title: A rapid and sensitive method to measure the functional activity of Shiga toxins in human serum.
abstract: Shiga toxins (Stx) have a definite role in the development of hemolytic uremic syndrome in children with hemorrhagic colitis caused by pathogenic Stx-producing Escherichia coli (STEC) strains. The dramatic effects of these toxins on the microvasculature of different organs, particularly of the kidney, are well known, whereas there is no consensus on the mechanism by which Stx reach the endothelia of target organs and/or indirectly injure these body sites. We hereby describe a quick (4 h), radioactive, Raji cell-based method designed for the detection of Stx in human sera. The assay monitors the translation impairment induced by these powerful inhibitors of protein synthesis, which are identified properly by neutralizing their activity with specific monoclonal antibodies. By this method, we detected for the first time the functional activity of Stx in sera of STEC-infected patients during hemorrhagic colitis. Recent research has pointed to a dynamic process of Stx-induced renal intoxication in which concurrent and interactive steps are involved. Our rapid and specific method could be useful for studying the kinetics of Stx during the natural course of STEC infection and the interplay between Stx activity in serum and Stx presence in different blood fractions (neutrophils, monocytes, platelets, leukocyte-platelet aggregates, microvesicles, lipoproteins).
authors.affiliation: Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia Generale, Università di Bologna, Via San Giacomo 14, 40126 Bologna, Italy. arfilli.v@libero.it.
authors.forename: Valentina
authors.initials: V
authors.lastname: Arfilli
authors.affiliation: Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia Generale, Università di Bologna, Via San Giacomo 14, 40126 Bologna, Italy. domenica.carnicelli@unibo.it.
authors.forename: Domenica
authors.initials: D
authors.lastname: Carnicelli
authors.affiliation: Center for HUS Control, Prevention and Management, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy. ardissino@centroseu.org.
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Ardissino
authors.affiliation: Unit of Microbiology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy. e.torresani@policlinico.mi.it.
authors.forename: Erminio
authors.initials: E
authors.lastname: Torresani
authors.affiliation: Istituto Superiore di Sanità, 00161 Rome, Italy. gaia.scavia@iss.it.
authors.forename: Gaia
authors.initials: G
authors.lastname: Scavia
authors.affiliation: Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale, Sede di Patologia Generale, Università di Bologna, Via San Giacomo 14, 40126 Bologna, Italy. maurizio.brigotti@unibo.it.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Brigotti
mesh_terms: D000911:Antibodies, Monoclonal / Q000032:analysis / Q000494:pharmacology; D002460:Cell Line; D002648:Child; D004927:Escherichia coli Infections / Q000097:blood / Q000188:drug therapy; D006463:Hemolytic-Uremic Syndrome / Q000188:drug therapy* / Q000382:microbiology; D006483:Hemorrhagic Septicemia / Q000097:blood; D006801:Humans; D011500:Protein Synthesis Inhibitors / Q000097:blood / Q000494:pharmacology / Q000633:toxicity; D022603:Shiga Toxins / Q000037:antagonists & inhibitors / Q000097:blood* / Q000633:toxicity*; D054323:Shiga-Toxigenic Escherichia coli / Q000472:pathogenicity
chemical_list: D000911:Antibodies, Monoclonal; D011500:Protein Synthesis Inhibitors; D022603:Shiga Toxins
keywords: Raji cells; Shiga toxin-producing Escherichia coli; eukaryotic protein synthesis; hemolytic uremic syndrome