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O'Sullivan D, Arora T, Durif C, Uriot O, Brun M, Riu M, Foguet-Romero E, Samarra I, Domingo-Almenara X, Gahan CGM, Etienne-Mesmin L, Blanquet-Diot S. Impact of Western Diet on Enterohemorrhagic Escherichia coli Colonization in the Human In Vitro Mucosal Artificial Colon as Mediated by Gut Microbiota. Nutrients 2024; 16:2046. [PMID: 38999794 PMCID: PMC11243482 DOI: 10.3390/nu16132046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/19/2024] [Accepted: 06/20/2024] [Indexed: 07/14/2024] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a major food-borne pathogen that causes human disease ranging from diarrhea to life-threatening complications. Accumulating evidence demonstrates that the Western diet enhances the susceptibility to enteric infection in mice, but the effect of diet on EHEC colonization and the role of human gut microbiota remains unknown. Our research aimed to investigate the effects of a Standard versus a Western diet on EHEC colonization in the human in vitro Mucosal ARtificial COLon (M-ARCOL) and the associated changes in the gut microbiota composition and activities. After donor selection using simplified fecal batch experiments, two M-ARCOL bioreactors were inoculated with a human fecal sample (n = 4) and were run in parallel, one receiving a Standard diet, the other a Western diet and infected with EHEC O157:H7 strain EDL933. EHEC colonization was dependent on the donor and diet in the luminal samples, but was maintained in the mucosal compartment without elimination, suggesting a favorable niche for the pathogen, and may act as a reservoir. The Western diet also impacted the bacterial short-chain fatty acid and bile acid profiles, with a possible link between high butyrate concentrations and prolonged EHEC colonization. The work demonstrates the application of a complex in vitro model to provide insights into diet, microbiota, and pathogen interactions in the human gut.
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Affiliation(s)
- Deborah O'Sullivan
- UMR 454 INRAe, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France
| | - Trisha Arora
- Centre for Omics Sciences (COS), Unique Scientific and Technical Infrastructures (ICTS), Eurecat-Technology Centre of Catalonia & Rovira i Virgili University Joint Unit, 43204 Reus, Spain
- Department of Electrical, Electronic and Control Engineering (DEEEA), Universitat Rovira i Virgili, 43007 Tarragona, Spain
- Computational Metabolomics for Systems Biology Lab, Eurecat-Technology Centre of Catalonia, 08005 Barcelona, Spain
| | - Claude Durif
- UMR 454 INRAe, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France
| | - Ophélie Uriot
- UMR 454 INRAe, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France
| | - Morgane Brun
- UMR 454 INRAe, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France
| | - Marc Riu
- Centre for Omics Sciences (COS), Unique Scientific and Technical Infrastructures (ICTS), Eurecat-Technology Centre of Catalonia & Rovira i Virgili University Joint Unit, 43204 Reus, Spain
| | - Elisabet Foguet-Romero
- Centre for Omics Sciences (COS), Unique Scientific and Technical Infrastructures (ICTS), Eurecat-Technology Centre of Catalonia & Rovira i Virgili University Joint Unit, 43204 Reus, Spain
| | - Iris Samarra
- Centre for Omics Sciences (COS), Unique Scientific and Technical Infrastructures (ICTS), Eurecat-Technology Centre of Catalonia & Rovira i Virgili University Joint Unit, 43204 Reus, Spain
| | - Xavier Domingo-Almenara
- Centre for Omics Sciences (COS), Unique Scientific and Technical Infrastructures (ICTS), Eurecat-Technology Centre of Catalonia & Rovira i Virgili University Joint Unit, 43204 Reus, Spain
- Department of Electrical, Electronic and Control Engineering (DEEEA), Universitat Rovira i Virgili, 43007 Tarragona, Spain
- Computational Metabolomics for Systems Biology Lab, Eurecat-Technology Centre of Catalonia, 08005 Barcelona, Spain
| | - Cormac G M Gahan
- APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland
- School of Microbiology, University College Cork, T12 K8AF Cork, Ireland
- School of Pharmacy, University College Cork, T12 K8AF Cork, Ireland
| | - Lucie Etienne-Mesmin
- UMR 454 INRAe, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France
| | - Stéphanie Blanquet-Diot
- UMR 454 INRAe, Microbiology, Digestive Environment and Health (MEDIS), Université Clermont Auvergne, 28 Place Henri Dunant, F-63000 Clermont-Ferrand, France
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2
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Miner MV, Rauch I. Why put yourself on a pedestal? The pathogenic role of the A/E pedestal. Infect Immun 2024:e0048923. [PMID: 38591884 DOI: 10.1128/iai.00489-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024] Open
Abstract
Certain Escherichia coli (E. coli) strains are attaching and effacing (A/E) lesion pathogens that primarily infect intestinal epithelial cells. They cause actin restructuring and polymerization within the host cell to create an actin-rich protrusion below the site of adherence, termed the pedestal. Although there is clarity on the pathways initiating pedestal formation, the underlying purpose(s) of the pedestal remains ambiguous. The conservation of pedestal-forming activity across multiple pathogens and redundancy in formation pathways indicate a pathogenic advantage. However, few decisive conclusions have been drawn, given that the results vary between model systems. Some research argues that the pedestal increases the colonization capability of the bacterium. These studies utilize A/E pathogens specifically deficient in pedestal formation to evaluate adhesion and intestinal colonization following infection. There have been many proposed mechanisms for the colonization benefit conferred by the pedestal. One suggested benefit is that the pedestal allows for direct cytosolic anchoring through incorporation of the established host cortical actin, causing a stable link between the pathogen and cell structure. The pedestal may confer enhanced motility, as enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC) are better able to migrate on the surface of host cells and infect neighboring cells in the presence of the pedestal. Additionally, some research suggests that the pedestal improves effector delivery. This review will investigate the purpose of pedestal formation using evidence from recent literature and will critically evaluate the methodology and model systems. Most importantly, we will contextualize the proposed functions to reconcile potential synergistic effects.
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Affiliation(s)
- M V Miner
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
| | - I Rauch
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
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3
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Elshimy R, Zedan H, Elmorsy TH, Khattab RA. Prevalence and In Vivo Assessment of Virulence in Shiga Toxin-Producing Escherichia coli Clinical Isolates from Greater Cairo Area. Microb Drug Resist 2023; 29:407-415. [PMID: 37579256 DOI: 10.1089/mdr.2022.0348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2023] Open
Abstract
Background: Shiga toxin-producing Escherichia coli (STEC) has been identified as an important etiologic agent of human disease in Egypt. Aims: To investigate the occurrence and describe the characterization as well as prevalence of STEC in Greater Cairo hospitals as well as molecular characterization of virulence and resistance genes. Methods: Four hundred seventy E. coli clinical isolates were collected from eight hospitals and analyzed by genotypic and phenotypic methods for STEC, followed by histopathological examination and scoring of different organs lesions. Results: The highest proportion of isolates was from urine (151 isolates), whereas the lowest was from splenic drain (3 isolates). In tandem, when serogrouping was performed, 15 serogroups were obtained where the most prevalent was O157 and the least prevalent was O151. All isolates were positive when screened for identity gene gad A, while only typable strains were screened for seven virulence genes stx1 (gene encoding Shiga toxin 1), stx2 (gene encoding Shiga toxin 2), tsh (gene encoding thermostable hemagglutinin), eaeA (gene encoding intimin), invE (gene encoding invasion protein), aggR (gene encoding aggregative adherence transcriptional regulator), and astA (aspartate transaminase) where the prevalence was 48%, 30%, 50%, 57%, 7.5%, 12%, and 58%, respectively. Of 254 typable isolates, 152 were STEC carrying stx1 or stx2 genes or both. Conclusions: Relying on in vivo comparison between different E. coli pathotypes via histopathological examination of different organs, E. coli pathotypes could be divided into mild virulent, moderate virulent, and high virulent strains. Statistical analysis revealed significant correlation between different serogroups and presence of virulence genes.
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Affiliation(s)
- Rana Elshimy
- Department of Microbiology and Immunology, Egyptian Drug Authority, Giza, Egypt
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ahram Canadian University, 6th of October City, Egypt
| | - Hamdallah Zedan
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Tarek H Elmorsy
- Department of Microbiology and Immunology, Egyptian Drug Authority, Giza, Egypt
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4
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Patkowski JB, Dahlberg T, Amin H, Gahlot DK, Vijayrajratnam S, Vogel JP, Francis MS, Baker JL, Andersson M, Costa TRD. The F-pilus biomechanical adaptability accelerates conjugative dissemination of antimicrobial resistance and biofilm formation. Nat Commun 2023; 14:1879. [PMID: 37019921 PMCID: PMC10076315 DOI: 10.1038/s41467-023-37600-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 03/22/2023] [Indexed: 04/07/2023] Open
Abstract
Conjugation is used by bacteria to propagate antimicrobial resistance (AMR) in the environment. Central to this process are widespread conjugative F-pili that establish the connection between donor and recipient cells, thereby facilitating the spread of IncF plasmids among enteropathogenic bacteria. Here, we show that the F-pilus is highly flexible but robust at the same time, properties that increase its resistance to thermochemical and mechanical stresses. By a combination of biophysical and molecular dynamics methods, we establish that the presence of phosphatidylglycerol molecules in the F-pilus contributes to the structural stability of the polymer. Moreover, this structural stability is important for successful delivery of DNA during conjugation and facilitates rapid formation of biofilms in harsh environmental conditions. Thus, our work highlights the importance of F-pilus structural adaptations for the efficient spread of AMR genes in a bacterial population and for the formation of biofilms that protect against the action of antibiotics.
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Affiliation(s)
- Jonasz B Patkowski
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
| | - Tobias Dahlberg
- Department of Physics, Umeå University, 901 87, Umeå, Sweden
| | - Himani Amin
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
| | | | - Sukhithasri Vijayrajratnam
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Joseph P Vogel
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Matthew S Francis
- Department of Molecular Biology, Umeå University, 901 87, Umeå, Sweden
| | - Joseph L Baker
- Department of Chemistry, The College of New Jersey, Ewing, NJ, 08628, USA.
| | | | - Tiago R D Costa
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK.
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5
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Vogt SL, Serapio-Palacios A, Woodward SE, Santos AS, de Vries SP, Daigneault MC, Brandmeier LV, Grant AJ, Maskell DJ, Allen-Vercoe E, Finlay BB. Enterohemorrhagic Escherichia coli responds to gut microbiota metabolites by altering metabolism and activating stress responses. Gut Microbes 2023; 15:2190303. [PMID: 36951510 PMCID: PMC10038027 DOI: 10.1080/19490976.2023.2190303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 03/08/2023] [Indexed: 03/24/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a major cause of severe bloody diarrhea, with potentially lethal complications, such as hemolytic uremic syndrome. In humans, EHEC colonizes the colon, which is also home to a diverse community of trillions of microbes known as the gut microbiota. Although these microbes and the metabolites that they produce represent an important component of EHEC's ecological niche, little is known about how EHEC senses and responds to the presence of gut microbiota metabolites. In this study, we used a combined RNA-Seq and Tn-Seq approach to characterize EHEC's response to metabolites from an in vitro culture of 33 human gut microbiota isolates (MET-1), previously demonstrated to effectively resolve recurrent Clostridioides difficile infection in human patients. Collectively, the results revealed that EHEC adjusts to growth in the presence of microbiota metabolites in two major ways: by altering its metabolism and by activating stress responses. Metabolic adaptations to the presence of microbiota metabolites included increased expression of systems for maintaining redox balance and decreased expression of biotin biosynthesis genes, reflecting the high levels of biotin released by the microbiota into the culture medium. In addition, numerous genes related to envelope and oxidative stress responses (including cpxP, spy, soxS, yhcN, and bhsA) were upregulated during EHEC growth in a medium containing microbiota metabolites. Together, these results provide insight into the molecular mechanisms by which pathogens adapt to the presence of competing microbes in the host environment, which ultimately may enable the development of therapies to enhance colonization resistance and prevent infection.
