STRUCTURES OF THE 2 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. and Richard, C. (1983) J. Clin. Microbiol. 18, 738-740 ] produces a lipopolysaccharide containing two distinct polymers. Atte mpts to separate the polymers chromatographically were unsuccessful, b ut the periodate-resistant major polymer could be isolated by applicat ion of the Smith degradation technique to the mixture. By means of che mical and NMR spectroscopic analyses, the following structure could be assigned to the repeating unit of the major polymer: -(1-->3)-beta-D- Galp-(1-->3)-beta-D-GalpNAc-(1-->. The following structure of the repe ating unit of the minor polymer was established from similar studies o f its degradation product, resulting from the oxidation of L-rhamnose (Rha), and of the original mixture: pha-D-GalpNAc-(1-->3)-beta-D-GalpN Ac-(1-->4)-alpha l-L-Rhap-(1-->. Individually, the polymers have recen tly 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. and Ferry, M. B. (1993) Biochem. Cell Biol. 71, 417-42 0], and the major polymer in serotype C of a Japanese typing scheme [P aramonov, N. A., Shashkov, A. S., Knirel, Y. A., Soldatkina, M, A. and Zakharova, I. Y. (1994) Bioorg. Khim. 20, 984-993]. In the case of th e O4 strain studied here, both polymers were produced under a variety of growth conditions.