Adhesin-Encoding Genes from Shiga Toxin-Producing Escherichia coli Are More Prevalent in Atypical than in Typical Enteropathogenic E. coli

Shiga toxin (Stx) can be classified into two types, Stx1 and Stx2, and different subtypes. Stx2e is a subtype commonly causing porcine edema disease and rarely reported in humans. The purpose of this study was to analyze the prevalence and genetic characteristics of Stx2e-producing Escherichia coli (Stx2e-STEC) strains from humans compared to strains from animals and meats in China. Stx2e-STEC strains were screened from our STEC collection, and whole-genome sequencing was performed to characterize their genetic features. Our study showed a wide distribution of Stx2e-STEC among diverse hosts and a higher proportion of Stx2e-STEC among human STEC strains in China. Three human Stx2e-STEC isolates belonged to O100:H30, Onovel26:H30, and O8:H9 serotypes and varied in genetic features. Human Stx2e-STECs phylogenetically clustered with animal- and food-derived strains. Stx2e-STEC strains from animals and meat showed multidrug resistance, while human strains were only resistant to azithromycin and tetracycline. Of note, a high proportion (55.9%) of Stx2e-STEC strains, including one human strain, carried the heat-stable and heat-labile enterotoxin-encoding genes st and lt, exhibiting a STEC/enterotoxigenic E. coli (ETEC) hybrid pathotype. Given that no distinct genetic feature was found in Stx2e-STEC strains from different sources, animal- and food-derived strains may pose the risk of causing human disease.

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Autotransporter Protein-Encoding Genes of Diarrheagenic Escherichia coli Are Found in both Typical and Atypical Enteropathogenic E. coli Strains

Applied and Environmental Microbiology ◽

10.1128/aem.02635-12 ◽

2012 ◽

Vol 79 (1) ◽

pp. 411-414 ◽

Cited By ~ 21

Author(s):

Afonso G. Abreu ◽

Vanessa Bueris ◽

Tatiane M. Porangaba ◽

Marcelo P. Sircili ◽

Fernando Navarro-Garcia ◽

...

Keyword(s):

Escherichia Coli ◽

Content Type ◽

E Coli ◽

Diarrheagenic Escherichia Coli ◽

Virulence Markers ◽

Protein Encoding ◽

Encoding Genes ◽

Specific Virulence

ABSTRACTAutotransporter (AT) protein-encoding genes of diarrheagenicEscherichia coli(DEC) pathotypes (cah,eatA,ehaABCDJ,espC,espI,espP,pet,pic,sat, andtibA) were detected in typical and atypical enteropathogenicE. coli(EPEC) in frequencies between 0.8% and 39.3%. Although these ATs have been described in particular DEC pathotypes, their presence in EPEC indicates that they should not be considered specific virulence markers.

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Prevalence and molecular characterisation of shiga-toxin-producing Escherichia coli in raw milk cheeses from Lazio region, Italy

Italian Journal of Food Safety ◽

10.4081/ijfs.2016.4566 ◽

2016 ◽

Vol 5 (1) ◽

Cited By ~ 3

Author(s):

Selene Marozzi ◽

Paola De Santis ◽

Sarah Lovari ◽

Roberto Condoleo ◽

Stefano Bilei ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Raw Milk ◽

Foodborne Diseases ◽

Control Plan ◽

Lazio Region ◽

Standard Methods ◽

E Coli ◽

Regional Control ◽

Unpasteurized Milk

In recent years, the incidence of foodborne diseases caused by shiga toxin-producing Escherichia coli (STEC) has increased globally. For this reason, within the specific regional control plan for the detection of STEC in food products in Italy, the presence of STEC in unpasteurized milk cheeses was investigated. In total 203 samples obtained from March 2011 to December 2013 were analysed, with two standard methods (ISO 16654:2001 and ISO 13136:2012). Two strains of E. coli O157 were isolated (2/161, 1.2%) but did not carry any virulence-associated genes and 22 stx-positive samples (22/146, 15.1%) were detected in enrichment cultures, mostly from ovine cheeses. Only two strains isolated from different ovine cheeses carried stx gene and none of these was eae-positive. This study confirms the presence of stx-positive E. coli and suggests that this type of food cannot be excluded as a potential vehicle of STEC.

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Novel Hybrid of Typical Enteropathogenic Escherichia coli and Shiga-Toxin-Producing E. coli (tEPEC/STEC) Emerging From Pet Birds

Frontiers in Microbiology ◽

10.3389/fmicb.2018.02975 ◽

2018 ◽

Vol 9 ◽

Cited By ~ 9

Author(s):

Rosely Martins Gioia-Di Chiacchio ◽

Marcos Paulo Vieira Cunha ◽

Lilian Rose Marques de Sá ◽

Yamê Minieiro Davies ◽

Camila Bueno Pacheco Pereira ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Enteropathogenic Escherichia Coli ◽

E Coli ◽

Pet Birds

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Enterohemorrhagic Escherichia coli Colony Check Assay for the Identification of Serogroups O26, O45, O103, O111, O121, O145, and O157 Colonies Isolated on Plating Media