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Affiliation(s)
- Stefanie L. Vogt
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Sarah E. Woodward
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrew S. Santos
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stefan P.W. de Vries
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Michelle C. Daigneault
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Lisa V. Brandmeier
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrew J. Grant
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Duncan J. Maskell
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Emma Allen-Vercoe
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - B. Brett Finlay
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
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6
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Prophylactic Catechin-Rich Green Tea Extract Treatment Ameliorates Pathogenic Enterotoxic Escherichia coli-Induced Colitis. Pathogens 2021; 10:pathogens10121573. [PMID: 34959529 PMCID: PMC8704293 DOI: 10.3390/pathogens10121573] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/26/2021] [Accepted: 11/30/2021] [Indexed: 12/12/2022] Open
Abstract
In this study, we explored the potential beneficial effects of green tea extract (GTE) in a pathogenic Escherichia coli (F18:LT:STa:Stx2e)-induced colitis model. The GTE was standardized with catechin and epigallocatechin-3-gallate content using chromatography analysis. Ten consecutive days of GTE (500 and 1000 mg/kg) oral administration was followed by 3 days of a pathogenic E. coli challenge (1 × 109 CFU/mL). In vitro antibacterial analysis showed that GTE successfully inhibited the growth of pathogenic E. coli, demonstrating over a 3-fold reduction under time- and concentration-dependent conditions. The in vivo antibacterial effect of GTE was confirmed, with an inhibition rate of approximately 90% when compared to that of the E. coli alone group. GTE treatment improved pathogenic E. coli-induced intestinal injury with well-preserved epithelial linings and villi. In addition, the increased expression of annexin A1 in GTE-treated jejunum tissue was detected, which was accompanied by suppressed inflammation-related signal expression, including TNFA, COX-2, and iNOS. Moreover, proliferation-related signals such as PCNA, CD44, and Ki-67 were enhanced in the GTE group compared to those in the E. coli alone group. Taken together, these results indicate that GTE has an antibacterial activity against pathogenic E. coli and ameliorates pathogenic E. coli-induced intestinal damage by modulating inflammation and epithelial cell proliferation.
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7
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Ageorges V, Monteiro R, Leroy S, Burgess CM, Pizza M, Chaucheyras-Durand F, Desvaux M. Molecular determinants of surface colonisation in diarrhoeagenic Escherichia coli (DEC): from bacterial adhesion to biofilm formation. FEMS Microbiol Rev 2021; 44:314-350. [PMID: 32239203 DOI: 10.1093/femsre/fuaa008] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/31/2020] [Indexed: 12/11/2022] Open
Abstract
Escherichia coli is primarily known as a commensal colonising the gastrointestinal tract of infants very early in life but some strains being responsible for diarrhoea, which can be especially severe in young children. Intestinal pathogenic E. coli include six pathotypes of diarrhoeagenic E. coli (DEC), namely, the (i) enterotoxigenic E. coli, (ii) enteroaggregative E. coli, (iii) enteropathogenic E. coli, (iv) enterohemorragic E. coli, (v) enteroinvasive E. coli and (vi) diffusely adherent E. coli. Prior to human infection, DEC can be found in natural environments, animal reservoirs, food processing environments and contaminated food matrices. From an ecophysiological point of view, DEC thus deal with very different biotopes and biocoenoses all along the food chain. In this context, this review focuses on the wide range of surface molecular determinants acting as surface colonisation factors (SCFs) in DEC. In the first instance, SCFs can be broadly discriminated into (i) extracellular polysaccharides, (ii) extracellular DNA and (iii) surface proteins. Surface proteins constitute the most diverse group of SCFs broadly discriminated into (i) monomeric SCFs, such as autotransporter (AT) adhesins, inverted ATs, heat-resistant agglutinins or some moonlighting proteins, (ii) oligomeric SCFs, namely, the trimeric ATs and (iii) supramolecular SCFs, including flagella and numerous pili, e.g. the injectisome, type 4 pili, curli chaperone-usher pili or conjugative pili. This review also details the gene regulatory network of these numerous SCFs at the various stages as it occurs from pre-transcriptional to post-translocational levels, which remains to be fully elucidated in many cases.
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Affiliation(s)
- Valentin Ageorges
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Ricardo Monteiro
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France.,GSK, Via Fiorentina 1, 53100 Siena, Italy
| | - Sabine Leroy
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Catherine M Burgess
- Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland
| | | | - Frédérique Chaucheyras-Durand
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France.,Lallemand Animal Nutrition SAS, F-31702 Blagnac Cedex, France
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
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8
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Ruano-Gallego D, Fernández LÁ. Identification of Nanobodies Blocking Intimate Adherence of Shiga Toxin-Producing Escherichia coli to Epithelial Cells. Methods Mol Biol 2021; 2291:253-272. [PMID: 33704757 DOI: 10.1007/978-1-0716-1339-9_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Therapeutic antibodies (Abs) inhibiting bacterial adhesion to host epithelia are an attractive option to reduce the load of Shiga toxin-producing E. coli (STEC) in the intestine of the patient and also in the bovine reservoir, thereby minimizing the risk of STEC contamination in the food chain. Of particular interest are recombinant single-domain Ab fragments called nanobodies (Nbs) derived from the variable domain of camelid heavy chain-only antibodies (VHH). The outer membrane adhesin intimin and the translocated intimin receptor (Tir) are essential for the attachment of STEC to host epithelia. In addition, EspA filaments of the bacterial type III protein secretion system are needed for Tir translocation into the host cell. Given their importance for bacterial adhesion and colonization, we developed Nbs against intimin, Tir and EspA proteins of STEC serotype O157:H7. Here, we report the screening methods used to isolate inhibitory Nbs blocking intimin-Tir protein-protein interaction, actin-pedestal formation, and intimate adhesion of STEC to epithelial cells in vitro. First, we describe how VHH gene repertoires can be produced as Nbs secreted by E. coli using the α-hemolysin (HlyA) protein secretion system. Next, we report the methods for identification of inhibitors of intimin-Tir protein-protein interaction and of STEC intimate adhesion to HeLa cells in culture. These methods can be adapted for the screening of Nbs against different adhesin-receptor complexes to block the adhesion of other pathogens to host cells.
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Affiliation(s)
- David Ruano-Gallego
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Madrid, Spain
| | - Luis Ángel Fernández
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Madrid, Spain.
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9
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Desvaux M, Dalmasso G, Beyrouthy R, Barnich N, Delmas J, Bonnet R. Pathogenicity Factors of Genomic Islands in Intestinal and Extraintestinal Escherichia coli. Front Microbiol 2020; 11:2065. [PMID: 33101219 PMCID: PMC7545054 DOI: 10.3389/fmicb.2020.02065] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/05/2020] [Indexed: 12/20/2022] Open
Abstract
Escherichia coli is a versatile bacterial species that includes both harmless commensal strains and pathogenic strains found in the gastrointestinal tract in humans and warm-blooded animals. The growing amount of DNA sequence information generated in the era of "genomics" has helped to increase our understanding of the factors and mechanisms involved in the diversification of this bacterial species. The pathogenic side of E. coli that is afforded through horizontal transfers of genes encoding virulence factors enables this bacterium to become a highly diverse and adapted pathogen that is responsible for intestinal or extraintestinal diseases in humans and animals. Many of the accessory genes acquired by horizontal transfers form syntenic blocks and are recognized as genomic islands (GIs). These genomic regions contribute to the rapid evolution, diversification and adaptation of E. coli variants because they are frequently subject to rearrangements, excision and transfer, as well as to further acquisition of additional DNA. Here, we review a subgroup of GIs from E. coli termed pathogenicity islands (PAIs), a concept defined in the late 1980s by Jörg Hacker and colleagues in Werner Goebel's group at the University of Würzburg, Würzburg, Germany. As with other GIs, the PAIs comprise large genomic regions that differ from the rest of the genome by their G + C content, by their typical insertion within transfer RNA genes, and by their harboring of direct repeats (at their ends), integrase determinants, or other mobility loci. The hallmark of PAIs is their contribution to the emergence of virulent bacteria and to the development of intestinal and extraintestinal diseases. This review summarizes the current knowledge on the structure and functional features of PAIs, on PAI-encoded E. coli pathogenicity factors and on the role of PAIs in host-pathogen interactions.
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Affiliation(s)
- Mickaël Desvaux
- Université Clermont Auvergne, INRAE, MEDiS, Clermont-Ferrand, France
| | - Guillaume Dalmasso
- UMR Inserm 1071, USC-INRAE 2018, M2iSH, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Racha Beyrouthy
- UMR Inserm 1071, USC-INRAE 2018, M2iSH, Université Clermont Auvergne, Clermont-Ferrand, France
- Laboratoire de Bactériologie, CHU Clermont-Ferrand, Clermont-Ferrand, France
| | - Nicolas Barnich
- UMR Inserm 1071, USC-INRAE 2018, M2iSH, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Julien Delmas
- UMR Inserm 1071, USC-INRAE 2018, M2iSH, Université Clermont Auvergne, Clermont-Ferrand, France
- Laboratoire de Bactériologie, CHU Clermont-Ferrand, Clermont-Ferrand, France
| | - Richard Bonnet
- UMR Inserm 1071, USC-INRAE 2018, M2iSH, Université Clermont Auvergne, Clermont-Ferrand, France
- Laboratoire de Bactériologie, CHU Clermont-Ferrand, Clermont-Ferrand, France
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10
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Teng L, Lee S, Park D, Jeong KC. Genetic and Functional Analyses of Virulence Potential of an Escherichia coli O157:H7 Strain Isolated From Super-Shedder Cattle. Front Cell Infect Microbiol 2020; 10:271. [PMID: 32582570 PMCID: PMC7289925 DOI: 10.3389/fcimb.2020.00271] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 05/07/2020] [Indexed: 12/19/2022] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) O157:H7 is an enteric pathogen that causes life-threatening disease in humans, with cattle being major natural reservoirs. A group of STEC O157:H7 with a dramatic combination of high virulence potentials and super-shedder bovine origin have been isolated. Here, an STEC O157:H7 isolate, JEONG-1266, was analyzed by comparative genomics, stx genotyping, and phenotypic analyses. The phylogenetic typing and whole-genome comparison consistently showed that JEONG-1266 is genetically close to EC4115 (one of 2006 Spinach outbreak isolates) and SS17 (an isolate from super-shedder cattle) strains, all of which belong to lineage I/II and Clade 8. Both lineage I/II and Clade 8 are known to be mostly associated with clinical strains with high virulence and severe clinical symptoms. Further, JEONG-1266, like EC4115 and SS17, harbors stx2a/stx2c genes, and carries Stx-encoding prophages, specifically the φstx2a-γ subtype. Possession of the φstx2a-γ subtype of Stx-encoding prophages and production of Stx2a have been shown to be a key signature associated with hypervirulent STEC O157:H7 strains. In silico virulence typing elucidated JEONG-1266, EC4115, and SS17 shared a highly conserved profile of key virulence genes at the nucleotide sequence level. Consistently, phenotypic data showed that JEONG-1266 expressed a high level of Stx2 toxins and had the full capacity of adhesion in vitro. Taken together, our study suggests that JEONG-1266 may represent an emerging STEC O157:H7 group, which are hypervirulent strains that originate from super-shedders, that can be a threat to food safety and public health.
