Shigella flexneri O-antigens revisited: final elucidation of the O-acetylation profiles and a survey of the O-antigen structure diversity.
Shigella flexneri is an important human pathogen causing shigellosis. Strains of S. flexneri are serologically heterogeneous and, based on O-antigens, are currently classified into 14 types. Structures of the O-antigens (O-polysaccharides) of S. flexneri have been under study since 1960s but some gaps still remained. In this work, using one- and two-dimensional (1) H- and (13) C-NMR spectroscopy, the O-polysaccharides of several S. flexneri types were reinvestigated, and their structures were either confirmed (types 2b, 3b, 3c, 5b, X) or amended in respect to the O-acetylation pattern (types 3a, Y, 6, 6a). As a result, the O-acetylation sites were defined in all O-polysaccharides that had not been studied in detail earlier, and the long story of S. flexneri type strain O-antigen structure elucidation is thus completed. New and published data on the S. flexneri O-antigen structures are summarized and discussed in view of serological and genetic relationships of the O-antigens within the Shigella group and between S. flexneri and Escherichia coli.
N D Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia.
Andrei V
AV
Perepelov
Maria E
ME
Shekht
Bin
B
Liu
Sergei D
SD
Shevelev
Vladimir A
VA
Ledov
Sof'ya N
SN
Senchenkova
Vyacheslav L
VL
L'vov
Alexander S
AS
Shashkov
Lu
L
Feng
Petr G
PG
Aparin
Lei
L
Wang
Yuriy A
YA
Knirel
D000107:Acetylation; D002240:Carbohydrate Sequence; D009682:Magnetic Resonance Spectroscopy; D019081:O Antigens / Q000737:chemistry*; D012763:Shigella flexneri / Q000737:chemistry*
D019081:O Antigens