Journal of Food Protection ◽

10.4315/0362-028x.jfp-13-555 ◽

2014 ◽

Vol 77 (7) ◽

pp. 1212-1218 ◽

Cited By ~ 1

Author(s):

BURTON BLAIS ◽

MYLÈNE DESCHÊNES ◽

GEORGE HUSZCZYNSKI ◽

MARTINE GAUTHIER

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

High Throughput Screening ◽

Enterohemorrhagic Escherichia Coli ◽

Test Results ◽

Bacterial Strains ◽

Enrichment Broth ◽

Substrate Solution ◽

E Coli ◽

Assay Performance

A simple immunoenzymatic enterohemorrhagic Escherichia coli (EHEC) colony check (ECC) assay was developed for the presumptive identification of priority EHEC colonies isolated on plating media from enrichment broth cultures of foods. With this approach, lipopolysaccharide extracted from a colony is spotted on the grid of a polymyxin-coated polyester cloth strip, and bound E. coli serogroup O26, O45, O103, O111, O121, O145, and O157 antigens are subsequently detected by sequential reactions with a pool of commercially available peroxidase-conjugated goat antibodies and tetramethylbenzidine substrate solution. Each strip can accommodate up to 15 colonies, and test results are available within 30 min. Assay performance was verified using colonies from a total of 73 target EHEC isolates covering the range of designated priority serogroups (all of which were reactive), 41 nontarget E. coli isolates including several nontarget Shiga toxin–producing E. coli serogroups (all unreactive), and 33 non–E. coli strains (all unreactive except two bacterial strains possessing O-antigenic structures in common with those of the priority EHEC). The ECC assay was reactive with target colonies grown on several types of selective and nonselective plating media designed for their cultivation. These results support the use of the ECC assay for high-throughput screening of colonies isolated on plating media for detecting priority EHEC strains in foods.

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Transcriptomic Analysis of Shiga Toxin-Producing Escherichia coli during Initial Contact with Cattle Colonic Explants

Microorganisms ◽

10.3390/microorganisms8111662 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1662

Author(s):

Zachary R. Stromberg ◽

Rick E. Masonbrink ◽

Melha Mellata

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Bacterial Colonization ◽

Coli Strain ◽

Fold Change ◽

Initial Contact ◽

Lon Protease ◽

E Coli ◽

Log2 Fold Change ◽

Colonization Factors

Foodborne pathogens are a public health threat globally. Shiga toxin-producing Escherichia coli (STEC), particularly O26, O111, and O157 STEC, are often associated with foodborne illness in humans. To create effective preharvest interventions, it is critical to understand which factors STEC strains use to colonize the gastrointestinal tract of cattle, which serves as the reservoir for these pathogens. Several colonization factors are known, but little is understood about initial STEC colonization factors. Our objective was to identify these factors via contrasting gene expression between nonpathogenic E. coli and STEC. Colonic explants were inoculated with nonpathogenic E. coli strain MG1655 or STEC strains (O26, O111, or O157), bacterial colonization levels were determined, and RNA was isolated and sequenced. STEC strains adhered to colonic explants at numerically but not significantly higher levels compared to MG1655. After incubation with colonic explants, flagellin (fliC) was upregulated (log2 fold-change = 4.0, p < 0.0001) in O157 STEC, and collectively, Lon protease (lon) was upregulated (log2 fold-change = 3.6, p = 0.0009) in STEC strains compared to MG1655. These results demonstrate that H7 flagellum and Lon protease may play roles in early colonization and could be potential targets to reduce colonization in cattle.

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Prevalence and molecular detection of shiga toxin producing Escherichia coli from diarrheic cattle

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v14i1.30598 ◽

2016 ◽

Vol 14 (1) ◽

pp. 63-68 ◽

Cited By ~ 1

Author(s):

MM Akter ◽

S Majumder ◽

KH MNH Nazir ◽

M Rahman

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Molecular Detection ◽

Chain Reaction ◽

Specific Primers ◽

Fecal Samples ◽

E Coli ◽

Uremic Syndrome ◽

Polymerase Chain ◽

Positive Isolate

Shiga toxin-producing Escherichia coli (STEC) are zoonotically important pathogen which causes hemorrhagic colitis, diarrhea, and hemolytic uremic syndrome in animals and humans. The present study was designed to isolate and identify the STEC from fecal samples of diarrheic cattle. A total of 35 diarrheic fecal samples were collected from Bangladesh Agricultural University (BAU) Veterinary Teaching Hospital. The samples were primarily examined for the detection of E. coli by cultural, morphological and biochemical characteristics, followed by confirmation of the isolates by Polymerase Chain Reaction (PCR) using gene specific primers. Later, the STEC were identified among the isolated E. coli through detection of Stx-1 and Stx-2 genes using duplex PCR. Out of 35 samples, 25 (71.43%) isolates were confirmed to be associated with E. coli, of which only 7 (28%) isolates were shiga toxin producers, and all of them were positive for Stx-1. However, no Stx-2 positive isolate could be detected. From this study, it may be concluded that cattle can act as a reservoir of STEC which may transmit to human or other animals.J. Bangladesh Agril. Univ. 14(1): 63-68, June 2016

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Seasonal prevalence and characterization of Shiga toxin-producing Escherichia coli on pork carcasses at three steps of the harvest process at two commercial processing plants in the US

10.1101/2020.07.15.205773 ◽

2020 ◽

Author(s):

Ivan Nastasijevic ◽

John W. Schmidt ◽

Marija Boskovic ◽

Milica Glisic ◽

Norasak Kalchayanand ◽

...

