scholarly journals Seropathotypes, Phylogroups, Stx Subtypes, and Intimin Types of Wildlife-Carried, Shiga Toxin-Producing Escherichia coli Strains with the Same Characteristics as Human-Pathogenic Isolates

2012 ◽  
Vol 78 (8) ◽  
pp. 2578-2585 ◽  
Author(s):  
Azucena Mora ◽  
Cecilia López ◽  
Ghizlane Dhabi ◽  
Ana M. López-Beceiro ◽  
Luís E. Fidalgo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Roe Deer ◽  
Geographic Area ◽  
Potential Health ◽  
Highly Pathogenic ◽  
Content Type ◽  
Domestic Livestock ◽  
High Level ◽  
Bovine Feces

ABSTRACTThe objectives of this study were to investigate the presence of Shiga toxin-producingEscherichia coli(STEC) strains in wildlife that have spread in Europe, living near human settlements; to analyze their epidemiological role in maintenance and transmission to domestic livestock; and to assess the potential health risk of wildlife-carried strains. STEC strains were recovered from 53% of roe deer, 8.4% of wild boars, and 1.9% of foxes sampled in the northwest of Spain (Galicia). Of the 40 serotypes identified, 21 were classified as seropathotypes associated with human disease, accounting for 81.5% of the wildlife-carried STEC strains, including the enterohemorrhagic serotypes O157:H7-D-eae-γ1, O26:[H11]-B1-eae-β1, O121:H19-B1-eae-ε1, and O145:[H28]-D-eae-γ1. None of the wildlife-carried strains belonged to the highly pathogenic serotype O104:H4-B1 from the recent Germany outbreak. Forty percent of wildlife-carried STEC strains shared serotypes, phylogroups, intimin types, and Stx profiles with isolates from human patients from the same geographic area. Furthermore, wildlife-carried strains belonging to serotypes O5:HNM-A, O26:[H11]-B1, O76:H19-B1, O145:[H28]-D, O146:H21-B1, and O157:H7-D showed pulsed-field gel electrophoresis (PFGE) profiles with >85% similarity to human-pathogenic STEC strains. We also found a high level of similarity among STEC strains of serotypes O5:HNM-A, O26:[H11]-B1, and O145:HNM-D of bovine (feces and beef) and wildlife origins. Interestingly, O146:H21-B1, the second most frequently detected serotype in this study, is commonly associated with human diarrhea and isolated from beef and vegetables sold in Galicia. Importantly, at least 3 STEC isolates from foxes (O5:HNM-A-eae-β1, O98:[H21]-B1-eae-ζ1, and O146:[H21]-B1) showed characteristics similar to those of human STEC strains. In conclusion, roe deer, wild boar, and fox in Galicia are confirmed to be carriers of STEC strains potentially pathogenic for humans and seem to play an important role in the maintenance of STEC.

Characteristics of Shiga Toxin–Producing Escherichia coli O157 in Slaughtered Reindeer from Northern Finland

2017 ◽  
Vol 80 (3) ◽  
pp. 454-458 ◽  
Author(s):  
Claudio Zweifel ◽  
Lisa Fierz ◽  
Nicole Cernela ◽  
Sauli Laaksonen ◽  
Maria Fredriksson-Ahomaa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Geographic Area ◽  
Sequence Type ◽  
E Coli ◽  
Indirect Transmission ◽  
Toxin Genes ◽  
Domestic Livestock ◽  
Shiga Toxin Genes ◽  
Subtilase Cytotoxin

