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Edison LK, Kudva IT, Kariyawasam S. Host-Pathogen Interactions during Shiga Toxin-Producing Escherichia coli Adherence and Colonization in the Bovine Gut: A Comprehensive Review. Microorganisms 2024; 12:2009. [PMID: 39458318 PMCID: PMC11509540 DOI: 10.3390/microorganisms12102009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2024] [Revised: 09/28/2024] [Accepted: 10/01/2024] [Indexed: 10/28/2024] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is a significant public health threat due to its ability to cause severe gastrointestinal diseases in humans, ranging from diarrhea to life-threatening conditions such as hemorrhagic colitis and hemolytic uremic syndrome (HUS). As the primary reservoir of STEC, cattle play a crucial role in its transmission through contaminated food and water, posing a considerable risk to human health. This comprehensive review explores host-pathogen interactions during STEC colonization of the bovine gut, focusing on the role of gut microbiota in modulating these interactions and influencing disease outcomes. We integrated findings from published transcriptomics, proteomics, and genomics studies to provide a thorough understanding of how STEC adheres to and colonizes the bovine gastrointestinal tract. The insights from this review offer potential avenues for the development of novel preventative and therapeutic strategies aimed at controlling STEC colonization in cattle, thereby reducing the risk of zoonotic transmission.
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Affiliation(s)
- Lekshmi K. Edison
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA;
| | - Indira T. Kudva
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA 50010, USA;
| | - Subhashinie Kariyawasam
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA;
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Colello R, Vélez MV, Farias MVN, Rodríguez M, Montero D, Vidal R, Etcheverría AI, Padola NL. Expression of hes, iha, and tpsA codified in locus of adhesion and autoaggregation and their involvement in the capability of shiga toxin-producing Escherichia coli strains to adhere to epithelial cells. BMC Res Notes 2023; 16:163. [PMID: 37550739 PMCID: PMC10408066 DOI: 10.1186/s13104-023-06433-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 07/17/2023] [Indexed: 08/09/2023] Open
Abstract
OBJECTIVES Shiga toxin-producing Escherichia coli strains LAA-positive are important cause of human infection. The capability to adhere to epithelial cells is a key virulence trait, and genes codified in LAA pathogenicity island could be involved in the adhesion during the pathogenesis of LAA-positive STEC strains. Thus, our objectives were to compare hes-negative and hes-positive STEC strains in their adherence capability to epithelial cells (HEp-2) and to evaluate the expression levels of the hes, iha, and tpsA in the bacteria adhered and non-adhered to HEp-2 cells. These genes are encoded in LAA, and are virulence factors that participate in adhesion and autoaggregation. RESULTS We could not observe differences between the adhesion of strains but also in the expression level of of hes, iha, and tpsA. Genes encoded in LAA contribute to the adhesion phenotype though the expression of STEC adhesins is a coordinated event that depends not only the strain but also on the environment as well as its genetic background. Therefore, the results of this study suggest that LAA ,the most prevalent PAI among LEE-negative STEC strains, plays a role in pathogenesis.
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Affiliation(s)
- Rocío Colello
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), CISAPA, Tandil, Buenos Aires, 7000, Argentina.
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA- CICPBA- CONICET, Tandil, 7000, Argentina.
| | - M Victoria Vélez
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), CISAPA, Tandil, Buenos Aires, 7000, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA- CICPBA- CONICET, Tandil, 7000, Argentina
| | - M Victoria Nieto Farias
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), CISAPA, Tandil, Buenos Aires, 7000, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA- CICPBA- CONICET, Tandil, 7000, Argentina
| | - Marcelo Rodríguez
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), SAMP, Tandil, Buenos Aires, 7000, Argentina
| | - David Montero
- Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, 4030555, Chile
- Centro Integrativo de Biología y Química Aplicada (CIBQA), Universidad Bernardo O'Higgins, Santiago, 8320000, Chile
| | - Roberto Vidal
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, 8320000, Chile
| | - Analía I Etcheverría
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), CISAPA, Tandil, Buenos Aires, 7000, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA- CICPBA- CONICET, Tandil, 7000, Argentina
| | - Nora Lía Padola
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), CISAPA, Tandil, Buenos Aires, 7000, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA- CICPBA- CONICET, Tandil, 7000, Argentina
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3
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Arredondo-Alonso S, Blundell-Hunter G, Fu Z, Gladstone RA, Fillol-Salom A, Loraine J, Cloutman-Green E, Johnsen PJ, Samuelsen Ø, Pöntinen AK, Cléon F, Chavez-Bueno S, De la Cruz MA, Ares MA, Vongsouvath M, Chmielarczyk A, Horner C, Klein N, McNally A, Reis JN, Penadés JR, Thomson NR, Corander J, Taylor PW, McCarthy AJ. Evolutionary and functional history of the Escherichia coli K1 capsule. Nat Commun 2023; 14:3294. [PMID: 37322051 PMCID: PMC10272209 DOI: 10.1038/s41467-023-39052-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 05/26/2023] [Indexed: 06/17/2023] Open
Abstract
Escherichia coli is a leading cause of invasive bacterial infections in humans. Capsule polysaccharide has an important role in bacterial pathogenesis, and the K1 capsule has been firmly established as one of the most potent capsule types in E. coli through its association with severe infections. However, little is known about its distribution, evolution and functions across the E. coli phylogeny, which is fundamental to elucidating its role in the expansion of successful lineages. Using systematic surveys of invasive E. coli isolates, we show that the K1-cps locus is present in a quarter of bloodstream infection isolates and has emerged in at least four different extraintestinal pathogenic E. coli (ExPEC) phylogroups independently in the last 500 years. Phenotypic assessment demonstrates that K1 capsule synthesis enhances E. coli survival in human serum independent of genetic background, and that therapeutic targeting of the K1 capsule re-sensitizes E. coli from distinct genetic backgrounds to human serum. Our study highlights that assessing the evolutionary and functional properties of bacterial virulence factors at population levels is important to better monitor and predict the emergence of virulent clones, and to also inform therapies and preventive medicine to effectively control bacterial infections whilst significantly lowering antibiotic usage.
