Effects of Ampicillin, Gentamicin, and Cefotaxime on the Release of Shiga Toxins from Shiga Toxin–ProducingEscherichia coliIsolated During a Diarrhea Episode in Faisalabad, Pakistan

2010 ◽  
Vol 7 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Mashkoor Mohsin ◽  
Abdul Haque ◽  
Aamir Ali ◽  
Yasra Sarwar ◽  
Saira Bashir ◽  
...  
Keyword(s):  
Shiga Toxin ◽  
Shiga Toxins

scholarly journals Shiga Toxins, and the Genes Encoding Them, in Fecal Samples from Native Idaho Ungulates

2008 ◽  
Vol 75 (3) ◽  
pp. 862-865 ◽  
Author(s):  
Jeremy J. Gilbreath ◽  
Malcolm S. Shields ◽  
Rebekah L. Smith ◽  
Larry D. Farrell ◽  
Peter P. Sheridan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Wild Ungulates ◽  
Fecal Samples ◽  
Shiga Toxins ◽  
Toxin Genes ◽  
Genes Encoding ◽  
Shiga Toxin Genes

ABSTRACT Cattle are a known reservoir of Shiga toxin-producing Escherichia coli. The prevalence and stability of Shiga toxin and/or Shiga toxin genes among native wild ungulates in Idaho were investigated. The frequency of both Shiga genes and toxin was similar to that reported for Idaho cattle (∼19%).

Detection, enumeration and isolation of strains carrying the stx2 gene from urban sewage

2003 ◽  
Vol 47 (3) ◽  
pp. 109-116 ◽  
Author(s):  
A.R. Blanch ◽  
C. García-Aljaro ◽  
M. Muniesa ◽  
J. Jofre
Keyword(s):  
Shiga Toxin ◽  
Colony Growth ◽  
Coliform Bacteria ◽  
Shiga Toxins ◽  
E Coli ◽  
Urban Sewage ◽  
Shiga Toxin 2 ◽  
Shiga Toxin Genes ◽  
Lateral Transmission ◽  
Stx2 Gene

Verotoxigenic Escherichia coli strains have been related with waterborne outbreaks. Besides 0157:H7, several serotypes of E. coli and other enterobacteria have been implicated in outbreaks and reported to carry the shiga toxin genes. Shiga toxins, stx1 and stx2, are important virulence factors of these strains. These genes have been linked to bacteriophages and consequently are susceptible to lateral transmission. To better understand the ecology of these genes a study of the presence of the shiga toxin 2 gene (stx2) among coliform bacteria present in sewage samples was carried out. A procedure based on colony hybridisation was developed for the isolation of enterobacteria carrying this gene. Colony growth on Chromocult® agar was transferred to a membrane and hybridised with a gene specific probe. The procedure allowed detection of about one colony carrying the gene among around 1,000 faecal coliform colonies. The numbers of bacteria carrying the gene in sewage were also estimated by PCR indicating that the numbers of bacteria carrying the stx2 gene were about 1/1,000 faecal coliforms. The detected numbers by both methods were similar. Positive colony hybridisation was detected in four sewage origins. Fifty-two colonies showing positive signal were isolated from the Chromocult® agar plates, confirmed to be stx2 positive by PCR and phenotypically characterised. Results of the characterisation showed certain diversity among the isolates even in isolates from the same sample. Most of these isolates would not have been isolated with the methods regularly used for the isolation of E. coli 0157:H7 strains. The method will allow study of the numbers and characteristics of bacteria carrying the stx2 gene in different water environments and isolate them in order to determine their role in the spread of the gene.

scholarly journals Rapid and Label-Free Immunosensing of Shiga Toxin Subtypes with Surface Plasmon Resonance Imaging

Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 280
Author(s):  
Bin Wang ◽  
Bosoon Park ◽  
Jing Chen ◽  
Xiaohua He
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
High Throughput ◽  
Plasmon Resonance ◽  
Shiga Toxin ◽  
The United States ◽  
Surface Plasmon Resonance Imaging ◽  
Label Free ◽  
Resonance Imaging ◽  
Shiga Toxins