ABSTRACT Fecal samples collected from 470 slaughtered reindeer 6 to 7 months of age were screened by real-time PCR (after enrichment) for Shiga toxin genes (stx) and then for Escherichia coli serogroup O157. Shiga toxin genes were found frequently (>30% of samples), and serogroup O157 was detected in 20% of the stx-positive samples. From these samples, a total of 25 E. coli O157:H− isolates (nonmotile but PCR positive for fliCH7) were obtained. Twenty-four of these E. coli O157:H− isolates did not ferment sorbitol and originated from one geographic area. These 24 isolates belonged to the multilocus sequence type 11, typical for Shiga toxin–producing E. coli (STEC) O157:H7 and O157:H−, and harbored genes stx1a, stx2c, eae, and hlyA; the stx2c subtype has been associated with high virulence. In contrast, one E. coli O157:H− isolate (multilocus sequence type 11) did ferment sorbitol, lacked Shiga toxin genes, but was positive for eae, hlyA, and sfpA. This isolate closely resembled an STEC that has lost its Shiga toxin genes. Additional examination revealed that reindeer can be colonized by various other STEC isolates; 21 non-O157 STEC isolates belonged to four multilocus sequence types, harbored stx1a (8 isolates) or stx2b (13 isolates), and in the stx2b-positive isolates the recently described new allelic variants (subAB2-2 and subAB2-3) for subtilase cytotoxin were identified. Hence, slaughtered semidomesticated Finnish reindeer might constitute a little known reservoir for STEC O157:H7/H− and other serogroups, and the risk of direct or indirect transmission of these pathogens from reindeer to humans and domestic livestock must not be overlooked.

scholarly journals Emergence of a Multidrug-Resistant Shiga Toxin-Producing Enterotoxigenic Escherichia coli Lineage in Diseased Swine in Japan

2016 ◽  
Vol 54 (4) ◽  
pp. 1074-1081 ◽  
Author(s):  
Masahiro Kusumoto ◽  
Yuna Hikoda ◽  
Yuki Fujii ◽  
Misato Murata ◽  
Hirotsugu Miyoshi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Significant Risk ◽  
Multidrug Resistant ◽  
Limited Range ◽  
Enterotoxigenic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Shigella Boydii ◽  
High Level

EnterotoxigenicEscherichia coli(ETEC) and Shiga toxin-producingE. coli(STEC) are important causes of diarrhea and edema disease in swine. The majority of swine-pathogenicE. colistrains belong to a limited range of O serogroups, including O8, O138, O139, O141, O147, O149, and O157, which are the most frequently reported strains worldwide. However, the circumstances of ETEC and STEC infections in Japan remain unknown; there have been few reports on the prevalence or characterization of swine-pathogenicE. coli. In the present study, we determined the O serogroups of 967E. coliisolates collected between 1991 and 2014 from diseased swine in Japan, and we found that O139, O149, O116, and OSB9 (O serogroup ofShigella boydiitype 9) were the predominant serogroups. We further analyzed these four O serogroups using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing, and virulence factor profiling. Most of the O139 and O149 strains formed serogroup-specific PFGE clusters (clusters I and II, respectively), whereas the O116 and OSB9 strains were grouped together in the same cluster (cluster III). All of the cluster III strains belonged to a single sequence type (ST88) and carried genes encoding both enterotoxin and Shiga toxin. This PFGE cluster III/ST88 lineage exhibited a high level of multidrug resistance (to a median of 10 antimicrobials). Notably, these bacteria were resistant to fluoroquinolones. Thus, this lineage should be considered a significant risk to animal production due to the toxigenicity and antimicrobial resistance of these bacteria.

scholarly journals An Environmental Shiga Toxin-Producing Escherichia coli O145 Clonal Population Exhibits High-Level Phenotypic Variation That Includes Virulence Traits

2015 ◽  
Vol 82 (4) ◽  
pp. 1090-1101 ◽  
Author(s):  
Michelle Qiu Carter ◽  
Beatriz Quinones ◽  
Xiaohua He ◽  
Wayne Zhong ◽  
Jacqueline W. Louie ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Determinants ◽  
Content Type ◽  
Clinical Strains ◽  
Production Region ◽  
E Coli ◽  
Virulence Traits ◽  
Virulence Potential ◽  
High Level

