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Whelan S, Lucey B, Finn K. Uropathogenic Escherichia coli (UPEC)-Associated Urinary Tract Infections: The Molecular Basis for Challenges to Effective Treatment. Microorganisms 2023; 11:2169. [PMID: 37764013 PMCID: PMC10537683 DOI: 10.3390/microorganisms11092169] [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: 07/28/2023] [Revised: 08/23/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
Urinary tract infections (UTIs) are among the most common bacterial infections, especially among women and older adults, leading to a significant global healthcare cost burden. Uropathogenic Escherichia coli (UPEC) are the most common cause and accounts for the majority of community-acquired UTIs. Infection by UPEC can cause discomfort, polyuria, and fever. More serious clinical consequences can result in urosepsis, kidney damage, and death. UPEC is a highly adaptive pathogen which presents significant treatment challenges rooted in a complex interplay of molecular factors that allow UPEC to evade host defences, persist within the urinary tract, and resist antibiotic therapy. This review discusses these factors, which include the key genes responsible for adhesion, toxin production, and iron acquisition. Additionally, it addresses antibiotic resistance mechanisms, including chromosomal gene mutations, antibiotic deactivating enzymes, drug efflux, and the role of mobile genetic elements in their dissemination. Furthermore, we provide a forward-looking analysis of emerging alternative therapies, such as phage therapy, nano-formulations, and interventions based on nanomaterials, as well as vaccines and strategies for immunomodulation. This review underscores the continued need for research into the molecular basis of pathogenesis and antimicrobial resistance in the treatment of UPEC, as well as the need for clinically guided treatment of UTIs, particularly in light of the rapid spread of multidrug resistance.
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Affiliation(s)
- Shane Whelan
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland;
| | - Brigid Lucey
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland;
| | - Karen Finn
- Department of Analytical, Biopharmaceutical and Medical Sciences, Atlantic Technological University Galway City, Dublin Road, H91 T8NW Galway, Ireland
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2
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Tsoumtsa Meda LL, Landraud L, Petracchini S, Descorps-Declere S, Perthame E, Nahori MA, Ramirez Finn L, Ingersoll MA, Patiño-Navarrete R, Glaser P, Bonnet R, Dussurget O, Denamur E, Mettouchi A, Lemichez E. The cnf1 gene is associated with an expanding Escherichia coli ST131 H30Rx/C2 subclade and confers a competitive advantage for gut colonization. Gut Microbes 2022; 14:2121577. [PMID: 36154446 PMCID: PMC9519008 DOI: 10.1080/19490976.2022.2121577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Epidemiological projections point to acquisition of ever-expanding multidrug resistance (MDR) by Escherichia coli, a commensal of the digestive tract and a source of urinary tract pathogens. Bioinformatics analyses of a large collection of E. coli genomes from EnteroBase, enriched in clinical isolates of worldwide origins, suggest the Cytotoxic Necrotizing Factor 1 (CNF1)-toxin encoding gene, cnf1, is preferentially distributed in four common sequence types (ST) encompassing the pandemic E. coli MDR lineage ST131. This lineage is responsible for a majority of extraintestinal infections that escape first-line antibiotic treatment, with known enhanced capacities to colonize the gastrointestinal tract. Statistical projections based on this dataset point to a global expansion of cnf1-positive multidrug-resistant ST131 strains from subclade H30Rx/C2, accounting for a rising prevalence of cnf1-positive strains in ST131. Despite the absence of phylogeographical signals, cnf1-positive isolates segregated into clusters in the ST131-H30Rx/C2 phylogeny, sharing a similar profile of virulence factors and the same cnf1 allele. The suggested dominant expansion of cnf1-positive strains in ST131-H30Rx/C2 led us to uncover the competitive advantage conferred by cnf1 for gut colonization to the clinical strain EC131GY ST131-H30Rx/C2 versus cnf1-deleted isogenic strain. Complementation experiments showed that colon tissue invasion was compromised in the absence of deamidase activity on Rho GTPases by CNF1. Hence, gut colonization factor function of cnf1 was confirmed for another clinical strain ST131-H30Rx/C2. In addition, functional analysis of the cnf1-positive clinical strain EC131GY ST131-H30Rx/C2 and a cnf1-deleted isogenic strain showed no detectable impact of the CNF1 gene on bacterial fitness and inflammation during the acute phase of bladder monoinfection. Together these data argue for an absence of role of CNF1 in virulence during UTI, while enhancing gut colonization capacities of ST131-H30Rx/C2 and suggested expansion of cnf1-positive MDR isolates in subclade ST131-H30Rx/C2.
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Affiliation(s)
- Landry L. Tsoumtsa Meda
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité des Toxines Bactériennes, Département de Microbiologie, Paris, France
| | - Luce Landraud
- Université Paris Cité et Université Sorbonne Paris Nord, INSERM U1137, IAME, Paris, France,Laboratoire Microbiologie-hygiène, AP-HP, Hôpital Louis Mourier, Colombes, France
| | - Serena Petracchini
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité des Toxines Bactériennes, Département de Microbiologie, Paris, France
| | - Stéphane Descorps-Declere
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité des Toxines Bactériennes, Département de Microbiologie, Paris, France,Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, Paris, France
| | - Emeline Perthame
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, Paris, France
| | - Marie-Anne Nahori
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité des Toxines Bactériennes, Département de Microbiologie, Paris, France
| | - Laura Ramirez Finn
- Institut Pasteur, Department of Immunology, Mucosal Inflammation and Immunity group, Paris, France,Université Paris Cité, Institut Cochin, CNRS UMR8104, INSERM U1016, Paris, France
| | - Molly A. Ingersoll
- Institut Pasteur, Department of Immunology, Mucosal Inflammation and Immunity group, Paris, France,Université Paris Cité, Institut Cochin, CNRS UMR8104, INSERM U1016, Paris, France
| | - Rafael Patiño-Navarrete
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Unité Ecologie et Evolution de la Résistance aux Antibiotiques, Département de Microbiologie, Paris, France
| | - Philippe Glaser
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Unité Ecologie et Evolution de la Résistance aux Antibiotiques, Département de Microbiologie, Paris, France
| | - Richard Bonnet
- UMR INSERM U1071, INRA USC-2018, Université Clermont Auvergne, Clermont-Ferrand, France,Centre National de Référence de la Résistance aux Antibiotiques, Centre Hospitalier Universitaire, Clermont-Ferrand, France
| | - Olivier Dussurget
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Unité de Recherche Yersinia, Département de Microbiologie, Paris, France
| | - Erick Denamur
- Université Paris Cité et Université Sorbonne Paris Nord, INSERM U1137, IAME, Paris, France,AP-HP, Laboratoire de Génétique Moléculaire, Hôpital Bichat, Paris, France
| | - Amel Mettouchi
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité des Toxines Bactériennes, Département de Microbiologie, Paris, France,Amel Mettouchi Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité des Toxines Bactériennes, Département de Microbiologie, 75015Paris, France
| | - Emmanuel Lemichez
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité des Toxines Bactériennes, Département de Microbiologie, Paris, France,CONTACT Emmanuel Lemichez
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3
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The Cytotoxic Necrotizing Factors (CNFs)-A Family of Rho GTPase-Activating Bacterial Exotoxins. Toxins (Basel) 2021; 13:toxins13120901. [PMID: 34941738 PMCID: PMC8709095 DOI: 10.3390/toxins13120901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 11/17/2022] Open
Abstract
The cytotoxic necrotizing factors (CNFs) are a family of Rho GTPase-activating single-chain exotoxins that are produced by several Gram-negative pathogenic bacteria. Due to the pleiotropic activities of the targeted Rho GTPases, the CNFs trigger multiple signaling pathways and host cell processes with diverse functional consequences. They influence cytokinesis, tissue integrity, cell barriers, and cell death, as well as the induction of inflammatory and immune cell responses. This has an enormous influence on host-pathogen interactions and the severity of the infection. The present review provides a comprehensive insight into our current knowledge of the modular structure, cell entry mechanisms, and the mode of action of this class of toxins, and describes their influence on the cell, tissue/organ, and systems levels. In addition to their toxic functions, possibilities for their use as drug delivery tool and for therapeutic applications against important illnesses, including nervous system diseases and cancer, have also been identified and are discussed.
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Mezerova K, Raclavsky V, Stary L. Which bacterial toxins are worthy of validation as markers in colorectal cancer screening? A critical review. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2021; 166:1-11. [PMID: 34747413 DOI: 10.5507/bp.2021.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 08/25/2021] [Indexed: 12/21/2022] Open
Abstract
Appropriate screening of early asymptomatic cases can reduce the disease burden and mortality rate of sporadic colorectal cancer (CRC) significantly. Currently, fecal occult blood testing (FOBT) is able to detect up to 80% of asymptomatic cases in the population aged 50+. Therefore, there is still a demand for new screening tests that would complement FOBT, mainly by detecting at least a part of the FOBT-negative CRC and adenoma cases, or possibly by identifying person at increased risk of sporadic CRC in order to offer them tailored follow-up. Among the potential markers studied, our knowledge has advanced at most in toxigenic gram-negative bacteria. In this review, we assess their potential critically and recommend those best suited for prospective evaluation of their true ability to increase the sensitivity of FOBT when combined during general population screening. In our opinion, colibactin and Bacteroides fragilis toxin are the best candidates, possibly complemented by the cytotoxic necrotizing factor (CNF).