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Affiliation(s)
- Lin Teng
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States.,Department of Animal Sciences, University of Florida, Gainesville, FL, United States
| | - Shinyoung Lee
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States.,Department of Animal Sciences, University of Florida, Gainesville, FL, United States
| | - Dongjin Park
- Food Science and Technology Department, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Kwangcheol Casey Jeong
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States.,Department of Animal Sciences, University of Florida, Gainesville, FL, United States
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11
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Enterohemorrhagic Escherichia coli infection inhibits colonic thiamin pyrophosphate uptake via transcriptional mechanism. PLoS One 2019; 14:e0224234. [PMID: 31639155 PMCID: PMC6804999 DOI: 10.1371/journal.pone.0224234] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/08/2019] [Indexed: 01/19/2023] Open
Abstract
Colonocytes possess a specific carrier-mediated uptake process for the microbiota-generated thiamin (vitamin B1) pyrophosphate (TPP) that involves the TPP transporter (TPPT; product of the SLC44A4 gene). Little is known about the effect of exogenous factors (including enteric pathogens) on the colonic TPP uptake process. Our aim in this study was to investigate the effect of Enterohemorrhagic Escherichia coli (EHEC) infection on colonic uptake of TPP. We used human-derived colonic epithelial NCM460 cells and mice in our investigation. The results showed that infecting NCM460 cells with live EHEC (but not with heat-killed EHEC, EHEC culture supernatant, or with non-pathogenic E. Coli) to lead to a significant inhibition in carrier-mediated TPP uptake, as well as in level of expression of the TPPT protein and mRNA. Similarly, infecting mice with EHEC led to a significant inhibition in colonic TPP uptake and in level of expression of TPPT protein and mRNA. The inhibitory effect of EHEC on TPP uptake by NCM460 was found to be associated with reduction in the rate of transcription of the SLC44A4 gene as indicated by the significant reduction in the activity of the SLC44A4 promoter transfected into EHEC infected cells. The latter was also associated with a marked reduction in the level of expression of the transcription factors CREB-1 and ELF3, which are known to drive the activity of the SLC44A4 promoter. Finally, blocking the ERK1/2 and NF-kB signaling pathways in NCM460 cells significantly reversed the level of EHEC inhibition in TPP uptake and TPPT expression. Collectively, these findings show, for the first time, that EHEC infection significantly inhibit colonic uptake of TPP, and that this effect appears to be exerted at the level of SLC44A4 transcription and involves the ERK1/2 and NF-kB signaling pathways.
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12
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Sarkar S, Hutton ML, Vagenas D, Ruter R, Schüller S, Lyras D, Schembri MA, Totsika M. Intestinal Colonization Traits of Pandemic Multidrug-Resistant Escherichia coli ST131. J Infect Dis 2019; 218:979-990. [PMID: 29471349 PMCID: PMC6093498 DOI: 10.1093/infdis/jiy031] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 02/01/2018] [Indexed: 01/09/2023] Open
Abstract
Background Epidemiological studies point to the gut as a key reservoir of multidrug resistant Escherichia coli multilocus sequence type 131 (ST131), a globally dominant pathogenic clone causing urinary tract and bloodstream infections. Here we report a detailed investigation of its intestinal lifestyle. Methods Clinical ST131 isolates and type 1 fimbriae null mutants were assessed for colonization of human intestinal epithelia and in mouse intestinal colonization models. Mouse gut tissue underwent histologic analysis for pathology and ST131 localization. Key findings were corroborated in mucus-producing human cell lines and intestinal biopsy specimens. Results ST131 strains adhered to and invaded human intestinal epithelial cells more than probiotic and commensal strains. The reference ST131 strain EC958 established persistent intestinal colonization in mice, and expression of type 1 fimbriae mediated higher colonization levels. Bacterial loads were highest in the distal parts of the mouse intestine and did not cause any obvious pathology. Further analysis revealed that EC958 could bind to both mucus and underlying human intestinal epithelia. Conclusions ST131 strains can efficiently colonize the mammalian gut and persist long term. Type 1 fimbriae enhance ST131 intestinal colonization, suggesting that mannosides, currently developed as therapeutics for bladder infections and Crohn’s disease, could also be used to limit intestinal ST131 reservoirs.
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Affiliation(s)
- Sohinee Sarkar
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Queensland, Australia
- School of Biomedical Sciences, Queensland University of Technology, Queensland, Australia
| | - Melanie L Hutton
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Clayton, Australia
- Department of Microbiology, Monash University, Clayton, Australia
| | - Dimitrios Vagenas
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Queensland, Australia
- School of Biomedical Sciences, Queensland University of Technology, Queensland, Australia
| | - Rinaldo Ruter
- Gut Health and Food Safety Programme, Quadram Institute Bioscience, Norwich, United Kingdom
| | - Stephanie Schüller
- Gut Health and Food Safety Programme, Quadram Institute Bioscience, Norwich, United Kingdom
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Clayton, Australia
- Department of Microbiology, Monash University, Clayton, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Queensland, Australia
- School of Biomedical Sciences, Queensland University of Technology, Queensland, Australia
- Correspondence: M. Totsika, PhD, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, QLD 4059, Australia ()
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13
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Ruano-Gallego D, Yara DA, Di Ianni L, Frankel G, Schüller S, Fernández LÁ. A nanobody targeting the translocated intimin receptor inhibits the attachment of enterohemorrhagic E. coli to human colonic mucosa. PLoS Pathog 2019; 15:e1008031. [PMID: 31465434 PMCID: PMC6738647 DOI: 10.1371/journal.ppat.1008031] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 09/11/2019] [Accepted: 08/15/2019] [Indexed: 12/31/2022] Open
Abstract
Enterohemorrhagic E. coli (EHEC) is a human intestinal pathogen that causes hemorrhagic colitis and hemolytic uremic syndrome. No vaccines or specific therapies are currently available to prevent or treat these infections. EHEC tightly attaches to the intestinal epithelium by injecting the intimin receptor Tir into the host cell via a type III secretion system (T3SS). In this project, we identified a camelid single domain antibody (nanobody), named TD4, that recognizes a conserved Tir epitope overlapping the binding site of its natural ligand intimin with high affinity and stability. We show that TD4 inhibits attachment of EHEC to cultured human HeLa cells by preventing Tir clustering by intimin, activation of downstream actin polymerization and pedestal formation. Furthermore, we demonstrate that TD4 significantly reduces EHEC adherence to human colonic mucosa in in vitro organ cultures. Altogether, these results suggest that nanobody-based therapies hold potential in the development of much needed treatment and prevention strategies against EHEC infection. Currently, there is no effective treatment or vaccine against enterohemorrhagic E. coli (EHEC), a bacterial pathogen that infects human colon after the ingestion of contaminated food. It thrives in the colon thanks to its ability to attach intimately to the intestinal epithelium. Here, we have identified and characterised a small antibody fragment (nanobody) that recognises Tir, a receptor injected by the bacterium into the host cell to mediate intimate attachment. This nanobody shows higher affinity against Tir than its natural bacterial ligand (intimin) and, most importantly, blocks the intimate attachment of the pathogen to the human colonic tissue. Our results show the potential of this nanobody to prevent and treat EHEC infection.
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Affiliation(s)
- David Ruano-Gallego
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus UAM-Cantoblanco, Madrid, Spain
- MRC Centre for Molecular Bacteriology and Infection, Life Sciences Department, Imperial College London, London, United Kingdom
| | - Daniel A. Yara
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
- Quadram Institute Bioscience, Norwich Research Park, Norwich, United Kingdom
| | - Lorenza Di Ianni
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus UAM-Cantoblanco, Madrid, Spain
| | - Gad Frankel
- MRC Centre for Molecular Bacteriology and Infection, Life Sciences Department, Imperial College London, London, United Kingdom
| | - Stephanie Schüller
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
- Quadram Institute Bioscience, Norwich Research Park, Norwich, United Kingdom
| | - Luis Ángel Fernández
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus UAM-Cantoblanco, Madrid, Spain
- * E-mail:
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14
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Essential Oils-Loaded Polymer Particles: Preparation, Characterization and Antimicrobial Property. Polymers (Basel) 2019; 11:polym11061017. [PMID: 31181851 PMCID: PMC6630521 DOI: 10.3390/polym11061017] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/03/2019] [Accepted: 06/05/2019] [Indexed: 12/04/2022] Open
Abstract
In the last few years, essential oils (EOs) derived from plants have aroused great interest due to their well-known antimicrobial activity. Unfortunately, they present several limitations in their use, such as photosensitivity, temperature sensitivity, high volatility, and poor water solubility. The encapsulation technique represents a good solution to these problems and ensures protection of the functional properties of essential oils. In this work, bergamot essential oil (BEO) and sweet orange essential oil (OEO) loaded-Eudragit® RS 100 (EuRS100) nanoparticles (NPs) were prepared by using the nanoprecipitation technique. We obtained nanoparticles characterized by a mean diameter of 57 to 208 nm and a positive surface charge (39 to 74 mV). The antibacterial activity of the obtained systems against Escherichia coli was in vitro investigated. We demonstrated that both orange and bergamot essential oils were successfully encapsulated and our nanoparticles have good antibacterial activity. Finally, in order to evaluate the potential applicability of OEONps to prolong fresh orange juice shelf-life, survival of E. coli during a storage period of one week at 25 °C was investigated: Orange essential oil-loaded nanoparticles (OEONPs) have been able to prolong the orange juice shelf life.
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15
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Etienne-Mesmin L, Chassaing B, Desvaux M, De Paepe K, Gresse R, Sauvaitre T, Forano E, de Wiele TV, Schüller S, Juge N, Blanquet-Diot S. Experimental models to study intestinal microbes–mucus interactions in health and disease. FEMS Microbiol Rev 2019; 43:457-489. [DOI: 10.1093/femsre/fuz013] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 05/31/2019] [Indexed: 02/06/2023] Open
Abstract
ABSTRACT
A close symbiotic relationship exists between the intestinal microbiota and its host. A critical component of gut homeostasis is the presence of a mucus layer covering the gastrointestinal tract. Mucus is a viscoelastic gel at the interface between the luminal content and the host tissue that provides a habitat to the gut microbiota and protects the intestinal epithelium. The review starts by setting up the biological context underpinning the need for experimental models to study gut bacteria-mucus interactions in the digestive environment. We provide an overview of the structure and function of intestinal mucus and mucins, their interactions with intestinal bacteria (including commensal, probiotics and pathogenic microorganisms) and their role in modulating health and disease states. We then describe the characteristics and potentials of experimental models currently available to study the mechanisms underpinning the interaction of mucus with gut microbes, including in vitro, ex vivo and in vivo models. We then discuss the limitations and challenges facing this field of research.
