title: Serodiagnosis of Salmonella enterica serovar Typhi and S. enterica serovars Paratyphi A, B and C human infections.
abstract: The aim of this study was to evaluate an immunoassay for the detection of human serum antibodies to the LPS and flagellar antigens of Salmonella Typhi and Salmonella Paratyphi A, B and C, and to the Vi capsular polysaccharide of S. Typhi and S. Paratyphi C. A total of 330 sera were used; these originated from 15 patients who were culture-positive for S. Typhi and 15 healthy controls, together with 300 sera submitted to the Laboratory of Enteric Pathogens for Salmonella serodiagnosis. By SDS-PAGE/immunoblotting, all 15 sera from culture-positive patients had serum antibodies to the 9,12 LPS antigens and 10 had antibodies to the 'd' flagellar antigens. Of the 300 reference sera, 22 had antibodies to the 9,12 LPS antigens, one to the 1,4,5,12 LPS antigens and 12 to the 6,7 LPS antigens. Only two sera had antibodies to flagellar antigens, one of which bound to the 'b' and the other to the 'd' antigen. An ELISA was developed that successfully detected serum antibodies to the Vi capsular polysaccharides, but because of the kinetics of serum antibody production to the Vi, these antibodies may be of limited value in the serodiagnosis of acute infection with S. Typhi and S. Paratyphi C. The immunoassays described here provide a sensitive means of detecting serum antibodies to the LPS, flagellar and Vi antigens of S. Typhi and S. Paratyphi, and constitute a viable replacement for the Widal assay for the screening of sera. The Salmonella serodiagnosis protocols described here are the new standard operating procedures used by the Health Protection Agency's National Salmonella Reference Centre based in the Laboratory of Enteric Pathogens, Colindale, UK.
authors.affiliation: Laboratory of Enteric Pathogens, Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK.
authors.forename: Henrik
authors.initials: H
authors.lastname: Chart
authors.affiliation: Laboratory of Enteric Pathogens, Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK.
authors.forename: Thomas
authors.initials: T
authors.lastname: Cheasty
authors.affiliation: Laboratory of Enteric Pathogens, Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: de Pinna
authors.affiliation: Laboratory of Enteric Pathogens, Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK.
authors.forename: Lisa
authors.initials: L
authors.lastname: Siorvanes
authors.affiliation: The Wellcome Trust Sanger Institute Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK.
authors.forename: John
authors.initials: J
authors.lastname: Wain
authors.affiliation: Department of Paediatrics and Child Health, The Aga Khan University Medical Centre, PO Box 3500, Karachi, Pakistan.
authors.forename: Didar
authors.initials: D
authors.lastname: Alam
authors.affiliation: Department of Paediatrics and Child Health, The Aga Khan University Medical Centre, PO Box 3500, Karachi, Pakistan.
authors.forename: Qamarauddin
authors.initials: Q
authors.lastname: Nizami
authors.affiliation: Department of Paediatrics and Child Health, The Aga Khan University Medical Centre, PO Box 3500, Karachi, Pakistan.
authors.forename: Zulfiqar
authors.initials: Z
authors.lastname: Bhutta
authors.affiliation: Laboratory of Enteric Pathogens, Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK.
authors.forename: E John
authors.initials: EJ
authors.lastname: Threlfall
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology; D005260:Female; D005407:Flagella / Q000276:immunology; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D015151:Immunoblotting; D008070:Lipopolysaccharides / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010284:Paratyphoid Fever / Q000175:diagnosis*; D011135:Polysaccharides, Bacterial / Q000276:immunology; D019779:Salmonella enterica / Q000145:classification* / Q000276:immunology; D012482:Salmonella paratyphi A / Q000276:immunology; D012484:Salmonella paratyphi B / Q000276:immunology; D012479:Salmonella paratyphi C / Q000276:immunology; D012485:Salmonella typhi / Q000276:immunology; D012680:Sensitivity and Specificity; D012698:Serologic Tests; D014435:Typhoid Fever / Q000175:diagnosis*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D008070:Lipopolysaccharides; D011135:Polysaccharides, Bacterial