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Amemiya K, Rozak DA, Dankmeyer JL, Dorman WR, Marchand C, Fetterer DP, Worsham PL, Purcell BK. Shiga-Toxin-Producing Strains of Escherichia coli O104:H4 and a Strain of O157:H7, Which Can Cause Human Hemolytic Uremic Syndrome, Differ in Biofilm Formation in the Presence of CO 2 and in Their Ability to Grow in a Novel Cell Culture Medium. Microorganisms 2023; 11:1744. [PMID: 37512916 PMCID: PMC10384166 DOI: 10.3390/microorganisms11071744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/13/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023] Open
Abstract
One pathogen that commonly causes gastrointestinal illnesses from the consumption of contaminated food is Escherichia coli O157:H7. In 2011 in Germany, however, there was a prominent outbreak of bloody diarrhea with a high incidence of hemolytic uremic syndrome (HUS) caused by an atypical, more virulent E. coli O104:H4 strain. To facilitate the identification of this lesser-known, atypical E. coli O104:H4 strain, we wanted to identify phenotypic differences between it and a strain of O157:H7 in different media and culture conditions. We found that E. coli O104:H4 strains produced considerably more biofilm than the strain of O157:H7 at 37 °C (p = 0.0470-0.0182) Biofilm production was significantly enhanced by the presence of 5% CO2 (p = 0.0348-0.0320). In our study on the innate immune response to the E. coli strains, we used HEK293 cells that express Toll-like receptors (TLRs) 2 or 4. We found that E. coli O104:H4 strains had the ability to grow in a novel HEK293 cell culture medium, while the E. coli O157:H7 strain could not. Thus, we uncovered previously unknown phenotypic properties of E. coli O104:H4 to further differentiate this pathogen from E. coli O157:H7.
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Affiliation(s)
- Kei Amemiya
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - David A Rozak
- Diagnostic Systems Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - Jennifer L Dankmeyer
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - William R Dorman
- Diagnostic Systems Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - Charles Marchand
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - David P Fetterer
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - Patricia L Worsham
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - Brett K Purcell
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
- Department of Medicine, University of Florida, Orlando, FL 32816, USA
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Monteiro R, Chafsey I, Caccia N, Ageorges V, Leroy S, Viala D, Hébraud M, Livrelli V, Pizza M, Pezzicoli A, Desvaux M. Specific Proteomic Identification of Collagen-Binding Proteins in Escherichia coli O157:H7: Characterisation of OmpA as a Potent Vaccine Antigen. Cells 2023; 12:1634. [PMID: 37371104 DOI: 10.3390/cells12121634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/02/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Escherichia coli is a versatile commensal species of the animal gut that can also be a pathogen able to cause intestinal and extraintestinal infections. The plasticity of its genome has led to the evolution of pathogenic strains, which represent a threat to global health. Additionally, E. coli strains are major drivers of antibiotic resistance, highlighting the urgent need for new treatment and prevention measures. The antigenic and structural heterogeneity of enterohaemorrhagic E. coli colonisation factors has limited their use for the development of effective and cross-protective vaccines. However, the emergence of new strains that express virulence factors deriving from different E. coli diarrhoeagenic pathotypes suggests that a vaccine targeting conserved proteins could be a more effective approach. In this study, we conducted proteomics analysis and functional protein characterisation to identify a group of proteins potentially involved in the adhesion of E. coli O157:H7 to the extracellular matrix and intestinal epithelial cells. Among them, OmpA has been identified as a highly conserved and immunogenic antigen, playing a significant role in the adhesion phenotype of E. coli O157:H7 and in bacterial aggregation. Furthermore, antibodies raised against recombinant OmpA effectively reduced the adhesion of E. coli O157:H7 to intestinal epithelial cells. The present work highlights the role of OmpA as a potent antigen for the development of a vaccine against intestinal pathogenic E. coli.
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Affiliation(s)
- Ricardo Monteiro
- INRAE, UCA, UMR0454 MEDIS, 63000 Clermont-Ferrand, France
- GSK, 53100 Siena, Italy
- Instituto de Investigação e Inovação em Saúde-i3S, Universidade do Porto, 4150-564 Porto, Portugal
| | - Ingrid Chafsey
- INRAE, UCA, UMR0454 MEDIS, 63000 Clermont-Ferrand, France
| | - Nelly Caccia
- INRAE, UCA, UMR0454 MEDIS, 63000 Clermont-Ferrand, France
| | | | - Sabine Leroy
- INRAE, UCA, UMR0454 MEDIS, 63000 Clermont-Ferrand, France
| | - Didier Viala
- INRAE, Metabolism Exploration Platform, Proteomic Component (PFEMcp), 63122 Saint-Genès Champanelle, France
| | - Michel Hébraud
- INRAE, UCA, UMR0454 MEDIS, 63000 Clermont-Ferrand, France
- INRAE, Metabolism Exploration Platform, Proteomic Component (PFEMcp), 63122 Saint-Genès Champanelle, France
| | | | - Mariagrazia Pizza
- GSK, 53100 Siena, Italy
- Imperial College London, South Kensington Campus, London SW7 2AZ, UK
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Tiwari SK, van der Putten BCL, Fuchs TM, Vinh TN, Bootsma M, Oldenkamp R, La Ragione R, Matamoros S, Hoa NT, Berens C, Leng J, Álvarez J, Ferrandis-Vila M, Ritchie JM, Fruth A, Schwarz S, Domínguez L, Ugarte-Ruiz M, Bethe A, Huber C, Johanns V, Stamm I, Wieler LH, Ewers C, Fivian-Hughes A, Schmidt H, Menge C, Semmler T, Schultsz C. Genome-wide association reveals host-specific genomic traits in Escherichia coli. BMC Biol 2023; 21:76. [PMID: 37038177 PMCID: PMC10088187 DOI: 10.1186/s12915-023-01562-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/10/2023] [Indexed: 04/12/2023] Open
Abstract
BACKGROUND Escherichia coli is an opportunistic pathogen which colonizes various host species. However, to what extent genetic lineages of E. coli are adapted or restricted to specific hosts and the genomic determinants of such adaptation or restriction is poorly understood. RESULTS We randomly sampled E. coli isolates from four countries (Germany, UK, Spain, and Vietnam), obtained from five host species (human, pig, cattle, chicken, and wild boar) over 16 years, from both healthy and diseased hosts, to construct a collection of 1198 whole-genome sequenced E. coli isolates. We identified associations between specific E. coli lineages and the host from which they were isolated. A genome-wide association study (GWAS) identified several E. coli genes that were associated with human, cattle, or chicken hosts, whereas no genes associated with the pig host could be found. In silico characterization of nine contiguous genes (collectively designated as nan-9) associated with the human host indicated that these genes are involved in the metabolism of sialic acids (Sia). In contrast, the previously described sialic acid regulon known as sialoregulon (i.e. nanRATEK-yhcH, nanXY, and nanCMS) was not associated with any host species. In vitro growth experiments with a Δnan-9 E. coli mutant strain, using the sialic acids 5-N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc) as sole carbon source, showed impaired growth behaviour compared to the wild-type. CONCLUSIONS This study provides an extensive analysis of genetic determinants which may contribute to host specificity in E. coli. Our findings should inform risk analysis and epidemiological monitoring of (antimicrobial resistant) E. coli.
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Affiliation(s)
- Sumeet K Tiwari
- Robert Koch Institute, Genome Sequencing and Genomic Epidemiology, Berlin, Germany
- Quadram Institute Bioscience, Gut Microbes and Health Institute Strategic Program, Norwich Research Park, Norwich, UK
| | - Boas C L van der Putten
- Department of Global Health, Amsterdam Institute for Global Health and Development, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Thilo M Fuchs
- Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Jena, Germany
| | - Trung N Vinh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Faculty of Veterinary Medicine, College of Agriculture, Can Tho University, Can Tho, Vietnam
| | | | - Rik Oldenkamp
- Department of Global Health, Amsterdam Institute for Global Health and Development, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Institute for Life and Environment, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Roberto La Ragione
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, UK
- Department of Microbial Sciences, School of Biosciences, University of Surrey, Guildford, UK
| | - Sebastien Matamoros
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Ngo T Hoa
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Tropical medicine and global health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK
- Microbiology- Parasitology Unit, Biomedical Research Center and Microbiology Department, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
| | - Christian Berens
- Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Jena, Germany
| | - Joy Leng
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, UK
| | - Julio Álvarez
- VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
| | | | - Jenny M Ritchie
- Department of Microbial Sciences, School of Biosciences, University of Surrey, Guildford, UK
| | - Angelika Fruth
- Robert Koch Institute, Enteropathogenic Bacteria and Legionella, Wernigerode, Germany
| | - Stefan Schwarz
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
- Veterinary Centre for Resistance Research (TZR), Freie Universität Berlin, Berlin, Germany
| | - Lucas Domínguez
- Tropical medicine and global health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK
- Microbiology- Parasitology Unit, Biomedical Research Center and Microbiology Department, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
| | - María Ugarte-Ruiz
- VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
| | - Astrid Bethe
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
- Veterinary Centre for Resistance Research (TZR), Freie Universität Berlin, Berlin, Germany
| | - Charlotte Huber
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Vanessa Johanns
- Robert Koch Institute, Advanced Light and Electron Microscopy, Berlin, Germany
| | - Ivonne Stamm
- Vet Med Labor GmbH, Division of IDEXX Laboratories, Kornwestheim, Germany
| | | | - Christa Ewers
- Institute of Hygiene and Infectious Diseases of Animals, Giessen, Germany
| | - Amanda Fivian-Hughes
- Department of Microbial Sciences, School of Biosciences, University of Surrey, Guildford, UK
| | - Herbert Schmidt
- Institute of Food Science and Biotechnology, Department of Food Microbiology and Hygiene, University of Hohenheim, Stuttgart, Germany
| | - Christian Menge
- Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Jena, Germany
| | - Torsten Semmler
- Robert Koch Institute, Genome Sequencing and Genomic Epidemiology, Berlin, Germany.
| | - Constance Schultsz
- Department of Global Health, Amsterdam Institute for Global Health and Development, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.
