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 Complete Genome Sequences of Two Shiga Toxin-Producing Escherichia coli Strains Isolated from Crows

2019 ◽  
Vol 8 (45) ◽  
Author(s):  
Michelle Q. Carter ◽  
Antares Pham ◽  
Diana K. Carychao ◽  
Michael B. Cooley
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Complete Genome ◽  
Enteric Pathogens ◽  
Genome Sequences ◽  
Content Type ◽  
Shiga Toxins ◽  
Leafy Greens ◽  
Genes Encoding ◽  
Growing Region

Escherichia coli strains RM9088 and RM10410 were isolated from crows near a leafy greens-growing region in California in April and July 2009, respectively. Both strains carry genes encoding Shiga toxins and other virulence factors in enteric pathogens. Here, we report the complete genome sequences of RM9088 and RM10410.

scholarly journals Diversity of Shiga Toxin-Producing Escherichia coli (STEC) O26:H11 Strains Examined viastxSubtypes and Insertion Sites of Stx and EspK Bacteriophages

2015 ◽  
Vol 81 (11) ◽  
pp. 3712-3721 ◽  
Author(s):  
Ludivine Bonanno ◽  
Estelle Loukiadis ◽  
Patricia Mariani-Kurkdjian ◽  
Eric Oswald ◽  
Lucille Garnier ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Sequence Type ◽  
Phylogenetic Groups ◽  
Content Type ◽  
Shiga Toxins ◽  
E Coli ◽  
Food Borne ◽  
Insertion Sites ◽  
Human Infections

ABSTRACTShiga toxin-producingEscherichia coli(STEC) is a food-borne pathogen that may be responsible for severe human infections. Only a limited number of serotypes, including O26:H11, are involved in the majority of serious cases and outbreaks. The main virulence factors, Shiga toxins (Stx), are encoded by bacteriophages. Seventy-four STEC O26:H11 strains of various origins (including human, dairy, and cattle) were characterized for theirstxsubtypes and Stx phage chromosomal insertion sites. The majority of food and cattle strains possessed thestx1asubtype, while human strains carried mainlystx1aorstx2a. ThewrbAandyehVgenes were the main Stx phage insertion sites in STEC O26:H11, followed distantly byyecEandsbcB. Interestingly, the occurrence of Stx phages inserted in theyecEgene was low in dairy strains. In most of the 29stx-negativeE. coliO26:H11 strains also studied here, these bacterial insertion sites were vacant. Multilocus sequence typing of 20stx-positive orstx-negativeE. coliO26:H11 strains showed that they were distributed into two phylogenetic groups defined by sequence type 21 (ST21) and ST29. Finally, an EspK-carrying phage was found inserted in thessrAgene in the majority of the STEC O26:H11 strains but in only a minority of thestx-negativeE. coliO26:H11 strains. The differences in thestxsubtypes and Stx phage insertion sites observed in STEC O26:H11 according to their origin might reflect that strains circulating in cattle and foods are clonally distinct from those isolated from human patients.

scholarly journals Single-Cell-Based Digital PCR Detection and Association of Shiga Toxin-Producing Escherichia coli Serogroups and Major Virulence Genes

2020 ◽  
Vol 58 (3) ◽  
Author(s):  
Xuming Liu ◽  
Lance Noll ◽  
Xiaorong Shi ◽  
Elizabeth Porter ◽  
Yin Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Single Cell ◽  
High Throughput ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Ground Beef ◽  
Digital Pcr ◽  
Content Type ◽  
E Coli ◽  
Cattle Feces

