Structures of the two Polymers Present in the Lipopolysaccharide of Burkholderia (Pseudomonas) Cepacia Serogroup O4

Abstract

Like several other strains of Burkholderia (Pseudomonas) cepacia, the reference strain for serogroup 04 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 analyses, the following structure could be assigned to the repeating unit of the major polymer: →3)‐α‐d‐Galp ‐(1→3)‐β‐d‐Galp ‐(1→3)‐β‐d‐Galp NAc‐(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)‐α‐d‐Galp NAc‐(1→3)‐β‐d‐Galp NAc‐(1→4)‐α‐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.

Lipopolysaccharide from Burkholderia vietnamiensis strain LMG 6999 contains two polymers identical to those present in the reference strain for Burkholderia cepacia serogroup O4

“…Further assignments of the NMR data based on 2D spectroscopy (Table 1) led to the identification of structure I as the repeating unit of polymer A . This structure is the same as that proposed [13] for the major polymer in the LPS of B. cepacia O4, and that in LPS from the corresponding serogroup C [11]. The matching NMR spectra were convincing proof of identity (including the D configuration for GalNAc).…”

“…Monosaccharide analysis identified the components as galactosamine (GalN), d ‐galactose (Gal) and l ‐rhamnose (Rha). These are also the components of mixed polymers present in LPS of the reference strain for B. cepacia O4 [13], and the anomeric regions of the 1 H‐NMR spectra were very similar. Methylation analysis of the polymer(s) from B. vietnamiensis showed that the Gal and GalN occurred as 3‐substituted pyranoside residues, and the Rha as 4‐substituted residues (assuming the pyranoid form).…”

“…Taken together, the NMR data indicated that the oligomeric product was a trisaccharide‐alditol constructed from α‐GalNAc, β‐GalNAc and 1‐deoxyerythritol (the latter being produced from the original 4‐substituted Rha). As the 13 C‐NMR spectrum could be superimposed on that for the corresponding degradation product from the minor polymer present in LPS from B. cepacia O4 [13], structure II may be inferred for the repeating unit of the parent polymer ( B ) in B. vietnamiensis LMG 6999. The same polymer has also been reported [27] as the O antigen in B. cepacia serogroup A [28].…”

Microbiological characterisation ofBurkholderia cepaciaisolates from cystic fibrosis patients: investigation of the exopolysaccharides produced

“…All the EPSs examined contained the neutral monosaccharides present in IST408: rhamnose, mannose, galactose and glucose. Some strains showed the presence of other sugars: strains BTS2 and 13 contained arabinose, strain BTS3 contained N ‐acetylgalactosamine and BTS10 presented a heptose residue, which may derive from lipopolysaccharide contamination [18]. The EPSs were treated for the simultaneous detection of neutral and acidic sugars.…”

Intracellular survival and innate immune evasion of Burkholderia cepacia: Improved understanding of quorum sensing‐controlled virulence factors, biofilm, and inhibitors

“…LPS production in Bcc is controlled by the QS system. The O polysaccharide structure of B. cepacia serotype O4 consists of two polymers such as a major polymer, composed of Gal 2 ‐GalNAc 1 and a minor polymer, composed of GalNAc 2 –Rha . It has an inner core saccharide region adjacent to the lipid A.…”