scholarly journals Virulence Gene Profiles and Population Genetic Analysis for Exploration of Pathogenic Serogroups of Shiga Toxin-Producing Escherichia coli

2013 ◽  
Vol 51 (12) ◽  
pp. 4022-4028 ◽  
Author(s):  
N. Kobayashi ◽  
K.-i. Lee ◽  
A. Yamazaki ◽  
S. Saito ◽  
I. Furukawa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Analysis ◽  
Shiga Toxin ◽  
Population Genetic ◽  
Virulence Gene ◽  
Population Genetic Analysis ◽  
Gene Profiles

scholarly journals Serotypes and Virulence Gene Profiles of Shiga Toxin-Producing Escherichia coli Strains Isolated from Feces of Pasture-Fed and Lot-Fed Sheep

2004 ◽  
Vol 70 (7) ◽  
pp. 3910-3917 ◽  
Author(s):  
Steven P. Djordjevic ◽  
Vidiya Ramachandran ◽  
Karl A. Bettelheim ◽  
Barbara A. Vanselow ◽  
Peter Holst ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Human Consumption ◽  
Gene Profiles ◽  
Healthy Sheep ◽  
Uremic Syndrome ◽  
Australian Sheep ◽  
Cattle And Sheep

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) strains possessing genes for enterohemolysin (ehxA) and/or intimin (eae), referred to here as complex STEC (cSTEC), are more commonly recovered from the feces of humans with hemolytic uremic syndrome and hemorrhagic colitis than STEC strains that do not possess these accessory virulence genes. Ruminants, particularly cattle and sheep, are recognized reservoirs of STEC populations that may contaminate foods destined for human consumption. We isolated cSTEC strains from the feces of longitudinally sampled pasture-fed sheep, lot-fed sheep maintained on diets comprising various combinations of silage and grain, and sheep simultaneously grazing pastures with cattle to explore the diversity of cSTEC serotypes capable of colonizing healthy sheep. A total of 67 cSTEC serotypes were isolated, of which 21 (31.3%), mainly isolated from lambs, have not been reported. Of the total isolations, 58 (86.6%) were different from cSTEC serotypes isolated from a recent study of longitudinally sampled healthy Australian cattle (M. Hornitzky, B. A. Vanselow, K. Walker, K. A. Bettelheim, B. Corney, P. Gill, G. Bailey, and S. P. Djordjevic, Appl. Environ. Microbiol. 68:6439-6445, 2002). Our data suggest that cSTEC serotypes O5:H−, O75:H8, O91:H−, O123:H−, and O128:H2 are well adapted to colonizing the ovine gastrointestinal tract, since they were the most prevalent serotypes isolated from both pasture-fed and lot-fed sheep. Collectively, our data show that Australian sheep are colonized by diverse cSTEC serotypes that are rarely isolated from healthy Australian cattle.

Virulence gene profiles and intimin subtypes of Shiga toxin-producing Escherichia coli isolated from healthy and diarrhoeic calves

2010 ◽  
Vol 167 (22) ◽  
pp. 858-861 ◽  
Author(s):  
M. A. Badouei ◽  
T. Z. Salehi ◽  
M. R. Khorasgani ◽  
H. Tadjbakhsh ◽  
G. N. Brujeni ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Gene ◽  
Gene Profiles

scholarly journals Shiga Toxin-Producing Escherichia coli (STEC) and STEC-Associated Virulence Genes in Raw Ground Pork in Canada

2021 ◽  
Author(s):  
Helen Zhang ◽  
Etsuko Yamamoto ◽  
Johanna Murphy ◽  
Catherine Carrillo ◽  
Annie Locas
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Toxin Gene ◽  
Gene Profiles ◽  
Ground Pork ◽  
Genes Encoding ◽  
Human Illness

