese typing scheme [Paramonov, N. A., Shashkov, A. S., Knirel, Y. A., Soldatkina, M. A. & Zakharova, I. Y. (1994) Bioorg. Khim. 20, 984-993]. In the case of the O4 strain studied here, both polymers were produced under a variety of growth conditions.