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Affiliation(s)
- Lucie Etienne-Mesmin
- Université Clermont Auvergne, INRA, MEDIS, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France
| | - Benoit Chassaing
- Neuroscience Institute, Georgia State University, 100 Piedmont Ave SE, Atlanta, GA 30303 , USA
- Institute for Biomedical Sciences, Georgia State University, 100 Piedmont Ave, Atlanta, GA 30303 , USA
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRA, MEDIS, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France
| | - Kim De Paepe
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Raphaële Gresse
- Université Clermont Auvergne, INRA, MEDIS, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France
| | - Thomas Sauvaitre
- Université Clermont Auvergne, INRA, MEDIS, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France
| | - Evelyne Forano
- Université Clermont Auvergne, INRA, MEDIS, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France
| | - Tom Van de Wiele
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Stephanie Schüller
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
- Quadram Institute Bioscience, Norwich Research Park, Norwich NR7UQ, United Kingdom
| | - Nathalie Juge
- Quadram Institute Bioscience, Norwich Research Park, Norwich NR7UQ, United Kingdom
| | - Stéphanie Blanquet-Diot
- Université Clermont Auvergne, INRA, MEDIS, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France
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16
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Response to Questions Posed by the Food and Drug Administration Regarding Virulence Factors and Attributes that Define Foodborne Shiga Toxin-Producing Escherichia coli (STEC) as Severe Human Pathogens †. J Food Prot 2019; 82:724-767. [PMID: 30969806 DOI: 10.4315/0362-028x.jfp-18-479] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
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- NACMCF Executive Secretariat, * U.S. Department of Agriculture, Food Safety and Inspection Service, Office of Public Health Science, PP3, 9-178, 1400 Independence Avenue S.W., Washington, D.C. 20250-3700, USA
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17
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Tovaglieri A, Sontheimer-Phelps A, Geirnaert A, Prantil-Baun R, Camacho DM, Chou DB, Jalili-Firoozinezhad S, de Wouters T, Kasendra M, Super M, Cartwright MJ, Richmond CA, Breault DT, Lacroix C, Ingber DE. Species-specific enhancement of enterohemorrhagic E. coli pathogenesis mediated by microbiome metabolites. MICROBIOME 2019; 7:43. [PMID: 30890187 PMCID: PMC6425591 DOI: 10.1186/s40168-019-0650-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 02/21/2019] [Indexed: 05/24/2023]
Abstract
BACKGROUND Species-specific differences in tolerance to infection are exemplified by the high susceptibility of humans to enterohemorrhagic Escherichia coli (EHEC) infection, whereas mice are relatively resistant to this pathogen. This intrinsic species-specific difference in EHEC infection limits the translation of murine research to human. Furthermore, studying the mechanisms underlying this differential susceptibility is a difficult problem due to complex in vivo interactions between the host, pathogen, and disparate commensal microbial communities. RESULTS We utilize organ-on-a-chip (Organ Chip) microfluidic culture technology to model damage of the human colonic epithelium induced by EHEC infection, and show that epithelial injury is greater when exposed to metabolites derived from the human gut microbiome compared to mouse. Using a multi-omics approach, we discovered four human microbiome metabolites-4-methyl benzoic acid, 3,4-dimethylbenzoic acid, hexanoic acid, and heptanoic acid-that are sufficient to mediate this effect. The active human microbiome metabolites preferentially induce expression of flagellin, a bacterial protein associated with motility of EHEC and increased epithelial injury. Thus, the decreased tolerance to infection observed in humans versus other species may be due in part to the presence of compounds produced by the human intestinal microbiome that actively promote bacterial pathogenicity. CONCLUSION Organ-on-chip technology allowed the identification of specific human microbiome metabolites modulating EHEC pathogenesis. These identified metabolites are sufficient to increase susceptibility to EHEC in our human Colon Chip model and they contribute to species-specific tolerance. This work suggests that higher concentrations of these metabolites could be the reason for higher susceptibility to EHEC infection in certain human populations, such as children. Furthermore, this research lays the foundation for therapeutic-modulation of microbe products in order to prevent and treat human bacterial infection.
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Affiliation(s)
- Alessio Tovaglieri
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Department of Health Sciences and Technology, ETH Zurich, 8092, Zurich, Switzerland
| | - Alexandra Sontheimer-Phelps
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Department of Biology, University of Freiburg, 79085, Freiburg, Germany
| | - Annelies Geirnaert
- Department of Health Sciences and Technology, ETH Zurich, 8092, Zurich, Switzerland
| | - Rachelle Prantil-Baun
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Diogo M Camacho
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - David B Chou
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, 02115, USA
| | - Sasan Jalili-Firoozinezhad
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Department of Bioengineering and iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1649-004, Lisbon, Portugal
| | - Tomás de Wouters
- Department of Health Sciences and Technology, ETH Zurich, 8092, Zurich, Switzerland
| | - Magdalena Kasendra
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Present Address: Emulate Inc., 27 Drydock Avenue, Boston, MA, 02210, USA
| | - Michael Super
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Mark J Cartwright
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Camilla A Richmond
- Division of Gastroenterology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
- Harvard Stem Cell Institute, Harvard University, Boston, MA, 02139, USA
| | - David T Breault
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
- Harvard Stem Cell Institute, Harvard University, Boston, MA, 02139, USA
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Christophe Lacroix
- Department of Health Sciences and Technology, ETH Zurich, 8092, Zurich, Switzerland
| | - Donald E Ingber
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA.
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
- Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA, 02139, USA.
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18
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Stromberg ZR, Redweik GAJ, Mellata M. Detection, Prevalence, and Pathogenicity of Non-O157 Shiga Toxin-Producing Escherichia coli from Cattle Hides and Carcasses. Foodborne Pathog Dis 2019; 15:119-131. [PMID: 29638166 DOI: 10.1089/fpd.2017.2401] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Cattle are a major reservoir for Shiga toxin-producing Escherichia coli (STEC) and harbor these bacteria in the intestinal tract. The prevalence, concentration, and STEC serogroup isolated in cattle varies between individuals. Hide removal at slaughter serves as a major point of carcass contamination and ultimately beef products. Certain STEC serogroups, such as O26, O45, O103, O111, O121, O145, and O157, containing the intestinal adherence factor intimin, pose a large economic burden to food producers because of testing and recalls. Human infection with STEC can cause illnesses ranging from diarrhea to hemorrhagic colitis and hemolytic uremic syndrome, and is commonly acquired through ingestion of contaminated foods, often beef products. Previously, most studies focused on O157 STEC, but there is growing recognition of the importance of non-O157 STEC serogroups. This review summarizes detection methods, prevalence, and methods for prediction of pathogenicity of non-O157 STEC from cattle hides and carcasses. A synthesis of procedures is outlined for general non-O157 STEC and targeted detection of specific STEC serogroups. Standardization of sample collection and processing procedures would allow for more robust comparisons among studies. Presence of non-O157 STEC isolated from cattle hides and carcasses and specific factors, such as point of sample collection and season, are summarized. Also, factors that might influence STEC survival on these surfaces, such as the microbial population on hides and microbial adherence genes, are raised as topics for future investigation. Finally, this review gives an overview on studies that have used genetic and cell-based methods to identify specific phenotypes of non-O157 STEC strains isolated from cattle to assess their risk to human health.
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Affiliation(s)
- Zachary R Stromberg
- Department of Food Science and Human Nutrition, Iowa State University , Ames, Iowa
| | - Graham A J Redweik
- Department of Food Science and Human Nutrition, Iowa State University , Ames, Iowa
| | - Melha Mellata
- Department of Food Science and Human Nutrition, Iowa State University , Ames, Iowa
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19
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Takahashi K, Hanamura Y, Tokunoh N, Kassai K, Matsunishi M, Watanabe S, Sugiyama T, Inoue N. Protective effects of oral immunization with formalin-inactivated whole-cell Citrobacter rodentium on Citrobacter rodentium infection in mice. J Microbiol Methods 2019; 159:62-68. [PMID: 30817947 DOI: 10.1016/j.mimet.2019.02.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/20/2019] [Accepted: 02/22/2019] [Indexed: 10/27/2022]
Abstract
Evaluation of the efficacy of vaccine candidates that prevent enteropathogenic and enterohemorrhagic Escherichia coli (EPEC/EHEC) infection in mouse models is difficult due to their limited pathogenicity in mice. Citrobacter rodentium, a murine pathogenic bacterium that shares its infection strategy and virulence genes with EPEC/EHEC, has been used as a model pathogen to develop novel vaccine strategies or platforms for these bacteria. However, there are few reports on the comparative effectiveness of novel vaccine platforms as no C. rodentium vaccines have yet been prepared by standard methods such as bacteria attenuation or inactivation. In this study, we investigated the protective effect of the oral administration of formalin-inactivated C. rodentium (Fo-CR) on C. rodentium infection in two mouse strains, C57BL/6 and C3H/HeN, as these strains have different degrees of susceptibility to infection. In C57BL/6 mice, administration of Fo-CR induced significant C. rodentium-specific mucosal and systemic antibody responses, promoted bacterial clearance from the gut and inhibited colonic hyperplasia. Furthermore, in C3H/HeN mice, the administration followed by lethal C. rodentium infection induced significantly high avidity serum IgG specific to C. rodentium and inhibited death, body weight loss, and bacterial invasion to visceral organs. In conclusion, the oral administration of Fo-CR resulted in the protection of mice from C. rodentium infection, indicating that it serves as a reference method for evaluating the efficacy of novel oral vaccine candidates or platforms.
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Affiliation(s)
- Keita Takahashi
- Department of Pharmacy, Laboratory of Microbiology and Immunology, Gifu Pharmaceutical University, Gifu 501-1196, Japan.
| | - Yuki Hanamura
- Department of Pharmacy, Laboratory of Microbiology and Immunology, Gifu Pharmaceutical University, Gifu 501-1196, Japan
| | - Nagisa Tokunoh
- Department of Pharmacy, Laboratory of Microbiology and Immunology, Gifu Pharmaceutical University, Gifu 501-1196, Japan
| | - Kohei Kassai
- Department of Pharmacy, Laboratory of Microbiology and Immunology, Gifu Pharmaceutical University, Gifu 501-1196, Japan
| | - Masaru Matsunishi
- Department of Pharmacy, Laboratory of Microbiology and Immunology, Gifu Pharmaceutical University, Gifu 501-1196, Japan
| | - Shiori Watanabe
- Department of Pharmacy, Laboratory of Microbiology and Immunology, Gifu Pharmaceutical University, Gifu 501-1196, Japan
| | - Tsuyoshi Sugiyama
- Department of Pharmacy, Laboratory of Microbiology and Immunology, Gifu Pharmaceutical University, Gifu 501-1196, Japan; Department of Medical Technology, Gifu University of Medical Science, Gifu 501-3892, Japan
| | - Naoki Inoue
- Department of Pharmacy, Laboratory of Microbiology and Immunology, Gifu Pharmaceutical University, Gifu 501-1196, Japan.
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20
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Ellis SJ, Yasir M, Browning DF, Busby SJW, Schüller S. Oxygen and contact with human intestinal epithelium independently stimulate virulence gene expression in enteroaggregative Escherichia coli. Cell Microbiol 2019; 21:e13012. [PMID: 30673154 PMCID: PMC6563437 DOI: 10.1111/cmi.13012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 12/14/2018] [Accepted: 01/14/2019] [Indexed: 12/22/2022]
Abstract
Enteroaggregative Escherichia coli (EAEC) are important intestinal pathogens causing acute and persistent diarrhoeal illness worldwide. Although many putative EAEC virulence factors have been identified, their association with pathogenesis remains unclear. As environmental cues can modulate bacterial virulence, we investigated the effect of oxygen and human intestinal epithelium on EAEC virulence gene expression to determine the involvement of respective gene products in intestinal colonisation and pathogenesis. Using in vitro organ culture of human intestinal biopsies, we established the colonic epithelium as the major colonisation site of EAEC strains 042 and 17‐2. We subsequently optimised a vertical diffusion chamber system with polarised T84 colon carcinoma cells for EAEC infection and showed that oxygen induced expression of the global regulator AggR, aggregative adherence fimbriae, E. coli common pilus, EAST‐1 toxin, and dispersin in EAEC strain 042 but not in 17‐2. Furthermore, the presence of T84 epithelia stimulated additional expression of the mucinase Pic and the toxins HlyE and Pet. This induction was dependent on physical host cell contact and did not require AggR. Overall, these findings suggest that EAEC virulence in the human gut is modulated by environmental signals including oxygen and the intestinal epithelium.