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Affiliation(s)
- Kristina Mezerova
- Department of Microbiology, Faculty of Medicine & Dentistry, Palacky University Olomouc, Czech Republic
| | - Vladislav Raclavsky
- Department of Microbiology, Faculty of Medicine & Dentistry, Palacky University Olomouc, Czech Republic
| | - Lubomir Stary
- Department of Surgery I, University Hospital Olomouc, Czech Republic
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5
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The role of bacterial toxins and spores in cancer therapy. Life Sci 2019; 235:116839. [PMID: 31499068 DOI: 10.1016/j.lfs.2019.116839] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 08/21/2019] [Accepted: 09/04/2019] [Indexed: 12/16/2022]
Abstract
Cancer is one of the leading causes of human death worldwide. Conventional anticancer therapies are ineffective in treating cancer patients due to various reasons. Thus, more effective and accessible alternative anticancer strategies have been evolved with time with high specificity towards tumor cells and with less or no adverse effects to normal cells. One such promising therapy is the use of bacterial toxins and spores to treat advanced solid tumors. Initially, Coley paved the way towards the bacterial anticancer therapy several decades ago and now it has emerged as a potential tool to eliminate tumor cells. Bacterial spores of obligate anaerobes exclusively germinate in the hypoxic/necrotic areas and not in the well-oxygenated areas of the body. This unique phenomenon has been exploited in using bacterial spores as a remedy for cancer. Bacterial toxins also play a significant role in either directly killing tumor cells or altering the cellular processes of the tumor cells which ultimately leads to the inhibition and regression of the solid tumor. With the advancement of molecular techniques, a number of genetically-modified non-pathogenic bacteria have been developed to use in bacterial anticancer strategies. Although promising results have shown so far, further investigations are required to ensure the efficacy and the safety of the bacterial spores and toxins in treating cancer.
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Sedighi M, Zahedi Bialvaei A, Hamblin MR, Ohadi E, Asadi A, Halajzadeh M, Lohrasbi V, Mohammadzadeh N, Amiriani T, Krutova M, Amini A, Kouhsari E. Therapeutic bacteria to combat cancer; current advances, challenges, and opportunities. Cancer Med 2019; 8:3167-3181. [PMID: 30950210 PMCID: PMC6558487 DOI: 10.1002/cam4.2148] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 03/17/2019] [Accepted: 03/20/2019] [Indexed: 12/26/2022] Open
Abstract
Successful treatment of cancer remains a challenge, due to the unique pathophysiology of solid tumors, and the predictable emergence of resistance. Traditional methods for cancer therapy including radiotherapy, chemotherapy, and immunotherapy all have their own limitations. A novel approach is bacteriotherapy, either used alone, or in combination with conventional methods, has shown a positive effect on regression of tumors and inhibition of metastasis. Bacteria-assisted tumor-targeted therapy used as therapeutic/gene/drug delivery vehicles has great promise in the treatment of tumors. The use of bacteria only, or in combination with conventional methods was found to be effective in some experimental models of cancer (tumor regression and increased survival rate). In this article, we reviewed the major advantages, challenges, and prospective directions for combinations of bacteria with conventional methods for tumor therapy.
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Affiliation(s)
- Mansour Sedighi
- Department of Microbiology, School of MedicineIran University of Medical SciencesTehranIran
| | - Abed Zahedi Bialvaei
- Department of Microbiology, School of MedicineIran University of Medical SciencesTehranIran
| | - Michael R. Hamblin
- Wellman Center for PhotomedicineMassachusetts General HospitalBostonMassachusetts
- Department of DermatologyHarvard Medical SchoolBostonMassachusetts
- Harvard‐MIT Division of Health Sciences and TechnologyCambridgeMassachusetts
| | - Elnaz Ohadi
- Department of Microbiology, School of MedicineIran University of Medical SciencesTehranIran
| | - Arezoo Asadi
- Department of Microbiology, School of MedicineIran University of Medical SciencesTehranIran
| | - Masoumeh Halajzadeh
- Department of Microbiology, School of MedicineIran University of Medical SciencesTehranIran
| | - Vahid Lohrasbi
- Department of Microbiology, School of MedicineIran University of Medical SciencesTehranIran
| | - Nima Mohammadzadeh
- Department of Microbiology, School of MedicineIran University of Medical SciencesTehranIran
| | - Taghi Amiriani
- Golestan Research Center of Gastroenterology and HepatologyGolestan University of Medical SciencesGorganIran
| | - Marcela Krutova
- 2nd Faculty of Medicine, Department of Medical MicrobiologyCharles University and Motol University HospitalPragueCzech Republic
| | - Abolfazl Amini
- Laboratory Sciences Research CenterGolestan University of Medical SciencesGorganIran
| | - Ebrahim Kouhsari
- Department of Microbiology, School of MedicineIran University of Medical SciencesTehranIran
- Laboratory Sciences Research CenterGolestan University of Medical SciencesGorganIran
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7
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Bacterial Infection and Associated Cancers. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1018:181-191. [DOI: 10.1007/978-981-10-5765-6_11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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9
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Abstract
ABSTRACT
Four prostatitis syndromes are recognized clinically: acute bacterial prostatitis, chronic bacterial prostatitis, chronic prostatitis/chronic pelvic pain syndrome, and asymptomatic prostatitis. Because
Escherichia coli
represents the most common cause of bacterial prostatitis, we investigated the importance of bacterial virulence factors and antimicrobial resistance in
E. coli
strains causing prostatitis and the potential association of these characteristics with clinical outcomes. A structured literature review revealed that we have limited understanding of the virulence-associated characteristics of
E. coli
causing acute prostatitis. Therefore, we completed a comprehensive microbiological and molecular investigation of a unique strain collection isolated from healthy young men. We also considered new data from an animal model system suggesting certain
E. coli
might prove important in the etiology of chronic prostatitis/chronic pelvic pain syndrome. Our human data suggest that
E. coli
needs multiple pathogenicity-associated traits to overcome anatomic and immune responses in healthy young men without urological risk factors. The phylogenetic background and accumulation of an exceptional repertoire of extraintestinal pathogenic virulence-associated genes indicate that these
E. coli
strains belong to a highly virulent subset of uropathogenic variants. In contrast, antibiotic resistance confers little added advantage to
E. coli
strains in these healthy outpatients. Our animal model data also suggest that certain pathogenic
E. coli
may be important in the etiology of chronic prostatitis/chronic pelvic pain syndrome through mechanisms that are dependent on the host genetic background and the virulence of the bacterial strain.
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Oloomi M, Javadi M, Bouzari S. Presence of pathogenicity island related and plasmid encoded virulence genes in cytolethal distending toxin producing Escherichia coli isolates from diarrheal cases. Int J Appl Basic Med Res 2015; 5:181-6. [PMID: 26539367 PMCID: PMC4606577 DOI: 10.4103/2229-516x.165366] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Context: Mobile genetic elements such as plasmids, bacteriophages, insertion elements, and genomic islands play a critical role in virulence of bacterial pathogens. These elements transfer horizontally and could play an important role in the evolution and virulence of many pathogens. A broad spectrum of gram-negative bacterial species has been shown to produce a cytolethal distending toxin (CDT). On the other hand, Shiga toxin producing Escherichia coli are the one carry virulence genes such as stx 1 and stx 2 (Shiga toxin) and these genes can be acquired by horizontal gene transfer. Aim: The aim of this study was to investigate the presence of other virulence associated genes among CDT producing E. coli strains. Materials and Methods: Thirty CDT positive strains isolated from patients with diarrhea were characterized. Thereafter, the association with virulent genetic elements in known pathogenicity islands (PAIs) was assessed by polymerase chain reaction. Results: In this study, it was shown that the most CDT producing E. coli isolates express Shiga toxin. Moreover, the presence of prophages framing cdt genes (like P2 phage) was also identified in each cdt-type genomic group. Flanked regions of cdt-I, cdt-IV, and cdt-V-type was similar to plasmid sequences while cdt-II and cdt-III-type regions similarity with hypothetical protein (orf3) was observed. Conclusion: The occurrence of each cdt-type groups with specific virulence genes and PAI genetic elements is indicative of horizontal gene transfer by these mobile genetic elements, which could lead to diversity among the isolates.