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Escherichia coli 0157:H7 virulence factors and the ruminant reservoir. Curr Opin Infect Dis 2022; 35:205-214. [PMID: 35665714 PMCID: PMC9302714 DOI: 10.1097/qco.0000000000000834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW This review updates recent findings about Escherichia coli O157:H7 virulence factors and its bovine reservoir. This Shiga toxin (Stx)-producing E. coli belongs to the Enterohemorrhagic E. coli (EHEC) pathotype causing hemorrhagic colitis. Its low infectious dose makes it an efficient, severe, foodborne pathogen. Although EHEC remains in the intestine, Stx can translocate systemically and is cytotoxic to microvascular endothelial cells, especially in the kidney and brain. Disease can progress to life-threatening hemolytic uremic syndrome (HUS) with hemolytic anemia, acute kidney failure, and thrombocytopenia. Young children, the immunocompromised, and the elderly are at the highest risk for HUS. Healthy ruminants are the major reservoir of EHEC and cattle are the primary source of human exposure. RECENT FINDINGS Advances in understanding E. coli O157:H7 pathogenesis include molecular mechanisms of virulence, bacterial adherence, type three secretion effectors, intestinal microbiome, inflammation, and reservoir maintenance. SUMMARY Many aspects of E. coli O157:H7 disease remain unclear and include the role of the human and bovine intestinal microbiomes in infection. Therapeutic strategies involve controlling inflammatory responses and/or intestinal barrier function. Finally, elimination/reduction of E. coli O157:H7 in cattle using CRISPR-engineered conjugative bacterial plasmids and/or on-farm management likely hold solutions to reduce infections and increase food safety/security.
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Segura A, Bertin Y, Durand A, Benbakkar M, Forano E. Transcriptional analysis reveals specific niche factors and response to environmental stresses of enterohemorrhagic Escherichia coli O157:H7 in bovine digestive contents. BMC Microbiol 2021; 21:284. [PMID: 34663220 PMCID: PMC8524897 DOI: 10.1186/s12866-021-02343-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 09/24/2021] [Indexed: 02/08/2023] Open
Abstract
Background Enterohemorrhagic Escherichia coli (EHEC) are responsible for severe diseases in humans, and the ruminant digestive tract is considered as their main reservoir. Their excretion in bovine feces leads to the contamination of foods and the environment. Thus, providing knowledge of processes used by EHEC to survive and/or develop all along the bovine gut represents a major step for strategies implementation. Results We compared the transcriptome of the reference EHEC strain EDL933 incubated in vitro in triplicate samples in sterile bovine rumen, small intestine and rectum contents with that of the strain grown in an artificial medium using RNA-sequencing (RNA-seq), focusing on genes involved in stress response, adhesion systems including the LEE, iron uptake, motility and chemotaxis. We also compared expression of these genes in one digestive content relative to the others. In addition, we quantified short chain fatty acids and metal ions present in the three digestive contents. RNA-seq data first highlighted response of EHEC EDL933 to unfavorable physiochemical conditions encountered during its transit through the bovine gut lumen. Seventy-eight genes involved in stress responses including drug export, oxidative stress and acid resistance/pH adaptation were over-expressed in all the digestive contents compared with artificial medium. However, differences in stress fitness gene expression were observed depending on the digestive segment, suggesting that these differences were due to distinct physiochemical conditions in the bovine digestive contents. EHEC activated genes encoding three toxin/antitoxin systems in rumen content and many gene clusters involved in motility and chemotaxis in rectum contents. Genes involved in iron uptake and utilization were mostly down-regulated in all digestive contents compared with artificial medium, but feo genes were over-expressed in rumen and small intestine compared with rectum. The five LEE operons were more expressed in rectum than in rumen content, and LEE1 was also more expressed in rectum than in small intestine content. Conclusion Our results highlight various strategies that EHEC may implement to survive in the gastrointestinal environment of cattle. These data could also help defining new targets to limit EHEC O157:H7 carriage and shedding by cattle. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02343-7.
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Affiliation(s)
- Audrey Segura
- Université Clermont Auvergne, INRAE, MEDIS 0454, F-63000, Clermont-Ferrand, France
| | - Yolande Bertin
- Université Clermont Auvergne, INRAE, MEDIS 0454, F-63000, Clermont-Ferrand, France
| | - Alexandra Durand
- Université Clermont Auvergne, INRAE, MEDIS 0454, F-63000, Clermont-Ferrand, France
| | - Mhammed Benbakkar
- Université Clermont Auvergne, CNRS, IRD, OPGC, Laboratoire Magmas et Volcans, F-63000, Clermont-Ferrand, France
| | - Evelyne Forano
- Université Clermont Auvergne, INRAE, MEDIS 0454, F-63000, Clermont-Ferrand, France.
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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: 29] [Impact Index Per Article: 9.7] [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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Escherichia coli O157:H7 F9 Fimbriae Recognize Plant Xyloglucan and Elicit a Response in Arabidopsis thaliana. Int J Mol Sci 2020; 21:ijms21249720. [PMID: 33352760 PMCID: PMC7766294 DOI: 10.3390/ijms21249720] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/04/2020] [Accepted: 12/14/2020] [Indexed: 11/16/2022] Open
Abstract
Fresh produce is often a source of enterohaemorrhagic Escherichia coli (EHEC) outbreaks. Fimbriae are extracellular structures involved in cell-to-cell attachment and surface colonisation. F9 (Fml) fimbriae have been shown to be expressed at temperatures lower than 37 °C, implying a function beyond the mammalian host. We demonstrate that F9 fimbriae recognize plant cell wall hemicellulose, specifically galactosylated side chains of xyloglucan, using glycan arrays. E. coli expressing F9 fimbriae had a positive advantage for adherence to spinach hemicellulose extract and tissues, which have galactosylated oligosaccharides as recognized by LM24 and LM25 antibodies. As fimbriae are multimeric structures with a molecular pattern, we investigated whether F9 fimbriae could induce a transcriptional response in model plant Arabidopsis thaliana, compared with flagella and another fimbrial type, E. coli common pilus (ECP), using DNA microarrays. F9 induced the differential expression of 435 genes, including genes involved in the plant defence response. The expression of F9 at environmentally relevant temperatures and its recognition of plant xyloglucan adds to the suite of adhesins EHEC has available to exploit the plant niche.
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Andreozzi E, Uhlich GA. PchE Regulation of Escherichia coli O157:H7 Flagella, Controlling the Transition to Host Cell Attachment. Int J Mol Sci 2020; 21:ijms21134592. [PMID: 32605187 PMCID: PMC7369912 DOI: 10.3390/ijms21134592] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 06/24/2020] [Accepted: 06/26/2020] [Indexed: 11/16/2022] Open
Abstract
Shiga toxins and intimate adhesion controlled by the locus of enterocyte effacement are major enterohemorrhagic Escherichia coli (EHEC) virulence factors. Curli fimbriae also contribute to cell adhesion and are essential biofilm components. The transcriptional regulator PchE represses the expression of curli and their adhesion to HEp-2 cells. Past studies indicate that pchE also represses additional adhesins that contribute to HEp-2 cell attachment. In this study, we tested for pchE regulation of several tissue adhesins and their regulators. Three adhesin-encoding genes (eae, lpfA1, fliC) and four master regulators (csgD, stpA, ler, flhDC) were controlled by pchE. pchE over-expression strongly up-regulated fliC but the marked flagella induction reduced the attachment of O157:H7 clinical isolate PA20 to HEp-2 cells, indicating that flagella were blocking cell attachments rather than functioning as an adhesin. Chemotaxis, motor, structural, and regulatory genes in the flagellar operons were all increased by pchE expression, as was PA20 motility. This study identifies new members in the pchE regulon and shows that pchE stimulates flagellar motility while repressing cell adhesion, likely to support EHEC movement to the intestinal surface early in infection. However, induced or inappropriate pchE-dependent flagellar expression could block cell attachments later during disease progression.
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Sapountzis P, Segura A, Desvaux M, Forano E. An Overview of the Elusive Passenger in the Gastrointestinal Tract of Cattle: The Shiga Toxin Producing Escherichia coli. Microorganisms 2020; 8:microorganisms8060877. [PMID: 32531983 PMCID: PMC7355788 DOI: 10.3390/microorganisms8060877] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/05/2020] [Accepted: 06/07/2020] [Indexed: 02/07/2023] Open
Abstract
For approximately 10,000 years, cattle have been our major source of meat and dairy. However, cattle are also a major reservoir for dangerous foodborne pathogens that belong to the Shiga toxin-producing Escherichia coli (STEC) group. Even though STEC infections in humans are rare, they are often lethal, as treatment options are limited. In cattle, STEC infections are typically asymptomatic and STEC is able to survive and persist in the cattle GIT by escaping the immune defenses of the host. Interactions with members of the native gut microbiota can favor or inhibit its persistence in cattle, but research in this direction is still in its infancy. Diet, temperature and season but also industrialized animal husbandry practices have a profound effect on STEC prevalence and the native gut microbiota composition. Thus, exploring the native cattle gut microbiota in depth, its interactions with STEC and the factors that affect them could offer viable solutions against STEC carriage in cattle.
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Affiliation(s)
- Panagiotis Sapountzis
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
- Correspondence:
| | - Audrey Segura
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
- Chr. Hansen Animal Health & Nutrition, 2970 Hørsholm, Denmark
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
| | - Evelyne Forano
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
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10
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Bustamante P, Vidal R. Repertoire and Diversity of Toxin - Antitoxin Systems of Crohn's Disease-Associated Adherent-Invasive Escherichia coli. New Insight of T his Emergent E. coli Pathotype. Front Microbiol 2020; 11:807. [PMID: 32477289 PMCID: PMC7232551 DOI: 10.3389/fmicb.2020.00807] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
Adherent-invasive Escherichia coli (AIEC) corresponds to an E. coli pathovar proposed as a possible agent trigger associated to Crohn's disease. It is characterized for its capacity to adhere and to invade epithelial cells, and to survive and replicate inside macrophages. Mechanisms that allow intestinal epithelium colonization, and host factors that favor AIEC persistence have been partly elucidated. However, bacterial factors involved in AIEC persistence are currently unknown. Toxin-antitoxin (TA) systems are recognized elements involved in bacterial persistence, in addition to have a role in stabilization of mobile genetic elements and stress response. The aim of this study was to elucidate the repertoire and diversity of TA systems in the reference AIEC NRG857c strain and to compare it with AIEC strains whose genomes are available at databases. In addition, toxin expression levels under in vitro stress conditions found by AIEC through the intestine and within the macrophage were measured. Our results revealed that NRG857c encodes at least 33 putative TA systems belonging to types I, II, IV, and V, distributed around all the chromosome, and some in close proximity to genomic islands. A TA toxin repertoire marker of the pathotype was not found and the repertoire of 33 TA toxin genes described here was exclusive of the reference strains, NRG857c and LF82. Most toxin genes were upregulated in the presence of bile salts and acidic pH, as well as within the macrophage. However, different transcriptional responses were detected between reference strains (NRG857c and HM605), recalling the high diversity associated to this pathotype. To our knowledge this is the first analysis of TA systems associated to AIEC and it has revealed new insight associated to this emergent E. coli pathotype.