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Affiliation(s)
- Samuel J Ellis
- Norwich Medical School, University of East Anglia, Norwich, UK.,Quadram Institute Bioscience, Norwich, UK
| | - Muhammad Yasir
- Quadram Institute Bioscience, Norwich, UK.,Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Douglas F Browning
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Stephen J W Busby
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Stephanie Schüller
- Norwich Medical School, University of East Anglia, Norwich, UK.,Quadram Institute Bioscience, Norwich, UK
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21
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Gioia-Di Chiacchio RM, Cunha MPV, de Sá LRM, Davies YM, Pereira CBP, Martins FH, Munhoz DD, Abe CM, Franzolin MR, Dos Santos LF, Guth BEC, Elias WP, Piazza RMF, Knöbl T. Novel Hybrid of Typical Enteropathogenic Escherichia coli and Shiga-Toxin-Producing E. coli (tEPEC/STEC) Emerging From Pet Birds. Front Microbiol 2018; 9:2975. [PMID: 30574131 PMCID: PMC6291465 DOI: 10.3389/fmicb.2018.02975] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/19/2018] [Indexed: 12/01/2022] Open
Abstract
Exotic psittacine birds have been implicated as reservoir of diarrheagenic Escherichia coli (E. coli), including enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC). Here, we present a genotypic and phenotypic characterization of typical EPEC/STEC hybrid strains isolated from exotic psittacine birds. The strains were positive for eae, bfpA, and stx2f genes, belong to serotype O137:H6 and ST2678. Two strains were subject to whole genome sequencing, confirming the presence of the virulence factors of both E. coli pathotypes. Phenotypical in vitro tests confirmed their ability to adhere to HeLa cells and cause cytotoxicity to Vero cells. The rabbit ileal loop assays showed the attaching and effacing lesion, in addition to inflammatory process and overproduction of intestinal mucus. This is the first report of hybrid typical EPEC/STEC (O137:H6/ST2678) strains isolated from companion psittacine birds and the results suggest zoonotic risks.
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Affiliation(s)
- Rosely Martins Gioia-Di Chiacchio
- Department of Pathology, School of Veterinary Medicine and Animal Science, São Paulo, Brazil.,School of Veterinary Medicine, Paulista University, São Paulo, Brazil
| | | | | | - Yamê Minieiro Davies
- Department of Pathology, School of Veterinary Medicine and Animal Science, São Paulo, Brazil
| | | | | | | | | | | | | | | | | | | | - Terezinha Knöbl
- Department of Pathology, School of Veterinary Medicine and Animal Science, São Paulo, Brazil
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22
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Modulation of Enterohaemorrhagic Escherichia coli Survival and Virulence in the Human Gastrointestinal Tract. Microorganisms 2018; 6:microorganisms6040115. [PMID: 30463258 PMCID: PMC6313751 DOI: 10.3390/microorganisms6040115] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/16/2018] [Accepted: 11/18/2018] [Indexed: 01/05/2023] Open
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) is a major foodborne pathogen responsible for human diseases ranging from diarrhoea to life-threatening complications. Survival of the pathogen and modulation of virulence gene expression along the human gastrointestinal tract (GIT) are key features in bacterial pathogenesis, but remain poorly described, due to a paucity of relevant model systems. This review will provide an overview of the in vitro and in vivo studies investigating the effect of abiotic (e.g., gastric acid, bile, low oxygen concentration or fluid shear) and biotic (e.g., gut microbiota, short chain fatty acids or host hormones) parameters of the human gut on EHEC survival and/or virulence (especially in relation with motility, adhesion and toxin production). Despite their relevance, these studies display important limitations considering the complexity of the human digestive environment. These include the evaluation of only one single digestive parameter at a time, lack of dynamic flux and compartmentalization, and the absence of a complex human gut microbiota. In a last part of the review, we will discuss how dynamic multi-compartmental in vitro models of the human gut represent a novel platform for elucidating spatial and temporal modulation of EHEC survival and virulence along the GIT, and provide new insights into EHEC pathogenesis.
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23
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After the Fact(or): Posttranscriptional Gene Regulation in Enterohemorrhagic Escherichia coli O157:H7. J Bacteriol 2018; 200:JB.00228-18. [PMID: 29967119 DOI: 10.1128/jb.00228-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To adapt to ever-changing environments, pathogens quickly alter gene expression. This can occur through transcriptional, posttranscriptional, or posttranslational regulation. Historically, transcriptional regulation has been thoroughly studied to understand pathogen niche adaptation, whereas posttranscriptional and posttranslational gene regulation has only relatively recently been appreciated to play a central role in bacterial pathogenesis. Posttranscriptional regulation may involve chaperones, nucleases, and/or noncoding small RNAs (sRNAs) and typically controls gene expression by altering the stability and/or translation of the target mRNA. In this review, we highlight the global importance of posttranscriptional regulation to enterohemorrhagic Escherichia coli (EHEC) gene expression and discuss specific mechanisms of how EHEC regulates expression of virulence factors critical to host colonization and disease progression. The low infectious dose of this intestinal pathogen suggests that EHEC is particularly well adapted to respond to the host environment.
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24
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Rojas-Lopez M, Monterio R, Pizza M, Desvaux M, Rosini R. Intestinal Pathogenic Escherichia coli: Insights for Vaccine Development. Front Microbiol 2018; 9:440. [PMID: 29615989 PMCID: PMC5869917 DOI: 10.3389/fmicb.2018.00440] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/26/2018] [Indexed: 12/13/2022] Open
Abstract
Diarrheal diseases are one of the major causes of mortality among children under five years old and intestinal pathogenic Escherichia coli (InPEC) plays a role as one of the large causative groups of these infections worldwide. InPECs contribute significantly to the burden of intestinal diseases, which are a critical issue in low- and middle-income countries (Asia, Africa and Latin America). Intestinal pathotypes such as enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC) are mainly endemic in developing countries, while ETEC strains are the major cause of diarrhea in travelers to these countries. On the other hand, enterohemorrhagic E. coli (EHEC) are the cause of large outbreaks around the world, mainly affecting developed countries and responsible for not only diarrheal disease but also severe clinical complications like hemorrhagic colitis and hemolytic uremic syndrome (HUS). Overall, the emergence of antibiotic resistant strains, the annual cost increase in the health care system, the high incidence of traveler diarrhea and the increased number of HUS episodes have raised the need for effective preventive treatments. Although the use of antibiotics is still important in treating such infections, non-antibiotic strategies are either a crucial option to limit the increase in antibiotic resistant strains or absolutely necessary for diseases such as those caused by EHEC infections, for which antibiotic therapies are not recommended. Among non-antibiotic therapies, vaccine development is a strategy of choice but, to date, there is no effective licensed vaccine against InPEC infections. For several years, there has been a sustained effort to identify efficacious vaccine candidates able to reduce the burden of diarrheal disease. The aim of this review is to summarize recent milestones and insights in vaccine development against InPECs.
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Affiliation(s)
- Maricarmen Rojas-Lopez
- GSK, Siena, Italy.,Institut National de la Recherche Agronomique, Université Clermont Auvergne, UMR454 MEDiS, Clermont-Ferrand, France
| | - Ricardo Monterio
- Institut National de la Recherche Agronomique, Université Clermont Auvergne, UMR454 MEDiS, Clermont-Ferrand, France
| | | | - Mickaël Desvaux
- Institut National de la Recherche Agronomique, Université Clermont Auvergne, UMR454 MEDiS, Clermont-Ferrand, France
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25
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Tran SL, Jenkins C, Livrelli V, Schüller S. Shiga toxin 2 translocation across intestinal epithelium is linked to virulence of Shiga toxin-producing Escherichia coli in humans. MICROBIOLOGY-SGM 2018. [PMID: 29533744 PMCID: PMC5982136 DOI: 10.1099/mic.0.000645] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
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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Affiliation(s)
- Seav-Ly Tran
- Norwich Medical School, University of East Anglia, Norwich, UK.,Gut Health and Food Safety Programme, Quadram Institute Bioscience, Norwich, UK.,Present address: Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Claire Jenkins
- Gastrointestinal Bacteria Reference Unit, Public Health England, London, UK
| | - Valérie Livrelli
- Université Clermont Auvergne, Inserm U1071, M2iSH 'Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte', USC-INRA 2018, Clermont-Ferrand, France.,CHU Clermont-Ferrand, Service de Bactériologie, Parasitologie Mycologie, Clermont-Ferrand, France
| | - Stephanie Schüller
- Norwich Medical School, University of East Anglia, Norwich, UK.,Gut Health and Food Safety Programme, Quadram Institute Bioscience, Norwich, UK
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26
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Attaching and effacing (A/E) lesion formation by enteropathogenic E. coli on human intestinal mucosa is dependent on non-LEE effectors. PLoS Pathog 2017; 13:e1006706. [PMID: 29084270 PMCID: PMC5685641 DOI: 10.1371/journal.ppat.1006706] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 11/14/2017] [Accepted: 10/20/2017] [Indexed: 01/31/2023] Open
Abstract
Enteropathogenic E. coli (EPEC) is a human pathogen that causes acute and chronic pediatric diarrhea. The hallmark of EPEC infection is the formation of attaching and effacing (A/E) lesions in the intestinal epithelium. Formation of A/E lesions is mediated by genes located on the pathogenicity island locus of enterocyte effacement (LEE), which encode the adhesin intimin, a type III secretion system (T3SS) and six effectors, including the essential translocated intimin receptor (Tir). Seventeen additional effectors are encoded by genes located outside the LEE, in insertion elements and prophages. Here, using a stepwise approach, we generated an EPEC mutant lacking the entire effector genes (EPEC0) and intermediate mutants. We show that EPEC0 contains a functional T3SS. An EPEC mutant expressing intimin but lacking all the LEE effectors but Tir (EPEC1) was able to trigger robust actin polymerization in HeLa cells and mucin-producing intestinal LS174T cells. However, EPEC1 was unable to form A/E lesions on human intestinal in vitro organ cultures (IVOC). Screening the intermediate mutants for genes involved in A/E lesion formation on IVOC revealed that strains lacking non-LEE effector/s have a marginal ability to form A/E lesions. Furthermore, we found that Efa1/LifA proteins are important for A/E lesion formation efficiency in EPEC strains lacking multiple effectors. Taken together, these results demonstrate the intricate relationships between T3SS effectors and the essential role non-LEE effectors play in A/E lesion formation on mucosal surfaces. Enteropathogenic E. coli (EPEC) causes diarrhea and generates the attaching and effacing (A/E) lesion in human gut epithelium. A/E lesion formation requires the locus of enterocyte effacement (LEE) in the bacterial genome, which encodes a protein injection system delivering the translocated intimin receptor (Tir), which binds to intimin on the bacterial surface. Intimin-Tir interaction is sufficient for bacterial attachment to epithelial cells in vitro but additional effectors may be needed for A/E lesion formation in the human gut. By generating deletion mutants lacking combinations or the whole repertoire of protein effectors encoded by EPEC, we show that intimin-Tir interaction is not sufficient and reveal an additive role of non-LEE effectors for A/E lesion formation in human intestinal tissue.