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Affiliation(s)
- Mana Oloomi
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran 13164, Iran
| | - Maryam Javadi
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran 13164, Iran
| | - Saeid Bouzari
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran 13164, Iran
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Khan S. Potential role of Escherichia coli DNA mismatch repair proteins in colon cancer. Crit Rev Oncol Hematol 2015; 96:475-82. [PMID: 26014615 DOI: 10.1016/j.critrevonc.2015.05.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 03/15/2015] [Accepted: 05/05/2015] [Indexed: 02/07/2023] Open
Abstract
The epithelium of gastrointestinal tract organizes many innate defense systems against microbial intruders such as integrity of epithelial, rapid eviction of infected cells, quick turnover of epithelial cell, intrinsic immune responses and autophagy. However, Enteropathogenic Escherichia coli (EPEC) are equipped with well developed infectious tricks that evade the host defense systems and utilize the gastrointestinal epithelium as a multiplicative foothold. During multiplication on and within the epithelium, EPEC secrete various toxins that can weaken, usurp, and use many host cellular systems. However, the possible mechanisms of pathogenesis are still poorly elusive. Recent study reveals the existence of EPEC in colorectal cancer patients and their potential role in depletion of DNA mismatch repair (MMR) proteins of host cell in colonic cell lines. The EPEC colonised intracellularly in colon mucosa of colorectal carcinoma whereas extracellular strain was detected in mucosa of normal colon cells. Interestingly, alteration in MutS, MutL complexes and MUTYH of mammalian cells may be involved in development of CRC. These data propose that MMR of E. coli may be potential therapeutic targets and early detection biomarkers for CRC. This article reviews the potential role of E. coli MutS, MutL and MutY protein in CRC aetiology.
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Affiliation(s)
- Shahanavaj Khan
- Nanomedicine & Biotechnology Research Unit, Department of Pharmaceutics, College of Pharmacy, King Saud University, PO Box 2457, Riyadh 11451, Saudi Arabia.
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12
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Splichalova A, Splichal I, Sonnenborn U, Rada V. A modified MacConkey agar for selective enumeration of necrotoxigenic E. coli O55 and probiotic E. coli Nissle 1917. J Microbiol Methods 2014; 104:82-6. [PMID: 25008462 DOI: 10.1016/j.mimet.2014.06.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 05/10/2014] [Accepted: 06/25/2014] [Indexed: 11/18/2022]
Abstract
An agar selective enumeration of necrotoxigenic Escherichia coli O55 (NTEC2) and probiotic E. coli Nissle 1917, using modified MacConkey agar, was developed to study bacterial interference between these E. coli strains in a gnotobiotic piglet model. Replacement of lactose with saccharose in the agar enables the direct visual enumeration of red colonies of E. coli O55 and yellow colonies of E. coli Nissle 1917 that are co-cultured in the same Petri dish. A total of 336 colonies (168 for each color) were subjected to strain-specific PCR identification with LNA probes. Sensitivity, specificity, and positive and negative predictive values were 96.43%, 95.83%, 95.86% and 96.41% respectively in E. coli O55, and 98.21%, 97.02%, 97.06% and 98.19% respectively in E. coli Nissle 1917. Color-based enumeration of both E. coli strains in colonic contents and mesenteric lymph nodes homogenates of gnotobiotic piglets demonstrated the applicability of this method for the gnotobiotic piglet model of enteric diseases.
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Affiliation(s)
- Alla Splichalova
- Laboratory of Gnotobiology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Doly 183, 549 22 Novy Hradek, Czech Republic
| | - Igor Splichal
- Laboratory of Gnotobiology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Doly 183, 549 22 Novy Hradek, Czech Republic.
| | - Ulrich Sonnenborn
- Biological Research Department, Ardeypharm GmbH, Loerfeldstrasse 20, 58313 Herdecke, Germany
| | - Vojtech Rada
- Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka129, 165 21 Prague 6- Suchdol, Czech Republic
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Tang F, Saier MH. Transport proteins promoting Escherichia coli pathogenesis. Microb Pathog 2014; 71-72:41-55. [PMID: 24747185 DOI: 10.1016/j.micpath.2014.03.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/19/2014] [Accepted: 03/20/2014] [Indexed: 12/26/2022]
Abstract
Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies.
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Affiliation(s)
- Fengyi Tang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA.
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA.
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Kovalchuk O, Walz P, Kovalchuk I. Does bacterial infection cause genome instability and cancer in the host cell? Mutat Res 2014; 761:1-14. [PMID: 24472301 DOI: 10.1016/j.mrfmmm.2014.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 12/08/2013] [Accepted: 01/16/2014] [Indexed: 06/03/2023]
Abstract
Research of the past several decades suggests that bacterial infection can lead to genome instability of the host cell often resulting in cancer development. However, there is still a substantial lack of knowledge regarding possible mechanisms involved in the development of genomic instability. Several questions remain unanswered, namely: Why has the causative relationship between the bacterial infection and cancer been established only for a small number of cancers? What is the mechanism responsible for the induction of genome instability and cancer? Is the infection process required to cause genome instability and cancer? In this review, we present a hypothesis that the bacterial infection, exposure to heat-killed bacteria or even some bacterial determinants may trigger genome instability of exposed and distal cells, and thus may cause cancer. We will discuss the mechanisms of host responses to the bacterial infection and present the possible pathways leading to genome instability and cancer through exposure to bacteria.
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Affiliation(s)
- Olga Kovalchuk
- Department of Biological Sciences, University of Lethbridge, Lethbridge T1K 3M4, Alberta, Canada.
| | - Paul Walz
- Department of Biological Sciences, University of Lethbridge, Lethbridge T1K 3M4, Alberta, Canada.
| | - Igor Kovalchuk
- Department of Biological Sciences, University of Lethbridge, Lethbridge T1K 3M4, Alberta, Canada.
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15
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Repella TL, Ho M, Wilson BA. Determinants of pH-dependent modulation of translocation in dermonecrotic G-protein-deamidating toxins. Toxins (Basel) 2013; 5:1167-79. [PMID: 23888517 PMCID: PMC3717775 DOI: 10.3390/toxins5061167] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cytotoxic necrotizing factors from E. coli (CNF1, CNF2) and Yersinia (CNFy) share N-terminal sequence similarity with Pasteurella multocida toxin (PMT). This common N-terminal region harbors the receptor-binding and translocation domains that mediate uptake and delivery of the C-terminal catalytic cargo domains into the host cytosol. Subtle variations in the N-terminal ~500 amino acids of CNFs and PMT could allow for selective recognition of cellular receptors and thus, selective target cell specificity. Through studies with cellular inhibitors, we have identified an additional novel function for this region in modulating responses of these toxin proteins to changes in pH during intoxication and delivery of the catalytic cargo domain into the cytosol.
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Affiliation(s)
- Tana L Repella
- Department of Microbiology, School of Molecular and Cell Biology, University of Illinois atUrbana-Champaign, Urbana, IL 61801, USA.
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Khan AA, Cash P. E. coli and colon cancer: is mutY a culprit? Cancer Lett 2013; 341:127-31. [PMID: 23933175 DOI: 10.1016/j.canlet.2013.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 07/24/2013] [Accepted: 08/02/2013] [Indexed: 12/13/2022]
Abstract
The recent demonstration of a role of Escherichia coli in the development of invasive carcinoma in mice ushers a new era of bacterial involvement in cancer etiology. It has been shown previously that the colonic mucosa of colorectal carcinoma (CRC) is exclusively colonized by intracellular E. coli instead of extracellular form found in normal colonic mucosa. Surprisingly, the DNA repair gene MUTYH, which is a homologue of the E. coli gene mutY, is responsible for CRC. The current paper discusses the potential role of mutY in CRC etiology and concludes that research in this area can bring together the diverse threads of the CRC etiology puzzle.
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Affiliation(s)
- Abdul Arif Khan
- Department of Microbiology, College of Life Sciences, Cancer Hospital & Research Institute, Gwalior, MP, India; Department of Pharmaceutics, College of Pharmacy, PO Box 2457, King Saud University, Riyadh 11451, Saudi Arabia.
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17
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Swine atrophic rhinitis caused by pasteurella multocida toxin and bordetella dermonecrotic toxin. Curr Top Microbiol Immunol 2012; 361:113-29. [PMID: 22411430 DOI: 10.1007/82_2012_206] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Atrophic rhinitis is a widespread and economically important swine disease caused by Pasteurella multocida and Bordetella bronchiseptica. The disease is characterized by atrophy of the nasal turbinate bones, which results in a shortened and deformed snout in severe cases. P. multocida toxin and B. bronchiseptica dermonecrotic toxin have been considered to independently or cooperatively disturb the osteogenesis of the turbinate bone by inhibiting osteoblastic differentiation and/or stimulating bone resorption by osteoclasts. Recently, the intracellular targets and molecular actions of both toxins have been clarified, enabling speculation on the intracellular signals leading to the inhibition of osteogenesis.
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Pasteurella multocida toxin interaction with host cells: entry and cellular effects. Curr Top Microbiol Immunol 2012; 361:93-111. [PMID: 22552700 PMCID: PMC4408768 DOI: 10.1007/82_2012_219] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The mitogenic dermonecrotic toxin from Pasteurella multocida (PMT) is a 1285-residue multipartite protein that belongs to the A-B family of bacterial protein toxins. Through its G-protein-deamidating activity on the α subunits of heterotrimeric G(q)-, G(i)- and G(12/13)-proteins, PMT potently stimulates downstream mitogenic, calcium, and cytoskeletal signaling pathways. These activities lead to pleiotropic effects in different cell types, which ultimately result in cellular proliferation, while inhibiting cellular differentiation, and account for the myriad of physiological outcomes observed during infection with toxinogenic strains of P. multocida.
