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Sheikh A, Ganguli D, Vickers TJ, Singer BB, Foulke-Abel J, Akhtar M, Khatoon N, Setu B, Basu S, Harro C, Maier N, Beatty WL, Chakraborty S, Bhuiyan TR, Qadri F, Donowitz M, Fleckenstein JM. Host-derived CEACAM-laden vesicles engage enterotoxigenic Escherichia coli for elimination and toxin neutralization. Proc Natl Acad Sci U S A 2024; 121:e2410679121. [PMID: 39264739 PMCID: PMC11420188 DOI: 10.1073/pnas.2410679121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 08/10/2024] [Indexed: 09/14/2024] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) cause hundreds of millions of diarrheal illnesses annually ranging from mildly symptomatic cases to severe, life-threatening cholera-like diarrhea. Although ETEC are associated with long-term sequelae including malnutrition, the acute diarrheal illness is largely self-limited. Recent studies indicate that in addition to causing diarrhea, the ETEC heat-labile toxin (LT) modulates the expression of many genes in intestinal epithelia, including carcinoembryonic cell adhesion molecules (CEACAMs) which ETEC exploit as receptors, enabling toxin delivery. Here, however, we demonstrate that LT also enhances the expression of CEACAMs on extracellular vesicles (EV) shed by intestinal epithelia and that CEACAM-laden EV increase in abundance during human infections, mitigate pathogen-host interactions, scavenge free ETEC toxins, and accelerate ETEC clearance from the gastrointestinal tract. Collectively, these findings indicate that CEACAMs play a multifaceted role in ETEC pathogen-host interactions, transiently favoring the pathogen, but ultimately contributing to innate responses that extinguish these common infections.
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Affiliation(s)
- Alaullah Sheikh
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, MO63110
| | - Debayan Ganguli
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, MO63110
| | - Tim J. Vickers
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, MO63110
| | - Bernhard B. Singer
- Institute of Anatomy, Medical Faculty, University of Duisburg-Essen, 45147Essen, Germany
| | - Jennifer Foulke-Abel
- Division of Gastroenterology & Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD21287
| | - Marjahan Akhtar
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, MO63110
- Enteric and Respiratory. Infections, Infectious Disease Division, International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka1212, Bangladesh
| | - Nazia Khatoon
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, MO63110
| | - Bipul Setu
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, MO63110
| | - Supratim Basu
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, MO63110
| | - Clayton Harro
- Division of Global Disease Epidemiology and Control with the Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD21205
| | - Nicole Maier
- Center for Vaccine Innovation and Access, PATH, Seattle, WA98121
| | - Wandy L. Beatty
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO63110
| | - Subhra Chakraborty
- Division of Global Disease Epidemiology and Control with the Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD21205
| | - Taufiqur R. Bhuiyan
- Enteric and Respiratory. Infections, Infectious Disease Division, International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka1212, Bangladesh
| | - Firdausi Qadri
- Enteric and Respiratory. Infections, Infectious Disease Division, International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka1212, Bangladesh
| | - Mark Donowitz
- Division of Gastroenterology & Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD21287
| | - James M. Fleckenstein
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, MO63110
- Medicine Service, Infectious Disease Section, Veterans Affairs Health Care System, Saint Louis, MO63106
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2
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Sheikh A, Ganguli D, Vickers TJ, Singer B, Foulke-Abel J, Akhtar M, Khatoon N, Setu B, Basu S, Harro C, Maier N, Beatty WL, Chakraborty S, Bhuiyan TR, Qadri F, Donowitz M, Fleckenstein JM. Host-derived CEACAM-laden vesicles engage enterotoxigenic E. coli for elimination and toxin neutralization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.24.604983. [PMID: 39091797 PMCID: PMC11291149 DOI: 10.1101/2024.07.24.604983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Enterotoxigenic Escherichia coli (ETEC) cause hundreds of millions of diarrheal illnesses annually ranging from mildly symptomatic cases to severe, life-threatening cholera-like diarrhea. Although ETEC are associated with long-term sequelae including malnutrition, the acute diarrheal illness is largely self-limited. Recent studies indicate that in addition to causing diarrhea, the ETEC heat-labile toxin (LT) modulates the expression of many genes in intestinal epithelia, including carcinoembryonic cell adhesion molecules (CEACAMs) which ETEC exploit as receptors, enabling toxin delivery. Here however, we demonstrate that LT also enhances the expression of CEACAMs on extracellular vesicles (EV) shed by intestinal epithelia and that CEACAM-laden EV increase in abundance during human infections, mitigate pathogen-host interactions, scavenge free ETEC toxins, and accelerate ETEC clearance from the gastrointestinal tract. Collectively, these findings indicate that CEACAMs play a multifaceted role in ETEC pathogen-host interactions, transiently favoring the pathogen, but ultimately contributing to innate responses that extinguish these common infections.
