title: Structure and genetics of the O-antigen of Cronobacter turicensis G3882 from a new serotype, C. turicensis O2, and identification of a serotype-specific gene.
abstract: Lipopolysaccharides on the cell surface of Gram-negative bacteria are an important factor in pathogenicity, and the O-specific polysaccharide chain (O-polysaccharide, O-antigen) defines the immunospecificity of different bacterial strains. Cronobacter turicensis is an emerging foodborne pathogen which causes severe invasive infections in neonates. In this study, a new O serotype, C. turicensis O2, was established, the structure and genetics of the O-antigen were investigated, and a serotype-specific gene was identified. Sugar and methylation analyses, and nuclear magnetic resonance spectroscopy indicated that the O-polysaccharide contains D-galactose (D-Gal), N-acetyl-D-glucosamine (D-GlcNAc), L-rhamnose (L-Rha) and 5,7-diacetamido-3,5,7,9-tetradeoxy-D-glycero-D-galacto-non-2-ulosonic acid (di-N-acetyllegionaminic acid, Leg5Ac7Ac). The structure of the tetrasaccharide repeat of the O-polysaccharide was established as: [Formula: see text]. The O-antigen gene cluster of C. turicensis O2 was sequenced and compared with related gene clusters from available databases. Putative genes for the synthesis of L-Rha and Leg5Ac7Ac, and genes encoding sugar transferases and O-antigen processing genes (wzx and wzy) were found. The tentatively assigned functions of the O-antigen genes were in agreement with the structure of the O-polysaccharide. In addition, primers based on the wzy gene were shown to be specific for C. turicensis O2 in a screen against 145 strains.
authors: The Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin, China.
authors: Yamin
authors: Y
authors: Sun
authors: Nikolay P
authors: NP
authors: Arbatsky
authors: Min
authors: M
authors: Wang
authors: Alexander S
authors: AS
authors: Shashkov
authors: Bin
authors: B
authors: Liu
authors: Lei
authors: L
authors: Wang
authors: Yuriy A
authors: YA
authors: Knirel
mesh_terms: D059126:Cronobacter / Q000737:chemistry* / Q000145:classification / Q000235:genetics* / Q000276:immunology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005517:Foodborne Diseases / Q000382:microbiology; D005826:Genetics, Medical; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology; D006801:Humans; D007231:Infant, Newborn; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry* / Q000235:genetics* / Q000276:immunology; D017422:Sequence Analysis, DNA; D012703:Serotyping
chemical_list: D004269:DNA, Bacterial; D019081:O Antigens