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Brothers MC, Ho M, Maharjan R, Clemons NC, Bannai Y, Waites MA, Faulkner MJ, Kuhlenschmidt TB, Kuhlenschmidt MS, Blanke SR, Rienstra CM, Wilson BA. Membrane interaction of Pasteurella multocida toxin involves sphingomyelin. FEBS J 2011; 278:4633-48. [PMID: 21951695 PMCID: PMC3220749 DOI: 10.1111/j.1742-4658.2011.08365.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pasteurella multocida toxin (PMT) is an AB toxin that causes pleiotropic effects in targeted host cells. The N-terminus of PMT (PMT-N) is considered to harbor the membrane receptor binding and translocation domains responsible for mediating cellular entry and delivery of the C-terminal catalytic domain into the host cytosol. Previous studies have implicated gangliosides as the host receptors for PMT binding. To gain further insight into the binding interactions involved in PMT binding to cell membranes, we explored the role of various membrane components in PMT binding, utilizing four different approaches: (a) TLC-overlay binding experiments with (125) I-labeled PMT, PMT-N or the C-terminus of PMT; (b) pull-down experiments using reconstituted membrane liposomes with full-length PMT; (c) surface plasmon resonance analysis of PMT-N binding to reconstituted membrane liposomes; (d) and surface plasmon resonance analysis of PMT-N binding to HEK-293T cell membranes without or with sphingomyelinase, phospholipase D or trypsin treatment. The results obtained revealed that, in our experimental system, full-length PMT and PMT-N did not bind to gangliosides, including monoasialogangliosides GM(1) , GM(2) or GM(3) , but instead bound to membrane phospholipids, primarily the abundant sphingophospholipid sphingomyelin or phosphatidylcholine with other lipid components. Collectively, these studies demonstrate the importance of sphingomyelin for PMT binding to membranes and suggest the involvement of a protein co-receptor.
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Affiliation(s)
| | - Mengfei Ho
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA
| | - Ram Maharjan
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | - Nathan C. Clemons
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | - Yuka Bannai
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | - Mark A. Waites
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | | | | | | | - Steven R. Blanke
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA
| | - Chad M. Rienstra
- Department of Chemistry, University of Illinois, Urbana, IL 61801, USA
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA
| | - Brenda A. Wilson
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA
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20
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Abstract
The mitogenic toxin from Pasteurella multocida (PMT) is a member of the dermonecrotic toxin family, which includes toxins from Bordetella, Escherichia coli and Yersinia. Members of the dermonecrotic toxin family modulate G-protein targets in host cells through selective deamidation and/or transglutamination of a critical active site Gln residue in the G-protein target, which results in the activation of intrinsic GTPase activity. Structural and biochemical data point to the uniqueness of PMT among these toxins in its structure and action. Whereas the other dermonecrotic toxins act on small Rho GTPases, PMT acts on the α subunits of heterotrimeric G(q) -, G(i) - and G(12/13) -protein families. To date, experimental evidence supports a model in which PMT potently stimulates various mitogenic and survival pathways through the activation of G(q) and G(12/13) signaling, ultimately leading to cellular proliferation, whilst strongly inhibiting pathways involved in cellular differentiation through the activation of G(i) signaling. The resulting cellular outcomes account for the global physiological effects observed during infection with toxinogenic P. multocida, and hint at potential long-term sequelae that may result from PMT exposure.
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Affiliation(s)
- Brenda A Wilson
- Department of Microbiology and Host-Microbe Systems Theme of the Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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21
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Abstract
Many bacterial pathogens produce protein toxins to outmanoeuvre the immune system of the host. Some of these proteins target regulatory GTPases such as those belonging to the RHO family, which control the actin cytoskeleton of the host cell. In this Review, I discuss a diversity of mechanisms that are used by bacterial effectors and toxins to modulate the activity of host GTPases, with a focus on covalent modifications such as ADP-ribosylation, glucosylation, adenylylation, proteolysis, deamidation and transglutamination.
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Affiliation(s)
- Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
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Kamitani S, Ao S, Toshima H, Tachibana T, Hashimoto M, Kitadokoro K, Fukui-Miyazaki A, Abe H, Horiguchi Y. Enzymatic actions of Pasteurella multocida toxin detected by monoclonal antibodies recognizing the deamidated α subunit of the heterotrimeric GTPase Gq. FEBS J 2011; 278:2702-12. [PMID: 21624053 DOI: 10.1111/j.1742-4658.2011.08197.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pasteurella multocida toxin (PMT) is a virulence factor responsible for the pathogenesis of some Pasteurellosis. PMT exerts its toxic effects through the activation of heterotrimeric GTPase (G(q), G(12/13) and G(i))-dependent pathways, by deamidating a glutamine residue in the α subunit of these GTPases. However, the enzymatic characteristics of PMT are yet to be analyzed in detail because the deamidation has only been observed in cell-based assays. In the present study, we developed rat monoclonal antibodies, specifically recognizing the deamidated Gα(q), to detect the actions of PMT by immunological techniques such as western blotting. Using the monoclonal antibodies, we found that the toxin deamidated Gα(q) only under reducing conditions. The C-terminal region of PMT, C-PMT, was more active than the full-length PMT. The C3 domain possessing the enzyme core catalyzed the deamidation in vitro without any other domains. These results not only support previous observations on toxicity, but also provide insights into the enzymatic nature of PMT. In addition, we present several lines of evidence that Gα(11), as well as Gα(q), could be a substrate for PMT.
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Affiliation(s)
- Shigeki Kamitani
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Suita-shi, Osaka, Japan.
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Jinadasa RN, Bloom SE, Weiss RS, Duhamel GE. Cytolethal distending toxin: a conserved bacterial genotoxin that blocks cell cycle progression, leading to apoptosis of a broad range of mammalian cell lineages. MICROBIOLOGY-SGM 2011; 157:1851-1875. [PMID: 21565933 DOI: 10.1099/mic.0.049536-0] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cytolethal distending toxin (CDT) is a heterotrimeric AB-type genotoxin produced by several clinically important Gram-negative mucocutaneous bacterial pathogens. Irrespective of the bacterial species of origin, CDT causes characteristic and irreversible cell cycle arrest and apoptosis in a broad range of cultured mammalian cell lineages. The active subunit CdtB has structural homology with the phosphodiesterase family of enzymes including mammalian DNase I, and alone is necessary and sufficient to account for cellular toxicity. Indeed, mammalian cells treated with CDT initiate a DNA damage response similar to that elicited by ionizing radiation-induced DNA double strand breaks resulting in cell cycle arrest and apoptosis. The mechanism of CDT-induced apoptosis remains incompletely understood, but appears to involve both p53-dependent and -independent pathways. While epithelial, endothelial and fibroblast cell lines respond to CDT by undergoing arrest of cell cycle progression resulting in nuclear and cytoplasmic distension that precedes apoptotic cell death, cells of haematopoietic origin display rapid apoptosis following a brief period of cell cycle arrest. In this review, the ecology of pathogens producing CDT, the molecular biology of bacterial CDT and the molecular mechanisms of CDT-induced cytotoxicity are critically appraised. Understanding the contribution of a broadly conserved bacterial genotoxin that blocks progression of the mammalian cell cycle, ultimately causing cell death, should assist with elucidating disease mechanisms for these important pathogens.
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Affiliation(s)
- Rasika N Jinadasa
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Stephen E Bloom
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Robert S Weiss
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Gerald E Duhamel
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
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24
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Intestinal epithelial cells and their role in innate mucosal immunity. Cell Tissue Res 2010; 343:5-12. [PMID: 21104188 DOI: 10.1007/s00441-010-1082-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 10/22/2010] [Indexed: 01/15/2023]
Abstract
The mucosal surfaces of the respiratory, gastrointestinal and urogenital tracts are covered by a layer of epithelial cells that are responsible for sensing and promoting a host immune response in order to establish the limits not only for commensal microorganisms but also for foreign organisms or particles. This is a remarkable task as the human body represents a composite of about 10 trillion human-self cells plus non-self cells from autochthonous or indigenous microbes that outnumber human cells 10:1. Hence, the homeostasis of epithelial cells that line mucosal surfaces relies on a fine-tuned immune system that patrols the boundaries between human and microbial cells. In the case of the intestine, the epithelial layer is composed of at least six epithelial cell lineages that act as a physiological barrier in addition to aiding digestion and the absorption of nutrients, water and electrolytes. In this review, we highlight the immense role of the intestinal epithelium in coordinating the mucosal innate immune response.
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25
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Kamitani S, Kitadokoro K, Miyazawa M, Toshima H, Fukui A, Abe H, Miyake M, Horiguchi Y. Characterization of the membrane-targeting C1 domain in Pasteurella multocida toxin. J Biol Chem 2010; 285:25467-75. [PMID: 20534589 DOI: 10.1074/jbc.m110.102285] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Pasteurella multocida toxin (PMT) is a virulence factor responsible for the pathogenesis of some forms of pasteurellosis. The toxin activates G(q)- and G(12/13)-dependent pathways through the deamidation of a glutamine residue in the alpha-subunit of heterotrimeric GTPases. We recently reported the crystal structure of the C terminus (residues 575-1285) of PMT (C-PMT), which is composed of three domains (C1, C2, and C3), and that the C1 domain is involved in the localization of C-PMT to the plasma membrane, and the C3 domain possesses a cysteine protease-like catalytic triad. In this study, we analyzed the membrane-targeting function of the C1 domain in detail. The C1 domain consists of seven helices of which the first four (residues 590-670), showing structural similarity to the N terminus of Clostridium difficile toxin B, were found to be involved in the recruitment of C-PMT to the plasma membrane. C-PMT lacking these helices (C-PMT DeltaC1(4H)) neither localized to the plasma membrane nor stimulated the G(q/12/13)-dependent signaling pathways. When the membrane-targeting property was complemented by a peptide tag with an N-myristoylation motif, C-PMT DeltaC1(4H) recovered the PMT activity. Direct binding between the C1 domain and liposomes containing phospholipids was evidenced by surface plasmon resonance analyses. These results indicate that the C1 domain of C-PMT functions as a targeting signal for the plasma membrane.