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Affiliation(s)
- Sergio Arredondo-Alonso
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
| | | | - Zuyi Fu
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | - Rebecca A Gladstone
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
| | - Alfred Fillol-Salom
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | | | - Elaine Cloutman-Green
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Pål J Johnsen
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Ørjan Samuelsen
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
| | - Anna K Pöntinen
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
| | - François Cléon
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Susana Chavez-Bueno
- University of Missouri Kansas City, Kansas City, USA
- Division of Infectious Diseases, Children's Mercy Hospital Kansas City, UMKC School of Medicine, Kansas City, USA
| | - Miguel A De la Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Facultad de Medicina, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Miguel A Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Manivanh Vongsouvath
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
| | - Agnieszka Chmielarczyk
- Faculty of Medicine, Chair of Microbiology, Jagiellonian University Medical College, Czysta str. 18, 31-121, Kraków, Poland
| | - Carolyne Horner
- British Society for Antimicrobial Chemotherapy, Birmingham, UK
| | - Nigel Klein
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Alan McNally
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Joice N Reis
- Laboratory of Pathology and Molecular Biology (LPBM), Gonçalo Moniz Research Institute, Oswaldo Cruz Foundation, Salvador, Brazil
- Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, Brazil
| | - José R Penadés
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | - Nicholas R Thomson
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
- London School of Hygiene and Tropical Medicine, London, UK
| | - Jukka Corander
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway.
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK.
- Helsinki Institute of Information Technology, Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland.
| | - Peter W Taylor
- School of Pharmacy, University College London, London, UK.
| | - Alex J McCarthy
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK.
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Identification and detection of iha subtypes in LEE-negative Shiga toxin-producing Escherichia coli (STEC) strains isolated from humans, cattle and food. Heliyon 2019; 5:e03015. [PMID: 31879713 PMCID: PMC6920203 DOI: 10.1016/j.heliyon.2019.e03015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/18/2019] [Accepted: 12/06/2019] [Indexed: 01/30/2023] Open
Abstract
LEE-negative Shiga toxin-producing Escherichia coli (STEC) strains are important cause of infection in humans and they should be included in the public health surveillance systems. Some isolates have been associated with haemolytic uremic syndrome (HUS) but the mechanisms of pathogenicity are is a field continuos broadening of knowledge. The IrgA homologue adhesin (Iha), encoded by iha, is an adherence-conferring protein and also a siderophore receptor distributed among LEE-negative STEC strains. This study reports the presence of different subtypes of iha in LEE-negative STEC strains. We used genomic analyses to design PCR assays for detecting each of the different iha subtypes and also, all the subtypes simultaneously. LEE-negative STEC strains were designed and different localizations of this gene in STEC subgroups were examinated. Genomic analysis detected iha in a high percentage of LEE-negative STEC strains. These strains generally carried iha sequences similar to those harbored by the Locus of Adhesion and Autoaggregation (LAA) or by the plasmid pO113. Besides, almost half of the strains carried both subtypes. Similar results were observed by PCR, detecting iha LAA in 87% of the strains (117/135) and iha pO113 in 32% of strains (43/135). Thus, we designed PCR assays that allow rapid detection of iha subtypes harbored by LEE-negative strains. These results highlight the need to investigate the individual and orchestrated role of virulence genes that determine the STEC capacity of causing serious disease, which would allow for identification of target candidates to develop therapies against HUS.
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Barrios-Villa E, Cortés-Cortés G, Lozano-Zaraín P, Arenas-Hernández MMDLP, Martínez de la Peña CF, Martínez-Laguna Y, Torres C, Rocha-Gracia RDC. Adherent/invasive Escherichia coli (AIEC) isolates from asymptomatic people: new E. coli ST131 O25:H4/H30-Rx virotypes. Ann Clin Microbiol Antimicrob 2018; 17:42. [PMID: 30526606 PMCID: PMC6287351 DOI: 10.1186/s12941-018-0295-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 12/01/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The widespread Escherichia coli clone ST131 implicated in multidrug-resistant infections has been recently reported, the majority belonging to O25:H4 serotype and classified into five main virotypes in accordance with the virulence genes carried. METHODS Pathogenicity Islands I and II (PAI-I and PAI-II) were determined using conventional PCR protocols from a set of four E. coli CTXR ST131 O25:H4/H30-Rx strains collected from healthy donors' stool. The virulence genes patterns were also analyzed and compared them with the virotypes reported previously; then adherence, invasion, macrophage survival and biofilm formation assays were evaluated and AIEC pathotype genetic determinants were investigated. FINDINGS Non-reported virulence patterns were found in our isolates, two of them carried satA, papA, papGII genes and the two-remaining isolates carried cnfI, iroN, satA, papA, papGII genes, and none of them belonged to classical ST131 virotypes, suggesting an endemic distribution of virulence genes and two new virotypes. The presence of PAI-I and PAI-II of Uropathogenic E. coli was determined in three of the four strains, furthermore adherence and invasion assays demonstrated higher degrees of attachment/invasion compared with the control strains. We also amplified intI1, insA and insB genes in all four samples. INTERPRETATION The results indicate that these strains own non-reported virotypes suggesting endemic distribution of virulence genes, our four strains also belong to an AIEC pathotype, being this the first report of AIEC in México and the association of AIEC with healthy donors.