Shiga toxin-producing Escherichia coli (STEC) are responsible for gastrointestinal diseases reported in numerous outbreaks around the world as well as in the United States. Current detection methods have limitation to implement for rapid field-deployable detection with high volume of samples that are needed for regulatory purposes. Surface plasmon resonance imaging (SPRi) has proved to achieve rapid and label-free screening of multiple pathogens simultaneously, so it was evaluated in this work for the detection of Shiga toxins (Stx1a and Stx2a toxoids were used as the less toxic alternatives to Stx1 and Stx2, respectively). Multiple antibodies (Stx1pAb, Stx1-1mAb, Stx1-2mAb, Stx1d-3mAb, Stx1e-4mAb, Stx2pAb, Stx2-1mAb, Stx2-2mAb, and Stx2-10mAb) were spotted one by one by programed microarrayer, on the same high-throughput biochip with 50-nm gold film through multiple crosslinking and blocking steps to improve the orientation of antibodies on the biochip surface. Shiga toxins were detected based on the SPRi signal difference (ΔR) between immobilized testing antibodies and immunoglobulin G (IgG) control. Among the antibodies tested, Stx1pAb showed the highest sensitivity for Stx1 toxoid, with the limit of detection (LOD) of 50 ng/mL and detection time of 20 min. Both Stx2-1mAb and Stx2-2mAb exhibited high sensitivity for Stx2 toxoid. Furthermore, gold nanoparticles (GNPs) were used to amplify the SPRi signals of monoclonal antibodies in a sandwich platform. The LOD reached the level of picogram (pg)/mL with the help of GNP-antibody conjugate. This result proved that SPRi biochip with selected antibodies has the potential for rapid, high-throughput and multiplex detection of Shiga toxins.

scholarly journals Virulence Characteristics and Antibiotic Resistance Profiles of Shiga Toxin-Producing Escherichia coli Isolates from Diverse Sources

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 587
Author(s):  
Momna Rubab ◽  
Deog-Hwan Oh
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Shiga Toxin ◽  
Multidrug Resistant ◽  
Control Measures ◽  
Diffusion Method ◽  
Shiga Toxins ◽  
E Coli ◽  
And Control ◽  
High Degree

Shiga toxin-producing Escherichia coli (STEC) is an enteric pathogen that causes several gastrointestinal ailments in humans across the world. STEC’s ability to cause ailment is attributed to the presence of a broad range of known and putative virulence factors (VFs) including those that encode Shiga toxins. A total of 51 E. coli strains belonging to serogroups O26, O45, O103, O104, O113, O121, O145, and O157 were tested for the presence of nine VFs via PCR and for their susceptibility to 17 frequently used antibiotics using the disc diffusion method. The isolates belonged to eight different serotypes, including eight O serogroups and 12 H types. The frequency of the presence of key VFs were stx1 (76.47%), stx2 (86.27%), eae (100%), ehxA (98.03%), nleA (100%), ureC (94.11%), iha (96.07%), subA (9.80%), and saa (94.11%) in the E. coli strains. All E. coli strains carried seven or more distinct VFs and, among these, four isolates harbored all tested VFs. In addition, all E. coli strains had a high degree of antibiotic resistance and were multidrug resistant (MDR). These results show a high incidence frequency of VFs and heterogeneity of VFs and MDR profiles of E. coli strains. Moreover, half of the E. coli isolates (74.5%) were resistant to > 9 classes of antibiotics (more than 50% of the tested antibiotics). Thus, our findings highlight the importance of appropriate epidemiological and microbiological surveillance and control measures to prevent STEC disease in humans worldwide.

scholarly journals Induction by Sphingomyelinase of Shiga Toxin Receptor and Shiga Toxin 2 Sensitivity in Human Microvascular Endothelial Cells

2003 ◽  
Vol 71 (2) ◽  
pp. 845-849 ◽  
Author(s):  
T. G. Obrig ◽  
R. M. Seaner ◽  
M. Bentz ◽  
C. A. Lingwood ◽  
B. Boyd ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shiga Toxin ◽  
Microvascular Endothelial Cells ◽  
Cytotoxic Action ◽  
Ceramide Level ◽  
Shiga Toxins ◽  
Shiga Toxin 2 ◽  
Toxin Receptor ◽  
Uremic Syndrome ◽  
Microvascular Endothelial

ABSTRACT Shiga toxin-producing enterohemorrhagic Escherichia coli is the major cause of acute renal failure in young children. The interaction of Shiga toxins 1 and 2 (Stx1 and Stx2) with endothelial cells is an important step in the renal coagulation and thrombosis observed in hemolytic uremic syndrome. Previous studies have shown that bacterial lipopolysaccharide and host cytokines slowly sensitize endothelial cells to Shiga toxins. In the present study, bacterial neutral sphingomyelinase (SMase) rapidly (1 h) sensitized human dermal microvascular endothelial cells (HDMEC) to the cytotoxic action of Stx2. Exposure of endothelial cells to neutral SMase (0.067 U/ml) caused a rapid increase of intracellular ceramide that persisted for hours. Closely following the change in ceramide level was an increase in the expression of globotriaosylceramide (Gb3), the receptor for Stx2. A rapid increase was also observed in the mRNA for ceramide:glucosyltransferase (CGT), the first of three glycosyltransferase enzymes of the Gb3 biosynthetic pathway. The product of CGT (glucosylceramide) was also increased. In contrast, mRNA for the third enzyme of the pathway, Gb3 synthase, was constitutively produced and was not influenced by SMase treatment of HDMEC. These results describe a rapid response mechanism by which extracellular neutral SMase derived from either bacteria or eukaryotic cells may signal endothelial cells to become sensitive to Shiga toxins.