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Affiliation(s)
- Shigeki Kamitani
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
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26
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Patyar S, Joshi R, Byrav DSP, Prakash A, Medhi B, Das BK. Bacteria in cancer therapy: a novel experimental strategy. J Biomed Sci 2010; 17:21. [PMID: 20331869 PMCID: PMC2854109 DOI: 10.1186/1423-0127-17-21] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Accepted: 03/23/2010] [Indexed: 11/24/2022] Open
Abstract
Resistance to conventional anticancer therapies in patients with advanced solid tumors has prompted the need of alternative cancer therapies. Moreover, the success of novel cancer therapies depends on their selectivity for cancer cells with limited toxicity to normal tissues. Several decades after Coley's work a variety of natural and genetically modified non-pathogenic bacterial species are being explored as potential antitumor agents, either to provide direct tumoricidal effects or to deliver tumoricidal molecules. Live, attenuated or genetically modified non-pathogenic bacterial species are capable of multiplying selectively in tumors and inhibiting their growth. Due to their selectivity for tumor tissues, these bacteria and their spores also serve as ideal vectors for delivering therapeutic proteins to tumors. Bacterial toxins too have emerged as promising cancer treatment strategy. The most potential and promising strategy is bacteria based gene-directed enzyme prodrug therapy. Although it has shown successful results in vivo yet further investigation about the targeting mechanisms of the bacteria are required to make it a complete therapeutic approach in cancer treatment.
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Affiliation(s)
- S Patyar
- Department of Pharmacology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - R Joshi
- Department of Pharmacology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - DS Prasad Byrav
- Department of Pharmacology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - A Prakash
- Department of Pharmacology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - B Medhi
- Department of Pharmacology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - BK Das
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi 110029, India
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27
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Abstract
Bacterial plasmids are self-replicating, extrachromosomal elements that are key agents of change in microbial populations. They promote the dissemination of a variety of traits, including virulence, enhanced fitness, resistance to antimicrobial agents, and metabolism of rare substances. Escherichia coli, perhaps the most studied of microorganisms, has been found to possess a variety of plasmid types. Included among these are plasmids associated with virulence. Several types of E. coli virulence plasmids exist, including those essential for the virulence of enterotoxigenic E. coli, enteroinvasive E. coli, enteropathogenic E. coli, enterohemorrhagic E. coli, enteroaggregative E. coli, and extraintestinal pathogenic E. coli. Despite their diversity, these plasmids belong to a few plasmid backbones that present themselves in a conserved and syntenic manner. Thanks to some recent research, including sequence analysis of several representative plasmid genomes and molecular pathogenesis studies, the evolution of these virulence plasmids and the implications of their acquisition by E. coli are now better understood and appreciated. Here, work involving each of the E. coli virulence plasmid types is summarized, with the available plasmid genomic sequences for several E. coli pathotypes being compared in an effort to understand the evolution of these plasmid types and define their core and accessory components.
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28
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Johnson TJ, DebRoy C, Belton S, Williams ML, Lawrence M, Nolan LK, Thorsness JL. Pyrosequencing of the Vir plasmid of necrotoxigenic Escherichia coli. Vet Microbiol 2009; 144:100-9. [PMID: 20060660 DOI: 10.1016/j.vetmic.2009.12.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2009] [Revised: 12/11/2009] [Accepted: 12/16/2009] [Indexed: 10/20/2022]
Abstract
Necrotoxigenic Escherichia coli, or NTEC, are defined as E. coli producing the toxin known as cytotoxic necrotizing factor, or CNF. NTEC are responsible for various diseases of humans and animals, including urinary tract infection, septicemia, and diarrhea. A subgroup of NTEC known as NTEC-2 produce a variant of CNF (CNF-2) whose gene is located on a plasmid known as Vir. Because of its involvement in NTEC-2 pathogenesis and its broad distribution among production animals, a Vir plasmid from a bovine NTEC-2 strain was sequenced and analyzed. This plasmid was found to belong to the RepFIB and RepFIIA replicon types, and it totaled 138,682 base pairs in size. Within this plasmid was an approximately 60-kb pathogenicity island, defined by its possession of multiple virulence factors within distinct genetic regions of lower G+C content bounded by inverted repeats. Within this PAI were a variety of putative virulence factors, including F17b fimbrial genes, genes of a novel fimbrial operon, tibAC, hemolysins, and the cnf2 and cdt toxin-encoding genes. The occurrence of this plasmid's virulence- and replication-associated genes was sought among a collection of 96 CNF-2-positive isolates. The most prevalent genes among this collection included repA (RepFIB), cnf2, an ompP homolog, and the tib-AC genes encoding for aggregation and biofilm formation. The Vir plasmid has evolved from an IncFIB ancestral backbone, with the RepFIB locus apparently driving the acquisition of its accessory virulence-associated elements via site-specific recombination. Overall, the completed sequence of a Vir plasmid increases our understanding of NTEC-2 pathogenomics and IncFIB plasmid evolution.
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Affiliation(s)
- Timothy J Johnson
- Department of Veterinary and Biomedical Sciences, University of Minnesota, 1971 Commonwealth Ave, 205 Veterinary Science, Saint Paul, MN 55108, United States.
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Cleavage of Escherichia coli cytotoxic necrotizing factor 1 is required for full biologic activity. Infect Immun 2009; 77:1835-41. [PMID: 19237521 DOI: 10.1128/iai.01145-08] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cytotoxic necrotizing factor 1 (CNF1) is a protein toxin produced by pathogenic Escherichia coli strains. CNF1 constitutively activates small GTPases of the Rho family by deamidation of a glutamine, which is crucial for GTP hydrolysis. The toxin is taken up into mammalian cells by receptor-mediated endocytosis and is delivered from late endosomes into the cytosol. Here, we show that an approximately 55-kDa fragment of CNF1, which contains the catalytic domain and an additional part of the toxin, is present in the cytosol. The processing of this fragment requires an acidic pH and insertion of the toxin into the endosomal membrane. We define the cleavage site region as the region located between amino acids 532 and 544 of CNF1. The data provide insight into the complex mechanism of uptake of bacterial toxins into mammalian cells.
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Lactobacilli facilitate maintenance of intestinal membrane integrity during Shigella dysenteriae 1 infection in rats. Nutrition 2008; 25:350-8. [PMID: 19036564 DOI: 10.1016/j.nut.2008.09.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2008] [Revised: 08/25/2008] [Accepted: 09/02/2008] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Lactobacilli are used in various dairy products and fermented foods for their potential health beneficial effects. Recently we reported the protective role of Lactobacillus rhamnosus and Lactobacillus acidophilus during Shigella dysenteriae 1 infection. Nevertheless, investigations on the membrane-stabilizing effect of L. rhamnosus and L. acidophilus have not been done. Hence, the present study evaluated the effect of L. rhamnosus and L. acidophilus on the maintenance of intestinal membrane integrity during S. dysenteriae 1-induced diarrhea in rats. METHODS Rats were divided into eight groups (n = 6 in each group). Induced rats received single oral dose of S. dysenteriae (12 x 10(8) colony-forming units [cfu]/mL). Treated rats received L. rhamnosus (1 x 10(7)cfu/mL) or L. acidophilus (1 x 10(7)cfu/mL) orally for 4 d, alone or in combination, followed by Shigella administration. At the end of the experimental period, animals were sacrificed and the assay of membrane-bound adenosine triphosphatases (Na(+)/K(+)-ATPase, Ca(2+)-ATPase, and total ATPase), immunoblot analysis of tight junctional proteins (claudin-1 and occludin), and transmission electron microscopic studies were performed. RESULTS Induced rats showed a significant (P < 0.05) reduction in the membrane-bound ATPases and reduced expression of tight junction proteins in the membrane, coupled with their increased expression in the cytosol, indicating membrane damage. Transmission electron microscopic studies correlated with biochemical parameters. Pretreatment with combination of L. rhamnosus and L. acidophilus significantly prevented these changes. CONCLUSION Lactobacillus rhamnosus and L. acidophilus synergistically offered better protection to the intestinal membrane when compared with individual treatments with these strains during S. dysenteriae 1 infection.
