Bacterially derived exotoxins kill eukaryotic cells by inactivating factors and/or pathways that are universally conserved among eukaryotic organisms. The genes that encode these exotoxins are commonly found in bacterial viruses (bacteriophages). In the context of mammals, these toxins cause diseases ranging from cholera to diphtheria to enterohemorrhagic diarrhea. Phage-carried exotoxin genes ...

Infection with the enteric pathogen enterohemorrhagic Escherichia coli (EHEC) causes a variety of symptoms ranging from nonbloody diarrhea to more severe sequelae including hemorrhagic colitis, altered sensorium and seizures, and even life-threatening complications, such as hemolytic uremic syndrome and thrombotic thrombocytopenic purpura. The more severe consequences of EHEC infection are attr...

The genes encoding Shiga toxin (Stx), the major virulence factor of Shiga toxin-producing Escherichia coli, are carried in the genomes of bacteriophages that belong to the lambdoid family of phages. Previous studies demonstrated that induction of prophages encoding stx significantly enhances the production and/or release of Stx from the bacterium. Therefore, factors that regulate the switch bet...

STX is an agonist for a recently characterized membrane estrogen receptor whose structure has not been identified. We evaluated whether STX suppresses gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) release from bovine anterior pituitary (AP) cells. We cultured AP cells (n=12) for 3 days in steroid-free conditions, followed by increasing concentrations (0.001, 0.01, 0.1, ...

Shiga toxins (Stx) are virulence factors produced by selected bacteria pathogenic for humans. These multicomponent protein complexes are among the more potent toxins known. As inhibitors of eukaryotic protein synthesis, these toxins selectively inactivate ribosomes in an enzymatic manner. Specificity of cell targeting is determined by the high-affinity binding of Stx to its receptor, a glycosph...

The effect of Shiga toxins (Stxs) produced by Escherichia coli on human lung epithelial cells was investigated. Specific antibodies for Stxs positively stained lung tissue from a patient who died of hemolytic uremic syndrome associated with Stx-producing E. coli (STEC) infection, indicating the deposition of Stxs in the lung. Binding experiments with normal lung tissue revealed apparent Stx bin...

The mouse bioassay (MBA) for paralytic shellfish poisoning (PSP) toxins has been used in the AOAC Official Method and the official Japanese method. In the AOAC Official Method, the saxitoxin (STX) standard provided by the U.S. Food and Drug Administration (FDA) is used, but no standard is used in the official Japanese method. The objective of this study was to compare the toxicity of decarbamoy...

Neurons from the butter clam Saxidomus giganteus and its congener the Washington clam S. nuttalli were shown to be 10 to 100 times more resistant to the dinoflagellate toxin saxitoxin (STX) than those from 4 CO-occurring infaunal bivalves, Mya arenaria, M, truncata, Tresus capax and Protothaca staminea. Only neurons from the venerid clam Humilan'a kennerlyi proved more resistant than those of S...