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Affiliation(s)
- Paula Bustamante
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Roberto Vidal
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Instituto Milenio de Inmunología e Inmunoterapia, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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11
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Werneburg GT, Thanassi DG. Pili Assembled by the Chaperone/Usher Pathway in Escherichia coli and Salmonella. EcoSal Plus 2018; 8:10.1128/ecosalplus.ESP-0007-2017. [PMID: 29536829 PMCID: PMC5940347 DOI: 10.1128/ecosalplus.esp-0007-2017] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Indexed: 12/12/2022]
Abstract
Gram-negative bacteria assemble a variety of surface structures, including the hair-like organelles known as pili or fimbriae. Pili typically function in adhesion and mediate interactions with various surfaces, with other bacteria, and with other types of cells such as host cells. The chaperone/usher (CU) pathway assembles a widespread class of adhesive and virulence-associated pili. Pilus biogenesis by the CU pathway requires a dedicated periplasmic chaperone and integral outer membrane protein termed the usher, which forms a multifunctional assembly and secretion platform. This review addresses the molecular and biochemical aspects of the CU pathway in detail, focusing on the type 1 and P pili expressed by uropathogenic Escherichia coli as model systems. We provide an overview of representative CU pili expressed by E. coli and Salmonella, and conclude with a discussion of potential approaches to develop antivirulence therapeutics that interfere with pilus assembly or function.
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Affiliation(s)
- Glenn T. Werneburg
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
- Center for Infectious Diseases, Stony Brook University, Stony Brook, NY, USA
| | - David G. Thanassi
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
- Center for Infectious Diseases, Stony Brook University, Stony Brook, NY, USA
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12
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Dufresne K, Saulnier-Bellemare J, Daigle F. Functional Analysis of the Chaperone-Usher Fimbrial Gene Clusters of Salmonella enterica serovar Typhi. Front Cell Infect Microbiol 2018; 8:26. [PMID: 29473020 PMCID: PMC5809473 DOI: 10.3389/fcimb.2018.00026] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 01/19/2018] [Indexed: 01/11/2023] Open
Abstract
The human-specific pathogen Salmonella enterica serovar Typhi causes typhoid, a major public health issue in developing countries. Several aspects of its pathogenesis are still poorly understood. S. Typhi possesses 14 fimbrial gene clusters including 12 chaperone-usher fimbriae (stg, sth, bcf, fim, saf, sef, sta, stb, stc, std, ste, and tcf). These fimbriae are weakly expressed in laboratory conditions and only a few are actually characterized. In this study, expression of all S. Typhi chaperone-usher fimbriae and their potential roles in pathogenesis such as interaction with host cells, motility, or biofilm formation were assessed. All S. Typhi fimbriae were better expressed in minimal broth. Each system was overexpressed and only the fimbrial gene clusters without pseudogenes demonstrated a putative major subunits of about 17 kDa on SDS-PAGE. Six of these (Fim, Saf, Sta, Stb, Std, and Tcf) also show extracellular structure by electron microscopy. The impact of fimbrial deletion in a wild-type strain or addition of each individual fimbrial system to an S. Typhi afimbrial strain were tested for interactions with host cells, biofilm formation and motility. Several fimbriae modified bacterial interactions with human cells (THP-1 and INT-407) and biofilm formation. However, only Fim fimbriae had a deleterious effect on motility when overexpressed. Overall, chaperone-usher fimbriae seem to be an important part of the balance between the different steps (motility, adhesion, host invasion and persistence) of S. Typhi pathogenesis.
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Affiliation(s)
- Karine Dufresne
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, Canada
| | - Julie Saulnier-Bellemare
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, Canada
| | - France Daigle
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, Canada
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13
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Hansmeier N, Miskiewicz K, Elpers L, Liss V, Hensel M, Sterzenbach T. Functional expression of the entire adhesiome of Salmonella enterica serotype Typhimurium. Sci Rep 2017; 7:10326. [PMID: 28871183 PMCID: PMC5583245 DOI: 10.1038/s41598-017-10598-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 08/10/2017] [Indexed: 12/21/2022] Open
Abstract
Adhesins are crucial virulence factors of pathogenic bacteria involved in colonization, transmission and pathogenesis. Many bacterial genomes contain the information for a surprisingly large number of diverse adhesive structures. One prominent example is the invasive and facultative intracellular pathogen Salmonella enterica with an adhesiome of up to 20 adhesins. Such large repertoire of adhesins contributes to colonization of a broad range of host species and may allow adaptation to various environments within the host, as well as in non-host environments. For S. enterica, only few members of the adhesiome are functionally expressed under laboratory conditions, and accordingly the structural and functional understanding of the majority of adhesins is sparse. We have devised a simple and versatile approach to functionally express all adhesins of S. enterica serotype Typhimurium, either within Salmonella or within heterologous hosts such as Escherichia coli. We demonstrate the surface expression of various so far cryptic adhesins and show ultrastructural features using atomic force microscopy and transmission electron microscopy. In summary, we report for the first time the expression of the entire adhesiome of S. enterica serotype Typhimurium.
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Affiliation(s)
- Nicole Hansmeier
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany
| | - Katarzyna Miskiewicz
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany
| | - Laura Elpers
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany
| | - Viktoria Liss
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany
| | - Michael Hensel
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany.
| | - Torsten Sterzenbach
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany.
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14
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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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15
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Fonseca BB, Ferreira Júnior A, Santos JPD, Coelho LR, Rossi DA, Melo RT, Mendonça EP, Araújo TG, Alves RN, Beletti ME. Campylobacter Jejuni Increases Transcribed Il-1 B and Causes Morphometric Changes in the Ileal Enterocytes of Chickens. BRAZILIAN JOURNAL OF POULTRY SCIENCE 2016. [DOI: 10.1590/1516-635x1801063-068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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16
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Abstract
Proteinaceous, nonflagellar surface appendages constitute a variety of structures, including those known variably as fimbriae or pili. Constructed by distinct assembly pathways resulting in diverse morphologies, fimbriae have been described to mediate functions including adhesion, motility, and DNA transfer. As these structures can represent major diversifying elements among Escherichia and Salmonella isolates, multiple fimbrial classification schemes have been proposed and a number of mechanistic insights into fimbrial assembly and function have been made. Herein we describe the classifications and biochemistry of fimbriae assembled by the chaperone/usher, curli, and type IV pathways.
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17
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Abstract
Adhesins are a group of proteins in enterohemorrhagic Escherichia coli (EHEC) that are involved in the attachment or colonization of this pathogen to abiotic (plastic or steel) and biological surfaces, such as those found in bovine and human intestines. This review provides the most up-to-date information on these essential adhesion factors, summarizing important historical discoveries and analyzing the current and future state of this research. In doing so, the proteins intimin and Tir are discussed in depth, especially regarding their role in the development of attaching and effacing lesions and in EHEC virulence. Further, a series of fimbrial proteins (Lpf1, Lpf2, curli, ECP, F9, ELF, Sfp, HCP, and type 1 fimbriae) are also described, emphasizing their various contributions to adherence and colonization of different surfaces and their potential use as genetic markers in detection and classification of different EHEC serotypes. This review also discusses the role of several autotransporter proteins (EhaA-D, EspP, Saa and Sab, and Cah), as well as other proteins associated with adherence, such as flagella, EibG, Iha, and OmpA. While these proteins have all been studied to varying degrees, all of the adhesins summarized in this chapter have been linked to different stages of the EHEC life cycle, making them good targets for the development of more effective diagnostics and therapeutics.
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Affiliation(s)
- Brian D. McWilliams
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, 77555. USA
| | - Alfredo G. Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, 77555. USA
- Department of Pathology and Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, Texas, 77555. USA
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18
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Tan X, Xiao H, Han Y, Hong X, Cui Q, Zhou Z. Encoded protein from ycbR gene of enterohemorrhagic Escherichia coli O157:H7 associated with adherence to HEp-2 cells. Microbiol Res 2014; 169:855-61. [DOI: 10.1016/j.micres.2014.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 02/28/2014] [Accepted: 03/03/2014] [Indexed: 01/14/2023]
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19
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Jaglic Z, Desvaux M, Weiss A, Nesse LL, Meyer RL, Demnerova K, Schmidt H, Giaouris E, Sipailiene A, Teixeira P, Kačániová M, Riedel CU, Knøchel S. Surface adhesins and exopolymers of selected foodborne pathogens. MICROBIOLOGY-SGM 2014; 160:2561-2582. [PMID: 25217529 DOI: 10.1099/mic.0.075887-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The ability of bacteria to bind different compounds and to adhere to biotic and abiotic surfaces provides them with a range of advantages, such as colonization of various tissues, internalization, avoidance of an immune response, and survival and persistence in the environment. A variety of bacterial surface structures are involved in this process and these promote bacterial adhesion in a more or less specific manner. In this review, we will focus on those surface adhesins and exopolymers in selected foodborne pathogens that are involved mainly in primary adhesion. Their role in biofilm development will also be considered when appropriate. Both the clinical impact and the implications for food safety of such adhesion will be discussed.