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Affiliation(s)
- Alaullah Sheikh
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Debayan Ganguli
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Tim J. Vickers
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Bernhard Singer
- Institute of Anatomy, Medical Faculty, University of Suisberg-Essen, 45147 Essen, Germany
| | - Jennifer Foulke-Abel
- Division of Gastroenterology & Hepatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Marjahan Akhtar
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
- International Centre for Diarrhoeal Disease Research, Bangladesh; Dhaka, Bangladesh
| | - Nazia Khatoon
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Bipul Setu
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Supratim Basu
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Clayton Harro
- Department of International Health, Division of Global Disease Epidemiology and Control, Johns Hopkins Bloomberg School of Public Health
| | | | - Wandy L. Beatty
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Subhra Chakraborty
- Department of International Health, Division of Global Disease Epidemiology and Control, Johns Hopkins Bloomberg School of Public Health
| | - Tafiqur R. Bhuiyan
- International Centre for Diarrhoeal Disease Research, Bangladesh; Dhaka, Bangladesh
| | - Firdausi Qadri
- International Centre for Diarrhoeal Disease Research, Bangladesh; Dhaka, Bangladesh
| | - Mark Donowitz
- Division of Gastroenterology & Hepatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - James M. Fleckenstein
- Division of Infectious Diseases, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
- Medicine Service, Infectious Disease Section, Veterans Affairs Health Care System, Saint Louis, Missouri, USA
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3
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Singh KKB, Salleh MZ, Ahmed N, Yean Yean C, Ismail A. Identification and analysis of immunoreactive proteins of Shigella flexneri in human sera and stool specimens. PeerJ 2024; 12:e17498. [PMID: 38827305 PMCID: PMC11141557 DOI: 10.7717/peerj.17498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 05/10/2024] [Indexed: 06/04/2024] Open
Abstract
Background The method currently available to diagnose shigellosis is insensitive and has many limitations. Thus, this study was designed to identify specific antigenic protein(s) among the cell surface associated proteins (SAPs) of Shigella that would be valuable in the development of an alternative diagnostic assay for shigellosis, particularly one that could be run using a stool sample rather than serum. Methods The SAPs of clinical isolates of S. dysenteriae, S. boydii, Shigella flexneri, and S. sonnei were extracted from an overnight culture grown at 37 °C using acidified-glycine extraction methods. Protein profiles were observed by SDS-PAGE. To determine if antibodies specific to certain Shigella SAPs were present in both sera and stool suspensions, Western blot analysis was used to detect the presence of IgA, IgG, and IgM. Results Immunoblot analysis revealed that sera from patients infected with S. flexneri recognized 31 proteins. These SAP antigens are recognized by the host humoral response during Shigella infection. Specific antibodies against these antigens were also observed in intestinal secretions of shigellosis patients. Of these 31 S. flexneri proteins, the 35 kDa protein specifically reacted against IgA present in patients' stool suspensions. Further study illustrated the immunoreactivity of this protein in S. dysenteriae, S. boydii, and S. sonnei. This is the first report that demonstrates the presence of immunoreactive Shigella SAPs in stool suspensions. The SAPSs could be very useful in developing a simple and rapid serodiagnostic assay for shigellosis directly from stool specimens.