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Affiliation(s)
- Edwin Barrios-Villa
- Benemérita Universidad Autónoma de Puebla, Posgrado en Ciencias Microbiológicas, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Puebla, Mexico
| | - Gerardo Cortés-Cortés
- Benemérita Universidad Autónoma de Puebla, Posgrado en Ciencias Microbiológicas, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Puebla, Mexico
| | - Patricia Lozano-Zaraín
- Benemérita Universidad Autónoma de Puebla, Posgrado en Ciencias Microbiológicas, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Puebla, Mexico
| | - Margarita María de la Paz Arenas-Hernández
- Benemérita Universidad Autónoma de Puebla, Posgrado en Ciencias Microbiológicas, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Puebla, Mexico
| | - Claudia Fabiola Martínez de la Peña
- Benemérita Universidad Autónoma de Puebla, Posgrado en Ciencias Microbiológicas, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Puebla, Mexico
| | - Ygnacio Martínez-Laguna
- Benemérita Universidad Autónoma de Puebla, Posgrado en Ciencias Microbiológicas, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Puebla, Mexico
| | - Carmen Torres
- Área de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain
| | - Rosa del Carmen Rocha-Gracia
- Benemérita Universidad Autónoma de Puebla, Posgrado en Ciencias Microbiológicas, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Puebla, Mexico
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6
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Eißenberger K, Moench D, Drissner D, Weiss A, Schmidt H. Adherence factors of enterohemorrhagic Escherichia coli O157:H7 strain Sakai influence its uptake into the roots of Valerianella locusta grown in soil. Food Microbiol 2018; 76:245-256. [PMID: 30166148 DOI: 10.1016/j.fm.2018.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 04/27/2018] [Accepted: 05/30/2018] [Indexed: 02/06/2023]
Abstract
Increasing numbers of outbreaks caused by enterohemorrhagic Escherichia coli (EHEC) are associated with the consumption of contaminated fresh produce. The contamination of the plants may occur directly on the field via irrigation water, surface water, manure or fecal contamination. Suggesting a low infectious dose of 10 to 102 cells, internalization of EHEC into plant tissue presents a serious public health threat. Therefore, the ability of EHEC O157:H7 strain Sakai to adhere to and internalize into root tissues of the lamb's lettuce Valerianella locusta was investigated under the environmental conditions of a greenhouse. Moreover, the influence of the two adherence and colonization associated genes hcpA and iha was surveyed regarding their role for attachment and invasion. Upon soil contamination, the number of root-internalized cells of EHEC O157:H7 strain Sakai exceeded 102 cfu/g roots. Deletion of one or both of the adherence factor genes did not alter the overall attachment of EHEC O157:H7 strain Sakai to the roots, but significantly reduced the numbers of internalized bacteria by a factor of between 10 and 30, indicating their importance for invasion of EHEC O157:H7 strain Sakai into plant roots. This study identified intrinsic bacterial factors that play a crucial role during the internalization of EHEC O157:H7 strain Sakai into the roots of Valerianella locusta grown under the growth conditions in a greenhouse.
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Affiliation(s)
- Kristina Eißenberger
- Institute of Food Science and Biotechnology, Department of Food Microbiology and Hygiene, University of Hohenheim, Germany
| | - Doris Moench
- Institute of Food Science and Biotechnology, Department of Food Microbiology and Hygiene, University of Hohenheim, Germany
| | - David Drissner
- Microbiology of Plant Foods, Agroscope, Waedenswil, Switzerland; Swiss Federal Institute for Forest, Snow, and Landscape Research WSL, Birmensdorf, Switzerland
| | - Agnes Weiss
- Institute of Food Science and Biotechnology, Department of Food Microbiology and Hygiene, University of Hohenheim, Germany
| | - Herbert Schmidt
- Institute of Food Science and Biotechnology, Department of Food Microbiology and Hygiene, University of Hohenheim, Germany.
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7
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Modulation of Enterohaemorrhagic Escherichia coli Survival and Virulence in the Human Gastrointestinal Tract. Microorganisms 2018; 6:microorganisms6040115. [PMID: 30463258 PMCID: PMC6313751 DOI: 10.3390/microorganisms6040115] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/16/2018] [Accepted: 11/18/2018] [Indexed: 01/05/2023] Open
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) is a major foodborne pathogen responsible for human diseases ranging from diarrhoea to life-threatening complications. Survival of the pathogen and modulation of virulence gene expression along the human gastrointestinal tract (GIT) are key features in bacterial pathogenesis, but remain poorly described, due to a paucity of relevant model systems. This review will provide an overview of the in vitro and in vivo studies investigating the effect of abiotic (e.g., gastric acid, bile, low oxygen concentration or fluid shear) and biotic (e.g., gut microbiota, short chain fatty acids or host hormones) parameters of the human gut on EHEC survival and/or virulence (especially in relation with motility, adhesion and toxin production). Despite their relevance, these studies display important limitations considering the complexity of the human digestive environment. These include the evaluation of only one single digestive parameter at a time, lack of dynamic flux and compartmentalization, and the absence of a complex human gut microbiota. In a last part of the review, we will discuss how dynamic multi-compartmental in vitro models of the human gut represent a novel platform for elucidating spatial and temporal modulation of EHEC survival and virulence along the GIT, and provide new insights into EHEC pathogenesis.
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8
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Krause M, Barth H, Schmidt H. Toxins of Locus of Enterocyte Effacement-Negative Shiga Toxin-Producing Escherichia coli. Toxins (Basel) 2018; 10:toxins10060241. [PMID: 29903982 PMCID: PMC6024878 DOI: 10.3390/toxins10060241] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/07/2018] [Accepted: 06/12/2018] [Indexed: 12/16/2022] Open
Abstract
Studies on Shiga toxin-producing Escherichia coli (STEC) typically examine and classify the virulence gene profiles based on genomic analyses. Among the screened strains, a subgroup of STEC which lacks the locus of enterocyte effacement (LEE) has frequently been identified. This raises the question about the level of pathogenicity of such strains. This review focuses on the advantages and disadvantages of the standard screening procedures in virulence profiling and summarizes the current knowledge concerning the function and regulation of toxins encoded by LEE-negative STEC. Although LEE-negative STEC usually come across as food isolates, which rarely cause infections in humans, some serotypes have been implicated in human diseases. In particular, the LEE-negative E. coli O104:H7 German outbreak strain from 2011 and the Australian O113:H21 strain isolated from a HUS patient attracted attention. Moreover, the LEE-negative STEC O113:H21 strain TS18/08 that was isolated from minced meat is remarkable in that it not only encodes multiple toxins, but in fact expresses three different toxins simultaneously. Their characterization contributes to understanding the virulence of the LEE-negative STEC.
