Shiga toxin-producing Escherichia coli (STEC) are characterized by the release of potent Shiga toxins (Stx), which are associated with severe intestinal and renal disease. Although all STEC strains produce Stx, only a few serotypes cause infection in humans. To determine which virulence traits in vitro are linked to human disease in vivo, 13 Stx2a-producing STEC strains of seropathotype (SPT) A or B (associated with severe human intestinal disease and outbreaks) and 6 strains of SPT D or E (rarely or not linked to human disease) were evaluated in a microaerobic human colonic epithelial infection model. All SPT strains demonstrated similar growth, colonization of polarized T84 colon carcinoma cells and Stx release into the medium. In contrast, Stx translocation across the T84 cell monolayer was significantly lower in SPT group DE compared to SPT group AB strains. Further experiments showed that Stx penetration occurred via a transcellular pathway and was independent of bacterial type III secretion and attaching and effacing lesion formation. These results suggest that the extent of Stx transcytosis across the gut epithelium may represent an important indicator of STEC pathogenicity for humans.
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http://dx.doi.org/10.1099/mic.0.000645 | DOI Listing |
Elife
January 2025
Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Canada.
Several areas of the world suffer a notably high incidence of Shiga toxin-producing . To assess the impact of persistent cross-species transmission systems on the epidemiology of O157:H7 in Alberta, Canada, we sequenced and assembled O157:H7 isolates originating from collocated cattle and human populations, 2007-2015. We constructed a timed phylogeny using BEAST2 using a structured coalescent model.
View Article and Find Full Text PDFMicroorganisms
January 2025
Department of Food Science and Biotechnology, College of Bionano Technology, Gachon University, Seongnam 13120, Republic of Korea.
Shiga toxin-producing (STEC) infections have increased in humans, animals, and the food industry, with ready-to-eat (RTE) food products being particularly susceptible to contamination. The prevalence of multidrug-resistant strains has rendered the current control strategies insufficient to effectively control STEC infections. Herein, we characterized the newly isolated STEC phage vB_ESM-pEJ01, a polyvalent phage capable of infecting and species, and assessed its efficacy in reducing STEC in vitro and food matrices.
View Article and Find Full Text PDFJ Med Microbiol
January 2025
NIHR Health Protection Research Unit in Gastrointestinal Infections, University of Liverpool, Liverpool, UK.
Diarrhoeagenic (DEC) pathotypes are defined by genes located on mobile genetic elements, and more than one definitive pathogenicity gene may be present in the same strain. In August 2022, UK Health Security Agency (UKHSA) surveillance systems detected an outbreak of hybrid Shiga toxin-producing /enterotoxigenic (STEC-ETEC) serotype O101:H33 harbouring both Shiga toxin () and heat-stable toxin (). These hybrid strains of DEC are a public health concern, as they are often associated with enhanced pathogenicity.
View Article and Find Full Text PDFEpidemiol Infect
January 2025
Gastrointestinal Infections and Food Safety (One Health) Division, Clinical and Public Health Group, UK Health Security Agency, London, UK.
In July 2022, a genetically linked and geographically dispersed cluster of 12 cases of Shiga toxin-producing (STEC) O103:H2 was detected by the UK Health Security Agency using whole genome sequencing. Review of food history questionnaires identified cheese (particularly an unpasteurized brie-style cheese) and mixed salad leaves as potential vehicles. A case-control study was conducted to investigate exposure to these products.
View Article and Find Full Text PDFJ Infect Dis
January 2025
Division of Environmental Health Sciences, School of Public Health, University of Minnesota, St. Paul, MN 55108, USA.
Shiga toxin-producing Escherichia coli (STEC) infections pose a significant public health challenge, characterized by severe complications including hemolytic uremic syndrome (HUS) due to Shiga toxin (Stx) production. Current therapeutic approaches encounter a critical limitation, as conventional antibiotic treatment is contraindicated due to its propensity to trigger bacterial SOS response and subsequently enhance Stx production, which increases the likelihood of developing HUS in antibiotic-treated patients. The lack of effective, safe therapeutic options has created an urgent need for alternative treatment strategies for STEC infections.
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