Exposure of renal tubular epithelial cells to shiga toxin 2 (Stx-2) causes cytotoxicity, and the potency of this toxin is enhanced in the presence of tumor necrosis factor– (TNF). It has been shown that Stx-2 induces TNFproduction and that activation of 2-adrenoceptors downregulates TNF. However, little is known about the signaling pathway by which 2-adrenoceptor agonists suppress the Stx-2–ind...

This study was conducted to evaluate post-weaning growth, carcass traits and parasite burdens St. Croix White (STX) and Dorper X St. Croix White (DRP) lambs grazing guinea grass pastures during the wet and dry seasons. Lambs (77 d of age) were placed in guinea grass pastures (0.5 ha) in a rotational grazing system. Fecal egg count (FEC), packed cell volume (PCV) and BW were measured weekly. Lam...

PCR assays have proved useful for detecting and characterizing Shiga toxin-producing Escherichia coli (STEC). Recent advances in PCR technology have facilitated the development of real-time fluorescence PCR assays with greatly reduced amplification times and improved methods for the detection of amplified target sequences. We developed and evaluated two such assays for the LightCycler instrumen...

background and objectives: diarrhea is one of the most prevalent diseases in the world, specially in developing countries. one of the most important causative agents of bacterial diarrhea is diarrheagenic escherichia coli (dec) which causes gastroenteritis and this group involving enterotoxigenic e. coli (etec), enteropathogenic e. coli (epec), enteroaggregative e. coli (eaec), enterohemoragic ...

This study was conducted to characterize virulence genes of Escherichia coli isolates from water, sediment, fish, and crab in Aby Lagoon. Serogrouping was performed by EPEC antisera in 113 E. coli strains. The presence of diarrhea-associated genes (eae, stx, AggR, elt, and est) was assessed by multiplex PCR using specific primers. Based on the multiplex PCR, sixty-two isolates (42 from water, 1...

BACKGROUND In the less-sensitive mouse model, Shiga toxin-producing Escherichia coli (STEC) challenges result in shedding that reflect the amount of infection and the expression of virulence factors such as Shiga toxins (Stx). The purpose of this study was to characterize the contribution of STEC diversity and Stx expression to shedding in beef feeder calves and to evaluate the effectiveness of...

Potassium (K+) channels mediate numerous electrical events in excitable cells, including cellular membrane potential repolarization. The hERG K+ channel plays an important role in myocardial repolarization, and inhibition of these K+ channels is associated with long QT syndromes that can cause fatal cardiac arrhythmias. In this study, we identify saxitoxin (STX) as a hERG channel modifier and i...

Shiga toxin-producing Escherichia coli (STEC) O26 is the second leading E. coli serogroup responsible for human illness outbreaks behind E. coli O157:H7. Recent outbreaks have been linked to emerging pathogenic O26:H11 strains harboring stx 2 only. Cattle have been recognized as an important reservoir of O26 strains harboring stx 1; however the reservoir of these emerging stx 2 strains is unkno...

BACKGROUND Shiga toxins (Stxs, also referred to as verotoxins) are a family of bacterial protein toxins generated by Stx producing-Escherichia coli (STEC), such as E. coli serotype O157:H7. OBJECTIVES The aim of this study was to investigate the effect of recombinant and native Shiga toxin (Stx) in induction of pro- and anti-apoptosis factors and stimulation of immune response to HeLa and THP...

The effects of tetrodotoxin (TTX) and saxitoxin (STX) on the action potentials recorded in Ca2+-free solution in the absence of Ca2+ and K+ currents were investigated in the Retzius cell of three hirudinid leech species (Hirudo medicinalis, Macrobdella decora and Poecilobdella granulosa) and in the glossiphoniid leech Haementeria ghilianii. In the four leech species, stimulation of the Retzius ...