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Affiliation(s)
- Maike Krause
- Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, Garbenstrasse 28, University of Hohenheim, 70599 Stuttgart, Germany.
| | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| | - Herbert Schmidt
- Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, Garbenstrasse 28, University of Hohenheim, 70599 Stuttgart, Germany.
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9
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Mathieu S, Cissé C, Vitale S, Ahmadova A, Degardin M, Pérard J, Colas P, Miras R, Boturyn D, Covès J, Crouzy S, Michaud-Soret I. From Peptide Aptamers to Inhibitors of FUR, Bacterial Transcriptional Regulator of Iron Homeostasis and Virulence. ACS Chem Biol 2016; 11:2519-28. [PMID: 27409249 DOI: 10.1021/acschembio.6b00360] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
FUR (Ferric Uptake Regulator) protein is a global transcriptional regulator that senses iron status and controls the expression of genes involved in iron homeostasis, virulence, and oxidative stress. Ubiquitous in Gram-negative bacteria and absent in eukaryotes, FUR is an attractive antivirulence target since the inactivation of the fur gene in various pathogens attenuates their virulence. The characterization of 13-aa-long anti-FUR linear peptides derived from the variable part of the anti-FUR peptide aptamers, that were previously shown to decrease pathogenic E. coli strain virulence in a fly infection model, is described herein. Modeling, docking, and experimental approaches in vitro (activity and interaction assays, mutations) and in cells (yeast two-hybrid assays) were combined to characterize the interactions of the peptides with FUR, and to understand their mechanism of inhibition. As a result, reliable structure models of two peptide-FUR complexes are given. Inhibition sites are mapped in the groove between the two FUR subunits where DNA should also bind. Another peptide behaves differently and interferes with the dimerization itself. These results define these novel small peptide inhibitors as lead compounds for inhibition of the FUR transcription factor.
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Affiliation(s)
- Sophie Mathieu
- CNRS,
Laboratoire
de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UJF, F-38054 Grenoble, France
- CEA, LCBM, F-38054 Grenoble, France
- Univ. Grenoble Alpes,
LCBM, F-38054 Grenoble, France
| | - Cheickna Cissé
- CNRS,
Laboratoire
de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UJF, F-38054 Grenoble, France
- CEA, LCBM, F-38054 Grenoble, France
- Univ. Grenoble Alpes,
LCBM, F-38054 Grenoble, France
| | - Sylvia Vitale
- CNRS,
Laboratoire
de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UJF, F-38054 Grenoble, France
- CEA, LCBM, F-38054 Grenoble, France
- Univ. Grenoble Alpes,
LCBM, F-38054 Grenoble, France
| | - Aynur Ahmadova
- CNRS,
Laboratoire
de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UJF, F-38054 Grenoble, France
- CEA, LCBM, F-38054 Grenoble, France
- Univ. Grenoble Alpes,
LCBM, F-38054 Grenoble, France
| | - Mélissa Degardin
- CNRS,
Laboratoire
de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UJF, F-38054 Grenoble, France
- CEA, LCBM, F-38054 Grenoble, France
- Univ. Grenoble Alpes,
LCBM, F-38054 Grenoble, France
- Univ. Grenoble
Alpes, DCM UMR 5250, F-38000 Grenoble, France
- CNRS, DCM UMR
5250, F-38000 Grenoble, France
| | - Julien Pérard
- CNRS,
Laboratoire
de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UJF, F-38054 Grenoble, France
- CEA, LCBM, F-38054 Grenoble, France
- Univ. Grenoble Alpes,
LCBM, F-38054 Grenoble, France
| | - Pierre Colas
- P2I2 Group, Protein Phosphorylation
and Human Disease Unit, CNRS Unité de Service et de Recherche
USR3151, Station Biologique de Roscoff, F-29680 Roscoff, France
| | - Roger Miras
- CNRS,
Laboratoire
de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UJF, F-38054 Grenoble, France
- CEA, LCBM, F-38054 Grenoble, France
- Univ. Grenoble Alpes,
LCBM, F-38054 Grenoble, France
| | - Didier Boturyn
- Univ. Grenoble
Alpes, DCM UMR 5250, F-38000 Grenoble, France
- CNRS, DCM UMR
5250, F-38000 Grenoble, France
| | - Jacques Covès
- Univ. Grenoble
Alpes, IBS, F-38044 Grenoble, France
- CNRS, IBS, F-38044 Grenoble, France
- CEA, IBS, F-38044 Grenoble, France
| | - Serge Crouzy
- CNRS,
Laboratoire
de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UJF, F-38054 Grenoble, France
- CEA, LCBM, F-38054 Grenoble, France
- Univ. Grenoble Alpes,
LCBM, F-38054 Grenoble, France
| | - Isabelle Michaud-Soret
- CNRS,
Laboratoire
de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UJF, F-38054 Grenoble, France
- CEA, LCBM, F-38054 Grenoble, France
- Univ. Grenoble Alpes,
LCBM, F-38054 Grenoble, France
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10
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Gölz G, Alter T, Bereswill S, Heimesaat MM. Toll-Like Receptor-4 Dependent Intestinal Gene Expression During Arcobacter Butzleri Infection of Gnotobiotic Il-10 Deficient Mice. Eur J Microbiol Immunol (Bp) 2016; 6:67-80. [PMID: 27141316 PMCID: PMC4838987 DOI: 10.1556/1886.2016.00006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 03/09/2016] [Indexed: 02/04/2023] Open
Abstract
We have previously shown that Arcobacter butzleri infection induces Toll-like receptor (TLR) -4 dependent immune responses in perorally infected gnotobiotic IL-10–/– mice. Here, we analyzed TLR-4-dependent expression of genes encoding inflammatory mediators and matrix-degrading gelatinases MMP-2 and -9 in the small and large intestines of gnotobiotic TLR-4-deficient IL-10–/– mice that were perorally infected with A. butzleri strains CCUG 30485 or C1, of human and chicken origin, respectively. At day 6 following A. butzleri infection, colonic mucin-2 mRNA, as integral part of the intestinal mucus layer, was downregulated in the colon, but not ileum, of IL-10–/– but not TLR-4–/– IL-10–/– mice. CCUG 30485 strain-infected TLR-4-deficient IL-10–/– mice displayed less distinctly upregulated IFN-γ, IL-17A, and IL-1β mRNA levels in ileum and colon, which was also true for colonic IL-22. These changes were accompanied by upregulated colonic MMP-2 and ileal MMP-9 mRNA exclusively in IL-10–/– mice. In conclusion, TLR-4 is essentially involved in A. butzleri mediated modulation of gene expression in the intestines of gnotobiotic IL-10–/– mice.