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Affiliation(s)
- Zoran Jaglic
- Veterinary Research Institute, Brno, Czech Republic
| | - Mickaël Desvaux
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France
| | - Agnes Weiss
- Department of Food Microbiology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 28, 70599 Stuttgart, Germany
| | | | - Rikke L Meyer
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Katerina Demnerova
- Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Technicka 5, Prague, 166 28, Czech Republic
| | - Herbert Schmidt
- Department of Food Microbiology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 28, 70599 Stuttgart, Germany
| | - Efstathios Giaouris
- Department of Food Science and Nutrition, Faculty of the Environment, University of the Aegean, 81400 Myrina, Lemnos Island, Greece
| | | | - Pilar Teixeira
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | | | - Christian U Riedel
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Susanne Knøchel
- Department of Food Science, University of Copenhagen, Rolighedsvej 30, Frederiksberg C 1958, Denmark
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20
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Chagnot C, Caccia N, Loukiadis E, Ganet S, Durand A, Bertin Y, Talon R, Astruc T, Desvaux M. Colonization of the meat extracellular matrix proteins by O157 and non-O157 enterohemorrhagic Escherichia coli. Int J Food Microbiol 2014; 188:92-8. [PMID: 25090606 DOI: 10.1016/j.ijfoodmicro.2014.07.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 05/27/2014] [Accepted: 07/15/2014] [Indexed: 11/28/2022]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) are anthropozoonotic agents that range third among food-borne pathogens respective to their incidence and dangerousness in the European Union. EHEC are Shiga-toxin producing E. coli (STEC) responsible for foodborne poisoning mainly incriminated to the consumption of contaminated beef meat. Among the hundreds of STEC serotypes identified, EHEC mainly belong to O157:H7 but non-O157 can represent 20 to 70% of EHEC infections per year. Seven of those serogroups are especially of high-risk for human health, i.e. O26, O45, O103, O111, O121, O145 and O104. While meat can be contaminated all along the food processing chain, EHEC contamination essentially occurs at the dehiding stage of slaughtering. Investigating bacterial colonization to the skeletal-muscle extracellular matrix (ECM) proteins, it appeared that environmental factors influenced specific and non-specific bacterial adhesion of O157 and non-O157 EHEC as well as biofilm formation. Importantly, mechanical treatment (i.e. shaking, centrifugation, pipetting and vortexing) inhibited and biased the results of bacterial adhesion assay. Besides stressing the importance of the protocol to investigate bacterial adhesion to ECM proteins, this study demonstrated that the colonization abilities to ECM proteins vary among EHEC serogroups and should ultimately be taken into consideration to evaluate the risk of contamination for different types of food matrices.
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Affiliation(s)
- Caroline Chagnot
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France; INRA, UR370 Qualité des Produits Animaux, F-63122 Saint-Genès Champanelle, France
| | - Nelly Caccia
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France
| | - Estelle Loukiadis
- Université de Lyon, VetAgro Sup, LMAP Laboratory, National Reference Laboratory for E. coli (including STEC), F-69280 Marcy l'Etoile, France; Université de Lyon, UMR 5557 Ecologie Microbienne, Université Lyon 1, CNRS, VetAgro Sup, Research Group on Bacterial Opportunistic Pathogens and Environment, F-69622 Villeurbanne, France
| | - Sarah Ganet
- Université de Lyon, VetAgro Sup, LMAP Laboratory, National Reference Laboratory for E. coli (including STEC), F-69280 Marcy l'Etoile, France; Université de Lyon, UMR 5557 Ecologie Microbienne, Université Lyon 1, CNRS, VetAgro Sup, Research Group on Bacterial Opportunistic Pathogens and Environment, F-69622 Villeurbanne, France
| | - Alexandra Durand
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France
| | - Yolande Bertin
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France
| | - Régine Talon
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France
| | - Thierry Astruc
- INRA, UR370 Qualité des Produits Animaux, F-63122 Saint-Genès Champanelle, France
| | - Mickaël Desvaux
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France.
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21
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Wurpel DJ, Totsika M, Allsopp LP, Hartley-Tassell LE, Day CJ, Peters KM, Sarkar S, Ulett GC, Yang J, Tiralongo J, Strugnell RA, Jennings MP, Schembri MA. F9 fimbriae of uropathogenic Escherichia coli are expressed at low temperature and recognise Galβ1-3GlcNAc-containing glycans. PLoS One 2014; 9:e93177. [PMID: 24671091 PMCID: PMC3966885 DOI: 10.1371/journal.pone.0093177] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Accepted: 03/03/2014] [Indexed: 11/29/2022] Open
Abstract
Uropathogenic Escherichia coli (UPEC) is the leading causative agent of urinary tract infections (UTI) in the developed world. Among the major virulence factors of UPEC, surface expressed adhesins mediate attachment and tissue tropism. UPEC strains typically possess a range of adhesins, with type 1 fimbriae and P fimbriae of the chaperone-usher class the best characterised. We previously identified and characterised F9 as a new chaperone-usher fimbrial type that mediates biofilm formation. However, the regulation and specific role of F9 fimbriae remained to be determined in the context of wild-type clinical UPEC strains. In this study we have assessed the distribution and genetic context of the f9 operon among diverse E. coli lineages and pathotypes and demonstrated that f9 genes are significantly more conserved in a UPEC strain collection in comparison to the well-defined E. coli reference (ECOR) collection. In the prototypic UPEC strain CFT073, the global regulator protein H-NS was identified as a transcriptional repressor of f9 gene expression at 37°C through its ability to bind directly to the f9 promoter region. F9 fimbriae expression was demonstrated at 20°C, representing the first evidence of functional F9 fimbriae expression by wild-type E. coli. Finally, glycan array analysis demonstrated that F9 fimbriae recognise and bind to terminal Galβ1-3GlcNAc structures.
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Affiliation(s)
- Daniël J. Wurpel
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Makrina Totsika
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
- * E-mail: (MAS); (MT)
| | - Luke P. Allsopp
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | | | - Christopher J. Day
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Kate M. Peters
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Sohinee Sarkar
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Glen C. Ulett
- School of Medical Sciences, Centre for Medicine and Oral Health, Griffith University, Southport, Queensland, Australia
| | - Ji Yang
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria, Australia
| | - Joe Tiralongo
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Richard A. Strugnell
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria, Australia
| | - Michael P. Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Mark A. Schembri
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
- * E-mail: (MAS); (MT)
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22
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Ethanolamine and choline promote expression of putative and characterized fimbriae in enterohemorrhagic Escherichia coli O157:H7. Infect Immun 2013; 82:193-201. [PMID: 24126525 DOI: 10.1128/iai.00980-13] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important food-borne pathogen responsible for disease outbreaks worldwide. In order to colonize the human gastrointestinal (GI) tract and cause disease, EHEC must be able to sense the host environment and promote expression of virulence genes essential for adherence. Ethanolamine (EA) is an important metabolite for EHEC in the GI tract, and EA is also a signal that EHEC uses to activate virulence traits. Here, we report that EA influenced EHEC adherence to epithelial cells and fimbrial gene expression. Quantitative reverse transcriptase PCR indicated that EA promoted the transcription of the genes in characterized and putative fimbrial operons. Moreover, putative fimbrial structures were produced by EHEC cells grown with EA but not in medium lacking EA. Additionally, we defined two previously uncharacterized EA-regulated fimbrial operons, loc10 and loc11. We also tested whether choline or serine, both of which are also components of cell membranes, activated fimbrial gene expression. In addition to EA, choline activated fimbrial gene expression in EHEC. These findings describe for the first time the transcription of several putative fimbrial loci in EHEC. Importantly, the biologically relevant molecules EA and choline, which are abundant in the GI tract, promoted expression of these fimbriae.
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23
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Bile salts affect expression of Escherichia coli O157:H7 genes for virulence and iron acquisition, and promote growth under iron limiting conditions. PLoS One 2013; 8:e74647. [PMID: 24058617 PMCID: PMC3769235 DOI: 10.1371/journal.pone.0074647] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Accepted: 08/08/2013] [Indexed: 01/17/2023] Open
Abstract
Bile salts exhibit potent antibacterial properties, acting as detergents to disrupt cell membranes and as DNA-damaging agents. Although bacteria inhabiting the intestinal tract are able to resist bile’s antimicrobial effects, relatively little is known about how bile influences virulence of enteric pathogens. Escherichia coli O157:H7 is an important pathogen of humans, capable of causing severe diarrhea and more serious sequelae. In this study, the transcriptome response of E. coli O157:H7 to bile was determined. Bile exposure induced significant changes in mRNA levels of genes related to virulence potential, including a reduction of mRNA for the 41 genes making up the locus of enterocyte effacement (LEE) pathogenicity island. Bile treatment had an unusual effect on mRNA levels for the entire flagella-chemotaxis regulon, resulting in two- to four-fold increases in mRNA levels for genes associated with the flagella hook-basal body structure, but a two-fold decrease for “late” flagella genes associated with the flagella filament, stator motor, and chemotaxis. Bile salts also caused increased mRNA levels for seventeen genes associated with iron scavenging and metabolism, and counteracted the inhibitory effect of the iron chelating agent 2,2’-dipyridyl on growth of E. coli O157:H7. These findings suggest that E. coli O157:H7 may use bile as an environmental signal to adapt to changing conditions associated with the small intestine, including adaptation to an iron-scarce environment.
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Advances in the development of enterohemorrhagic Escherichia coli vaccines using murine models of infection. Vaccine 2013; 31:3229-35. [PMID: 23707170 DOI: 10.1016/j.vaccine.2013.05.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/06/2013] [Accepted: 05/07/2013] [Indexed: 01/22/2023]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) strains are food borne pathogens with importance in public health. EHEC colonizes the large intestine and causes diarrhea, hemorrhagic colitis and in some cases, life-threatening hemolytic-uremic syndrome (HUS) due to the production of Shiga toxins (Stx). The lack of effective clinical treatment, sequelae after infection and mortality rate in humans supports the urgent need of prophylactic approaches, such as development of vaccines. Shedding from cattle, the main EHEC reservoir and considered the principal food contamination source, has prompted the development of licensed vaccines that reduce EHEC colonization in ruminants. Although murine models do not fully recapitulate human infection, they are commonly used to evaluate EHEC vaccines and the immune/protective responses elicited in the host. Mice susceptibility differs depending of the EHEC inoculums; displaying different mortality rates and Stx-mediated renal damage. Therefore, several experimental protocols have being pursued in this model to develop EHEC-specific vaccines. Recent candidate vaccines evaluated include those composed of virulence factors alone or as fused-subunits, DNA-based, attenuated bacteria and bacterial ghosts. In this review, we summarize progress in the design and testing of EHEC vaccines and the use of different strategies for the evaluation of novel EHEC vaccines in the murine model.
