This review covers the structures and genetics of the 46 O antigens of Salmonella, a major pathogen of humans and domestic animals. The variation in structures underpins the serological specificity of the 46 recognized serogroups. The O antigen is important for the full function and virulence of many bacteria, and the considerable diversity of O antigens can confer selective advantage. Salmonella O antigens can be divided into two major groups: those which have N-acetylglucosamine (GlcNAc) or N-acetylgalactosamine (GalNAc) and those which have galactose (Gal) as the first sugar in the O unit. In recent years, we have determined 21 chemical structures and sequenced 28 gene clusters for GlcNAc-/GalNAc-initiated O antigens, thus completing the structure and DNA sequence data for the 46 Salmonella O antigens. The structures and gene clusters of the GlcNAc-/GalNAc-initiated O antigens were found to be highly diverse, and 24 of them were found to be identical or closely related to Escherichia coli O antigens. Sequence comparisons indicate that all or most of the shared gene clusters were probably present in the common ancestor, although alternative explanations are also possible. In contrast, the better-known eight Gal-initiated O antigens are closely related both in structures and gene cluster sequences.
polysaccharide, glycosyltransferase, pathogen, serotyping, evolution, polymorphism
NCBI PubMed ID: 23848592Publication DOI: 10.1111/1574-6976.12034Journal NLM ID: 8902526Publisher: Oxford University Press
Correspondence: wanglei@nankai.edu.cn
Institutions: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia, TEDA School of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, China, Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, China, Tianjin Research Center for Functional Genomics and Biochip, Tianjin, China, The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China, School of Molecular and Microbial Bioscience (G08), University of Sydney, Sydney, Australia
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