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Affiliation(s)
- Greta Gölz
- Institute of Food Hygiene, Free University Berlin , Berlin, Germany
| | - Thomas Alter
- Institute of Food Hygiene, Free University Berlin , Berlin, Germany
| | - Stefan Bereswill
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin , Berlin, Germany
| | - Markus M Heimesaat
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin , Berlin, Germany
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11
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Escherichia coli O104:H4 Pathogenesis: an Enteroaggregative E. coli/Shiga Toxin-Producing E. coli Explosive Cocktail of High Virulence. Microbiol Spectr 2016; 2. [PMID: 26104460 DOI: 10.1128/microbiolspec.ehec-0008-2013] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
A major outbreak caused by Escherichia coli of serotype O104:H4 spread throughout Europe in 2011. This large outbreak was caused by an unusual strain that is most similar to enteroaggregative E. coli (EAEC) of serotype O104:H4. A significant difference, however, is the presence of a prophage encoding the Shiga toxin, which is characteristic of enterohemorrhagic E. coli (EHEC) strains. This combination of genomic features, associating characteristics from both EAEC and EHEC, represents a new pathotype. The 2011 E. coli O104:H4 outbreak of hemorrhagic diarrhea in Germany is an example of the explosive cocktail of high virulence and resistance that can emerge in this species. A total of 46 deaths, 782 cases of hemolytic-uremic syndrome, and 3,128 cases of acute gastroenteritis were attributed to this new clone of EAEC/EHEC. In addition, recent identification in France of similar O104:H4 clones exhibiting the same virulence factors suggests that the EHEC O104:H4 pathogen has become endemically established in Europe after the end of the outbreak. EAEC strains of serotype O104:H4 contain a large set of virulence-associated genes regulated by the AggR transcription factor. They include, among other factors, the pAA plasmid genes encoding the aggregative adherence fimbriae, which anchor the bacterium to the intestinal mucosa (stacked-brick adherence pattern on epithelial cells). Furthermore, sequencing studies showed that horizontal genetic exchange allowed for the emergence of the highly virulent Shiga toxin-producing EAEC O104:H4 strain that caused the German outbreak. This article discusses the role these virulence factors could have in EAEC/EHEC O104:H4 pathogenesis.
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12
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Prevalence of ten putative virulence genes in the emerging foodborne pathogen Arcobacter isolated from food products. Food Microbiol 2015; 52:146-9. [DOI: 10.1016/j.fm.2015.07.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 07/15/2015] [Accepted: 07/22/2015] [Indexed: 11/17/2022]
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13
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Heimesaat MM, Karadas G, Alutis M, Fischer A, Kühl AA, Breithaupt A, Göbel UB, Alter T, Bereswill S, Gölz G. Survey of small intestinal and systemic immune responses following murine Arcobacter butzleri infection. Gut Pathog 2015; 7:28. [PMID: 26483849 PMCID: PMC4610047 DOI: 10.1186/s13099-015-0075-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 09/29/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Arcobacter (A.) butzleri has been described as causative agent for sporadic cases of human gastroenteritis with abdominal pain and acute or prolonged watery diarrhea. In vitro studies revealed distinct adhesive, invasive and cytotoxic properties of A. butzleri. Information about the underlying immunopathological mechanisms of infection in vivo, however, are scarce. The aim of this study was to investigate the immunopathological properties of two different A. butzleri strains in a well-established murine infection model. RESULTS Gnotobiotic IL-10(-/-) mice, in which the intestinal microbiota was depleted by broad-spectrum antibiotic treatment, were perorally infected with two different A. butzleri strains isolated from a diseased patient (CCUG 30485) or fresh chicken meat (C1), respectively. Eventhough bacteria of either strain could stably colonize the intestinal tract at day 6 and day 16 postinfection (p.i.), mice did not exert infection induced symptoms such as diarrhea or wasting. In small intestines of infected mice, however, increased numbers of apoptotic cells could be detected at day 16, but not day 6 following infection with either strain. A strain-dependent influx of distinct immune cell populations such as T and B cells as well as of regulatory T cells could be observed upon A. butzleri infection which was accompanied by increased small intestinal concentrations of pro-inflammatory cytokines such as TNF, IFN-γ, MCP-1 and IL-6. Remarkably, inflammatory responses following A. butzleri infection were not restricted to the intestinal tract, given that the CCUG 30485 strain induced systemic immune responses as indicated by increased IFN-γ concentrations in spleens at day 6, but not day 16 following infection. CONCLUSION Upon peroral infection A. butzleri stably colonized the intestinal tract of gnotobiotic IL-10(-/-) mice. The dynamics of distinct local and systemic inflammatory responses could be observed in a strain-dependent fashion pointing towards an immunopathogenic potential of A. butzleri in vivo. These results indicate that gnotobiotic IL-10(-/-) mice are well suited to further investigate the molecular mechanisms underlying arcobacteriosis in vivo.