ABSTRACTShiga toxin-producingEscherichia coli(STEC) serotype O145 is one of the major non-O157 serotypes associated with severe human disease. Here we examined the genetic diversity, population structure, virulence potential, and antimicrobial resistance profiles of environmental O145 strains recovered from a major produce production region in California. Multilocus sequence typing analyses revealed that sequence type 78 (ST-78), a common ST in clinical strains, was the predominant genotype among the environmental strains. Similarly, all California environmental strains belonged to H28, a common H serotype in clinical strains. Although most environmental strains carried an intactfliCgene, only one strain retained swimming motility. Diversestxsubtypes were identified, includingstx1a,stx2a,stx2c, andstx2e. Although no correlation was detected between thestxgenotype and Stx1 production, high Stx2 production was detected mainly in strains carryingstx2aonly and was correlated positively with the cytotoxicity of Shiga toxin. All environmental strains were capable of producing enterohemolysin, whereas only 10 strains were positive for anaerobic hemolytic activity. Multidrug resistance appeared to be common, as nearly half of the tested O145 strains displayed resistance to at least two different classes of antibiotics. The core virulence determinants of enterohemorrhagicE. coliwere conserved in the environmental STEC O145 strains; however, there was large variation in the expression of virulence traits among the strains that were highly related genotypically, implying a trend of clonal divergence. Several cattle isolates exhibited key virulence traits comparable to those of the STEC O145 outbreak strains, emphasizing the emergence of hypervirulent strains in agricultural environments.

scholarly journals Molecular Profiling of Shiga Toxin-Producing Escherichia coli and Enteropathogenic E. coli Strains Isolated from French Coastal Environments

2016 ◽  
Vol 82 (13) ◽  
pp. 3913-3927 ◽  
Author(s):  
C. Balière ◽  
A. Rincé ◽  
S. Delannoy ◽  
P. Fach ◽  
M. Gourmelon
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Gene ◽  
Coastal Environment ◽  
Pathogenicity Islands ◽  
Content Type ◽  
E Coli ◽  
Gene Profiles ◽  
Genes Encoding ◽  
High Level

ABSTRACTShiga toxin-producingEscherichia coli(STEC) and enteropathogenicE. coli(EPEC) strains may be responsible for food-borne infections in humans. Twenty-eight STEC and 75 EPEC strains previously isolated from French shellfish-harvesting areas and their watersheds and belonging to 68 distinguishable serotypes were characterized in this study. High-throughput real-time PCR was used to search for the presence of 75E. colivirulence-associated gene targets, and genes encoding Shiga toxin (stx) and intimin (eae) were subtyped using PCR tests and DNA sequencing, respectively. The results showed a high level of diversity between strains, with 17 unique virulence gene profiles for STEC and 56 for EPEC. Seven STEC and 15 EPEC strains were found to display a large number or a particular combination of genetic markers of virulence and the presence ofstxand/oreaevariants, suggesting their potential pathogenicity for humans. Among these, an O26:H11stx1aeae-β1 strain was associated with a large number of virulence-associated genes (n= 47), including genes carried on the locus of enterocyte effacement (LEE) or other pathogenicity islands, such as OI-122, OI-71, OI-43/48, OI-50, OI-57, and the high-pathogenicity island (HPI). One O91:H21 STEC strain containing 4stxvariants (stx1a,stx2a,stx2c, andstx2d) was found to possess genes associated with pathogenicity islands OI-122, OI-43/48, and OI-15. Among EPEC strains harboring a large number of virulence genes (n, 34 to 50), eight belonged to serotype O26:H11, O103:H2, O103:H25, O145:H28, O157:H7, or O153:H2.IMPORTANCEThe speciesE. coliincludes a wide variety of strains, some of which may be responsible for severe infections. This study, a molecular risk assessment study ofE. colistrains isolated from the coastal environment, was conducted to evaluate the potential risk for shellfish consumers. This report describes the characterization of virulence gene profiles andstx/eaepolymorphisms ofE. coliisolates and clearly highlights the finding that the majority of strains isolated from coastal environment are potentially weakly pathogenic, while some are likely to be more pathogenic.