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Affiliation(s)
- Kirnpal Kaur Banga Singh
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Mohd Zaki Salleh
- Integrative Pharmacogenomics Institute (iPROMISE), UiTM Puncak Alam Campus, Bandar Puncak Alam, Puncak Alam, Selangor, Malaysia
| | - Naveed Ahmed
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Chan Yean Yean
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Asma Ismail
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
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Wu Z, Liu H, Wang X. Advancements in understanding bacterial enteritis pathogenesis through organoids. Mol Biol Rep 2024; 51:512. [PMID: 38622483 DOI: 10.1007/s11033-024-09495-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Bacterial enteritis has a substantial role in contributing to a large portion of the global disease burden and serves as a major cause of newborn mortality. Despite advancements gained from current animal and cell models in improving our understanding of pathogens, their widespread application is hindered by apparent drawbacks. Therefore, more precise models are imperatively required to develop more accurate studies on host-pathogen interactions and drug discovery. Since the emergence of intestinal organoids, massive studies utilizing organoids have been conducted to study the pathogenesis of bacterial enteritis, revealing new mechanisms and validating established ones. In this review, we focus on the advancements of several bacterial pathogenesis mechanisms observed in intestinal organoid/enteroid models, exploring the host response and bacterial effectors during the infection process. Finally, we address the features that warrant additional investigation or could be enhanced in existing organoid models in order to guide future research endeavors.
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Affiliation(s)
- Zhengyang Wu
- Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Hongyuan Liu
- Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Xianli Wang
- Shanghai Jiao Tong University School of Public Health, Shanghai, 200025, China.
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Candeliere F, Musmeci E, Sola L, Amaretti A, Raimondi S, Rossi M. Genomic and functional analysis of the mucinolytic species Clostridium celatum, Clostridium tertium, and Paraclostridium bifermentans. Front Microbiol 2024; 15:1359726. [PMID: 38511005 PMCID: PMC10952124 DOI: 10.3389/fmicb.2024.1359726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/28/2024] [Indexed: 03/22/2024] Open
Abstract
Mucins are large glycoproteins whose degradation requires the expression of several glycosil hydrolases to catalyze the cleavage of the oligosaccharide chains and release monosaccharides that can be assimilated. In this study, we present a characterization on the strains Clostridium celatum WC0700, Clostridium tertium WC0709, and Paraclostridium bifermentans WC0705. These three strains were previously isolated from enrichment cultures on mucin of fecal samples from healthy subjects and can use mucin as sole carbon and nitrogen source. Genome analysis and in vitro functional analysis of these strains elucidated their physiological and biochemical features. C. celatum WC0700 harbored the highest number of glycosyl hydrolases specific for mucin degradation, while P. bifermentans WC0705 had the least. These predicted differences were confirmed growing the strains on 5 mucin-decorating monosaccharides (L-fucose, N-Acetylneuraminic acid, galactose, N-acetylgalactosamine, and N-acetylglucosamine) as only source of carbon. Fermenting mucin, they all produced formic, acetic, propionic, butyric, isovaleric, and lactic acids, and ethanol; acetic acid was the main primary metabolite. Further catabolic capabilities were investigated, as well as antibiotic susceptibility, biofilm formation, tolerance to oxygen and temperature. The potential pathogenicity of the strains was evaluated through in silico research of virulence factors. The merge between comparative and functional genomics and biochemical/physiological characterization provided a comprehensive view of these mucin degraders, reassuring on the safety of these species and leaving ample scope for deeper investigations on the relationship with the host and for assessing if some relevant health-promoting effect could be ascribed to these SCFA producing species.