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Cytolethal distending toxin type I and type IV genes are framed with lambdoid prophage genes in extraintestinal pathogenic Escherichia coli. Infect Immun 2008; 77:492-500. [PMID: 18981247 DOI: 10.1128/iai.00962-08] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Five types of cytolethal distending toxin (CDT-I to CDT-V) have been identified in Escherichia coli. In the present study we cloned and sequenced the cdt-IV operon and flanking region from a porcine extraintestinal pathogenic E. coli (ExPEC) strain belonging to serogroup O75. We confirmed that similar to other CDTs, CDT-IV induced phosphorylation of host histone H2AX, a sensitive marker of DNA double-strand breaks, and blocked the HeLa cell cycle at the G(2)-M transition. The cdt-IV genes were framed by lambdoid prophage genes. We cloned and sequenced the cdt-I operon and flanking regions from a human ExPEC O18:K1:H7 strain and observed that cdt-I genes were also flanked by lambdoid prophage genes. PCR studies indicated that a gene coding for a putative protease was always associated with the cdtC-IV gene but was not associated with cdtC genes in strains producing CDT-I, CDT-III, and CDT-V. Our results suggest that the cdt-I and cdt-IV genes might have been acquired from a common ancestor by phage transduction and evolved in their bacterial hosts. The lysogenic bacteriophages have the potential to carry nonessential "cargo" genes or "morons" and therefore play a crucial role in the generation of genetic diversity within ExPEC.
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32
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McNichol BA, Rasmussen SB, Carvalho HM, Meysick KC, O'Brien AD. Two domains of cytotoxic necrotizing factor type 1 bind the cellular receptor, laminin receptor precursor protein. Infect Immun 2007; 75:5095-104. [PMID: 17709415 PMCID: PMC2168285 DOI: 10.1128/iai.00075-07] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Cytotoxic necrotizing factor type 1 (CNF1) and CNF2 are highly homologous toxins that are produced by certain pathogenic strains of Escherichia coli. These 1,014-amino-acid toxins catalyze the deamidation of a specific glutamine residue in RhoA, Rac1, and Cdc42 and consist of a putative N-terminal binding domain, a transmembrane region, and a C-terminal catalytic domain. To define the regions of CNF1 that are responsible for binding of the toxin to its cellular receptor, the laminin receptor precursor protein (LRP), a series of CNF1 truncated toxins were characterized and assessed for toxin binding. In particular, three truncated toxins, DeltaN63, DeltaN545, and DeltaC469, retained conformational integrity and in vitro enzymatic activity and were immunologically reactive against a panel of anti-CNF1 monoclonal antibodies (MAbs). Based on a comparison of these truncated toxins with wild-type CNF1 and CNF2 in LRP and HEp-2 cell binding assays and in MAb and LRP competitive binding inhibition assays and based on the results of confocal microscopy, we concluded that CNF1 contains two major binding regions: one located within the N terminus, which contained amino acids 135 to 164, and one which resided in the C terminus and included amino acids 683 to 730. The data further indicate that CNF1 can bind to an additional receptor(s) on HEp-2 cells and that LRP can also serve as a cellular receptor for CNF2.
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Affiliation(s)
- Beth A McNichol
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814-4799, USA
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33
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Lemonnier M, Landraud L, Lemichez E. Rho GTPase-activating bacterial toxins: from bacterial virulence regulation to eukaryotic cell biology. FEMS Microbiol Rev 2007; 31:515-34. [PMID: 17680807 DOI: 10.1111/j.1574-6976.2007.00078.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Studies on the interactions of bacterial pathogens with their host have provided an invaluable source of information on the major functions of eukaryotic and prokaryotic cell biology. In addition, this expanding field of research, known as cellular microbiology, has revealed fascinating examples of trans-kingdom functional interplay. Bacterial factors actually exploit eukaryotic cell machineries using refined molecular strategies to promote invasion and proliferation within their host. Here, we review a family of bacterial toxins that modulate their activity in eukaryotic cells by activating Rho GTPases and exploiting the ubiquitin/proteasome machineries. This family, found in human and animal pathogenic Gram-negative bacteria, encompasses the cytotoxic necrotizing factors (CNFs) from Escherichia coli and Yersinia species as well as dermonecrotic toxins from Bordetella species. We survey the genetics, biochemistry, molecular and cellular biology of these bacterial factors from the standpoint of the CNF1 toxin, the paradigm of Rho GTPase-activating toxins produced by urinary tract infections causing pathogenic Escherichia coli. Because it reveals important connections between bacterial invasion and the host inflammatory response, the mode of action of CNF1 and its related Rho GTPase-targetting toxins addresses major issues of basic and medical research and constitutes a privileged experimental model for host-pathogen interaction.
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Affiliation(s)
- Marc Lemonnier
- INSERM U627, UNSA, Faculté de Médecine, 28 Avenue de Valombrose, 06107 Nice cedex 2, France.
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Beau I, Cotte-Laffitte J, Amsellem R, Servin AL. A protein kinase A-dependent mechanism by which rotavirus affects the distribution and mRNA level of the functional tight junction-associated protein, occludin, in human differentiated intestinal Caco-2 cells. J Virol 2007; 81:8579-86. [PMID: 17553883 PMCID: PMC1951370 DOI: 10.1128/jvi.00263-07] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We found that at the tight junctions (TJs) of Caco-2 cell monolayers, rhesus monkey rotavirus (RRV) infection induced the disappearance of occludin. Confocal laser scanning microscopy showed the disappearance of occludin from the cell-cell boundaries without modifying the expression of the other TJ-associated proteins, ZO-1 and ZO-3. Western immunoblot analysis of RRV-infected cells showed a significant fall in the levels of the nonphosphorylated form of occludin in both Triton X-100-insoluble and Triton X-100-soluble fractions, without any change in the levels of the phosphorylated form of occludin. Quantitative reverse transcription-PCRs revealed that the level of transcription of the gene that encodes occludin was significantly reduced in RRV-infected cells. Treatment of RRV-infected cells with Rp-cyclic AMP and protein kinase A inhibitors H89 and KT5720 during the time course of the infection restored the distribution of occludin and a normal level of transcription of the gene that encodes occludin.
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Affiliation(s)
- Isabelle Beau
- Faculté de Pharmacie, INSERM Unit 510, Châtenay-Malabry, France 92296
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Kitadokoro K, Kamitani S, Miyazawa M, Hanajima-Ozawa M, Fukui A, Miyake M, Horiguchi Y. Crystal structures reveal a thiol protease-like catalytic triad in the C-terminal region of Pasteurella multocida toxin. Proc Natl Acad Sci U S A 2007; 104:5139-44. [PMID: 17360394 PMCID: PMC1829276 DOI: 10.1073/pnas.0608197104] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pasteurella multocida toxin (PMT), one of the virulence factors produced by the bacteria, exerts its toxicity by up-regulating various signaling cascades downstream of the heterotrimeric GTPases Gq and G12/13 in an unknown fashion. Here, we present the crystal structure of the C-terminal region (residues 575-1,285) of PMT, which carries an intracellularly active moiety. The overall structure of C-terminal region of PMT displays a Trojan horse-like shape, composed of three domains with a "feet"-,"body"-, and "head"-type arrangement, which were designated C1, C2, and C3 from the N to the C terminus, respectively. The C1 domain, showing marked similarity in steric structure to the N-terminal domain of Clostridium difficile toxin B, was found to lead the toxin molecule to the plasma membrane. The C3 domain possesses the Cys-His-Asp catalytic triad that is organized only when the Cys is released from a disulfide bond. The steric alignment of the triad corresponded well to that of papain or other enzymes carrying Cys-His-Asp. PMT toxicities on target cells were completely abrogated when one of the amino acids constituting the triad was mutated. Our results indicate that PMT is an enzyme toxin carrying the cysteine protease-like catalytic triad dependent on the redox state and functions on the cytoplasmic face of the plasma membrane of target cells.
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Affiliation(s)
- Kengo Kitadokoro
- *Research Center for Low Temperature and Materials Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan; and
| | - Shigeki Kamitani
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
| | - Masayuki Miyazawa
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
| | - Miyuki Hanajima-Ozawa
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
| | - Aya Fukui
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
| | - Masami Miyake
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
| | - Yasuhiko Horiguchi
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
- To whom correspondence should be sent. E-mail:
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Nougayrède JP, Homburg S, Taieb F, Boury M, Brzuszkiewicz E, Gottschalk G, Buchrieser C, Hacker J, Dobrindt U, Oswald E. Escherichia coli induces DNA double-strand breaks in eukaryotic cells. Science 2006; 313:848-51. [PMID: 16902142 DOI: 10.1126/science.1127059] [Citation(s) in RCA: 730] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Transient infection of eukaryotic cells with commensal and extraintestinal pathogenic Escherichia coli of phylogenetic group B2 blocks mitosis and induces megalocytosis. This trait is linked to a widely spread genomic island that encodes giant modular nonribosomal peptide and polyketide synthases. Contact with E. coli expressing this gene cluster causes DNA double-strand breaks and activation of the DNA damage checkpoint pathway, leading to cell cycle arrest and eventually to cell death. Discovery of hybrid peptide-polyketide genotoxins in E. coli will change our view on pathogenesis and commensalism and open new biotechnological applications.
