Enterococci are the third most important
pathogens associated with nosocomial infections, including urinary tract infections,
bacteremia, and endocarditis. Risk groups for enterococcal infections
include neonates, immunocompromised hosts and ICU patients.
Especially Enterococcus faecium strains have
acquired multiple antibiotic resistances and are often resistant to vancomycin
(VRE). Since there are often virtually no antibiotics
available to treat patients with VRE infections, the development of alternative
treatment options is important.
While some limited information exists regarding
the presence and composition of capsular polysaccharides in E. faecalis, almost nothing is known
about surface carbohydrates in E. faecium.
Polysaccharides isolated from E. faecium were structurally and immunologically characterized in order to search for
carbohydrate virulence factors and for the development of glycoconjugate
vaccines to combat enterococcal infections.
Carbohydrates
were released from the cell by digestion with enzymes, and then purified using gel-permeation
chromatography and anion-exchange chromatography. Obtained polysaccharides
were studied by compositional analyses, and one-dimensional
(1H and 13C), and two-dimensional homonuclear (1H,1H
COSY, TOCSY, and ROESY), as well as two-dimensional heteronuclear (1H,13C
HMQC-DEPT, HMQC-TOCSY, and HMBC) NMR spectroscopy.
Acknowledgment: This work was supported by The National Science Centre (2011/01/B/NZ1/04338).