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Affiliation(s)
- Francesco Candeliere
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Eliana Musmeci
- Department of Civil, Chemical, Environmental and Material Engineering (DICAM), Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Laura Sola
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Alberto Amaretti
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Biogest Siteia, University of Modena and Reggio Emilia, Reggio Emilia, Italy
| | - Stefano Raimondi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Biogest Siteia, University of Modena and Reggio Emilia, Reggio Emilia, Italy
| | - Maddalena Rossi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Biogest Siteia, University of Modena and Reggio Emilia, Reggio Emilia, Italy
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Berberolli S, Wu M, Goycoolea FM. The Rosetta Stone of interactions of mucosa and associated bacteria in the gastrointestinal tract. Curr Opin Gastroenterol 2024; 40:1-6. [PMID: 37983559 PMCID: PMC10715687 DOI: 10.1097/mog.0000000000000992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
PURPOSE OF REVIEW Gut microbiota-mucosa-epithelial cells co-exist in an intricate three-way relationship that underpins gut homeostasis, and ultimately influences health and disease conditions. The O-glycans of mucin glycoproteins have been uncovered as a centrepiece of this system, although understanding the phenomena at play at the molecular level has been challenging and subject to significant traction over the last years. The purpose of this review is to discuss the recent advances in the phenomena that mediate microbiota and mucus multidirectional interactions in the human gut. RECENT FINDINGS The mucus biosynthesis and degradation by both commensal and pathogenic bacteria is under tight regulation and involves hundreds of carbohydrate-active enzymes (CAZy) and transporters. The fucosylation of O-glycans from mucin-2 seems to dictate binding by pathogenic species and to influence their virulence. Less clear is the influence of O-glycans in quorum sensing and biofilm formation. We have reviewed the advances in the in vitro models available to recreate the phenomena that capture the physiological context of the intestinal environment, emphasising models that include mucus and other aspects relevant to the physiological context. SUMMARY The recent findings highlight the importance of merging advances in analytical (glycans analysis) and omics techniques along with original robust in vitro models that enable to deconstruct part of the high complexity of the living gut and expand our understanding of the microbes-mucosa relationships and their significance in health and disease.
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Affiliation(s)
- Serena Berberolli
- School of Food Science and Nutrition, University of Leeds. Leeds, LS6 4RG, United Kingdom
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7
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Zha X, Su S, Wu D, Zhang P, Wei Y, Fan S, Huang Q, Peng X. The impact of gut microbiota changes on the intestinal mucus barrier in burned mice: a study using 16S rRNA and metagenomic sequencing. BURNS & TRAUMA 2023; 11:tkad056. [PMID: 38130728 PMCID: PMC10734567 DOI: 10.1093/burnst/tkad056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/29/2023] [Accepted: 11/06/2023] [Indexed: 12/23/2023]
Abstract
Background The gut microbiota is a complex ecosystem that plays a critical role in human health and disease. However, the relationship between gut microbiota and intestinal damage caused by burns is not well understood. The intestinal mucus layer is crucial for maintaining intestinal homeostasis and providing a physiological barrier against bacterial invasion. This study aims to investigate the impact of gut microbiota on the synthesis and degradation of intestinal mucus after burns and explore potential therapeutic targets for burn injury. Methods A modified histopathological grading system was employed to investigate the effects of burn injury on colon tissue and the intestinal mucus barrier in mice. Subsequently, 16S ribosomal RNA sequencing was used to analyze alterations in the gut microbiota at days 1-10 post-burn. Based on this, metagenomic sequencing was conducted on samples collected at days 1, 5 and 10 to investigate changes in mucus-related microbiota and explore potential underlying mechanisms. Results Our findings showed that the mucus barrier was disrupted and that bacterial translocation occurred on day 3 following burn injury in mice. Moreover, the gut microbiota in mice was significantly disrupted from days 1 to 3 following burn injury, but gradually recovered to normal as the disease progressed. Specifically, there was a marked increase in the abundance of symbiotic and pathogenic bacteria associated with mucin degradation on day 1 after burns, but the abundance returned to normal on day 5. Conversely, the abundance of probiotic bacteria associated with mucin synthesis changed in the opposite direction. Further analysis revealed that after a burn injury, bacteria capable of degrading mucus may utilize glycoside hydrolases, flagella and internalins to break down the mucus layer, while bacteria that synthesize mucus may help restore the mucus layer by promoting the production of short-chain fatty acids. Conclusions Burn injury leads to disruption of colonic mucus barrier and dysbiosis of gut microbiota. Some commensal and pathogenic bacteria may participate in mucin degradation via glycoside hydrolases, flagella, internalins, etc. Probiotics may provide short-chain fatty acids (particularly butyrate) as an energy source for stressed intestinal epithelial cells, promote mucin synthesis and accelerate repair of mucus layer.
