H. Masoud et al., CHARACTERIZATION OF THE CAPSULAR POLYSACCHARIDE OF BURKHOLDERIA (PSEUDOMONAS) PSEUDOMALLEI 304B, Journal of bacteriology, 179(18), 1997, pp. 5663-5669
Burkholderia (Pseudomonas) pseudomallei is the causative agent of meli
oidosis, a bacterial infection of considerable morbidity in areas of e
ndemicity of Southeast Asia and northern Australia. Clinical isolates
of B, pseudomallei have been demonstrated to produce a lipopolysacchar
ide (LPS) containing two separate and chemically distinct antigenic O
polysaccharides against which infected patients produced antibodies, A
putative capsular polysaccharide (CPS) has also been reported and is
thought to be antigenically conserved based on results of serological
studies with clinical B, pseudomallei isolates. In the present study,
the CPS isolated from B, pseudomallei 304b from northeastern Thailand
was found to have an [alpha](D) of +99 degrees (water), was composed o
f D-gatactose (D-Gal), 3-deoxy-D-manno-2-octulosonic acid (KDO), and O
-acetyl 3:1:1), and was a linear unbranched polymer of repeating tetra
saccharide units having the following structure: ha-D-Galp-(1-3)-beta-
D-Galp-(1-5)-beta-D-KDOp-(2-. Sera from 13 of 15 patients with differe
nt clinical manifestations of melioidosis but not normal controls reco
gnize the CPS, which suggests that it is immunogenic and raises the po
ssibility that it may have a role as a vaccine candidate and/or diagno
stic agent.