Taxonomic group: bacteria / Firmicutes
(Phylum: Firmicutes)
Associated disease: infection due to Enterococcus faecalis [ICD11:
XN2H4 
]
The structure was elucidated in this paperNCBI PubMed ID: 21437253Journal NLM ID: 101285081Publisher: San Francisco, CA: Public Library of Science
Correspondence: johannes.huebner
uniklinik-freiburg.de
Institutions: University Medical Center Freiburg, Freiburg, Germany
In a typing system based on opsonic antibodies against carbohydrate antigens of the cell envelope, 60% of Enterococcus faecalis strains can be assigned to one of four serotypes (CPS-A to CPS-D). The structural basis for enterococcal serotypes, however, is still incompletely understood. Here we demonstrate that antibodies raised against lipoteichoic acid (LTA) from a CPS-A strain are opsonic to both CPS-A and CPS-B strains. LTA-specific antibodies also bind to LTA of CPS-C and CPS-D strains, but fail to opsonize them. From CPS-C and CPS-D strains resistant to opsonization by anti-LTA, we purified a novel diheteroglycan with a repeating unit of →6)-β-Galf-(1→3)-β-D-Glcp-(1→ with O-acetylation in position 5 and lactic acid substitution at position 3 of the Galf residue. The purified diheteroglycan, but not LTA absorbed opsonic antibodies from whole cell antiserum against E. faecalis type 2 (a CPS-C strain) and type 5 (CPS-D). Rabbit antiserum raised against purified diheteroglycan opsonized CPS-C and CPS-D strains and passive protection with diheteroglycan-specific antiserum reduced bacterial counts by 1.4-3.4 logs in mice infected with E. faecalis strains of the CPS-C and CPS-D serotype. Diheteroglycan-specific opsonic antibodies were absorbed by whole bacterial cells of E. faecalis FA2-2 (CPS-C) but not by its isogenic acapsular cpsI-mutant and on native PAGE purified diheteroglycan co-migrated with the gene product of the cps-locus, suggesting that it is synthesized by this locus. In summary, two polysaccharide antigens, LTA and a novel diheteroglycan, are targets of opsonic antibodies against typeable E. faecalis strains. These cell-wall associated polymers are promising candidates for active and passive vaccination and add to our armamentarium to fight this important nosocomial pathogen.
antibodies, antibody specificity, teichoic acids, Serotypes, typing, vaccination, whole cell, Enterococcus faecalis, Structural Homology
Structure type: polymer chemical repeating unit
Location inside paper: abstract, p.4
Compound class: CPS, cell wall polysaccharide
Contained glycoepitopes: IEDB_136095,IEDB_137472,IEDB_142488,IEDB_146664,IEDB_190606,IEDB_983931,SB_192
Methods: 13C NMR, 1H NMR, NMR-2D, SDS-PAGE, ELISA, Western blotting, composition analysis, NMR-1D, serological methods, statistical analysis
Biological activity: serological data
Comments, role: CPS-C (E. faecalis FA2-2 and E. faecalis type 2) and CPS-D (E. faecalis type 5) strains
Related record ID(s): 26495
NCBI Taxonomy refs (TaxIDs): 1351
Show glycosyltransferases
There is only one chemically distinct structure:
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