scholarly journals Predicting the Presence of Non-O157 Shiga Toxin-Producing Escherichia coli in Ground Beef by Using Molecular Tests for Shiga Toxins, Intimin, and O Serogroups

2012 ◽  
Vol 78 (19) ◽  
pp. 7152-7155 ◽  
Author(s):  
Joseph M. Bosilevac ◽  
Mohammad Koohmaraie
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Ground Beef ◽  
Content Type ◽  
Shiga Toxins ◽  
Molecular Tests

ABSTRACTWhen 3,972 ground beef enrichments with 6 confirmed to contain a non-O157 Shiga toxin-producing intimin-positiveEscherichia coliisolate were tested for Shiga toxin, intimin, and O group (O26, O45, O103, O111, O121, and O145) genes, 183 potential positives and only 2 of the 6 confirmed positives were identified.

scholarly journals Shiga Toxin Gene Loss and Transfer In Vitro and In Vivo during Enterohemorrhagic Escherichia coli O26 Infection in Humans

2007 ◽  
Vol 73 (10) ◽  
pp. 3144-3150 ◽  
Author(s):  
Martina Bielaszewska ◽  
Rita Prager ◽  
Robin Köck ◽  
Alexander Mellmann ◽  
Wenlan Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Gene Loss ◽  
Pulsed Field Gel Electrophoresis ◽  
Enterohemorrhagic Escherichia Coli ◽  
Toxin Gene ◽  
Shiga Toxins ◽  
E Coli

ABSTRACT Escherichia coli serogroup O26 consists of enterohemorrhagic E. coli (EHEC) and atypical enteropathogenic E. coli (aEPEC). The former produces Shiga toxins (Stx), major determinants of EHEC pathogenicity, encoded by bacteriophages; the latter is Stx negative. We have isolated EHEC O26 from patient stools early in illness and aEPEC O26 from stools later in illness, and vice versa. Intrapatient EHEC and aEPEC isolates had quite similar pulsed-field gel electrophoresis (PFGE) patterns, suggesting that they might have arisen by conversion between the EHEC and aEPEC pathotypes during infection. To test this hypothesis, we asked whether EHEC O26 can lose stx genes and whether aEPEC O26 can be lysogenized with Stx-encoding phages from EHEC O26 in vitro. The stx 2 loss associated with the loss of Stx2-encoding phages occurred in 10% to 14% of colonies tested. Conversely, Stx2- and, to a lesser extent, Stx1-encoding bacteriophages from EHEC O26 lysogenized aEPEC O26 isolates, converting them to EHEC strains. In the lysogens and EHEC O26 donors, Stx2-converting bacteriophages integrated in yecE or wrbA. The loss and gain of Stx-converting bacteriophages diversifies PFGE patterns; this parallels findings of similar but not identical PFGE patterns in the intrapatient EHEC and aEPEC O26 isolates. EHEC O26 and aEPEC O26 thus exist as a dynamic system whose members undergo ephemeral interconversions via loss and gain of Stx-encoding phages to yield different pathotypes. The suggested occurrence of this process in the human intestine has diagnostic, clinical, epidemiological, and evolutionary implications.

scholarly journals A New Immunoassay for Detecting All Subtypes of Shiga Toxins Produced by Shiga Toxin-Producing E. coli in Ground Beef

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0148092 ◽  
Author(s):  
Xiaohua He ◽  
Qiulian Kong ◽  
Stephanie Patfield ◽  
Craig Skinner ◽  
Reuven Rasooly
Keyword(s):  
Shiga Toxin ◽  
Ground Beef ◽  
Shiga Toxins ◽  
E Coli

scholarly journals Shiga Toxin 1 Triggers a Ribotoxic Stress Response Leading to p38 and JNK Activation and Induction of Apoptosis in Intestinal Epithelial Cells

