A similarity in the O-acetylation pattern of the O-antigens of Shigellaflexneri types 1a, 1b, and 2a

Mechanisms of O-Antigen Structural Variation of Bacterial Lipopolysaccharide (LPS)

“…The O antigen of S. flexneri is called the Y serotype and consists of repeated units of a tetrasaccharide of N-acetylglucosamine-rhamnose I-rhamnose II, rhamnose III, which forms the structure of the vertebral column of the polysaccharide unit of all the serotypes of S. flexneri, except the 6 and 6a serotypes. There are 13 serotypes, which are differentiated by the addition of glucosyl groups or acetyl residue to the different sugar molecules in the tetrasaccharide unit [54,55].…”

Identification of an O -Acyltransferase Gene ( oacB ) That Mediates 3- and 4-O-Acetylation of Rhamnose III in Shigella flexneri O Antigens

“…Recently, two new O-antigen modifications have been identified: (i) O-acetylation at either position 3 or position 4 of Rha III (3/4-O-acetylation) in serotypes 1a, 1b, 2a, 5a, Y, and 6 and (ii) O-acetylation at position 6 of GlcNAc (6-O-acetylation) in serotypes 2a, 3a, Y, and Yv (2,(21)(22)(23). The degree of the 3/4-O-acetylation varies not only between serotypes but also between strains of the same serotype in the range of 30 to 70% at position 3 and 15 to 30% at position 4 (2, 24).…”

Serological Identification and Prevalence of a Novel O-Antigen Epitope Linked to 3- and 4- O -Acetylated Rhamnose III of Lipopolysaccharide in Shigella flexneri

“…Recently, yet another O-antigen modification, namely, the addition of an O-acetyl group to Rha III at position 3 or 4 (3/4-Oacetylation), was recognized in S. flexneri serotypes 1a, 1b, 2a, 5a, and Y and in serotype 6 as having a different basal O-antigen structure (16,(28)(29)(30). The new O-acyltransferase oacB gene mediates the 3/4-O-acetylation in serotypes 1a, 1b, 2a, 5a, and Y but not in serotype 6 (31).…”