A simple method to detect saxitoxin (STX), one of the main components of the paralytic shellfish poison from red tide, has been developed. By using a next generation dye for double-stranded DNA we were able to differentiate fluorescence from STX-binding aptamers when exposed to different concentrations of STX, suggesting a change in aptamer folding upon target binding. The developed method is e...

Enterohemorrhagic E. coli (EHEC) is an important subset of Shiga toxin-producing (Stx-producing) E. coli (STEC), pathogens that have been implicated in outbreaks of food-borne illness and can cause intestinal and systemic disease, including severe renal damage. Upon attachment to intestinal epithelium, EHEC generates "attaching and effacing" (AE) lesions characterized by intimate attachment and...

Enterohemorrhagic Escherichia coli (EHEC) are responsible for major outbreaks of bloody diarrhea and hemolytic uremic syndrome (HUS) throughout the world. The mortality associated with EHEC infections stems from the production and release of a potent Shiga toxin (Stx) by these bacteria. Stx induces cell death in endothelial cells, primarily in the urinary tract, causing HUS. Stx was first descr...

The markup language XML defines a simple syntax for structured data that can be used across application boundaries. One of the most important prerequisites for the interchange of such XML data is the possibility of its transformation. Among the currently available transformation approaches for XML, the W3C standard XSLT has gained the biggest popularity. However, XSLT doesn't scale for huge amo...

Shiga toxin (Stx) produced by enterohemorrhagic Escherichia coli causes diarrhea-associated hemolytic-uremic syndrome (DHUS), a severe renal thrombotic microangiopathy. We investigated the interaction between Stx and von Willebrand Factor (VWF), a multimeric plasma glycoprotein that mediates platelet adhesion, activation, and aggregation. Stx bound to ultra-large VWF (ULVWF) secreted from and a...

BACKGROUND The greater susceptibility of children to renal injury in post-diarrheal hemolytic-uremic syndrome (HUS) may be related, at least in part, to heightened renal cell sensitivity to the cytotoxic effect of Shiga toxin (Stx), the putative mediator of kidney damage in HUS. We hypothesized that sexual maturation, which coincides with a falling incidence of HUS, may induce a relatively Stx-...

Since high hydrostatic pressure is becoming increasingly important in modern food preservation, its potential effects on microorganisms need to be thoroughly investigated. In this context, mild pressures (<200 MPa) have recently been shown to induce an SOS response in Escherichia coli MG1655. Due to this response, we observed a RecA- and LexA-dependent induction of lambda prophage upon treating...

Out of 68 Escherichia coli O157 field isolates tested in vitro for Shiga toxin (Stx) 2 production, 12 (17.6%) produced no or a limited amount of Stx2 (Stx 2 non- or low-producing strain; TNLP) even though all 68 possessed the stx(2) gene. The remaining 56 were Stx2 high-producing strains. The 12 TNLPs carried the q21 gene allele, which encodes a transcription antiterminator Q protein and is hig...

Purification and characterization of Na+ channel protein from mammalian ventricular myocytes has heretofore been complicated by the low concentration of Na+ channels and by the finding that mammalian ventricles contain both tetrodotoxin (TTX)-sensitive channels (TSC), with high affinity for saxitoxin (STX), and TTX-insensitive channels (TIC), with low affinity for STX. Most (perhaps all) of the...

The Shiga-toxin producing Escherichia coli (STEC) may cause serious illness in human. Here we analyze O26:H11 strains known to be among the most reported STEC strains causing human infections. Genetic characterization of strains isolated from animal, food, and clinical specimens in Argentina showed that most carried either stx 1a or stx 2a subtypes. Interestingly, stx 2a-positive O26:H11 rarely...