ABSTRACT Escherichia coli serogroups O157, O26, O45, O103, O111, O121, and O145, when carrying major virulence genes, the Shiga toxin genes stx1 and stx2 and the intimin gene eae, are important foodborne pathogens. They are referred to as the “top 7” Shiga toxin-producing E. coli (STEC) serogroups and were declared by the USDA as adulterants to human health. Since top 7 serogroup-positive cattle feces and ground beef can also contain nonadulterant E. coli strains, regular PCR cannot confirm whether the virulence genes are carried by adulterant or nonadulterant E. coli serogroups. Thus, traditional gold-standard STEC detection requires bacterial isolation and characterization, which are not compatible with high-throughput settings and often take a week to obtain a definitive result. In this study, we demonstrated that the partition-based multichannel digital PCR (dPCR) system can be used to detect and associate the E. coli serogroup-specific gene with major virulence genes and developed a single-cell-based dPCR approach for rapid (within 1 day) and accurate detection and confirmation of major STEC serogroups in high-throughput settings. Major virulence genes carried by each of the top 7 STEC serogroups were detected by dPCR with appropriately diluted intact bacterial cells from pure cultures, culture-spiked cattle feces, and culture-spiked ground beef. Furthermore, from 100 randomly collected, naturally shed cattle fecal samples, 3 O103 strains carrying eae and 2 O45 strains carrying stx1 were identified by this dPCR assay and verified by the traditional isolation method. This novel and rapid dPCR assay is a culture-independent, high-throughput, accurate, and sensitive method for STEC detection and confirmation.

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%).

Survival comparison of Shiga toxin producing Escherichia coli (STEC) O26 and farm isolated O26 in ground beef

Meat Science ◽  
2014 ◽  
Vol 96 (1) ◽  
pp. 486
Author(s):  
C. Palmer ◽  
C. Bratcher ◽  
M. Singh ◽  
L. Wang
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Ground Beef

scholarly journals Cytotoxic and Apoptotic Effects of Recombinant Subtilase Cytotoxin Variants of Shiga Toxin-Producing Escherichia coli

2015 ◽  
Vol 83 (6) ◽  
pp. 2338-2349 ◽  
Author(s):  
J. Funk ◽  
N. Biber ◽  
M. Schneider ◽  
E. Hauser ◽  
S. Enzenmüller ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Vero Cells ◽  
Toxic Activity ◽  
Content Type ◽  
B Subunits ◽  
Induced Apoptosis ◽  
The Individual ◽  
Apoptotic Effects ◽  
Subtilase Cytotoxin

In this study, the cytotoxicity of the recently described subtilase variant SubAB2-2of Shiga toxin-producingEscherichia coliwas determined and compared to the plasmid-encoded SubAB1and the chromosome-encoded SubAB2-1variant. The genes for the respective enzymatic active (A) subunits and binding (B) subunits of the subtilase toxins were amplified and cloned. The recombinant toxin subunits were expressed and purified. Their cytotoxicity on Vero cells was measured for the single A and B subunits, as well as for mixtures of both, to analyze whether hybrids with toxic activity can be identified. The results demonstrated that all three SubAB variants are toxic for Vero cells. However, the values for the 50% cytotoxic dose (CD50) differ for the individual variants. Highest cytotoxicity was shown for SubAB1. Moreover, hybrids of subunits from different subtilase toxins can be obtained which cause substantial cytotoxicity to Vero cells after mixing the A and B subunits prior to application to the cells, which is characteristic for binary toxins. Furthermore, higher concentrations of the enzymatic subunit SubA1exhibited cytotoxic effects in the absence of the respective B1subunit. A more detailed investigation in the human HeLa cell line revealed that SubA1alone induced apoptosis, while the B1subunit alone did not induce cell death.

scholarly journals Phylogenetic structure of Shiga toxin-producing Escherichia coli O157:H7 from sub-lineage to SNPs

2021 ◽  
Author(s):  
Timothy J. Dallman ◽  
David R. Greig ◽  
Saheer E. Gharbia ◽  
Claire Jenkins
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Sequence Similarity ◽  
Evidence Base ◽  
Point Sources ◽  
Single Linkage ◽  
Phylogenetic Structure ◽  
Content Type ◽  
Geographically Dispersed ◽  
Cluster Threshold