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Etcheverría AI, Padola NL. Shiga toxin-producing Escherichia coli: factors involved in virulence and cattle colonization. Virulence 2013; 4:366-72. [PMID: 23624795 PMCID: PMC3714128 DOI: 10.4161/viru.24642] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) cause hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS) in humans. Outbreaks are linked to bovine food sources. STEC O157:H7 has been responsible for the most severe outbreaks worldwide. However, non-O157 serotypes have emerged as important enteric pathogens in several countries. The main virulence factor of STEC is the production of Shiga toxins 1 and 2. Additional virulence markers are a plasmid-encoded enterohemolysin (ehxA), an autoagglutinating adhesin (Saa), a catalase-peroxidase (katP), an extracellular serine protease (espP), a zinc metalloprotease (stcE), a subtilase cytotoxin (subAB), among others. Other virulence factors are intimin and adhesins that had a roll in the adherence of STEC to bovine colon. This review focuses on the virulence traits of STEC and especially on those related to the adhesion to bovine colon. The known of the interaction between STEC and the bovine host is crucial to develop strategies to control cattle colonization.
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Affiliation(s)
- Analía Inés Etcheverría
- Laboratorio de Imunoquímica y Biotecnología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET-CICPBA, Facultad de Ciencias Veterinarias, UNCPBA, Tandil, Argentina.
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26
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Barnett Foster D. Modulation of the enterohemorrhagic E. coli virulence program through the human gastrointestinal tract. Virulence 2013; 4:315-23. [PMID: 23552827 PMCID: PMC3710334 DOI: 10.4161/viru.24318] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Enteric pathogens must not only survive passage through the gastrointestinal tract but must also coordinate expression of virulence determinants in response to localized microenvironments with the host. Enterohemorrhagic Escherichia coli (EHEC), a serious food and waterborne human pathogen, is well equipped with an arsenal of molecular factors that allows it to survive passage through the gastrointestinal tract and successfully colonize the large intestine. This review will explore how EHEC responds to various environmental cues associated with particular microenvironments within the host and how it employs these cues to modulate virulence factor expression, with a view to developing a conceptual framework for understanding modulation of EHEC’s virulence program in response to the host. In vitro studies offer significant insights into the role of individual environmental cues but in vivo studies using animal models as well as data from natural infections will ultimately provide a more comprehensive picture of the highly regulated virulence program of this pathogen.
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Affiliation(s)
- Debora Barnett Foster
- Department of Chemistry and Biology, Faculty of Science, Ryerson University, Toronto, ONT, Canada.
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Wright KM, Chapman S, McGeachy K, Humphris S, Campbell E, Toth IK, Holden NJ. The endophytic lifestyle of Escherichia coli O157:H7: quantification and internal localization in roots. PHYTOPATHOLOGY 2013; 103:333-40. [PMID: 23506361 DOI: 10.1094/phyto-08-12-0209-fi] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The foodborne pathogen Escherichia coli O157:H7 is increasingly associated with fresh produce (fruit and vegetables). Bacterial colonization of fresh produce plants can occur to high levels on the external tissue but bacteria have also been detected within plant tissue. However, questions remain about the extent of internalization, its molecular basis, and internal location of the bacteria. We have determined the extent of internalization of E. coli O157:H7 in live spinach and lettuce plants and used high-resolution microscopy to examine colony formation in roots and pathways to internalization. E. coli O157:H7 was found within internal tissue of both produce species. Colonization occurred within the apoplast between plant cells. Furthermore, colonies were detected inside the cell wall of epidermal and cortical cells of spinach and Nicotiana benthamiana roots. Internal colonization of epidermal cells resembled that of the phytopathogen Pectobacterium atrosepticum on potato. In contrast, only sporadic cells of the laboratory strain of E. coli K-12 were found on spinach, with no internal bacteria evident. The data extend previous findings that internal colonization of plants appears to be limited to a specific group of plant-interacting bacteria, including E. coli O157:H7, and demonstrates its ability to invade the cells of living plants.
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Chingcuanco F, Yu Y, Kus JV, Que L, Lackraj T, Lévesque CM, Barnett Foster D. Identification of a novel adhesin involved in acid-induced adhesion of enterohaemorrhagic Escherichia coli O157 : H7. Microbiology (Reading) 2012; 158:2399-2407. [DOI: 10.1099/mic.0.056374-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Frances Chingcuanco
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Yijing Yu
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Julianne V. Kus
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Lynn Que
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Tracy Lackraj
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Céline M. Lévesque
- Dental Research Institute, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
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Transcriptional regulation of the ecp operon by EcpR, IHF, and H-NS in attaching and effacing Escherichia coli. J Bacteriol 2012; 194:5020-33. [PMID: 22797761 DOI: 10.1128/jb.00915-12] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enteropathogenic (EPEC) and enterohemorrhagic (EHEC) Escherichia coli are clinically important diarrheagenic pathogens that adhere to the intestinal epithelial surface. The E. coli common pili (ECP), or meningitis-associated and temperature-regulated (MAT) fimbriae, are ubiquitous among both commensal and pathogenic E. coli strains and play a role as colonization factors by promoting the interaction between bacteria and host epithelial cells and favoring interbacterial interactions in biofilm communities. The first gene of the ecp operon encodes EcpR (also known as MatA), a proposed regulatory protein containing a LuxR-like C-terminal helix-turn-helix (HTH) DNA-binding motif. In this work, we analyzed the transcriptional regulation of the ecp genes and the role of EcpR as a transcriptional regulator. EHEC and EPEC ecpR mutants produce less ECP, while plasmids expressing EcpR increase considerably the expression of EcpA and production of ECP. The ecp genes are transcribed as an operon from a promoter located 121 bp upstream of the start codon of ecpR. EcpR positively regulates this promoter by binding to two TTCCT boxes distantly located upstream of the ecp promoter, thus enhancing expression of downstream ecp genes, leading to ECP production. EcpR mutants in the putative HTH DNA-binding domain are no longer able to activate ecp expression or bind to the TTCCT boxes. EcpR-mediated activation is aided by integration host factor (IHF), which is essential for counteracting the repression exerted by histone-like nucleoid-structuring protein (H-NS) on the ecp promoter. This work demonstrates evidence about the interplay between a novel member of a diverse family of regulatory proteins and global regulators in the regulation of a fimbrial operon.
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Farfan MJ, Torres AG. Molecular mechanisms that mediate colonization of Shiga toxin-producing Escherichia coli strains. Infect Immun 2012; 80:903-13. [PMID: 22144484 PMCID: PMC3294676 DOI: 10.1128/iai.05907-11] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is a group of pathogens which cause gastrointestinal disease in humans and have been associated with numerous food-borne outbreaks worldwide. The intimin adhesin has been considered for many years to be the only colonization factor in these strains. However, the rapid progress in whole-genome sequencing of different STEC serotypes has accelerated the discovery of other adhesins (fimbrial and afimbrial), which have emerged as important contributors to the intestinal colonization occurring during STEC infection. This review summarizes recent progress to identify and characterize, at the molecular level, novel adhesion and colonization factors in STEC strains, with an emphasis on their contribution to virulence traits, their host-pathogen interactions, the regulatory mechanisms controlling their expression, and their role as targets eliciting immune responses in the host.
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Affiliation(s)
- Mauricio J. Farfan
- Centro de Estudios Moleculares, Departamento de Pediatría, Hospital Dr. Luis Calvo Mackenna, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Alfredo G. Torres
- Department of Microbiology and Immunology, Department of Pathology, Sealy Center for Vaccine Development, and Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, USA
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Flockhart AF, Tree JJ, Xu X, Karpiyevich M, McAteer SP, Rosenblum R, Shaw DJ, Low CJ, Best A, Gannon V, Laing C, Murphy KC, Leong JM, Schneiders T, La Ragione R, Gally DL. Identification of a novel prophage regulator in Escherichia coli controlling the expression of type III secretion. Mol Microbiol 2011; 83:208-23. [PMID: 22111928 PMCID: PMC3378721 DOI: 10.1111/j.1365-2958.2011.07927.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
This study has identified horizontally acquired genomic regions of enterohaemorrhagic Escherichia coli O157:H7 that regulate expression of the type III secretion (T3S) system encoded by the locus of enterocyte effacement (LEE). Deletion of O-island 51, a 14.93 kb cryptic prophage (CP-933C), resulted in a reduction in LEE expression and T3S. The deletion also had a reduced capacity to attach to epithelial cells and significantly reduced E. coli O157 excretion levels from sheep. Further characterization of O-island 51 identified a novel positive regulator of the LEE, encoded by ecs1581 in the E. coli O157:H7 strain Sakai genome and present but not annotated in the E. coli strain EDL933 sequence. Functionally important residues of ECs1581 were identified based on phenotypic variants present in sequenced E. coli strains and the regulator was termed RgdR based on a motif demonstrated to be important for stimulation of gene expression. While RgdR activated expression from the LEE1 promoter in the presence or absence of the LEE-encoded regulator (Ler), RgdR stimulation of T3S required ler and Ler autoregulation. RgdR also controlled the expression of other phenotypes, including motility, indicating that this new family of regulators may have a more global role in E. coli gene expression.
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Affiliation(s)
- Allen F Flockhart
- Immunity and Infection Division, The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh EH25 9RG, UK
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Bai J, McAteer SP, Paxton E, Mahajan A, Gally DL, Tree JJ. Screening of an E. coli O157:H7 Bacterial Artificial Chromosome Library by Comparative Genomic Hybridization to Identify Genomic Regions Contributing to Growth in Bovine Gastrointestinal Mucus and Epithelial Cell Colonization. Front Microbiol 2011; 2:168. [PMID: 21887152 PMCID: PMC3157008 DOI: 10.3389/fmicb.2011.00168] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 07/24/2011] [Indexed: 01/06/2023] Open
Abstract
Enterohemorrhagic E. coli (EHEC) O157:H7 can cause serious gastrointestinal and systemic disease in humans following direct or indirect exposure to ruminant feces containing the bacterium. The main colonization site of EHEC O157:H7 in cattle is the terminal rectum where the bacteria intimately attach to the epithelium and multiply in the intestinal mucus. This study aimed to identify genomic regions of EHEC O157:H7 that contribute to colonization and multiplication at this site. A bacterial artificial chromosome (BAC) library was generated from a derivative of the sequenced E. coli O157:H7 Sakai strain. The library contains 1152 clones averaging 150 kbp. To verify the library, clones containing a complete locus of enterocyte effacement (LEE) were identified by DNA hybridization. In line with a previous report, these did not confer a type III secretion (T3S) capacity to the K-12 host strain. However, conjugation of one of the BAC clones into a strain containing a partial LEE deletion restored T3S. Three hundred eighty-four clones from the library were subjected to two different selective screens; one involved three rounds of adherence assays to bovine primary rectal epithelial cells while the other competed the clones over three rounds of growth in bovine rectal mucus. The input strain DNA was then compared with the selected strains using comparative genomic hybridization (CGH) on an E. coli microarray. The adherence assay enriched for pO157 DNA indicating the importance of this plasmid for colonization of rectal epithelial cells. The mucus assay enriched for multiple regions involved in carbohydrate utilization, including hexuronate uptake, indicating that these regions provide a competitive growth advantage in bovine mucus. This BAC-CGH approach provides a positive selection screen that complements negative selection transposon-based screens. As demonstrated, this may be of particular use for identifying genes with redundant functions such as adhesion and carbon metabolism.