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27
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Ye W, Chen T, Mao Y, Tian F, Sun P, Yang M. The effect of pore size in an ultrasensitive DNA sandwich-hybridization assay for the Escherichia coli O157:H7 gene based on the use of a nanoporous alumina membrane. Mikrochim Acta 2017. [DOI: 10.1007/s00604-017-2530-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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28
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Hücker SM, Ardern Z, Goldberg T, Schafferhans A, Bernhofer M, Vestergaard G, Nelson CW, Schloter M, Rost B, Scherer S, Neuhaus K. Discovery of numerous novel small genes in the intergenic regions of the Escherichia coli O157:H7 Sakai genome. PLoS One 2017; 12:e0184119. [PMID: 28902868 PMCID: PMC5597208 DOI: 10.1371/journal.pone.0184119] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/20/2017] [Indexed: 12/29/2022] Open
Abstract
In the past, short protein-coding genes were often disregarded by genome annotation pipelines. Transcriptome sequencing (RNAseq) signals outside of annotated genes have usually been interpreted to indicate either ncRNA or pervasive transcription. Therefore, in addition to the transcriptome, the translatome (RIBOseq) of the enteric pathogen Escherichia coli O157:H7 strain Sakai was determined at two optimal growth conditions and a severe stress condition combining low temperature and high osmotic pressure. All intergenic open reading frames potentially encoding a protein of ≥ 30 amino acids were investigated with regard to coverage by transcription and translation signals and their translatability expressed by the ribosomal coverage value. This led to discovery of 465 unique, putative novel genes not yet annotated in this E. coli strain, which are evenly distributed over both DNA strands of the genome. For 255 of the novel genes, annotated homologs in other bacteria were found, and a machine-learning algorithm, trained on small protein-coding E. coli genes, predicted that 89% of these translated open reading frames represent bona fide genes. The remaining 210 putative novel genes without annotated homologs were compared to the 255 novel genes with homologs and to 250 short annotated genes of this E. coli strain. All three groups turned out to be similar with respect to their translatability distribution, fractions of differentially regulated genes, secondary structure composition, and the distribution of evolutionary constraint, suggesting that both novel groups represent legitimate genes. However, the machine-learning algorithm only recognized a small fraction of the 210 genes without annotated homologs. It is possible that these genes represent a novel group of genes, which have unusual features dissimilar to the genes of the machine-learning algorithm training set.
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Affiliation(s)
- Sarah M. Hücker
- Chair for Microbial Ecology, Technische Universität München, Freising, Germany
- ZIEL - Institute for Food & Health, Technische Universität München, Freising, Germany
| | - Zachary Ardern
- Chair for Microbial Ecology, Technische Universität München, Freising, Germany
- ZIEL - Institute for Food & Health, Technische Universität München, Freising, Germany
| | - Tatyana Goldberg
- Department of Informatics—Bioinformatics & TUM-IAS, Technische Universität München, Garching, Germany
| | - Andrea Schafferhans
- Department of Informatics—Bioinformatics & TUM-IAS, Technische Universität München, Garching, Germany
| | - Michael Bernhofer
- Department of Informatics—Bioinformatics & TUM-IAS, Technische Universität München, Garching, Germany
| | - Gisle Vestergaard
- Research Unit Environmental Genomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Chase W. Nelson
- Sackler Institute for Comparative Genomics, American Museum of Natural History New York, New York, United States of America
| | - Michael Schloter
- Research Unit Environmental Genomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Burkhard Rost
- Department of Informatics—Bioinformatics & TUM-IAS, Technische Universität München, Garching, Germany
| | - Siegfried Scherer
- Chair for Microbial Ecology, Technische Universität München, Freising, Germany
- ZIEL - Institute for Food & Health, Technische Universität München, Freising, Germany
| | - Klaus Neuhaus
- Chair for Microbial Ecology, Technische Universität München, Freising, Germany
- Core Facility Microbiome/NGS, ZIEL - Institute for Food & Health, Technische Universität München, Freising, Germany
- * E-mail:
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29
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Citrobacter rodentium: a model enteropathogen for understanding the interplay of innate and adaptive components of type 3 immunity. Mucosal Immunol 2017; 10:1108-1117. [PMID: 28612839 PMCID: PMC5969517 DOI: 10.1038/mi.2017.47] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 04/13/2017] [Indexed: 02/07/2023]
Abstract
Citrobacter rodentium is a natural murine intestinal pathogen that shares a core set of virulence factors with the related human pathogens enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC). C. rodentium is now the most widely used small animal model for studying the molecular underpinnings of EPEC and EHEC infections in vivo, including: enterocyte attachment; virulence; colonization resistance; and mucosal immunity. In this review, we discuss type 3 immunity in the context of C. rodentium infection and discuss recent publications that use this model to understand how the innate and adaptive components of immunity intersect to mediate host protection against enteric pathogens and maintain homeostasis with the microbiota.
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30
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Enterohemorrhagic Escherichia coli pathogenesis: role of Long polar fimbriae in Peyer's patches interactions. Sci Rep 2017; 7:44655. [PMID: 28317910 PMCID: PMC5357955 DOI: 10.1038/srep44655] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 02/13/2017] [Indexed: 11/14/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) are major food-borne pathogens whose survival and virulence in the human digestive tract remain unclear owing to paucity of relevant models. EHEC interact with the follicle-associated epithelium of Peyer’s patches of the distal ileum and translocate across the intestinal epithelium via M-cells, but the underlying molecular mechanisms are still unknown. Here, we investigated the involvement of Long polar fimbriae (Lpf) in EHEC pathogenesis. Of the 236 strains tested, a significant association was observed between the presence of lpf operons and pathogenicity. In sophisticated in vitro models of the human gastro-intestinal tract, lpf expression was induced during transit through the simulated stomach and small intestine, but not in the colonic compartment. To investigate the involvement of Lpf in EHEC pathogenesis, lpf isogenic mutants and their relative trans-complemented strains were generated. Translocation across M-cells, interactions with murine ileal biopsies containing Peyer’s patches and the number of hemorrhagic lesions were significantly reduced with the lpf mutants compared to the wild-type strain. Complementation of lpf mutants fully restored the wild-type phenotypes. Our results indicate that (i) EHEC might colonize the terminal ileum at the early stages of infection, (ii) Lpf are an important player in the interactions with Peyer’s patches and M-cells, and could contribute to intestinal colonization.
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31
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Hews CL, Tran SL, Wegmann U, Brett B, Walsham ADS, Kavanaugh D, Ward NJ, Juge N, Schüller S. The StcE metalloprotease of enterohaemorrhagic Escherichia coli reduces the inner mucus layer and promotes adherence to human colonic epithelium ex vivo. Cell Microbiol 2017; 19. [PMID: 28054754 PMCID: PMC5434857 DOI: 10.1111/cmi.12717] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 12/20/2016] [Accepted: 12/30/2016] [Indexed: 12/18/2022]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) is a major foodborne pathogen and tightly adheres to human colonic epithelium by forming attaching/effacing lesions. To reach the epithelial surface, EHEC must penetrate the thick mucus layer protecting the colonic epithelium. In this study, we investigated how EHEC interacts with the intestinal mucus layer using mucin‐producing LS174T colon carcinoma cells and human colonic mucosal biopsies. The level of EHEC binding and attaching/effacing lesion formation in LS174T cells was higher compared to mucin‐deficient colon carcinoma cell lines, and initial adherence was independent of the presence of flagellin, Escherichia coli common pilus, or long polar fimbriae. Although EHEC infection did not affect gene expression of secreted mucins, it resulted in reduced MUC2 glycoprotein levels. This effect was dependent on the catalytic activity of the secreted metalloprotease StcE, which reduced the inner mucus layer and thereby promoted EHEC access and binding to the epithelium in vitro and ex vivo. Given the lack of efficient therapies against EHEC infection, StcE may represent a suitable target for future treatment and prevention strategies.
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Affiliation(s)
- Claire L Hews
- Gut Health and Food Safety Programme, Institute of Food Research, Norwich, UK.,School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Seav-Ly Tran
- Norwich Medical School, University of East Anglia, Norwich, UK.,Gut Health and Food Safety Programme, Institute of Food Research, Norwich, UK
| | - Udo Wegmann
- Gut Health and Food Safety Programme, Institute of Food Research, Norwich, UK
| | - Bernard Brett
- Department of Gastroenterology, Norfolk and Norwich University Hospital, Norwich, UK.,Department of Gastroenterology, James Paget University Hospital, Great Yarmouth, UK
| | - Alistair D S Walsham
- Norwich Medical School, University of East Anglia, Norwich, UK.,Gut Health and Food Safety Programme, Institute of Food Research, Norwich, UK
| | - Devon Kavanaugh
- Gut Health and Food Safety Programme, Institute of Food Research, Norwich, UK
| | - Nicole J Ward
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Nathalie Juge
- Gut Health and Food Safety Programme, Institute of Food Research, Norwich, UK
| | - Stephanie Schüller
- Norwich Medical School, University of East Anglia, Norwich, UK.,Gut Health and Food Safety Programme, Institute of Food Research, Norwich, UK
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32
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Saeedi P, Yazdanparast M, Behzadi E, Salmanian AH, Mousavi SL, Nazarian S, Amani J. A review on strategies for decreasing E. coli O157:H7 risk in animals. Microb Pathog 2017; 103:186-195. [PMID: 28062285 DOI: 10.1016/j.micpath.2017.01.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 12/25/2016] [Accepted: 01/02/2017] [Indexed: 11/17/2022]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is a food-borne pathogen that younger children are most prone to this microorganism. Hemolytic Uremic Syndrome (HUS) caused by EHEC, leads to the destruction of red blood cells and kidney failure. The virulence of E.coli O157:H7 is attributed to fimbriae, that facilitate colonization of bacteria within the colon and verotoxins (VT) or Shiga toxins (Stx) that are released into the blood. Although, in most cases, the infection is self-limitedin young children and aged population, it may cause HUS. Therefore, several investigations are performed in order to offer effective therapies and vaccines, which can prevent and treat the infection in appropriate time. As the pathogenesis of this infection is complicated, a multi-targeted strategy is required. Since cattle are the most important reservoir of EHEC and the root of contamination, reducing E. coli O157:H7 at the farm level should decrease the risk of human illness. Several vaccine approaches have been employed with different proper outcomes in animal models, including recombinant proteins (virulence factors such as; Stx1/2, intimin, EspA, fusion proteins of A and B Stx subunits), avirulent ghost cells of EHEC O157:H7, live attenuated bacteria expressing recombinant proteins, recombinant fimbrial proteins. In addition to protein-based vaccines, DNA vaccines have provided proper prevention in the laboratory animal model. This review paper summarizes the previous studies, current status and future perspective of different immunization strategies for eradicating Enterohemorrhagic Escherichia coli O157:H7.