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Affiliation(s)
- Markus M Heimesaat
- Department of Microbiology and Hygiene, Charité-University Medicine Berlin, Berlin, Germany
| | - Gül Karadas
- Institute of Food Hygiene, Freie Universität Berlin, Königsweg 69, 14163 Berlin, Germany
| | - Marie Alutis
- Department of Microbiology and Hygiene, Charité-University Medicine Berlin, Berlin, Germany
| | - André Fischer
- Department of Microbiology and Hygiene, Charité-University Medicine Berlin, Berlin, Germany
| | - Anja A Kühl
- Department of Medicine I for Gastroenterology, Infectious Disease and Rheumatology/Research Center ImmunoSciences (RCIS), Charité-University Medicine Berlin, Berlin, Germany
| | - Angele Breithaupt
- Institute of Veterinary Pathology, Freie Universität Berlin, Berlin, Germany
| | - Ulf B Göbel
- Department of Microbiology and Hygiene, Charité-University Medicine Berlin, Berlin, Germany
| | - Thomas Alter
- Institute of Food Hygiene, Freie Universität Berlin, Königsweg 69, 14163 Berlin, Germany
| | - Stefan Bereswill
- Department of Microbiology and Hygiene, Charité-University Medicine Berlin, Berlin, Germany
| | - Greta Gölz
- Institute of Food Hygiene, Freie Universität Berlin, Königsweg 69, 14163 Berlin, Germany
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14
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Abstract
ABSTRACT
Coordinated expression of enterohemorrhagic
Escherichia coli
virulence genes enables the bacterium to cause hemorrhagic colitis and the complication known as hemolytic-uremic syndrome. Horizontally acquired genes and those common to
E. coli
contribute to the disease process, and increased virulence gene expression is correlated with more severe disease in humans. Researchers have gained considerable knowledge about how the type III secretion system, secreted effectors, adhesin molecules, and the Shiga toxins are regulated by environmental signals and multiple genetic pathways. Also emergent from the data is an understanding of how enterohemorrhagic
E. coli
regulates response to acid stress, the role of flagellar motility, and how passage through the human host and bovine intestinal tract causes disease and supports carriage in the cattle reservoir, respectively. Particularly exciting areas of discovery include data suggesting how expression of the myriad effectors is coordinately regulated with their cognate type III secretion system and how virulence is correlated with bacterial metabolism and gut physiology.
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15
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Arenas-Hernández MM, Rojas-López M, Medrano-López A, Nuñez-Reza KJ, Puente JL, Martínez-Laguna Y, Torres AG. Environmental regulation of the long polar fimbriae 2 of enterohemorrhagic Escherichia coli O157:H7. FEMS Microbiol Lett 2014; 357:105-14. [PMID: 24966050 DOI: 10.1111/1574-6968.12513] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 06/12/2014] [Accepted: 06/13/2014] [Indexed: 11/27/2022] Open
Abstract
The molecular mechanisms controlling expression of the long polar fimbriae 2 (Lpf2) of enterohemorrhagic Escherichia coli (EHEC) O157:H7 were evaluated. Primer extension was used to locate the lpfA2 transcriptional start site in EHEC strain EDL933 at 171 bp upstream of the lpfA2 start codon. Semi-quantitative RT-PCR demonstrated that the highest lpfA2 expression occurs between an OD600 of 1.0 and 1.2 in DMEM at pH 6.5 and 37 °C. The level of lpfA2 transcription at OD600 1.2 and pH 6.5 was four times greater than that at pH 7.2. Although lpfA2 expression was decreased under iron-depleted conditions, its expression was increased in a ferric-uptake-regulator (Fur) mutant strain. The lpfA2 transcript was 0.7 and 2 times more abundant in wt EHEC grown in DMEM pH 6.5 plus iron and MacConkey broth at 25 °C, respectively, than in DMEM at pH 6.5. The lpf2 expression in DMEM pH 6.5 plus iron and bile salts was 2.7 times more abundant than baseline conditions. Further, transcription in the EDL933∆fur was 0.6 and 0.8 times higher as compared with the wt strain grown in DMEM pH 6.5 plus iron and MacConkey broth, respectively. Electrophoretic mobility shift assays showed that purified Fur interacts with the lpf2 regulatory region, indicating that Fur repression is exerted by direct binding to the promoter region. In summary, we demonstrated that the EHEC lpf2 operon is regulated in response to temperature, pH, bile salts and iron, during the exponential phase of growth, and is controlled by Fur.
