title: Immunoproteomic analysis to identify Shiga toxin-producing Escherichia coli outer membrane proteins expressed during human infection.
abstract: Shiga-toxin producing Escherichia coli (STEC) is the etiologic agent of acute diarrhea, dysentery, and hemolytic-uremic syndrome (HUS). There is no approved vaccine for STEC infection in humans, and antibiotic use is contraindicated, as it promotes Shiga toxin production. In order to identify STEC-associated antigens and immunogenic proteins, outer membrane proteins (OMPs) were extracted from STEC O26:H11, O103, O113:H21, and O157:H7 strains, and commensal E. coli strain HS was used as a control. SDS-PAGE, two-dimensional-PAGE analysis, Western blot assays using sera from pediatric HUS patients and controls, and matrix-assisted laser desorption ionization-tandem time of flight analyses were used to identify 12 immunogenic OMPs, some of which were not reactive with control sera. Importantly, seven of these proteins have not been previously reported to be immunogenic in STEC strains. Among these seven proteins, OmpT and Cah displayed IgG and IgA reactivity with sera from HUS patients. Genes encoding these two proteins were present in a majority of STEC strains. Knowledge of the antigens produced during infection of the host and the immune response to those antigens will be important for future vaccine development.
authors.affiliation: Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: David
authors.initials: D
authors.lastname: Montero
authors.affiliation: Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Paz
authors.initials: P
authors.lastname: Orellana
authors.affiliation: Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Daniela
authors.initials: D
authors.lastname: Gutiérrez
authors.affiliation: Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Daniela
authors.initials: D
authors.lastname: Araya
authors.affiliation: Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Salazar
authors.affiliation: Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Valeria
authors.initials: V
authors.lastname: Prado
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.
authors.forename: Angel
authors.initials: A
authors.lastname: Oñate
authors.affiliation: Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Felipe
authors.initials: F
authors.lastname: Del Canto
authors.affiliation: Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile rvidal@med.uchile.cl.
authors.forename: Roberto
authors.initials: R
authors.lastname: Vidal
mesh_terms: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D004927:Escherichia coli Infections / Q000276:immunology / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D016680:Genome, Bacterial; D006801:Humans; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics / Q000378:metabolism*
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G