Sequence similarity of pathogen genomes can infer the relatedness between isolates as the fewer genetic differences identified between pairs of isolates, the less time since divergence from a common ancestor. Clustering based on hierarchical single linkage clustering of pairwise SNP distances has been employed to detect and investigate outbreaks. Here, we evaluated the evidence-base for the interpretation of phylogenetic clusters of Shiga toxin-producing Escherichia coli (STEC) O157:H7. Whole genome sequences of 1193 isolates of STEC O157:H7 submitted to Public Health England between July 2015 and December 2016 were mapped to the Sakai reference strain. Hierarchical single linkage clustering was performed on the pairwise SNP difference between all isolates at descending distance thresholds. Cases with known epidemiological links fell within 5-SNP single linkage clusters. Five-SNP single linkage community clusters where an epidemiological link was not identified were more likely to be temporally and/or geographically related than sporadic cases. Ten-SNP single linkage clusters occurred infrequently and were challenging to investigate as cases were few, and temporally and/or geographically dispersed. A single linkage cluster threshold of 5-SNPs has utility for the detection of outbreaks linked to both persistent and point sources. Deeper phylogenetic analysis revealed that the distinction between domestic UK and imported isolates could be inferred at the sub-lineage level. Cases associated with domestically acquired infection that fall within clusters that are predominantly travel associated are likely to be caused by contaminated imported food.

scholarly journals Antibiotic-Mediated Modulations of Outer Membrane Vesicles in Enterohemorrhagic Escherichia coli O104:H4 and O157:H7

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Andreas Bauwens ◽  
Lisa Kunsmann ◽  
Helge Karch ◽  
Alexander Mellmann ◽  
Martina Bielaszewska
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Shiga Toxin ◽  
Membrane Vesicles ◽  
Polymyxin B ◽  
Outer Membrane Vesicles ◽  
Enterohemorrhagic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Major Virulence Factor

ABSTRACT Ciprofloxacin, meropenem, fosfomycin, and polymyxin B strongly increase production of outer membrane vesicles (OMVs) in Escherichia coli O104:H4 and O157:H7. Ciprofloxacin also upregulates OMV-associated Shiga toxin 2a, the major virulence factor of these pathogens, whereas the other antibiotics increase OMV production without the toxin. These two effects might worsen the clinical outcome of infections caused by Shiga toxin-producing E. coli. Our data support the existing recommendations to avoid antibiotics for treatment of these infections.

Comparison of the Diatheva STEC FLUO with BAX System Kits for Detection of O157:H7 and Non-O157 Shiga Toxin-Producing Escherichia coli (STEC) in Ground Beef and Bean Sprout Samples Using Different Enrichment Protocols

2018 ◽  
Vol 11 (10) ◽  
pp. 2822-2834 ◽  
Author(s):  
Luca Rotundo ◽  
Pina M. Fratamico ◽  
Giulia Amagliani ◽  
Elisa Carloni ◽  
Enrica Omiccioli ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Ground Beef ◽  
Bean Sprout

scholarly journals Whole-Genome Analysis of a Shiga Toxin-Producing Escherichia coli O103:H2 Strain Isolated from Cattle Feces

2020 ◽  
Vol 9 (45) ◽  
Author(s):  
Yujie Zhang ◽  
Yen-Te Liao ◽  
Vivian C. H. Wu
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Whole Genome Analysis ◽  
Content Type ◽  
Cattle Feces ◽  
Beef Products ◽  
Foodborne Outbreaks ◽  
Enterocyte Effacement

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) serotype O103 is one of the primary pathogenic contaminants of beef products, contributing to several foodborne outbreaks in recent years. Here, we report the whole-genome sequence of a STEC O103:H2 strain isolated from cattle feces that contains a locus of enterocyte effacement (LEE) pathogenicity island.

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