scholarly journals Comparison of Shiga toxin-encoding bacteriophages in highly pathogenic strains of Shiga toxin-producing Escherichia coli O157:H7 in the UK

2019 ◽  
Author(s):  
Daniel A Yara ◽  
David R Greig ◽  
David L Gally ◽  
Timothy J Dallman ◽  
Claire Jenkins
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Severe Disease ◽  
Supporting Evidence ◽  
Highly Pathogenic ◽  
Vertical Inheritance ◽  
Oxford Nanopore ◽  
Environmental Reservoir ◽  
The Uk ◽  
High Level

2.AbstractOver the last 35 years in the UK the burden of Shiga toxin-producing Escherichia coli (STEC) O157:H7 infection has, during different periods of time, been associated with five different sub-lineages (1983-1995: Ia, I/IIa and I/IIb, 1996-2014: Ic and 2015-2018: IIb). The acquisition of a stx2a-encoding bacteriophage by these five sub-lineages appears to have coincided with their respective emergences. Oxford Nanopore Technology (ONT) was used to sequence, characterise and compare the stx-encoding prophage harboured by each sub-lineage to investigate the integration of this key virulence factor. The stx2a-encoding prophage from each of the lineages causing clinical disease in the UK were all different, including the two UK sub-lineages (Ia and I/IIa) circulating concurrently and causing severe disease in the early 1980s. Comparisons between the stx2a-encoding prophage in sub-lineages I/IIb and IIb revealed similarity to the prophage commonly found to encode stx2c, and the same site of bacteriophage integration (sbcB) as stx2c encoding prophage. These data suggest independent acquisition of previously unobserved stx2a-encoding phage is more likely to have contributed to the emergence of STEC O157:H7 sub-lineages in the UK than intra-UK lineage to lineage phage transmission. In contrast, the stx2c-encoding prophage showed a high level of similarity across lineage and time, consistent with the model of stx2c being present in the common ancestor to extant STEC O157:H7 and maintained by vertical inheritance in the majority of the population. Studying the nature of the stx-encoding bacteriophage contributes to our understanding of the emergence of highly pathogenic strains of STEC O157:H7.3.Impact statementThe application of ONT technology to sequence UK epidemic strains of STEC O157:H7 revealed stx2a-encoding prophage exhibit a high level of diversity. There was little evidence of geographical or temporal patterns of relatedness, or of intra-UK transmission of stx2a-encoding prophage between indigenous strains. The stx2a-encoding prophage in the UK lineages associated with severe disease appear to be acquired independently and most likely from different geographical and/or environmental sources. These data provide supporting evidence for the existence of a dynamic environmental reservoir of stx2a-encoding prophage that pose a threat public health due to their potential for integration into competent, indigenous sub-lineages of STEC O157:H7. We also provide further evidence that stx2c-encoding prophage exhibit a high level of similarity across lineage, geographical region and time, and have likely been maintained and inherited vertically.4.Data summaryAll FASTQ files and assemblies of samples sequenced in this project were submitted to the National Centre for Biotechnology Information (NCBI). All data can be found under BioProject: PRJNA315192 - https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA315192. Strain specific details can be found in the methods section under data deposition.Publicly available data used in this project can be found via Table 1 and data bibliography.

scholarly journals Factors Involved in the Persistence of a Shiga Toxin-Producing Escherichia coli O157:H7 Strain in Bovine Feces and Gastro-Intestinal Content

2018 ◽  
Vol 9 ◽  
Author(s):  
Audrey Segura ◽  
Pauline Auffret ◽  
Delphine Bibbal ◽  
Marine Bertoni ◽  
Alexandra Durand ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Intestinal Content ◽  
Escherichia Coli O157 ◽  
Bovine Feces

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.

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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