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Kouokam JC, Wai SN, Fällman M, Dobrindt U, Hacker J, Uhlin BE. Active cytotoxic necrotizing factor 1 associated with outer membrane vesicles from uropathogenic Escherichia coli. Infect Immun 2006; 74:2022-30. [PMID: 16552031 PMCID: PMC1418910 DOI: 10.1128/iai.74.4.2022-2030.2006] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cytotoxic necrotizing factor type 1 (CNF1) is one of the virulence factors produced by uropathogenic Escherichia coli (UPEC). How this toxin is translocated from the bacterial cytoplasm to the surrounding environment is not well understood. Our data suggest that CNF1 may be regarded as a secreted protein, since it could be detected in culture supernatants. Furthermore, we found that CNF1 was tightly associated to outer membrane vesicles, suggesting that such vesicles play a role in the secretion of this protein. Interestingly, vesicle samples containing CNF1 could exert the effects known for this protein on HeLa cell cultures, showing that CNF1 is transported by vesicles in its active form. Taken together, our results strongly suggest that outer membrane vesicles could be a means for the bacteria to deliver CNF1 to the environment and to the infected tissue. In addition, our results indicate that the histone-like nucleoid structuring protein H-NS has a role in the downregulation of CNF1 production and that it affects the outer membrane vesicle release in UPEC strain J96.
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Affiliation(s)
- J Clavin Kouokam
- Department of Molecular Biology, Umeå University, S-901 87 Umeå, Sweden
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Mager DL. Bacteria and cancer: cause, coincidence or cure? A review. J Transl Med 2006; 4:14. [PMID: 16566840 PMCID: PMC1479838 DOI: 10.1186/1479-5876-4-14] [Citation(s) in RCA: 176] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Accepted: 03/28/2006] [Indexed: 01/28/2023] Open
Abstract
Research has found that certain bacteria are associated with human cancers. Their role, however, is still unclear. Convincing evidence links some species to carcinogenesis while others appear promising in the diagnosis, prevention or treatment of cancers. The complex relationship between bacteria and humans is demonstrated by Helicobacter pylori and Salmonella typhi infections. Research has shown that H. pylori can cause gastric cancer or MALT lymphoma in some individuals. In contrast, exposure to H. pylori appears to reduce the risk of esophageal cancer in others. Salmonella typhi infection has been associated with the development of gallbladder cancer; however S. typhi is a promising carrier of therapeutic agents for melanoma, colon and bladder cancers. Thus bacterial species and their roles in particular cancers appear to differ among different individuals. Many species, however, share an important characteristic: highly site-specific colonization. This critical factor may lead to the development of non-invasive diagnostic tests, innovative treatments and cancer vaccines.
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Affiliation(s)
- D L Mager
- The Forsyth Institute, 140 The Fenway, Boston, MA, USA.
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Abstract
The CNF1 toxin is produced by some uropathogenic (UPECs) andmeningitis-causing Escherichia coli strains. It belongs to a large family of bacterial virulence factors and toxins modifying cellular regulators of the actin cytoskeleton, namely the Rho GTPases. CNF1 autonomously enters the host cell cytosol, where it catalyzes the constitutive activation of Rho GTPases by deamidation. This activation is, however, attenuated because of activated Rho protein ubiquitin-mediated proteasomal degradation. Both Rho protein activation and deactivation confer phagocytic properties on epithelial and endothelial cells, as well as epithelial cell motility and cell-cell junction dynamics. Transcriptome analysis using DNA microarray revealed that endothelial cells respond to high doses of CNF1 by launching a genetic program of host alarm. This host cell reaction to CNF1 intoxication also indicates that degradation of activated Rho proteins by the proteasome may lead to a lowering of the threshold of the intoxicated cell inflammatory response. These results are consistent with growing evidence that Rho proteins control the cell inflammatory responses. It is tempting to assume that Rho deregulation may participate in various immunological disorders also involved in cancer.
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Affiliation(s)
- P Munro
- Faculté de Médecine, 1/INSERM, U627, 28 Avenue de Valombrose, 06107 Nice, France
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Abstract
Many bacterial cytotoxins act on eukaryotic cells by targeting the regulators that are involved in controlling the cytoskeleton or by directly modifying actin, with members of the Rho GTPase family being particularly important targets. The actin cytoskeleton, and especially the GTPase 'molecular switches' that are involved in its control, have crucial functions in innate and adaptive immunity, and have pivotal roles in the biology of infection. In this review, we briefly discuss the role of the actin cytoskeleton and the Rho GTPases in host-pathogen interactions, and review the mode of actions of bacterial protein toxins that target these components.
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Affiliation(s)
- Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Albert-Ludwigs-Universität, Otto-Krayer-Haus, Albert-Strasse 25, D-79104 Freiburg, Germany.
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Nougayrède JP, Taieb F, De Rycke J, Oswald E. Cyclomodulins: bacterial effectors that modulate the eukaryotic cell cycle. Trends Microbiol 2005; 13:103-10. [PMID: 15737728 DOI: 10.1016/j.tim.2005.01.002] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Microbial pathogens have developed a variety of strategies to manipulate host-cell functions, presumably for their own benefit. We propose the term "cyclomodulins" to describe the growing family of bacterial toxins and effectors that interfere with the eukaryotic cell cycle. Inhibitory cyclomodulins, such as cytolethal distending toxins (CDTs) and the cycle inhibiting factor (Cif), block mitosis and might constitute powerful weapons for immune evasion by inhibiting clonal expansion of lymphocytes. Cell-cycle inhibitors might also impair epithelial-barrier integrity, allowing the entry of pathogenic bacteria into the body or prolonging their local existence by blocking the shedding of epithelia. Conversely, cyclomodulins that promote cellular proliferation, such as the cytotoxic necrotizing factor (CNF), exemplify another subversion mechanism by interfering with pathways of cell differentiation and development. The role of these cyclomodulins in bacterial virulence and carcinogenesis awaits further study and will delineate new perspectives in basic research and therapeutic applications.
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Affiliation(s)
- Jean-Philippe Nougayrède
- UMR 1225 Interactions Hôtes-Agents Pathogènes, Ecole Nationale Vétérinaire, 23 chemin des Capelles BP 87614 31076, Toulouse Cedex 3, France
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Oswald E, Nougayrède JP, Taieb F, Sugai M. Bacterial toxins that modulate host cell-cycle progression. Curr Opin Microbiol 2005; 8:83-91. [PMID: 15694861 DOI: 10.1016/j.mib.2004.12.011] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mammalian cell cycle is involved in many processes--such as immune responses, maintenance of epithelial barrier functions, and cellular differentiation--that affect the growth and colonization of pathogenic bacteria. Therefore it is not surprising that many bacterial pathogens manipulate the host cell cycle with respect to these functions. Cyclomodulins are a growing family of bacterial toxins and effectors that interfere with the eukaryotic cell cycle. Here, we review some of these cyclomodulins such as cytolethal distending toxins, vacuolating cytotoxin, the polyketide-derived macrolide mycolactone, cycle-inhibiting factor, cytotoxic necrotizing factors, dermonecrotic toxin, Pasteurella multocida toxin and cytotoxin-associated antigen A. We describe and compare their effects on the mammalian cell cycle and their putative role in disease, commensalism and symbiosis. We also discuss a possible link between these cyclomodulins and cancer.
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Affiliation(s)
- Eric Oswald
- UMR1225 "Interactions Hôtes-Agents Pathogènes", Ecole Nationale Vétérinaire, 23 chemin des Capelles, 31076 Toulouse, France.
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Munro P, Flatau G, Anjuère F, Hofman V, Czerkinsky C, Lemichez E. The Rho GTPase activators CNF1 and DNT bacterial toxins have mucosal adjuvant properties. Vaccine 2005; 23:2551-6. [PMID: 15780436 DOI: 10.1016/j.vaccine.2004.11.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2004] [Revised: 10/12/2004] [Accepted: 11/11/2004] [Indexed: 10/26/2022]
Abstract
Cytotoxic necrotizing factor 1 (CNF1) from uropathogenic Escherichia coli belongs to a family of factors activating Rho GTPases. We report the in vivo effects of CNF1 in mice co-fed toxin and the soluble protein antigen ovalbumin (OVA). Similar to cholera toxin, CNF1 elicits adjuvanticity anti-OVA responses, both systemic and mucosal. In contrast, the catalytic inactive mutant CNF1-C866S demonstrated no effects. Using dermonecrotic toxin (DNT), a closely related Rho activating toxin from Bordetella, we discovered that the adjuvant property is within the DNT catalytic domain. Manipulation of Rho proteins thus provides a possible new approach for the development of effective mucosal immunoadjuvants.
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Affiliation(s)
- Patrick Munro
- INSERM, U627, Faculté de Médecine, 28 Avenue de Valombrose, F-06107 Nice Cedex 2, France
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Chapter 8 Adhesins and receptors for colonization by different pathotypes of Escherichia coli in calves and young pigs. MICROBIAL ECOLOGY IN GROWING ANIMALS 2005. [PMCID: PMC7148974 DOI: 10.1016/s1877-1823(09)70041-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This chapter provides an overview of the virulence factors and their genetic regulators in Escherichia coli. The most important adhesins and their receptors playing a role in the pathogenesis of different pathotypes of enteric E. coli are also described. The main pathotypes involved in enteric colibacillosis of pigs and calves are the enterotoxigenic E. coli (ETEC), verotoxigenic E. coli (VTEC), enteropathogenic E. coli (EPEC), and necrotoxigenic E. coli (NTEC). Adhesion and colonization are the first (but not the only) functional prerequisites for a mucosal bacterium to be pathogenic. The adhesins represent surface proteins, governed by specific operons and constructed in ways according to the particular adhesin. Besides their structure, the adhesins can also be grouped according to their receptors present on the intestinal mucosal epithelium and on the urinary epithelium. Apart from direct practical applications, there are further significant scientific developments and applications expected in the area of neonatal biology and comparative human pathobacteriology.