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Affiliation(s)
- Pardis Saeedi
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Maryam Yazdanparast
- Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
| | - Elham Behzadi
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Ali Hatef Salmanian
- Plant Bioproducts Department, Institute of Agricultural Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Seyed Latif Mousavi
- Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
| | - Shahram Nazarian
- Department of Biology, Faculty of Science, Imam Hossein University, Tehran, Iran
| | - Jafar Amani
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
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33
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Cordonnier C, Thévenot J, Etienne-Mesmin L, Alric M, Livrelli V, Blanquet-Diot S. Probiotic and enterohemorrhagic Escherichia coli: An effective strategy against a deadly enemy? Crit Rev Microbiol 2016; 43:116-132. [PMID: 27798976 DOI: 10.1080/1040841x.2016.1185602] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) are major food-borne pathogens that constitute a serious public health threat. Currently, there is no specific treatment available for EHEC infections in human creating an urgent need for the development of alternative therapeutic strategies. Among them, one of the most promising approaches is the use of probiotic microorganisms. Even if many studies have shown the antagonistic effects of probiotic bacteria or yeast on EHEC survival, virulence, adhesion on intestinal epithelium or pathogen-induced inflammatory responses, mechanisms mediating their beneficial effects remain unclear. This review describes EHEC pathogenesis and novel therapeutic strategies, with a particular emphasis on probiotics. The interests and limits of a probiotic-based approach and the way it might be incorporated into global health strategies against EHEC infections will be discussed.
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Affiliation(s)
- Charlotte Cordonnier
- a EA 4678 CIDAM, "Conception, Ingénierie et Développement de l'Aliment et du Médicament", Centre de Recherche en Nutrition Humaine Auvergne , Université d'Auvergne , Clermont-Ferrand , France.,b M2iSH, "Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte" , UMR Inserm/Université d'Auvergne U1071, USC-INRA 2018, Centre de Recherche en Nutrition Humaine Auvergne, Université d'Auvergne , Clermont-Ferrand , France
| | - Jonathan Thévenot
- a EA 4678 CIDAM, "Conception, Ingénierie et Développement de l'Aliment et du Médicament", Centre de Recherche en Nutrition Humaine Auvergne , Université d'Auvergne , Clermont-Ferrand , France.,b M2iSH, "Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte" , UMR Inserm/Université d'Auvergne U1071, USC-INRA 2018, Centre de Recherche en Nutrition Humaine Auvergne, Université d'Auvergne , Clermont-Ferrand , France
| | - Lucie Etienne-Mesmin
- a EA 4678 CIDAM, "Conception, Ingénierie et Développement de l'Aliment et du Médicament", Centre de Recherche en Nutrition Humaine Auvergne , Université d'Auvergne , Clermont-Ferrand , France.,b M2iSH, "Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte" , UMR Inserm/Université d'Auvergne U1071, USC-INRA 2018, Centre de Recherche en Nutrition Humaine Auvergne, Université d'Auvergne , Clermont-Ferrand , France
| | - Monique Alric
- a EA 4678 CIDAM, "Conception, Ingénierie et Développement de l'Aliment et du Médicament", Centre de Recherche en Nutrition Humaine Auvergne , Université d'Auvergne , Clermont-Ferrand , France
| | - Valérie Livrelli
- b M2iSH, "Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte" , UMR Inserm/Université d'Auvergne U1071, USC-INRA 2018, Centre de Recherche en Nutrition Humaine Auvergne, Université d'Auvergne , Clermont-Ferrand , France.,c Service de Bactériologie , CHU Clermont-Ferrand , Clermont-Ferrand , France
| | - Stéphanie Blanquet-Diot
- a EA 4678 CIDAM, "Conception, Ingénierie et Développement de l'Aliment et du Médicament", Centre de Recherche en Nutrition Humaine Auvergne , Université d'Auvergne , Clermont-Ferrand , France
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34
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Gonzalez AGM, Cerqueira AMF, Guth BEC, Coutinho CA, Liberal MHT, Souza RM, Andrade JRC. Serotypes, virulence markers and cell invasion ability of Shiga toxin-producing Escherichia coli strains isolated from healthy dairy cattle. J Appl Microbiol 2016; 121:1130-43. [PMID: 27426967 DOI: 10.1111/jam.13230] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 06/10/2016] [Accepted: 06/20/2016] [Indexed: 01/25/2023]
Abstract
AIM The occurrence of virulence markers, serotypes and invasive ability were investigated in Shiga toxin-producing Escherichia coli (STEC) isolated from faecal samples of healthy dairy cattle at Rio de Janeiro State, Brazil. METHODS AND RESULTS From 1562 stx-positive faecal samples, 105 STEC strains were isolated by immuno-magnetic separation (IMS) or plating onto MacConkey agar (MC) followed by colony hybridisation. Fifty (47·6%) strains belonged to nine serotypes (O8:H19, O22:H8, O22:H16, O74:H42, O113:H21, O141:H21, O157:H7, O171:H2 and ONT:H21). The prevalent serotypes were O157:H7 (12·4%), O113:H21 (6·7%) and O8:H19 (5·7%). Virulence genes were identified by polymerase chain reaction (PCR). E-hlyA (77·1%) was the more prevalent virulence marker, followed by espP (64·8%), saa (39%), eae (24·8%) and astA (21·9%). All O157:H7 strains carried the γ (gamma) variant of the locus of enterocyte effacement (LEE) genes and the stx2c gene, while the stx1/stx2 genotype prevailed among the eae-negative strains. None of the eae-positive STEC produced the localized adherence (LA) phenotype in HEp-2 or Caco-2 cells. However, intimate attachment (judged by the fluorescent actin staining test) was detected in some eae-positive strains, both in HEp-2 (23·1%) and in Caco-2 cells (11·5%). Most strains (87·5%) showed 'peripheral association' (PA) adherence phenotype to undifferentiated Caco-2 cells. Twenty-five (92·6%) of 27 strains invaded Caco-2 cells. The highest average value of invasion (9·6%) was observed among the eae-negative bovine strains from serotypes described in human disease. CONCLUSION Healthy dairy cattle is a reservoir of STEC carrying virulence genes and properties associated with human disease. SIGNIFICANCE AND IMPACT OF THE STUDY Although reports of human disease associated with STEC are scarce in Brazil, the colonization of the animal reservoir by potentially pathogenic strains offers a significant risk to our population.
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Affiliation(s)
- A G M Gonzalez
- Departamento de Bromatologia, Universidade Federal Fluminense, Niterói, Brasil.
| | - A M F Cerqueira
- Departamento de Microbiologia e Parasitologia, Universidade Federal Fluminense, Niterói, Brasil
| | - B E C Guth
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brasil
| | - C A Coutinho
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil
| | - M H T Liberal
- Centro Estadual de Pesquisa em Sanidade Animal, Pesagro-Rio, Niterói, Brasil
| | - R M Souza
- Centro Estadual de Pesquisa em Sanidade Animal, Pesagro-Rio, Niterói, Brasil
| | - J R C Andrade
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil
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Lackraj T, Kim JI, Tran SL, Barnett Foster DE. Differential modulation of flagella expression in enterohaemorrhagic Escherichia coli O157: H7 by intestinal short-chain fatty acid mixes. MICROBIOLOGY-SGM 2016; 162:1761-1772. [PMID: 27535670 DOI: 10.1099/mic.0.000357] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
During passage through the gastrointestinal tract, enterohaemorrhagic Escherichia coli (EHEC) encounters numerous stresses, each producing unique antimicrobial conditions. Beyond surviving these stresses, EHEC may also use them as cues about the local microenvironment to modulate its virulence. Of particular interest is how exposure to changing concentrations of short-chain fatty acids (SCFAs) associated with passage through the small and large intestines affects EHEC virulence, as well as flagella expression and motility specifically. In this study, we investigate the impact of exposure to SCFA mixes simulating concentrations and compositions within the small and large intestines on EHEC flagella expression and function. Using a combination of DNA microarray, quantitative real-time PCR, immunoblot analysis, flow cytometry and motility assays, we show that there is a marked, significant upregulation of flagellar genes, the flagellar protein, FliC, and motility when EHEC is exposed to SCFA mixes representative of the small intestine. By contrast, when EHEC is exposed to SCFA mixes representative of the large intestine, there is a significant downregulation of flagellar genes, FliC and motility. Our results demonstrate that EHEC modulates flagella expression and motility in response to SCFAs, with differential responses associated with SCFA mixes typical of the small and large intestines. This research contributes to our understanding of how EHEC senses and responds to host environmental signals and the mechanisms it uses to successfully infect the human host. Significantly, it also suggests that EHEC is using this key gastrointestinal chemical signpost to cue changes in flagella expression and motility in different locations within the host intestinal tract.
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Affiliation(s)
- Tracy Lackraj
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Jee In Kim
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Seav-Ly Tran
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Debora E Barnett Foster
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.,Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada.,Program for Molecular Structure and Function, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
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Monteiro R, Ageorges V, Rojas-Lopez M, Schmidt H, Weiss A, Bertin Y, Forano E, Jubelin G, Henderson IR, Livrelli V, Gobert AP, Rosini R, Soriani M, Desvaux M. A secretome view of colonisation factors in Shiga toxin-encodingEscherichia coli(STEC): from enterohaemorrhagicE. coli(EHEC) to related enteropathotypes. FEMS Microbiol Lett 2016; 363:fnw179. [DOI: 10.1093/femsle/fnw179] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2016] [Indexed: 12/25/2022] Open
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Lewis SB, Prior A, Ellis SJ, Cook V, Chan SSM, Gelson W, Schüller S. Flagellin Induces β-Defensin 2 in Human Colonic Ex vivo Infection with Enterohemorrhagic Escherichia coli. Front Cell Infect Microbiol 2016; 6:68. [PMID: 27446815 PMCID: PMC4914554 DOI: 10.3389/fcimb.2016.00068] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 06/07/2016] [Indexed: 12/19/2022] Open
Abstract
Enterohemorrhagic E.coli (EHEC) is an important foodborne pathogen in the developed world and can cause life-threatening disease particularly in children. EHEC persists in the human gut by adhering intimately to colonic epithelium and forming characteristic attaching/effacing lesions. In this study, we investigated the innate immune response to EHEC infection with particular focus on antimicrobial peptide and protein expression by colonic epithelium. Using a novel human colonic biopsy model and polarized T84 colon carcinoma cells, we found that EHEC infection induced expression of human β-defensin 2 (hBD2), whereas hBD1, hBD3, LL-37, and lysozyme remained unchanged. Infection with specific EHEC deletion mutants demonstrated that this was dependent on flagellin, and apical exposure to purified flagellin was sufficient to stimulate hBD2 and also interleukin (IL)-8 expression ex vivo and in vitro. Flagellin-mediated hBD2 induction was significantly reduced by inhibitors of NF-κB, MAP kinase p38 and JNK but not ERK1/2. Interestingly, IL-8 secretion by polarized T84 cells was vectorial depending on the side of stimulation, and apical exposure to EHEC or flagellin resulted in apical IL-8 release. Our results demonstrate that EHEC only induces a modest immune response in human colonic epithelium characterized by flagellin-dependent induction of hBD2 and low levels of IL-8.