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Affiliation(s)
- Xule Zha
- Clinical Medical Research Center, Southwest Hospital, Third Military Medical University (Army Medical University), Gaotanyan Street, Shapingba District, Chongqing, 400038, China
| | - Sen Su
- Clinical Medical Research Center, Southwest Hospital, Third Military Medical University (Army Medical University), Gaotanyan Street, Shapingba District, Chongqing, 400038, China
| | - Dan Wu
- Clinical Medical Research Center, Southwest Hospital, Third Military Medical University (Army Medical University), Gaotanyan Street, Shapingba District, Chongqing, 400038, China
| | - Panyang Zhang
- Clinical Medical Research Center, Southwest Hospital, Third Military Medical University (Army Medical University), Gaotanyan Street, Shapingba District, Chongqing, 400038, China
| | - Yan Wei
- Clinical Medical Research Center, Southwest Hospital, Third Military Medical University (Army Medical University), Gaotanyan Street, Shapingba District, Chongqing, 400038, China
| | - Shijun Fan
- Clinical Medical Research Center, Southwest Hospital, Third Military Medical University (Army Medical University), Gaotanyan Street, Shapingba District, Chongqing, 400038, China
| | - Qianying Huang
- Clinical Medical Research Center, Southwest Hospital, Third Military Medical University (Army Medical University), Gaotanyan Street, Shapingba District, Chongqing, 400038, China
| | - Xi Peng
- Clinical Medical Research Center, Southwest Hospital, Third Military Medical University (Army Medical University), Gaotanyan Street, Shapingba District, Chongqing, 400038, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China
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8
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Smith EM, Papadimas A, Gabor C, Cooney C, Wu T, Rasko D, Barry EM. The role of the minor colonization factor CS14 in adherence to intestinal cell models by geographically diverse ETEC isolates. mSphere 2023; 8:e0030223. [PMID: 37787523 PMCID: PMC10597352 DOI: 10.1128/msphere.00302-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/15/2023] [Indexed: 10/04/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a primary causative agent of diarrhea in travelers and young children in low- to middle-income countries. ETEC adheres to small intestinal epithelia via colonization factors (CFs) and secretes heat-stable toxin and/or heat-labile toxin, causing dysregulated ion transport and water secretion. There are over 30 CFs identified, including major CFs associated with moderate-to-severe diarrhea (MSD) and minor CFs for which a role in pathogenesis is less clear. The Global Enteric Multicenter Study identified CS14, a class 5a fimbriae, as the only minor CF significantly associated with MSD and was recommended for inclusion in ETEC vaccines. Despite detection of CS14 in ETEC isolates, the sequence conservation of the CS14 operon, its role in adherence, and functional cross-reactivity to other class 5a fimbriae like CFA/I and CS4 are not understood. Sequence analysis determined that the CS14 operon is >99.9% identical among seven geographically diverse isolates with expanded sequence analysis demonstrating SNPs exclusively in the gene encoding the tip adhesin CsuD. Western blots and electron microscopy demonstrated that CS14 expression required the growth of isolates on CFA agar with the iron chelator deferoxamine mesylate. CS14 expression resulted in significantly increased adherence to cultured intestinal cells and human enteroids. Anti-CS14 antibodies and anti-CS4 antibodies, but not anti-CFA/I antibodies, inhibited the adherence of a subset of ETEC isolates, demonstrating CS14-specific inhibition with partial cross-reactivity within the class 5a fimbrial family. These data provide support for CS14 as an important fimbrial CF and its consideration as a vaccine antigen in future strategies. IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) infection causes profuse watery diarrhea in adults and children in low- to middle-income countries and is a leading cause of traveler's diarrhea. Despite increased use of rehydration therapies, young children especially can suffer long-term effects including gastrointestinal dysfunction as well as stunting and malnutrition. As there is no licensed vaccine for ETEC, there remains a need to identify and understand specific antigens for inclusion in vaccine strategies. This study investigated one adhesin named CS14. This adhesin is expressed on the bacterial surface of ETEC isolates and was recently recognized for its significant association with diarrheal disease. We demonstrated that CS14 plays a role in bacterial adhesion to human target cells, a critical first step in the disease process, and that adherence could be blocked by CS14-specific antibodies. This work will significantly impact the ETEC field by supporting inclusion of CS14 as an antigen for ETEC vaccines.