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Affiliation(s)
- Jianing Bai
- Infection and Immunity Division, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of EdinburghEdinburgh, UK
- College of Life Science, Hebei Normal UniversityShijiazhuang, Hebei Province, China
| | - Sean P. McAteer
- Infection and Immunity Division, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of EdinburghEdinburgh, UK
| | - Edith Paxton
- Infection and Immunity Division, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of EdinburghEdinburgh, UK
| | - Arvind Mahajan
- Infection and Immunity Division, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of EdinburghEdinburgh, UK
| | - David L. Gally
- Infection and Immunity Division, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of EdinburghEdinburgh, UK
| | - Jai J. Tree
- Infection and Immunity Division, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of EdinburghEdinburgh, UK
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Tildesley MJ, Gally DL, McNeilly TN, Low JC, Mahajan A, Savill NJ. Insights into mucosal innate responses to Escherichia coli O157 : H7 colonization of cattle by mathematical modelling of excretion dynamics. J R Soc Interface 2011; 9:518-27. [PMID: 21849385 DOI: 10.1098/rsif.2011.0293] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mathematical model-based statistical inference applied to within-host dynamics of infectious diseases can help dissect complex interactions between hosts and microbes. This work has applied advances in model-based inference to understand colonization of cattle by enterohaemorrhagic Escherichia coli O157 : H7 at the terminal rectum. A mathematical model was developed based on niche replication and transition rates at this site. A nested-model comparison, applied to excretion curves from 25 calves, was used to reduce complexity while maintaining integrity. We conclude that, 5-9 days post inoculation, the innate immune response negates bacterial replication on the epithelium and either reduces attachment to or increases detachment from the epithelium of the terminal rectum. Thus, we provide a broadly applicable model that gives novel insights into bacterial replication rates in vivo and the timing and impact of host responses.
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Affiliation(s)
- Michael J Tildesley
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK.
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Parti RP, Biswas D, Wang M, Liao M, Dillon JAR. A minD mutant of enterohemorrhagic E. coli O157:H7 has reduced adherence to human epithelial cells. Microb Pathog 2011; 51:378-83. [PMID: 21798335 DOI: 10.1016/j.micpath.2011.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 06/29/2011] [Accepted: 07/06/2011] [Indexed: 11/29/2022]
Abstract
Adherence to epithelial cells is a prerequisite for intestinal colonization by the bacterial pathogen, enterohemorrhagic Escherichia coli (EHEC). The deletion of minD, a cell division gene, in EHEC caused reduced adherence to human epithelioid cervical carcinoma (HeLa) and human colonic adenocarcinoma (Caco-2) cells as compared to wild-type. The minD mutant formed minicells and filaments owing to aberrant cytokinesis. Moreover, its ability to form microcolonies as typically seen in the co-cultures of wild-type with Caco-2 cells, was abolished. In conclusion, the present study highlights the importance of minD in regards to EHEC adherence to human epithelial cells.
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Affiliation(s)
- Rajinder P Parti
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada S7N 5E3
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Long polar fimbriae of enterohemorrhagic Escherichia coli O157:H7 bind to extracellular matrix proteins. Infect Immun 2011; 79:3744-50. [PMID: 21708988 DOI: 10.1128/iai.05317-11] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Adherence to intestinal cells is a key process in infection caused by enterohemorrhagic Escherichia coli (EHEC). Several adhesion factors that mediate the binding of EHEC to intestinal cells have been described, but the receptors involved in their recognition are not fully characterized. Extracellular matrix (ECM) proteins might act as receptors involved in the recognition of enteric pathogens, including EHEC. In this study, we sought to characterize the binding of EHEC O157:H7 to ECM proteins commonly present in the intestine. We found that EHEC prototype strains as well as other clinical isolates adhered more abundantly to surfaces coated with fibronectin, laminin, and collagen IV. Further characterization of this phenotype, by using antiserum raised against the LpfA1 putative major fimbrial subunit and by addition of mannose, showed that a reduced binding of EHEC to ECM proteins was observed in a long polar fimbria (lpf) mutant. We also found that the two regulators, H-NS and Ler, had an effect in EHEC Lpf-mediated binding to ECM, supporting the roles of these tightly regulated fimbriae as adherence factors. Purified Lpf major subunit bound to all of the ECM proteins tested. Finally, increased bacterial adherence was observed when T84 cells, preincubated with ECM proteins, were infected with EHEC. Taken together, these findings suggest that the interaction of Lpf and ECM proteins contributes to the EHEC colonization of the gastrointestinal tract.
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Saldaña Z, Sánchez E, Xicohtencatl-Cortes J, Puente JL, Girón JA. Surface structures involved in plant stomata and leaf colonization by shiga-toxigenic Escherichia coli o157:h7. Front Microbiol 2011; 2:119. [PMID: 21887151 PMCID: PMC3157101 DOI: 10.3389/fmicb.2011.00119] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 05/12/2011] [Indexed: 01/03/2023] Open
Abstract
Shiga-toxigenic Escherichia coli (STEC) O157:H7 uses a myriad of surface adhesive appendages including pili, flagella, and the type 3 secretion system (T3SS) to adhere to and inflict damage to the human gut mucosa. Consumption of contaminated ground beef, milk, juices, water, or leafy greens has been associated with outbreaks of diarrheal disease in humans due to STEC. The aim of this study was to investigate which of the known STEC O157:H7 adherence factors mediate colonization of baby spinach leaves and where the bacteria reside within tainted leaves. We found that STEC O157:H7 colonizes baby spinach leaves through the coordinated production of curli, the E. coli common pilus, hemorrhagic coli type 4 pilus, flagella, and T3SS. Electron microscopy analysis of tainted leaves revealed STEC bacteria in the internal cavity of the stomata, in intercellular spaces, and within vascular tissue (xylem and phloem), where the bacteria were protected from the bactericidal effect of gentamicin, sodium hypochlorite or ozonated water treatments. We confirmed that the T3S escN mutant showed a reduced number of bacteria within the stomata suggesting that T3S is required for the successful colonization of leaves. In agreement, non-pathogenic E. coli K-12 strain DH5α transformed with a plasmid carrying the locus of enterocyte effacement (LEE) pathogenicity island, harboring the T3SS and effector genes, internalized into stomata more efficiently than without the LEE. This study highlights a role for pili, flagella, and T3SS in the interaction of STEC with spinach leaves. Colonization of plant stomata and internal tissues may constitute a strategy by which STEC survives in a nutrient-rich microenvironment protected from external foes and may be a potential source for human infection.
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Affiliation(s)
- Zeus Saldaña
- Department of Molecular Genetics and Microbiology, Emerging Pathogens Institute, University of Florida Gainesville, FL, USA
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Korea CG, Ghigo JM, Beloin C. The sweet connection: Solving the riddle of multiple sugar-binding fimbrial adhesins in Escherichia coli. Bioessays 2011; 33:300-11. [DOI: 10.1002/bies.201000121] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Klemm P, Hancock V, Schembri MA. Fimbrial adhesins from extraintestinal Escherichia coli. ENVIRONMENTAL MICROBIOLOGY REPORTS 2010; 2:628-640. [PMID: 23766248 DOI: 10.1111/j.1758-2229.2010.00166.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) represent an important subclass of E. coli that cause a wide spectrum of diseases in human and animal hosts. Fimbriae are key virulence factors of ExPEC strains. These long surface located rod-shaped organelles mediate receptor-specific attachment to host tissue surfaces (tissue tropism). Some ExPEC fimbriae have additional functions such as the promotion of biofilm formation, cell aggregation and adherence to abiotic surfaces. Here we review the structure, function and contribution to virulence of fimbriae associated with ExPEC strains.
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Affiliation(s)
- Per Klemm
- Microbial Adhesion Group, DTU Food, Technical University of Denmark, Lyngby, Denmark. School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
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Xicohtencatl-Cortes J, Saldaña Z, Deng W, Castañeda E, Freer E, Tarr PI, Finlay BB, Puente JL, Girón JA. Bacterial macroscopic rope-like fibers with cytopathic and adhesive properties. J Biol Chem 2010; 285:32336-42. [PMID: 20688909 DOI: 10.1074/jbc.m110.162248] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We present a body of ultrastructural, biochemical, and genetic evidence that demonstrates the oligomerization of virulence-associated autotransporter proteins EspC or EspP produced by deadly human pathogens enterohemorrhagic and enteropathogenic Escherichia coli into novel macroscopic rope-like structures (>1 cm long). The rope-like structures showed high aggregation and insolubility, stability to anionic detergents and high temperature, and binding to Congo Red and thioflavin T dyes. These are properties also exhibited by human amyloidogenic proteins. These macroscopic ropes were not observed in cultures of nonpathogenic Escherichia coli or isogenic espP or espC deletion mutants of enterohemorrhagic or enteropathogenic Escherichia coli but were produced by an Escherichia coli K-12 strain carrying a plasmid expressing espP. Purified recombinant EspP monomers were able to self-assemble into macroscopic ropes upon incubation, suggesting that no other protein was required for assembly. The ropes bound to and showed cytopathic effects on cultured epithelial cells, served as a substratum for bacterial adherence and biofilm formation, and protected bacteria from antimicrobial compounds. We hypothesize that these ropes play a biologically significant role in the survival and pathogenic scheme of these organisms.