Shiga toxin-producing Escherichia coli (STEC) O157:H7/NM and some non-O157 STEC are foodborne pathogens. In response to pork-associated O157 STEC outbreaks in Canada, we investigated the occurrence of STEC in Canadian retail raw ground pork during the period of November 1, 2014 and March 31, 2016. Isolated STEC were characterized to determine the Shiga-toxin gene ( stx ) subtype and the presence of virulence genes encoding intimin ( eae ), and enterohemorrhagic E. coli hemolysin (hlyA) . O157 STEC and non-O157 STEC were isolated from 0.11% (1/879) and 2.24% (13/580) of the pork samples. STEC virulence gene profiles containing both eae and hlyA were found only in the O157 STEC ( stx 2a , eae , hlyA ) isolate. The eae gene was absent from all non-O157 STEC isolates. Of the 13 non-O157 STEC isolates, two virulence genes of stx 1a and hlyA were found in four (30.8%) O91:H14 STEC isolates, while one virulence gene of stx 2e, stx 1a , and stx 2a was identified in five (38.5%), two (15.4%) and one (7.7%) STEC isolates respectively of various serotypes. The remaining non-O157 STEC isolate carried stx 2 , but the subtype is unknown as this isolate could not be recovered for sequencing. O91:H14 STEC ( stx 1a, hlyA ) was previously reported in association with diarrhea illnesses, while the other non-O157 STEC isolates identified in this study are not known to be associated with severe human illnesses. Virulence gene profiles identified in this study indicate that the occurrence of non-O157 STEC capable of causing severe human illness is rare in Canadian retail pork. However, O157 STEC in ground pork can occasionally occur, therefore education regarding the potential risks associated with STEC contamination of pork would be beneficial for the public and those in the food industry in order to help reduce foodborne illnesses.

scholarly journals Relationship between Virulence Gene Profiles of Atypical Enteropathogenic Escherichia coli and Shiga Toxin- Producing E. coli Isolates from Cattle and Sheep in New Zealand

2010 ◽  
Vol 76 (11) ◽  
pp. 3744-3747 ◽  
Author(s):  
Adrian L. Cookson ◽  
Mingshu Cao ◽  
Jenny Bennett ◽  
Carolyn Nicol ◽  
Fiona Thomson-Carter ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Evolutionary Relationship ◽  
Virulence Gene ◽  
Type Ii Secretion ◽  
E Coli ◽  
Type Ii Secretion System ◽  
Gene Profiles ◽  
The Relationship ◽  
Cattle And Sheep

ABSTRACT Virulence gene profiles of atypical enteropathogenic Escherichia coli (aEPEC) and Shiga toxin-producing E. coli (STEC) from cattle, sheep, and humans were examined to determine the relationship between pathotypes. Shared virulence factors (intimin, EHEC hemolysin, serine protease, and a type II secretion system) were identified, suggesting a dynamic evolutionary relationship between aEPEC and STEC.

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 Genetic Variation in Shiga Toxin-producing Escherichia coli Recovered from Patients in Michigan and Connecticut

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S363-S363
Author(s):  
Heather Selheimer ◽  
Rebekah Mosci ◽  
James Rudrik ◽  
Shannon Manning
Keyword(s):  
Escherichia Coli ◽  
Genetic Variation ◽  
Shiga Toxin ◽  
Foodborne Pathogen ◽  
Virulence Gene ◽  
Genetic Characteristics ◽  
Department Of Health ◽  
Gene Profiles ◽  
The Us ◽  
Different Populations

Abstract Background Shiga toxin-producing Escherichia coli (STEC) is a gram-negative foodborne pathogen that causes approximately 265,000 illnesses in the US annually. STEC O157 and six non-O157 STEC serotypes are most commonly associated with illness, though variation exists in the ability of different STEC types to cause disease. Consequently, we sought to examine genetic variation in virulence genes and clustered regularly interspaced repeat (CRISPR) loci among clinical strains of diverse lineages from different geographic locations. Methods Isolates were collected from a sentinel surveillance in 2000–2006 by the Michigan Department of Health and Human Services (n = 44) and Connecticut Department of Public Health (n = 115). Whole genome sequencing was performed and genes for O-antigen (serotype), multilocus sequence typing (MLST) and virulence factors were extracted. CRISPRFinder and Geneious were used for CRISPR loci. Results A phylogenetic tree based on MLST found no geographic clustering of the strains. Similarly, no difference was observed for stx1 (MI: 89.6%, CT: 83.5%), stx2 (MI: 6.9%, CT: 7.1%), stx1/stx2 (MI: 3.4%, CT: 9.4%), ehxA (MI: 80.0%, CT: 81.2%) and eae (MI: 86.7%, CT: 94.1%) frequencies across geographical locations. Although the CRISPR loci were similar within related STs, which was independent of serotype, some variation was detected between locations. Conclusion These data highlight the circulation of common non-O157 STEC lineages capable of causing disease in different populations. Strains had similar virulence gene profiles, though the diversity of the CRISPR loci varied across strains. The latter could be impacted by varying selective pressures that could affect disease frequencies and symptom severity. Continued surveillance of non-O157 STEC is needed to elucidate the genetic characteristics that are most important for disease severity. Disclosures All authors: No reported disclosures.

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