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Affiliation(s)
- Emily M. Smith
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Antonia Papadimas
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Caitlin Gabor
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ceanna Cooney
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Tao Wu
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - David Rasko
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Eileen M. Barry
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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9
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Svennerholm AM, Lundgren A. Developments in oral enterotoxigenic Escherichia coli vaccines. Curr Opin Immunol 2023; 84:102372. [PMID: 37523966 DOI: 10.1016/j.coi.2023.102372] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 06/11/2023] [Accepted: 07/04/2023] [Indexed: 08/02/2023]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrhea in children in developing countries and in travelers. WHO has affirmed ETEC as a priority vaccine target, but there is no licensed ETEC vaccine available yet. We here describe recent, promising developments of different live, inactivated, and subunit ETEC candidate vaccines expressing or containing nontoxic enterotoxin and/or colonization factor antigens with a focus on oral vaccines. Many of the ETEC candidate vaccines have been tested in clinical trials for safety and immunogenicity and some of them also for protective efficacy in field trials or in challenge studies.
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Affiliation(s)
- Ann-Mari Svennerholm
- Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden.
| | - Anna Lundgren
- Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden
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10
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Luis AS, Hansson GC. Intestinal mucus and their glycans: A habitat for thriving microbiota. Cell Host Microbe 2023; 31:1087-1100. [PMID: 37442097 PMCID: PMC10348403 DOI: 10.1016/j.chom.2023.05.026] [Citation(s) in RCA: 40] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/07/2023] [Accepted: 05/23/2023] [Indexed: 07/15/2023]
Abstract
The colon mucus layer is organized with an inner colon mucus layer that is impenetrable to bacteria and an outer mucus layer that is expanded to allow microbiota colonization. A major component of mucus is MUC2, a glycoprotein that is extensively decorated, especially with O-glycans. In the intestine, goblet cells are specialized in controlling glycosylation and making mucus. Some microbiota members are known to encode multiple proteins that are predicted to bind and/or cleave mucin glycans. The interactions between commensal microbiota and host mucins drive intestinal colonization, while at the same time, the microbiota can utilize the glycans on mucins and affect the colonic mucus properties. This review will examine this interaction between commensal microbes and intestinal mucins and discuss how this interplay affects health and disease.
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Affiliation(s)
- Ana S Luis
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Gunnar C Hansson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 405 30 Gothenburg, Sweden.