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Affiliation(s)
- Juan Xicohtencatl-Cortes
- Laboratorio de Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Delegación Cuauhtémoc, México D.F. 06720, México
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Deacon V, Dziva F, van Diemen PM, Frankel G, Stevens MP. Efa-1/LifA mediates intestinal colonization of calves by enterohaemorrhagic Escherichia coli O26 : H- in a manner independent of glycosyltransferase and cysteine protease motifs or effects on type III secretion. MICROBIOLOGY (READING, ENGLAND) 2010; 156:2527-2536. [PMID: 20466763 DOI: 10.1099/mic.0.039685-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) comprise a group of animal and zoonotic pathogens of worldwide importance. Our previous research established that intestinal colonization of calves by EHEC serotypes O5 : H- and O111 : H- requires EHEC factor for adherence (Efa-1), also known as lymphostatin (LifA). Towards an understanding of the mode of action of Efa-1/LifA, chromosomal in-frame deletions of predicted glycosyltransferase (DXD) and cysteine protease (CHD) motifs were created in a Deltastx1 derivative of EHEC O26 : H-. The magnitude and duration of faecal excretion of EHEC O26 : H- were significantly reduced by null mutation of efa-1/lifA, but were not impaired by DeltaDXD or DeltaCHD mutations, in contrast to observations made with truncated Efa-1/LifA mutants of Citrobacter rodentium in mice. Although C. rodentium Efa-1/LifA influences the induction of colonic hyperplasia in mice, EHEC O26 : H- Efa-1/LifA was not required for fluid accumulation or neutrophil recruitment in bovine ileal loops. In contrast to observations with EHEC O5 : H- or O111 : H- mutants, inactivation of efa-1/lifA in EHEC O26 : H- did not significantly affect adherence or secretion of type III secreted proteins that play pivotal roles in calf colonization. Lymphostatin activity could not be reliably demonstrated in lysates of EHEC O26 : H-; however, deletion of the glycosyltransferase and cysteine protease motifs in Efa-1/LifA from enteropathogenic E. coli O127 : H6 abolished lymphostatin activity. Our data uncouple the role of Efa-1/LifA in calf colonization from effects on type III secretion and reinforce the potential for pathotype- and serotype-specific phenotypes.
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Affiliation(s)
- Victoria Deacon
- Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
- Enteric Bacterial Pathogens Laboratory, Institute for Animal Health, Compton, Berkshire RG20 7NN, UK
| | - Francis Dziva
- Enteric Bacterial Pathogens Laboratory, Institute for Animal Health, Compton, Berkshire RG20 7NN, UK
| | - Pauline M van Diemen
- Enteric Bacterial Pathogens Laboratory, Institute for Animal Health, Compton, Berkshire RG20 7NN, UK
| | - Gad Frankel
- Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
| | - Mark P Stevens
- Enteric Bacterial Pathogens Laboratory, Institute for Animal Health, Compton, Berkshire RG20 7NN, UK
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Bardiau M, Szalo M, Mainil JG. Initial adherence of EPEC, EHEC and VTEC to host cells. Vet Res 2010; 41:57. [PMID: 20423697 PMCID: PMC2881418 DOI: 10.1051/vetres/2010029] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Accepted: 04/27/2010] [Indexed: 12/26/2022] Open
Abstract
Initial adherence to host cells is the first step of the infection of enteropathogenic Escherichia coli (EPEC), enterohaemorrhagic Escherichia coli (EHEC) and verotoxigenic Escherichia coli (VTEC) strains. The importance of this step in the infection resides in the fact that (1) adherence is the first contact between bacteria and intestinal cells without which the other steps cannot occur and (2) adherence is the basis of host specificity for a lot of pathogens. This review describes the initial adhesins of the EPEC, EHEC and VTEC strains. During the last few years, several new adhesins and putative colonisation factors have been described, especially in EHEC strains. Only a few adhesins (BfpA, AF/R1, AF/R2, Ral, F18 adhesins) appear to be host and pathotype specific. The others are found in more than one species and/or pathotype (EPEC, EHEC, VTEC). Initial adherence of EPEC, EHEC and VTEC strains to host cells is probably mediated by multiple mechanisms.
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Affiliation(s)
- Marjorie Bardiau
- Department of Infectious and Parasitic Diseases, Bacteriology, Faculty of Veterinary Medicine, University of Liège, Liège B4000, Belgium.
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Saldaña Z, Xicohtencatl-Cortes J, Avelino F, Phillips AD, Kaper JB, Puente JL, Girón JA. Synergistic role of curli and cellulose in cell adherence and biofilm formation of attaching and effacing Escherichia coli and identification of Fis as a negative regulator of curli. Environ Microbiol 2009; 11:992-1006. [PMID: 19187284 DOI: 10.1111/j.1462-2920.2008.01824.x] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Curli are adhesive fimbriae of Escherichia coli and Salmonella enterica. Expression of curli (csgA) and cellulose (bcsA) is co-activated by the transcriptional activator CsgD. In this study, we investigated the contribution of curli and cellulose to the adhesive properties of enterohaemorragic (EHEC) O157:H7 and enteropathogenic E. coli (EPEC) O127:H6. While single mutations in csgA, csgD or bcsA in EPEC and EHEC had no dramatic effect on cell adherence, double csgAbcsA mutants were significantly less adherent than the single mutants or wild-type strains to human colonic HT-29 epithelial cells or to cow colon tissue in vitro. Overexpression of csgD (carried on plasmid pCP994) in a csgD mutant, but not in the single csgA or bscA mutants, led to significant increase in adherence and biofilm formation in EPEC and EHEC, suggesting that synchronized over-production of curli and cellulose enhances bacterial adherence. In line with this finding, csgD transcription was activated significantly in the presence of cultured epithelial cells as compared with growth in tissue culture medium. Analysis of the influence of virulence and global regulators in the production of curli in EPEC identified Fis (factor for inversion stimulation) as a, heretofore unrecognized, negative transcriptional regulator of csgA expression. An EPEC E2348/69Deltafis produced abundant amounts of curli whereas a double fis/csgD mutant yielded no detectable curli production. Our data suggest that curli and cellulose act in concert to favour host colonization, biofilm formation and survival in different environments.
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Affiliation(s)
- Zeus Saldaña
- Department of Immunobiology, University of Arizona, 1501 N. Tucson, AZ 85724, USA
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Samadder P, Xicohtencatl-Cortes J, Saldana Z, Jordan D, Tarr PI, Kaper JB, Giron JA. The Escherichia coli ycbQRST operon encodes fimbriae with laminin-binding and epithelial cell adherence properties in Shiga-toxigenic E. coli O157:H7. Environ Microbiol 2009; 11:1815-26. [PMID: 19508558 PMCID: PMC2888687 DOI: 10.1111/j.1462-2920.2009.01906.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The human pathogen Shiga-toxigenic Escherichia coli (STEC) O157:H7 contains a ycbQRST fimbrial-like operon, which shares significant homology to the family of F17 fimbrial biogenesis genes f17ADCG found in enterotoxigenic E. coli. We report that growth of STEC O157:H7 strain EDL933 in minimal Minca medium at 37°C and during adherence to epithelial cells led to the production of fine peritrichous fimbriae, which were found to be composed of a major subunit of 18 kDa whose N-terminal amino acid sequence matched the predicted protein product of the ycbQ gene; and showed significant homology to the F17a-A fimbrin. Similar to the F17 fimbriae, the purified STEC fimbriae and the recombinant YcbQ protein fused to a His peptide tag bound laminin, but not fibronectin or collagen. Thus, we propose the name E. coli YcbQ laminin-binding fimbriae (ELF) to designate the fimbriae encoded by the ycbQRST operon. The role of ELF as an adherence factor of STEC to cultured epithelial cells was investigated. We provide compelling evidence demonstrating that ELF contributes to adherence of STEC to human intestinal epithelial cells and to cow and pig gut tissue in vitro. Deletion in the fimbrin subunit gene elfA (or ycbQ) in STEC strain EDL933 led to an isogenic strain, which showed significant reduction (60%) in adherence to HEp-2 cells in comparison with the parental strain. In addition, antibodies against the purified ELF also partially blocked adherence of two STEC O157:H7 strains. These observations suggest that ELF functions as an accessory adherence factor that, along with other known redundant adhesins, contributes to the overall adhesive properties of STEC O157:H7 providing these organisms with ecological advantages to survive in different hosts and in the environment.
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Affiliation(s)
- Partha Samadder
- Department of Immunobiology, University of Arizona, Tucson, AZ, 85724, USA
| | | | - Zeus Saldana
- Department of Immunobiology, University of Arizona, Tucson, AZ, 85724, USA
| | - Dianna Jordan
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Phillip I. Tarr
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - James B. Kaper
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 West Baltimore St., Baltimore, MD 21201, USA
| | - Jorge A. Giron
- Department of Immunobiology, University of Arizona, Tucson, AZ, 85724, USA
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Xicohtencatl-Cortes J, Sánchez Chacón E, Saldaña Z, Freer E, Girón JA. Interaction of Escherichia coli O157:H7 with leafy green produce. J Food Prot 2009; 72:1531-7. [PMID: 19681282 DOI: 10.4315/0362-028x-72.7.1531] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen responsible for human diarrheal disease. EHEC lives in the intestinal tract of cattle and other farm and wild animals, which may be the source of environmental contamination particularly of agricultural fields. Human infections are associated with consumption of tainted animal products and fresh produce. How the bacteria interact with the plant phyllosphere and withstand industrial decontamination remain to be elucidated. The goals of the present study were to investigate the environmental conditions and surface structures that influence the interaction of EHEC O157:H7 with baby spinach and lettuce leaves in vitro. Independently of the production of Shiga toxin, EHEC O157:H7 colonizes the leaf surface via flagella and the type 3 secretion system (T3SS). Ultrastructural analysis of EHEC-infected leafy greens revealed the presence of flagellated bacteria, and mutation of the fliC flagellin gene in EHEC EDL933 rendered the bacteria significantly less adherent, suggesting the involvement of flagella in the bacteria-leaf interaction. EDL933 mutated in the escN (ATPase) gene associated with the function of the T3SS but not in the eae (intimin adhesin) gene required for adherence to host intestinal cells had significantly reduced adherence compared with that of the parental strain. The data suggest a compelling role of flagella and the T3SS in colonization of leafy green produce. Colonization of salad leaves by EHEC strains may be a strategy that ensures survival of these bacteria in the environment and allows transmission to the human host.
