title: Urea-induced release of heat-labile enterotoxin from Escherichia coli.
abstract: Urea induces the release of heat-labile enterotoxin (LT) from cells of LT-producing Escherichia coli strains. Optimal conditions were defined by using the checkerboard immunoblotting system. LT release was highest when E. coli cells were incubated in 8 M urea, pH 8.0, at 37 degrees C in a water bath for 30 min. Urea was more effective than polymyxin B in inducing the release of LT antigen from E. coli; the activity of LT from urea-treated cells was seven times that of LT from polymyxin B-treated cells. Urea also increased the antigenic and biological reactivities of purified LT. This procedure is potentially applicable for the detection of LT-producing E. coli strains in the clinical laboratory.
authors.affiliation: Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia 65212.
authors.forename: Z H
authors.initials: ZH
authors.lastname: Qu
authors.forename: M
authors.initials: M
authors.lastname: Boesman-Finkelstein
authors.forename: R A
authors.initials: RA
authors.lastname: Finkelstein
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000378:metabolism*; D001427:Bacterial Toxins / Q000276:immunology / Q000378:metabolism*; D004768:Enterotoxins / Q000276:immunology / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects / Q000276:immunology*; D029968:Escherichia coli Proteins; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015151:Immunoblotting; D011112:Polymyxin B / Q000494:pharmacology*; D013552:Swine; D013696:Temperature; D013997:Time Factors; D014508:Urea / Q000494:pharmacology*
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D014508:Urea; C027538:heat-labile enterotoxin, E coli; D011112:Polymyxin B