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Affiliation(s)
- Margarita M Arenas-Hernández
- Posgrado en Microbiología, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico; Licenciatura en Biomedicina, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico; Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
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16
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Miko A, Delannoy S, Fach P, Strockbine NA, Lindstedt BA, Mariani-Kurkdjian P, Reetz J, Beutin L. Genotypes and virulence characteristics of Shiga toxin-producing Escherichia coli O104 strains from different origins and sources. Int J Med Microbiol 2013; 303:410-21. [DOI: 10.1016/j.ijmm.2013.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 05/07/2013] [Accepted: 05/20/2013] [Indexed: 02/03/2023] Open
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17
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Karadas G, Sharbati S, Hänel I, Messelhäußer U, Glocker E, Alter T, Gölz G. Presence of virulence genes, adhesion and invasion of Arcobacter butzleri. J Appl Microbiol 2013; 115:583-90. [DOI: 10.1111/jam.12245] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 04/29/2013] [Accepted: 05/02/2013] [Indexed: 11/30/2022]
Affiliation(s)
- G. Karadas
- Institute of Food Hygiene; Freie Universität Berlin; Berlin Germany
| | - S. Sharbati
- Institute of Veterinary Biochemistry, Freie Universität Berlin; Berlin Germany
| | - I. Hänel
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut; Jena Germany
| | - U. Messelhäußer
- Bavarian Health and Food Safety Authority; Oberschleißheim Germany
| | - E. Glocker
- Institute of Medical Microbiology and Hygiene, University Medical Center Freiburg; Freiburg Germany
| | - T. Alter
- Institute of Food Hygiene; Freie Universität Berlin; Berlin Germany
| | - G. Gölz
- Institute of Food Hygiene; Freie Universität Berlin; Berlin Germany
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18
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Silverman JM, Brunet YR, Cascales E, Mougous JD. Structure and regulation of the type VI secretion system. Annu Rev Microbiol 2012; 66:453-72. [PMID: 22746332 DOI: 10.1146/annurev-micro-121809-151619] [Citation(s) in RCA: 282] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The type VI secretion system (T6SS) is a complex and widespread gram-negative bacterial export pathway with the capacity to translocate protein effectors into a diversity of target cell types. Current structural models of the T6SS indicate that the apparatus is composed of at least two complexes, a dynamic bacteriophage-like structure and a cell-envelope-spanning membrane-associated assembly. How these complexes interact to promote effector secretion and cell targeting remains a major question in the field. As a contact-dependent pathway with specific cellular targets, the T6SS is subject to tight regulation. Thus, the identification of regulatory elements that control T6S expression continues to shape our understanding of the environmental circumstances relevant to its function. This review discusses recent progress toward characterizing T6S structure and regulation.
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Affiliation(s)
- Julie M Silverman
- Department of Microbiology, University of Washington, Seattle, 98195, USA
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19
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Klemm P, Vejborg RM, Hancock V. Prevention of bacterial adhesion. Appl Microbiol Biotechnol 2010; 88:451-9. [PMID: 20694794 DOI: 10.1007/s00253-010-2805-y] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 07/26/2010] [Accepted: 07/27/2010] [Indexed: 11/25/2022]
Abstract
Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation. As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future.
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Affiliation(s)
- Per Klemm
- Technical University of Denmark, Lyngby, Denmark.
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20
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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: 3.1] [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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21
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Abolition of biofilm formation in urinary tract Escherichia coli and Klebsiella isolates by metal interference through competition for fur. Appl Environ Microbiol 2010; 76:3836-41. [PMID: 20418434 DOI: 10.1128/aem.00241-10] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Bacterial biofilms are associated with a large number of persistent and chronic infections. Biofilm-dwelling bacteria are particularly resistant to antibiotics and immune defenses, which makes it hard if not impossible to eradicate biofilm-associated infections. In the urinary tract, free iron is strictly limited but is critical for bacterial growth. Biofilm-associated Escherichia coli cells are particularly desperate for iron. An attractive way of inhibiting biofilm formation is to fool the bacterial regulatory system for iron uptake. Here, we demonstrate that biofilm formation can be impaired by the addition of divalent metal ions, such as Zn(II) and Co(II), which inhibit iron uptake by virtue of their higher-than-iron affinity for the master controller protein of iron uptake, Fur. Reduced biofilm formation of urinary tract-infectious E. coli strains in the presence of Zn(II) was observed in microtiter plates and flow chambers as well as on urinary catheters. These results further support that iron uptake is indeed crucial for biofilm formation, and thereby, targeting these uptake systems might be an effective way to eradicate biofilms caused by infectious strains.
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22
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Herold S, Paton JC, Srimanote P, Paton AW. Differential effects of short-chain fatty acids and iron on expression of iha in Shiga-toxigenic Escherichia coli. Microbiology (Reading) 2009; 155:3554-3563. [DOI: 10.1099/mic.0.029454-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Shiga-toxigenic Escherichia coli (STEC) colonizing the bowel are exposed to a variety of short-chain fatty acids (SCFAs), including acetate, propionate and butyrate, produced by gut microflora. However, the total concentrations and relative amounts of SCFAs in the lumen vary with intestinal niche. Here we report that conditions simulating SCFA concentrations present in the human gut trigger expression of the iha gene, which encodes an adherence-conferring outer-membrane protein of pathogenic E. coli. We show that growth under conditions simulating colonic, but not ileal, SCFA concentrations increases iha expression in three tested STEC strains, with the strongest expression detected in LEE-negative STEC O113:H21 strain 98NK2. Expression of iha is known to be subject to Fur-mediated iron repression in O157:H7 STEC, and the same occurs in 98NK2. However, exogenous iron did not repress iha expression in the presence of colonic SCFAs in either 98NK2 or the O157:H7 strain EDL933. Moreover, exposure to the iron chelator 2,2′-dipyridyl caused no further enhancement of iha expression over that induced by colonic SCFAs. These findings indicate that SCFAs regulate iha expression in STEC independently of iron. Increased expression of iha under colonic but not ileal SCFA conditions possibly may contribute to preferential colonization of the human colon by STEC.
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Affiliation(s)
- Sylvia Herold
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, South Australia, 5005, Australia
| | - James C. Paton
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, South Australia, 5005, Australia
| | - Potjanee Srimanote
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, South Australia, 5005, Australia
| | - Adrienne W. Paton
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, South Australia, 5005, Australia
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23
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Contributions of O island 48 to adherence of enterohemorrhagic Escherichia coli O157:H7 to epithelial cells in vitro and in ligated pig ileal loops. Appl Environ Microbiol 2009; 75:5779-86. [PMID: 19633120 DOI: 10.1128/aem.00507-09] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
O island 48 (OI-48) of Escherichia coli consists of three functional gene clusters that encode urease, tellurite resistance (Te(r)), and putative adhesins Iha and AIDA-1. The functions of these clusters in enterohemorrhagic E. coli (EHEC) O157:H7 infection are unknown. Deletion mutants for these three regions were constructed and evaluated for their ability to adhere to epithelial cells in vitro and in ligated pig ileal loops. Deletion of the Te(r) gene cluster reduced the ability of the organism to adhere to and form large clusters on IPEC-J2 and HEp-2 cells. Complementation of the mutation by introducing the wild-type ter genes restored adherence and large-cluster formation. Tests in ligated pig ileal loops showed a decrease in colonization by the Te(r)-negative mutant, but the difference was not significant compared to colonization by the wild type (26.4% +/- 21.2% versus 40.1% +/- 19.1%; P = 0.168). The OI-48 aidA gene deletion had no effect on adherence in vitro or in vivo. Deletion of the iha and ureC genes had no effect on adherence in vitro but significantly reduced the colonization of EHEC O157:H7 in the ligated pig intestine. These data suggest that Te(r), Iha, and urease may contribute to EHEC O157:H7 pathogenesis by promoting adherence of the pathogen to the host intestinal epithelium.