2003 ◽  
Vol 71 (3) ◽  
pp. 1497-1504 ◽  
Author(s):  
Wendy E. Smith ◽  
Anne V. Kane ◽  
Sausan T. Campbell ◽  
David W. K. Acheson ◽  
Brent H. Cochran ◽  
...  
Keyword(s):  
Shiga Toxin ◽  
Intestinal Epithelial Cell ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial ◽  
Shiga Toxins ◽  
Ribotoxic Stress Response ◽  
A Subunit ◽  
Jnk Activation

ABSTRACT Shiga toxins made by Shiga toxin-producing Escherichia coli (STEC) are associated with hemolytic uremic syndrome. Shiga toxins (Stxs) may access the host systemic circulation by absorption across the intestinal epithelium. The effects of Stxs on this cell layer are not completely understood, although animal models of STEC infection suggest that, in the gut, Stxs may participate in both immune activation and apoptosis. Stxs have one enzymatically active A subunit associated with five identical B subunits. The A subunit inactivates ribosomes by cleaving a specific adenine from the 28S rRNA. We have previously shown that Stxs can induce multiple C-X-C chemokines in intestinal epithelial cells in vitro, including interleukin-8 (IL-8), and that Stx-induced IL-8 expression is linked to induction of c-Jun mRNA and p38 mitogen-activated protein (MAP) kinase pathway activity. We now report Stx1 induction of both primary response genes c-jun and c-fos and activation of the stress-activated protein kinases, JNK/SAPK and p38, in the intestinal epithelial cell line HCT-8. By 1 h of exposure to Stx1, mRNAs for c-jun and c-fos are induced, and both JNK and p38 are activated; activation of both kinases persisted up to 24 h. Stx1 enzymatic activity was required for kinase activation; a catalytically defective mutant toxin did not activate either. Stx1 treatment of HCT-8 cells resulted in cell death that was associated with caspase 3 cleavage and internucleosomal DNA fragmentation; this cytotoxicity also required Stx1 enzymatic activity. Blocking Stx1-induced p38 and JNK activation with the inhibitor SB202190 prevented cell death and diminished Stx1-associated caspase 3 cleavage. In summary, these data link the Stx1-induced ribotoxic stress response with both chemokine expression and apoptosis in the intestinal epithelial cell line HCT-8 and suggest that blocking host cell MAP kinases may prevent these Stx-associated events.

scholarly journals Characterization of Shiga Toxin 2a Encoding Bacteriophages Isolated From High-Virulent O145:H25 Shiga Toxin-Producing Escherichia coli

2021 ◽  
Vol 12 ◽  
Author(s):  
Silje N. Ramstad ◽  
Yngvild Wasteson ◽  
Bjørn-Arne Lindstedt ◽  
Arne M. Taxt ◽  
Jørgen V. Bjørnholt ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Integration Site ◽  
Severe Disease ◽  
High Sequence Identity ◽  
Shiga Toxins ◽  
Sequence Identity ◽  
Diarrhea Case ◽  
The Usa ◽  
Uremic Syndrome

Shiga toxin-producing Escherichia coli (STEC) may cause severe disease mainly due to the ability to produce Shiga toxins (Stx) encoded on bacteriophages. In Norway, more than 30% of the reported cases with STEC O145:H25 develop hemolytic uremic syndrome (HUS), and most cases, with known travel history, acquired the infection domestically. To describe phage characteristics associated with high virulence, we extracted the Stx2a phage sequences from eight clinical Norwegian O145:H25 STEC to conduct in-depth molecular characterization using long and short read sequencing. The Stx2a phages were annotated, characterized, and compared with previously published Stx2a phages isolated from STEC of different serotypes. The Norwegian O145:H25 Stx2a phages showed high sequence identity (>99%) with 100% coverage. The Stx2a phages were located at the integration site yciD, were approximately 45 kbp long, and harbored several virulence-associated genes, in addition to stx2a, such as nanS and nleC. We observed high sequence identity (>98%) and coverage (≥94%) between Norwegian O145:H25 Stx2a phages and publicly available Stx2a phages from O145:H25 and O145:H28 STEC, isolated from HUS cases in the USA and a hemorrhagic diarrhea case from Japan, respectively. However, low similarity was seen when comparing the Norwegian O145:H25 Stx2a phage to Stx2a phages from STEC of other serotypes. In all the Norwegian O145:H25 STEC, we identified a second phage or remnants of a phage (a shadow phage, 61 kbp) inserted at the same integration site as the Stx2a phage. The shadow phage shared similarity with the Stx2a phage, but lacked stx2a and harbored effector genes not present in the Stx2a phage. We identified a conserved Stx2a phage among the Norwegian O145:H25 STEC that shared integration site with a shadow phage in all isolates. Both phage and shadow phage harbored several virulence-associated genes that may contribute to the increased pathogenicity of O145:H25 STEC.

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