Keyword(s):

Escherichia Coli ◽

Foodborne Pathogens ◽

Shiga Toxin ◽

Severe Disease ◽

Control Point ◽

Plate Count ◽

Seasonal Effect ◽

E Coli ◽

Significant Control ◽

Pork Products

ABSTRACTShiga toxin (stx) -producing Escherichia coli (STEC) are foodborne pathogens that have a significant impact on public health, with those possessing the attachment factor intimin (eae) referred to as enterohemorrhagic E. coli (EHEC) associated with life threatening illnesses. Cattle and beef are considered typical sources of STEC, but their presence in pork products is a growing concern. Therefore, carcasses (n=1536) at two U.S. pork processors were sampled once per season at three stages of harvest (post-stunning skins; post-scald carcasses; chilled carcasses) then examined using PCR for stx and eae, aerobic plate count (APC) and Enterobacteriaceae counts (EBC). Skins, post-scald, and chilled carcasses had prevalence of stx (85.3, 17.5, and 5.4%, respectively), with 82.3, 7.8, and 1.7% respectively, having stx and eae present. All stx positive samples were subjected to culture isolation that resulted in 368 STEC and 46 EHEC isolates. The most frequently identified STEC were serogroup O121, O8, and O91(63, 6.7, and 6.0% of total STEC, respectively). The most frequently isolated EHEC was serotype O157:H7 (63% of total EHEC). Results showed that scalding significantly reduced (P < 0.05) carcass APC and EBC by 3.00 and 2.50 log10 CFU/100 cm2 respectively. A seasonal effect was observed with STEC prevalence lower (P < 0.05) in winter. The data from this study shows significant (P < 0.05) reduction in the incidence of STEC (stx) from 85.3% to 5.4% and of EHEC (stx+eae) from 82.3% to 1.7% within slaughter-to-chilling continuum, respectively, and that potential EHEC can be confirmed present throughout using culture isolation.IMPORTANCESeven serogroups of Shiga toxin-producing Escherichia coli (STEC) are responsible for most (>75%) cases of severe illnesses caused by STEC and are considered adulterants of beef. However, some STEC outbreaks have been attributed to pork products although the same E. coli are not considered adulterants in pork because little is known of their prevalence along the pork chain. The significance of the work presented here is that it identifies disease causing STEC, enterohemorrhagic E. coli (EHEC), demonstrating that these same organisms are a food safety hazard in pork as well as beef. The results show that most STEC isolated from pork are not likely to cause severe disease in humans and that processes used in pork harvest, such as scalding, offer a significant control point to reduce contamination. The results will assist the pork processing industry and regulatory agencies to optimize interventions to improve the safety of pork products.

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Characterization of Escherichia coli O157:H7 and other Shiga toxin-producing E. coli serotypes isolated from sheep.

Journal of Clinical Microbiology ◽

10.1128/jcm.35.4.892-899.1997 ◽

1997 ◽

Vol 35 (4) ◽

pp. 892-899 ◽

Cited By ~ 90

Author(s):

I T Kudva ◽

P G Hatfield ◽

C J Hovde

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Escherichia Coli O157 ◽

E Coli

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Secondary transmissions during the outbreak of Shiga toxin-producing Escherichia coli O104 in Hesse, Germany, 2011

Eurosurveillance ◽

10.2807/ese.16.31.19937-en ◽

2011 ◽

Vol 16 (31) ◽

Author(s):

A M Hauri ◽

U Götsch ◽

I Strotmann ◽

J Krahn ◽

G Bettge-Weller ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Case Definition ◽

Case Definitions ◽

Secondary Transmission ◽

E Coli ◽

Outbreak Area ◽

The Family ◽

Satellite Clusters ◽

Outbreak Case

During the recent outbreak of Shiga toxin-producing Escherichia coli (STEC) O104:H4 in Germany most cases notified in the State of Hesse (6 million inhabitants) were linked to satellite clusters or had travelled to the outbreak area in northern Germany. Intensified surveillance was introduced to rapidly identify cases not linked to known clusters or cases and thus to obtain timely information on possible further contaminated vehicles distributed in Hesse, as well to describe the risk of secondary transmission among known cases. As of 2 August 2011*, 56 cases of haemolytic uraemic syndrome (HUS) including two fatal cases, and 124 cases of STEC gastroenteritis meeting the national case definitions have been reported in Hesse. Among the 55 HUS and 81 STEC gastroenteritis cases that met the outbreak case definition, one HUS case and eight STEC gastroenteritis cases may have acquired their infection through secondary transmission. They include six possible transmissions within the family, two possible nosocomial and one possible laboratory transmission. Our results do not suggest an increased transmissibility of the outbreak strain compared to what is already known about E. coli O157 and other STEC serotypes.

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