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Cytotoxic Necrotizing Factors: Rho-Activating Toxins from Escherichia coli. EcoSal Plus 2004; 1. [PMID: 26443355 DOI: 10.1128/ecosalplus.8.7.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This article reviews the Escherichia coli toxins called cytotoxic necrotizing factors (CNFs), which cause activation of Rho GTPases. It describes their modes of action, structure-function relationships, and roles in disease. Rho GTPases, the targets of CNFs, belong to the Ras superfamily of low molecular mass GTPases and act as molecular switches in various signaling pathways. Low molecular mass GTPases of the Rho family are known as master regulators of the actin cytoskeleton. Moreover, they are involved in various signal transduction processes, from transcriptional activation, cell cycle progression, and cell transformation to apoptosis. CNFs are cytotoxic for a wide variety of cells, including 3T3 fibroblasts, Chinese hamster ovary cells, Vero cells, HeLa cells, and cell lines of neuronal origin. This implies that a commonly expressed receptor is responsible for the uptake of CNF1. Cultured mammalian cells treated with CNFs are characterized by dramatic changes in actin-containing structures, including stress fibers, lamellipodia, and filopodia. Most striking is the formation of multinucleation in these cells. Rho GTPases are increasingly recognized as essential factors in the development of cancer and metastasis. This fact has initiated a discussion as to whether activation of Rho proteins by CNFs might be involved in tumorigenesis. Moreover, CNF1 increases the expression of the cyclooxygenase 2 (Cox2) gene in fibroblasts. Increased expression of Cox2 is observed in some types of tumors, e.g., colon carcinoma. Lipid-mediators produced by the enzyme are suggested to be responsible for tumor progression.
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Abstract
The actin cytoskeleton of mammalian cells is involved in many processes that affect the growth and colonization of bacteria, such as migration of immune cells, phagocytosis by macrophages, secretion of cytokines, maintenance of epithelial barrier functions and others. With respect to these functions, it is not surprising that many bacterial protein toxins, which are important virulence factors and causative agents of human and/or animal diseases, target the actin cytoskeleton of the host. Some toxins target actin directly, such as the C2 toxin produced by Clostridium botulinum. Moreover, bacterial toxins target the cytoskeleton indirectly by modifying actin regulators such as the low-molecular-mass guanosine triphosphate (GTP)-binding proteins of the Rho family. Remarkably, toxins affect these GTPases in a bidirectional manner. Some toxins inhibit and some activate the GTPases. Here we review the Rho-activating toxins CNF1 and CNF2 (cytotoxic necrotizing factors) from Escherichia coli, the Yersinia CNF(Y) and the dermonecrotic toxin (DNT) from Bordetella species. We describe and compare their uptake into mammalian cells, mode of action, structure-function relationship, substrate specificity and role in diseases.
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Affiliation(s)
- C Hoffmann
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Albert-Ludwigs-Universität Freiburg, Albert-Str. 25, 79104, Freiburg, Germany
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Horne SM, Goplin JL, Giddings CW, Dyer NW, Nolan LK. Cloning and sequencing of cnf1 from Escherichia coli incriminated in mink and bovine colibacillosis. Vet Res Commun 2004; 28:103-12. [PMID: 14992240 DOI: 10.1023/b:verc.0000012109.68007.1e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Colibacillosis is responsible for significant losses to the mink and cattle industries. Previous work in our laboratory and by others has suggested that possession of cnf1, the gene encoding cytotoxic necrotizing factor (CNF1), may contribute to the virulence of isolates of E. coli from mink and cattle. The cnf1 gene from E. coli isolated from a mink with colisepticaemia and a bovid with scours was amplified and cloned as a 3.5 kb fragment, and the fragment was sequenced. The cnf1 sequences from the mink and bovine isolates of E. coli were compared to each other and to cnf1 sequences of E. coli from urinary tract and diarrhoea-associated infections of humans. The difference was only 7 nucleotides between the cnf1 sequences of the mink and bovine isolates of E. coli, which translated into 7 differences in amino acids. The cnf1 sequence of the mink isolate of E. coli had 15 nucleotide differences from the cnf1 sequences of the human isolate of E. coli (GenBank X70670), which translated into 11 differences in amino acids between these proteins. The cnf1 sequence of the bovine isolate of E. coli had 14 nucleotide differences from the cnf1 sequence of the human isolate of E. coli (GenBank X70670), which translated into 10 differences in amino acids between these proteins. The highly conserved sequences of the amino acids of CNF1 proteins make them a promising target for detection and control of the CNF1-producing E. coli involved in disease among various host species.
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Affiliation(s)
- S M Horne
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, ND 58105, USA
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Van Bost S, Roels S, Oswald E, Mainil J. Putative roles of the CNF2 and CDTIII toxins in experimental infections with necrotoxigenic Escherichia coli type 2 (NTEC2) strains in calves. Microbes Infect 2004; 5:1189-93. [PMID: 14623014 PMCID: PMC7129549 DOI: 10.1016/j.micinf.2003.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Newborn colostrum-restricted calves were orally inoculated with an Escherichia coli strain, identified originally as non-pathogenic, and into which the plasmid pVir was conjugally transferred. This resulted in diarrhea, intestinal lesions and extra-intestinal invasion, suggesting that factors affecting these pathogenic properties are located on pVir. In order to analyze the respective roles of the toxins CNF2 and CDTIII in the pathogenesis, colostrum-restricted calves were inoculated with isogenic mutants in the cnf2 and the cdt-III genes. The loss of cnf2 is associated with a reduction in the pathogenicity, since diarrhea does not occur in calves challenged, in spite of successful colonization of the intestine. Nevertheless, the mutant strain remains able to invade the bloodstream and to localize in the internal organs. Conversely, the calves inoculated with mutant in the cdt-III gene evolved in the same way as wild-type strain-inoculated calves with regard to clinical signs and macroscopic or microscopic lesions.
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Affiliation(s)
- Sigrid Van Bost
- Laboratory of Bacteriology, Faculty of Veterinary Medicine, University of Liège, Sart-Tilman, B43a, 20, bd de Colonster, B-4000 Liege, Belgium.
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Essler M, Linder S, Schell B, Hüfner K, Wiedemann A, Randhahn K, Staddon JM, Aepfelbacher M. Cytotoxic necrotizing factor 1 of Escherichia coli stimulates Rho/Rho-kinase-dependent myosin light-chain phosphorylation without inactivating myosin light-chain phosphatase in endothelial cells. Infect Immun 2003; 71:5188-93. [PMID: 12933863 PMCID: PMC187342 DOI: 10.1128/iai.71.9.5188-5193.2003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2003] [Revised: 05/13/2003] [Accepted: 05/28/2003] [Indexed: 11/20/2022] Open
Abstract
Cytotoxic necrotizing factor 1 (CNF-1) is an exotoxin of Escherichia coli that constitutively activates the GTPases Rho, Rac, and CDC42. Stimulation of Rho was shown to enhance myosin light-chain (MLC) phosphorylation via Rho kinase-mediated inhibition of MLC phosphatase in endothelial cells. Here we report that 3 h after CNF stimulation of endothelial cells, RhoA was activated and MLC phosphorylation was increased in a Rho/Rho-kinase-dependent manner, but no decrease in MLC phosphatase activity could be detected. Despite continuous RhoA activation, MLC phosphatase activity was doubled after 24 h of CNF stimulation, and this coincided with decreased MLC phosphorylation and cell spreading. Rac was also activated at 3 to 24 h but did not contribute to MLC phosphorylation, and its amount gradually decreased in the CNF-stimulated cells. CDC42Hs was not activated above control values by CNF. These results suggest that CNF can induce specific decoupling (Rho kinase from MLC phosphatase) and deactivation events in Rho GTPase signaling, potentially reflecting cellular protection mechanisms against permanently active Rho GTPases.
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Affiliation(s)
- Markus Essler
- Institut für Prophylaxe und Epidemiologie der Kreislaufkrankheiten, LMU München, 80336 Munich, Germany
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50
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Van Bost S, Jacquemin E, Oswald E, Mainil J. Multiplex PCRs for identification of necrotoxigenic Escherichia coli. J Clin Microbiol 2003; 41:4480-2. [PMID: 12958300 PMCID: PMC193843 DOI: 10.1128/jcm.41.9.4480-4482.2003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two multiplex PCRs were developed for the detection of necrotoxigenic Escherichia coli virulence genes. M1 contained the primers for the toxins and the aerobactin, and M2 contained the primers for the adhesins. They were validated by single PCRs performed with reference E. coli strains and by multiplex PCRs with necrotoxigenic E. coli strains isolated from different animal species.
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Affiliation(s)
- Sigrid Van Bost
- University of Liège, Faculty of Veterinary Medicine, Laboratory of Bacteriology, Sart-Tilman B43a, B-4000 Liège, Belgium.
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