Comparison of two GM1-erythrocyte assays to detect heat-labile Escherichia coli enterotoxin in stool specimens.
AUTOR(ES)
Germani, Y
RESUMO
Two erythrocyte immunoassay techniques to detect the presence of Escherichia coli heat-labile enterotoxin (LTh) in stool supernatants and cell-free culture supernatants were compared. In the competitive assay, GM1 ganglioside was coated onto V-shaped-well microdilution plates and enterotoxin was coupled to sheep erythrocytes. As little as 0.8 ng of LTh per ml was detected by this method, which was based on the competition between the LTh of the test sample and the sensitized erythrocytes. The second assay made use of chimera antibody prepared by coupling polyclonal anti-LTh antibody to a monoclonal antibody specific for sheep erythrocytes. In this case, LTh, which was specifically bound to a GM1 ganglioside-coated plate, was detected by successively adding the chimera antibody and sheep erythrocytes. The limit of detection of the chimera antibody erythrocyte immunoassay was 0.2 ng/ml. Stool samples were collected from 167 infants hospitalized for diarrhea in the hospital of Noumea, New Caledonia. False-negative reactions due to proteases present in the stool samples were avoided by the addition of phenylmethylsulfonyl fluoride.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=266503Documentos Relacionados
- Comparison of methods to detect Escherichia coli heat-labile enterotoxin in stool and cell-free culture supernatants.
- Escherichia coli heat-labile enterotoxin: comparison of antitoxin assays and serum antitoxin levels.
- GM1 erythroimmunoassay for detection and titration of Escherichia coli heat-labile enterotoxin.
- Improved GM1-enzyme-linked immunosorbent assay for detection of Escherichia coli heat-labile enterotoxin.
- Cellular location of heat-labile enterotoxin in Escherichia coli.