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Affiliation(s)
- Juan Xicohtencatl-Cortes
- Department of Immunobiology, University of Arizona, 1501 North Campbell Avenue, Tucson, Arizona 85724, USA
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45
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Genes related to long polar fimbriae of pathogenic Escherichia coli strains as reliable markers to identify virulent isolates. J Clin Microbiol 2009; 47:2442-51. [PMID: 19494071 DOI: 10.1128/jcm.00566-09] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Lpf (stands for long polar fimbriae) is one of the few adhesive factors of enterohemorrhagic Escherichia coli O157:H7 associated with colonization of the intestine. E. coli O157:H7 strains possess two lpf loci encoding highly regulated fimbrial structures. Database analysis of the genes encoding the major fimbrial subunits demonstrated that they are present in commensal as well as pathogenic (both intestinal and extraintestinal) E. coli strains and in Salmonella strains and that the lpfA1 and lpfA2 genes are highly prevalent among LEE (locus of enterocyte effacement)-positive E. coli strains associated with severe and/or epidemic disease. Further DNA sequence analysis of the lpfA1 and lpfA2 genes from different attaching-and-effacing E. coli strains has led us to the identification of several polymorphisms and the classification of the major fimbrial subunits into distinct variants. Using collections of pathogenic E. coli isolates from Europe and Latin America, we demonstrated that the different lpfA types are associated with the presence of specific intimin (eae) adhesin variants and, most importantly, that they are found in specific E. coli pathotypes. Our results showed that the use of these fimbrial genes as markers, in combination with the different intimin types, resulted in a specific test for the identification of E. coli O157:H7, distinguishing it from other pathogenic E. coli strains.
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Putative adhesins of enteropathogenic and enterohemorrhagic Escherichia coli of serogroup O26 isolated from humans and cattle. J Clin Microbiol 2009; 47:2090-6. [PMID: 19403767 DOI: 10.1128/jcm.02048-08] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) strains are responsible for food poisoning in developed countries via consumption of vegetal and animal food sources contaminated by ruminant feces, and some strains (O26, O111, and O118 serogroups) are also responsible for diarrhea in young calves. The prevalence of 27 putative adhesins of EHEC and of bovine necrotoxigenic E. coli (NTEC) was studied with a collection of 43 bovine and 29 human enteropathogenic (EPEC) and EHEC strains and 5 non-EPEC/non-EHEC (1 bovine and 4 human) O26 strains, using specific PCRs. Four "groups" of adhesins exist, including adhesins present in all O26 strains, adhesins present in most O26 strains, adhesins present in a few O26 strains, and adhesins not present in O26 strains. The common profile of EHEC/EPEC strains was characterized by the presence of loc3, loc5, loc7, loc11, loc14, paa, efa1, iha, lpfA(O26), and lpfA(O113) genes and the absence of loc1, loc2, loc6, loc12, loc13, saa, and eibG genes. Except for the lpfA(O26) gene, which was marginally associated with bovine EHEC/EPEC strains in comparison with human strains (P = 0.012), none of the results significantly differentiated bovine strains from human strains. One adhesin gene (ldaE) was statistically (P < 0.01) associated with O26 EHEC/EPEC strains isolated from diarrheic calves in comparison with strains isolated from healthy calves. ldaE-positive strains could therefore represent a subgroup possessing the specific property of producing diarrhea in young calves. This is the first time that the distribution of putative adhesins has been described for such a large collection of EHEC/EPEC O26 strains isolated from both humans and cattle.
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Wells TJ, McNeilly TN, Totsika M, Mahajan A, Gally DL, Schembri MA. The Escherichia coli O157:H7 EhaB autotransporter protein binds to laminin and collagen I and induces a serum IgA response in O157:H7 challenged cattle. Environ Microbiol 2009; 11:1803-14. [PMID: 19508554 DOI: 10.1111/j.1462-2920.2009.01905.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) are a subgroup of Shiga toxin-producing E. coli that cause gastrointestinal disease with the potential for life-threatening sequelae. Cattle serve as the natural reservoir for EHEC and outbreaks occur sporadically as a result of contaminated beef and other farming products. While certain EHEC virulence mechanisms have been extensively studied, the factors that mediate host colonization are poorly defined. Previously, we identified four proteins (EhaA,B,C,D) from the prototypic EHEC strain EDL933 that belong to the autotransporter (AT) family. Here we characterize the EhaB AT protein. EhaB was shown to be located at the cell surface and overexpression in E. coli K-12 resulted in significant biofilm formation under continuous flow conditions. Overexpression of EhaB in E. coli K12 and EDL933 backgrounds also promoted adhesion to the extracellular matrix proteins collagen I and laminin. An EhaB-specific antibody revealed that EhaB is expressed in E. coli EDL933 following in vitro growth. EhaB also cross-reacted with serum IgA from cattle challenged with E. coli O157:H7, indicating that EhaB is expressed in vivo and elicits a host IgA immune response.
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Affiliation(s)
- Timothy J Wells
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane Queensland 4072, Australia
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48
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La Ragione RM, Best A, Woodward MJ, Wales AD. Escherichia coli O157:H7 colonization in small domestic ruminants. FEMS Microbiol Rev 2008; 33:394-410. [PMID: 19207740 DOI: 10.1111/j.1574-6976.2008.00138.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Enterohaemorrhagic Escherichia coli O157:H7 was first implicated in human disease in the early 1980s, with ruminants cited as the primary reservoirs. Preliminary studies indicated cattle to be the sole source of E. coli O157:H7 outbreaks in humans; however, further epidemiological studies soon demonstrated that E. coli O157:H7 was widespread in other food sources and that a number of transmission routes existed. More recently, small domestic ruminants (sheep and goats) have emerged as important sources of E. coli O157:H7 human infection, particularly with the widespread popularity of petting farms and the increased use of sheep and goat food products, including unpasteurized cheeses. Although the colonization and persistence characteristics of E. coli O157:H7 in the bovine host have been studied intensively, this is not the case for small ruminants. Despite many similarities to the bovine host, the pathobiology of E. coli O157:H7 in small domestic ruminants does appear to differ significantly from that described in cattle. This review aims to critically review the current knowledge regarding colonization and persistence of E. coli O157:H7 in small domestic ruminants, including comparisons with the bovine host where appropriate.
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Affiliation(s)
- Roberto M La Ragione
- Department of Food and Environmental Safety, Veterinary Laboratories Agency, Addlestone, Surrey, UK.
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49
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Chase-Topping M, Gally D, Low C, Matthews L, Woolhouse M. Super-shedding and the link between human infection and livestock carriage of Escherichia coli O157. Nat Rev Microbiol 2008; 6:904-12. [PMID: 19008890 PMCID: PMC5844465 DOI: 10.1038/nrmicro2029] [Citation(s) in RCA: 256] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cattle that excrete more Escherichia coli O157 than others are known as super-shedders. Super-shedding has important consequences for the epidemiology of E. coli O157 in cattle--its main reservoir--and for the risk of human infection, particularly owing to environmental exposure. Ultimately, control measures targeted at super-shedders may prove to be highly effective. We currently have only a limited understanding of both the nature and the determinants of super-shedding. However, super-shedding has been observed to be associated with colonization at the terminal rectum and might also occur more often with certain pathogen phage types. More generally, epidemiological evidence suggests that super-shedding might be important in other bacterial and viral infections.
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Affiliation(s)
- Margo Chase-Topping
- Centre for Infectious Diseases, University of Edinburgh, Kings Buildings, Edinburgh, EH9 3JT, UK.
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50
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Vazquez-Juarez RC, Kuriakose JA, Rasko DA, Ritchie JM, Kendall MM, Slater TM, Sinha M, Luxon BA, Popov VL, Waldor MK, Sperandio V, Torres AG. CadA negatively regulates Escherichia coli O157:H7 adherence and intestinal colonization. Infect Immun 2008; 76:5072-81. [PMID: 18794292 PMCID: PMC2573373 DOI: 10.1128/iai.00677-08] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 06/27/2008] [Accepted: 08/19/2008] [Indexed: 12/30/2022] Open
Abstract
Adherence of pathogenic Escherichia coli strains to intestinal epithelia is essential for infection. For enterohemorrhagic E. coli (EHEC) serotype O157:H7, we have previously demonstrated that multiple factors govern this pathogen's adherence to HeLa cells (A. G. Torres and J. B. Kaper, Infect. Immun. 71:4985-4995, 2003). One of these factors is CadA, a lysine decarboxylase, and this protein has been proposed to negatively regulate virulence in several enteric pathogens. In the case of EHEC strains, CadA modulates expression of the intimin, an outer membrane adhesin involved in pathogenesis. Here, we inactivated cadA in O157:H7 strain 86-24 to investigate the role of this gene in EHEC adhesion to tissue-cultured monolayers, global gene expression patterns, and colonization of the infant rabbit intestine. The cadA mutant did not possess lysine decarboxylation activity and was hyperadherent to tissue-cultured cells. Adherence of the cadA mutant was nearly twofold greater than that of the wild type, and the adherence phenotype was independent of pH, lysine, or cadaverine in the media. Additionally, complementation of the cadA defect reduced adherence back to wild-type levels, and it was found that the mutation affected the expression of the intimin protein. Disruption of the eae gene (intimin-encoding gene) in the cadA mutant significantly reduced its adherence to tissue-cultured cells. However, adherence of the cadA eae double mutant was greater than that of an 86-24 eae mutant, suggesting that the enhanced adherence of the cadA mutant is not entirely attributable to enhanced expression of intimin in this background. Gene array analysis revealed that the cadA mutation significantly altered EHEC gene expression patterns; expression of 1,332 genes was downregulated and that of 132 genes was upregulated in the mutant compared to the wild-type strain. Interestingly, the gene expression variation shows an EHEC-biased gene alteration including intergenic regions. Two putative adhesins, flagella and F9 fimbria, were upregulated in the cadA mutant, suggestive of their association with adherence in the absence of the Cad regulatory mechanism. In the infant rabbit model, the cadA mutant outcompeted the wild-type strain in the ileum but not in the cecum or mid-colon, raising the possibility that CadA negatively regulates EHEC pathogenicity in a tissue-specific fashion.
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Affiliation(s)
- Roberto C Vazquez-Juarez
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
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