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Affiliation(s)
- Steven B Lewis
- Norwich Medical School, University of East AngliaNorwich, UK; Gut Health and Food Safety Programme, Institute of Food ResearchNorwich, UK
| | - Alison Prior
- Gastroenterology Department, Norfolk and Norwich University Hospital Norwich, UK
| | - Samuel J Ellis
- Norwich Medical School, University of East AngliaNorwich, UK; Gut Health and Food Safety Programme, Institute of Food ResearchNorwich, UK
| | - Vivienne Cook
- Gastroenterology Department, Norfolk and Norwich University Hospital Norwich, UK
| | - Simon S M Chan
- Norwich Medical School, University of East AngliaNorwich, UK; Gastroenterology Department, Norfolk and Norwich University HospitalNorwich, UK
| | - William Gelson
- Gastroenterology Department, Norfolk and Norwich University Hospital Norwich, UK
| | - Stephanie Schüller
- Norwich Medical School, University of East AngliaNorwich, UK; Gut Health and Food Safety Programme, Institute of Food ResearchNorwich, UK
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De la Cruz MA, Morgan JK, Ares MA, Yáñez-Santos JA, Riordan JT, Girón JA. The Two-Component System CpxRA Negatively Regulates the Locus of Enterocyte Effacement of Enterohemorrhagic Escherichia coli Involving σ(32) and Lon protease. Front Cell Infect Microbiol 2016; 6:11. [PMID: 26904510 PMCID: PMC4742615 DOI: 10.3389/fcimb.2016.00011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/18/2016] [Indexed: 12/05/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a significant cause of serious human gastrointestinal disease worldwide. EHEC strains contain a pathogenicity island called the locus of enterocyte effacement (LEE), which encodes virulence factors responsible for damaging the gut mucosa. The Cpx envelope stress response of E. coli is controlled by a two-component system (TCS) consisting of a sensor histidine kinase (CpxA) and a cytoplasmic response regulator (CpxR). In this study, we investigated the role of CpxRA in the expression of LEE-encoded virulence factors of EHEC. We found that a mutation in cpxA significantly affected adherence of EHEC to human epithelial cells. Analysis of this mutant revealed the presence of high levels of CpxR which repressed transcription of grlA and ler, the main positive virulence regulators of the LEE, and influenced negatively the production of the type 3 secretion system–associated EspABD translocator proteins. It is known that CpxR activates rpoH (Sigma factor 32), which in turns activates transcription of the lon protease gene. We found that transcription levels of ler and grlA were significantly increased in the lon and cpxA lon mutants suggesting that lon is involved in down-regulating LEE genes. In addition, the Galleria mellonella model of infection was used to analyze the effect of the loss of the cpx and lon genes in EHEC's ability to kill the larvae. We found that the cpxA mutant was significantly deficient at killing the larvae however, the cpxA lon mutant which overexpresses LEE genes in vitro, was unable to kill the larvae, suggesting that virulence in the G. mellonella model is T3SS independent and that CpxA modulates virulence through a yet unknown EHEC-specific factor. Our data provides new insights and broadens our scope into the complex regulatory network of the LEE in which the CpxA sensor kinase plays an important role in a cascade involving both global and virulence regulators.
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Affiliation(s)
- Miguel A De la Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Centro Médico Nacional Siglo XXI-IMSSMexico City, Mexico; Emerging Pathogens Institute, University of FloridaGainesville, FL, USA
| | - Jason K Morgan
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida Tampa, FL, USA
| | - Miguel A Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Centro Médico Nacional Siglo XXI-IMSS Mexico City, Mexico
| | - Jorge A Yáñez-Santos
- Facultad de Estomatología, Benemerita Universidad Autonoma de Puebla Puebla, Mexico
| | - James T Riordan
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida Tampa, FL, USA
| | - Jorge A Girón
- Emerging Pathogens Institute, University of FloridaGainesville, FL, USA; Centro de Deteccion Biomolecular, Benemerita Universidad Autonoma de PueblaPuebla, Mexico
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39
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The Surface Sensor NlpE of Enterohemorrhagic Escherichia coli Contributes to Regulation of the Type III Secretion System and Flagella by the Cpx Response to Adhesion. Infect Immun 2015; 84:537-49. [PMID: 26644384 DOI: 10.1128/iai.00881-15] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/27/2015] [Indexed: 11/20/2022] Open
Abstract
Although the adhesion of enterohemorrhagic Escherichia coli (EHEC) is central to the EHEC-host interaction during infection, it remains unclear how such adhesion regulates virulence factors. Adhesion to abiotic surfaces by E. coli has been reported to be an outer membrane lipoprotein NlpE-dependent activation cue of the Cpx pathway. Therefore, we investigated the role of NlpE in EHEC on the adhesion-mediated expression of virulence genes. NlpE in EHEC contributed to upregulation of the locus of enterocyte effacement (LEE) genes encoded type III secretion system and to downregulated expression of the flagellin gene by activation of the Cpx pathway during adherence to hydrophobic glass beads and undifferentiated Caco-2 cells. Moreover, LysR homologue A (LrhA) in EHEC was involved in regulating the expression of the LEE genes and flagellin gene in response to adhesion. Gel mobility shift analysis revealed that response regulator CpxR bound to the lrhA promoter region and thereby regulated expressions of the LEE genes and flagellin gene via the transcriptional regulator LrhA in EHEC. Therefore, these results suggest that the sensing of adhesion signals via NlpE is important for regulation of the expression of the type III secretion system and flagella in EHEC during infection.
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40
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In J, Foulke-Abel J, Zachos NC, Hansen AM, Kaper JB, Bernstein HD, Halushka M, Blutt S, Estes MK, Donowitz M, Kovbasnjuk O. Enterohemorrhagic Escherichia coli reduce mucus and intermicrovillar bridges in human stem cell-derived colonoids. Cell Mol Gastroenterol Hepatol 2015; 2:48-62.e3. [PMID: 26855967 PMCID: PMC4740923 DOI: 10.1016/j.jcmgh.2015.10.001] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Enterohemorrhagic E. coli (EHEC) causes over 70,000 episodes of foodborne diarrhea annually in the USA. The early sequence of events which precede life-threatening hemorrhagic colitis and hemolytic uremic syndrome are not fully understood due to the initial asymptomatic phase of the disease and the lack of a suitable animal model. The aim of this study was to determine the initial molecular events in the interaction between EHEC and human colonic epithelium. METHODS Human colonoids derived from adult proximal colonic stem cells were developed into monolayers to study EHEC-epithelial interactions. Monolayer confluency and differentiation were monitored by transepithelial electrical resistance (TER) measurements. The monolayers were apically infected with EHEC and the progression of epithelial damage over time was assessed using biochemical and imaging approaches. RESULTS Human colonoid cultures recapitulate the differential protein expression patterns characteristic of the crypt and surface colonocytes. Mucus-producing differentiated colonoid monolayers are preferentially colonized by EHEC. Upon colonization, EHEC forms characteristic attaching and effacing lesions on the apical surface of colonoid monolayers. Mucin 2, a main component of colonic mucus, and protocadherin 24 (PCDH24), a microvillar resident protein, are targeted by EHEC at early stages of infection. The EHEC secreted serine protease, EspP, initiates brush border damage through PCDH24 reduction. CONCLUSIONS Human colonoid monolayers are a relevant pathophysiological model which allows the study of early molecular events during enteric infections. Colonoid monolayers provide access to both apical and basolateral surfaces, thus providing an advantage over 3D cultures to study host-pathogen interactions in a controllable and tractable manner. EHEC reduces colonic mucus and affects the brush border cytoskeleton in the absence of commensal bacteria.
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Affiliation(s)
- Julie In
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Jennifer Foulke-Abel
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Nicholas C. Zachos
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Anne-Marie Hansen
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland
| | - James B. Kaper
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Harris D. Bernstein
- Genetics and Biochemistry Branch, National Institutes of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, Maryland
| | - Marc Halushka
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Sarah Blutt
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Mary K. Estes
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Mark Donowitz
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Olga Kovbasnjuk
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, Maryland,Correspondence Address correspondence to: Olga Kovbasnjuk, PhD, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, 943 Ross Research Building, 720 Rutland Avenue, Baltimore, Maryland 21205.Division of Gastroenterology and HepatologyJohns Hopkins University School of Medicine943 Ross Research Building720 Rutland AvenueBaltimoreMaryland 21205
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41
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Thévenot J, Cordonnier C, Rougeron A, Le Goff O, Nguyen HTT, Denis S, Alric M, Livrelli V, Blanquet-Diot S. Enterohemorrhagic Escherichia coli infection has donor-dependent effect on human gut microbiota and may be antagonized by probiotic yeast during interaction with Peyer's patches. Appl Microbiol Biotechnol 2015; 99:9097-110. [PMID: 26084888 DOI: 10.1007/s00253-015-6704-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 05/13/2015] [Accepted: 05/17/2015] [Indexed: 01/05/2023]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) are major food-borne pathogens responsible for serious infections ranging from mild diarrhea to hemorrhagic colitis and life-threatening complications. Shiga toxins (Stxs) are the main virulence factor of EHEC. The antagonistic effect of a prophylactic treatment with the probiotic strain Saccharomyces cerevisiae against EHEC O157:H7 was investigated using complementary in vitro human colonic model and in vivo murine ileal loop assays. In vitro, the probiotic treatment had no effect on O157:H7 survival but favorably influenced gut microbiota activity through modulation of short-chain fatty acid production, increasing acetate production and decreasing that of butyrate. Both pathogen and probiotic strains had individual-dependent effects on human gut microbiota. For the first time, stx expression was followed in human colonic environment: at 9 and 12 h post EHEC infection, probiotic treatment significantly decreased stx mRNA levels. Besides, in murine ileal loops, the probiotic yeast specifically exerted a trophic effect on intestinal mucosa and inhibited O157:H7 interactions with Peyer's patches and subsequent hemorrhagic lesions. Taken together, the results suggest that S. cerevisiae may be useful in the fight against EHEC infection and that host associated factors such as microbiota could influence clinical evolution of EHEC infection and the effectiveness of probiotics.
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Affiliation(s)
- J Thévenot
- Centre de Recherche en Nutrition Humaine Auvergne, EA 4678 CIDAM, Conception Ingénierie et Développement de l'Aliment et du Médicament, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France.,Centre de Recherche en Nutrition Humaine Auvergne, M2iSH, Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte UMR INSERM / Université d'Auvergne U1071 USC-INRA 2018, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France
| | - C Cordonnier
- Centre de Recherche en Nutrition Humaine Auvergne, EA 4678 CIDAM, Conception Ingénierie et Développement de l'Aliment et du Médicament, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France.,Centre de Recherche en Nutrition Humaine Auvergne, M2iSH, Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte UMR INSERM / Université d'Auvergne U1071 USC-INRA 2018, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France
| | - A Rougeron
- Centre de Recherche en Nutrition Humaine Auvergne, M2iSH, Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte UMR INSERM / Université d'Auvergne U1071 USC-INRA 2018, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France
| | - O Le Goff
- Centre de Recherche en Nutrition Humaine Auvergne, EA 4678 CIDAM, Conception Ingénierie et Développement de l'Aliment et du Médicament, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France
| | - H T T Nguyen
- Centre de Recherche en Nutrition Humaine Auvergne, M2iSH, Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte UMR INSERM / Université d'Auvergne U1071 USC-INRA 2018, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France
| | - S Denis
- Centre de Recherche en Nutrition Humaine Auvergne, EA 4678 CIDAM, Conception Ingénierie et Développement de l'Aliment et du Médicament, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France
| | - M Alric
- Centre de Recherche en Nutrition Humaine Auvergne, EA 4678 CIDAM, Conception Ingénierie et Développement de l'Aliment et du Médicament, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France
| | - V Livrelli
- Centre de Recherche en Nutrition Humaine Auvergne, M2iSH, Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte UMR INSERM / Université d'Auvergne U1071 USC-INRA 2018, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France.,Service de Bactériologie, CHU Clermont-Ferrand, Clermont-Ferrand, France
| | - S Blanquet-Diot
- Centre de Recherche en Nutrition Humaine Auvergne, EA 4678 CIDAM, Conception Ingénierie et Développement de l'Aliment et du Médicament, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France.
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