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24
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Carpenter BM, Whitmire JM, Merrell DS. This is not your mother's repressor: the complex role of fur in pathogenesis. Infect Immun 2009; 77:2590-601. [PMID: 19364842 PMCID: PMC2708581 DOI: 10.1128/iai.00116-09] [Citation(s) in RCA: 167] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Beth M Carpenter
- Department of Microbiology and Immunology, Uniformed Services University of the Heath Sciences, Bethesda, MD 20814, USA
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25
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Carpenter BM, Gancz H, Gonzalez-Nieves RP, West AL, Whitmire JM, Michel SLJ, Merrell DS. A single nucleotide change affects fur-dependent regulation of sodB in H. pylori. PLoS One 2009; 4:e5369. [PMID: 19399190 PMCID: PMC2671405 DOI: 10.1371/journal.pone.0005369] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Accepted: 03/27/2009] [Indexed: 11/18/2022] Open
Abstract
Helicobacter pylori is a significant human pathogen that has adapted to survive the many stresses found within the gastric environment. Superoxide Dismutase (SodB) is an important factor that helps H. pylori combat oxidative stress. sodB was previously shown to be repressed by the Ferric Uptake Regulator (Fur) in the absence of iron (apo-Fur regulation) [1]. Herein, we show that apo regulation is not fully conserved among all strains of H. pylori. apo-Fur dependent changes in sodB expression are not observed under iron deplete conditions in H. pylori strains G27, HPAG1, or J99. However, Fur regulation of pfr and amiE occurs as expected. Comparative analysis of the Fur coding sequence between G27 and 26695 revealed a single amino acid difference, which was not responsible for the altered sodB regulation. Comparison of the sodB promoters from G27 and 26695 also revealed a single nucleotide difference within the predicted Fur binding site. Alteration of this nucleotide in G27 to that of 26695 restored apo-Fur dependent sodB regulation, indicating that a single base difference is at least partially responsible for the difference in sodB regulation observed among these H. pylori strains. Fur binding studies revealed that alteration of this single nucleotide in G27 increased the affinity of Fur for the sodB promoter. Additionally, the single base change in G27 enabled the sodB promoter to bind to apo-Fur with affinities similar to the 26695 sodB promoter. Taken together these data indicate that this nucleotide residue is important for direct apo-Fur binding to the sodB promoter.
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Affiliation(s)
- Beth M. Carpenter
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Hanan Gancz
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Reyda P. Gonzalez-Nieves
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Abby L. West
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland, United States of America
| | - Jeannette M. Whitmire
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Sarah L. J. Michel
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland, United States of America
| | - D. Scott Merrell
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
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26
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Toma C, Nakasone N, Miliwebsky E, Higa N, Rivas M, Suzuki T. Differential adherence of Shiga toxin-producing Escherichia coli harboring saa to epithelial cells. Int J Med Microbiol 2008; 298:571-8. [DOI: 10.1016/j.ijmm.2007.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Revised: 09/06/2007] [Accepted: 12/11/2007] [Indexed: 11/27/2022] Open
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Alteri CJ, Mobley HLT. Quantitative profile of the uropathogenic Escherichia coli outer membrane proteome during growth in human urine. Infect Immun 2007; 75:2679-88. [PMID: 17513849 PMCID: PMC1932884 DOI: 10.1128/iai.00076-07] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Outer membrane proteins (OMPs) of microbial pathogens are critical components that mediate direct interactions between microbes and their surrounding environment. Consequently, the study of OMPs is integral to furthering the understanding of host-pathogen interactions and to identifying key targets for development of improved antimicrobial agents and vaccines. In this study, we used two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and tandem mass spectrometry to characterize the uropathogenic Escherichia coli (UPEC) outer membrane subproteome; 30 individual OMPs present on the bacterial surface during growth in human urine were identified. Fluorescence difference gel electrophoresis was used to identify quantitative changes in levels of UPEC strain CFT073 OMPs during growth in urine; six known receptors for iron compounds were induced in this environment, i.e., ChuA, IutA, FhuA, IroN, IreA, and Iha. A seventh putative iron compound receptor, encoded by CFT073 open reading frame (ORF) c2482, was also identified and found to be induced in urine. Further, the induction of these seven iron receptors in human urine and during defined iron limitation was verified by using quantitative real-time PCR (qPCR). An eighth iron receptor, fepA, displayed similar induction levels under these conditions as measured by qPCR but was not identified by 2D-PAGE. Addition of 10 microM FeCl(2) to human urine repressed the transcription of all eight iron receptor genes. A number of fecal-commensal, intestinal pathogenic, and uropathogenic E. coli strains all displayed similar growth rates in human urine, showing that the ability to grow in urine per se is not a urovirulence trait. Thus, human urine is an iron-limiting environment and UPEC enriches its outer membrane with iron receptors to contend with this iron limitation.
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Affiliation(s)
- Christopher J Alteri
- Department of Microbiology and Immunology, University of Michigan Medical School, 5641 Medical Science Building II, 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA
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