title: Structural and genetic characterization of enterohemorrhagic Escherichia coli O145 O antigen and development of an O145 serogroup-specific PCR assay.
abstract: Enterohemorrhagic Escherichia coli O145 strains are emerging as causes of hemorrhagic colitis and hemolytic uremic syndrome. In this study, we present the structure of the E. coli O145 O antigen and the sequence of its gene cluster. The O145 antigen has repeat units containing three monosaccharide residues: 2-acetamido-2-deoxy-D-glucose (GlcNAc), 2-acetamidoylamino-2,6-dideoxy-L-galactose, and N-acetylneuraminic acid. It is very closely related to Salmonella enterica serovar Touera and S. enterica subsp. arizonae O21 antigen. The E. coli O145 gene cluster is located between the JUMPStart sequence and the gnd gene and consists of 15 open reading frames. Putative genes for the synthesis of the O-antigen constituents, for sugar transferase, and for O-antigen processing were annotated based on sequence similarities and the presence of conserved regions. The putative genes located in the E. coli O145 O-antigen gene cluster accounted for all functions expected for synthesis of the structure. An E. coli O145 serogroup-specific PCR assay based on the genes wzx and wzy was also developed by screening E. coli and Shigella isolates of different serotypes.
authors.affiliation: TEDA School of Biological Sciences and Biotechnology, Nankai University, TEDA College, 23# HongDa St., TEDA, Tianjin 300457, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Feng
authors.forename: Sof'ya N
authors.initials: SN
authors.lastname: Senchenkova
authors.forename: Jiang
authors.initials: J
authors.lastname: Tao
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Sergei D
authors.initials: SD
authors.lastname: Shevelev
authors.forename: Peter R
authors.initials: PR
authors.lastname: Reeves
authors.forename: Jianguo
authors.initials: J
authors.lastname: Xu
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
mesh_terms: D000606:Amino Sugars / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D019081:O Antigens / Q000032:analysis / Q000737:chemistry* / Q000235:genetics*; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D019779:Salmonella enterica / Q000737:chemistry; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D012760:Shigella / Q000737:chemistry / Q000235:genetics
chemical_list: D000606:Amino Sugars; D004269:DNA, Bacterial; D019081:O Antigens