Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Host organism: Homo sapiens
Associated disease: melioidosis [ICD11:
1C42 
, ICD11:
XN3LD ];
infection due to Burkholderia pseudomallei [ICD11:
XN3LD ]
The structure was elucidated in this paperNCBI PubMed ID: 25776750Publication DOI: 10.1128/IAI.02785-14Journal NLM ID: 0246127Publisher: American Society for Microbiology
Correspondence: narisara
tropmedres.ac (Narisara Chantratita)
Institutions: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand, Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand, Complex Carbohydrate Research Center, University of Georgia at Athens, USA, Department of Tropical Medicine, Medical Microbiology and Pharmacology, University of Hawaii, Honolulu, Hawaii, USA, Pathogen Sequencing Unit, Sanger Institute, Cambridge, UK, Department of Microbiology and Immunology, University of South Alabama, USA, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
Burkholderia pseudomallei is a CDC Tier 1 select agent that causes melioidosis, a severe disease in humans and animals. Persistent infections are common and there is currently no vaccine available. Lipopolysaccharide (LPS) is a potential vaccine candidate. B. pseudomallei expresses three serologically distinct LPS types. The predominant O-polysaccharide (OPS) is an unbranched heteropolymer with repeating d-glucose and 6-deoxy-l-talose residues in which the 6-deoxy-l-talose residues are variably substituted with O-acetyl and O-methyl modifications. We observed that primary clinical B. pseudomallei isolates with mucoid and non-mucoid colony morphologies from the same sample expressed different antigenic types distinguishable using a LPS-specific monoclonal antibody (Mab). Mab reactive (non-mucoid) and non-reactive (mucoid) strains from the same patient exhibited identical LPS banding patterns by silver staining and indistinguishable genotypes. We hypothesized that LPS antigenic variation reflected modification of the OPS moieties. Mutagenesis of three genes involved in LPS synthesis was performed in B. pseudomallei K96243. Loss of Mab reactivity was observed in both wbiA (encoding a 2-O-acetyltransferase) and wbiD (putative methyl transferase) mutants. The structural characteristics of the OPS moieties from isogenic non-mucoid strain 4095a and mucoid strain 4095c were further investigated. Utilizing NMR spectroscopy, we found that B. pseudomallei 4095a and 4095c OPS antigens exhibited substitution patterns that differed from the prototypic OPS structure. Specifically, 4095a lacked 4-O-acetylation while 4095c lacked both 4-O-acetylation and 2-O-methylation. Our studies indicate that B. pseudomallei OPS undergoes antigenic variation and suggest that the 9D5 Mab recognizes a conformational epitope that is influenced by both O-acetyl and O-methyl substitution patterns.
O-polysaccharide, Burkholderia pseudomallei, 6-deoxy-L-talose, antigenic variation
Structure type: polymer chemical repeating unit
Location inside paper: p.2135, fig.6, Bp 1026b OPS
Compound class: O-polysaccharide, O-antigen
Contained glycoepitopes: IEDB_142488,IEDB_146664,IEDB_983931,SB_192
Methods: 13C NMR, 1H NMR, NMR-2D, DNA sequencing, SDS-PAGE, mild acid hydrolysis, Western blotting, NMR-1D, serological methods, genetic methods, GPC, RT-PCR, statistical analysis, mutation analysis
Comments, role: Part of the OPS structure (see RR: 30691) expressed by B. pseudomallei (Bp) 1026b (prototype strain).
Related record ID(s): 30691, 30892, 30893
NCBI Taxonomy refs (TaxIDs): 884204
Show glycosyltransferases
There is only one chemically distinct structure:
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