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11
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Genomic diversity of non-diarrheagenic fecal Escherichia coli from children in sub-Saharan Africa and south Asia and their relatedness to diarrheagenic E. coli. Nat Commun 2023; 14:1400. [PMID: 36918537 PMCID: PMC10011798 DOI: 10.1038/s41467-023-36337-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 01/23/2023] [Indexed: 03/16/2023] Open
Abstract
Escherichia coli is a frequent member of the healthy human gastrointestinal microbiota, as well as an important human pathogen. Previous studies have focused on the genomic diversity of the pathogenic E. coli and much remains unknown about the non-diarrheagenic E. coli residing in the human gut, particularly among young children in low and middle income countries. Also, gaining additional insight into non-diarrheagenic E. coli is important for understanding gut health as non-diarrheagenic E. coli can prevent infection by diarrheagenic bacteria. In this study we examine the genomic diversity of non-diarrheagenic fecal E. coli from male and female children with or without diarrhea from countries in sub-Saharan Africa and south Asia as part of the Global Enteric Multicenter Study (GEMS). We find that these E. coli exhibit considerable genetic diversity as they were identified in all E. coli phylogroups and an Escherichia cryptic clade. Although these fecal E. coli lack the characteristic virulence factors of diarrheagenic E. coli pathotypes, many exhibit remarkable genomic similarity to previously described diarrheagenic isolates with differences attributed to mobile elements. This raises an important question of whether these non-diarrheagenic fecal E. coli may have at one time possessed the mobile element-encoded virulence factors of diarrheagenic pathotypes or may have the potential to acquire these virulence factors.
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Sheikh A, Tumala B, Vickers TJ, Martin JC, Rosa BA, Sabui S, Basu S, Simoes RD, Mitreva M, Storer C, Tyksen E, Head RD, Beatty W, Said HM, Fleckenstein JM. Enterotoxigenic Escherichia coli heat-labile toxin drives enteropathic changes in small intestinal epithelia. Nat Commun 2022; 13:6886. [PMID: 36371425 PMCID: PMC9653437 DOI: 10.1038/s41467-022-34687-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 11/01/2022] [Indexed: 11/14/2022] Open
Abstract
Enterotoxigenic E. coli (ETEC) produce heat-labile (LT) and/or heat-stable (ST) enterotoxins, and commonly cause diarrhea in resource-poor regions. ETEC have been linked repeatedly to sequelae in children including enteropathy, malnutrition, and growth impairment. Although cellular actions of ETEC enterotoxins leading to diarrhea are well-established, their contributions to sequelae remain unclear. LT increases cellular cAMP to activate protein kinase A (PKA) that phosphorylates ion channels driving intestinal export of salt and water resulting in diarrhea. As PKA also modulates transcription of many genes, we interrogated transcriptional profiles of LT-treated intestinal epithelia. Here we show that LT significantly alters intestinal epithelial gene expression directing biogenesis of the brush border, the major site for nutrient absorption, suppresses transcription factors HNF4 and SMAD4 critical to enterocyte differentiation, and profoundly disrupts microvillus architecture and essential nutrient transport. In addition, ETEC-challenged neonatal mice exhibit substantial brush border derangement that is prevented by maternal vaccination with LT. Finally, mice repeatedly challenged with toxigenic ETEC exhibit impaired growth recapitulating the multiplicative impact of recurring ETEC infections in children. These findings highlight impacts of ETEC enterotoxins beyond acute diarrheal illness and may inform approaches to prevent major sequelae of these common infections including malnutrition that impact millions of children.
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Affiliation(s)
- Alaullah Sheikh
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Brunda Tumala
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Tim J Vickers
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - John C Martin
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Bruce A Rosa
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Subrata Sabui
- Departments of Medicine and Physiology/Biophysics, School of Medicine, University of California-Irvine, Irvine, CA, 92697, USA
- Department of Research, VA Medical Center, Long Beach, CA, 90822, USA
| | - Supratim Basu
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Rita D Simoes
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Makedonka Mitreva
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Chad Storer
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Erik Tyksen
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Richard D Head
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Wandy Beatty
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Hamid M Said
- Departments of Medicine and Physiology/Biophysics, School of Medicine, University of California-Irvine, Irvine, CA, 92697, USA
- Department of Research, VA Medical Center, Long Beach, CA, 90822, USA
| | - James M Fleckenstein
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Infectious Diseases, Medicine Service, Veterans Affairs Saint Louis Health Care System, Saint Louis, MO, 63106, USA.
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Sauvaitre T, Van Landuyt J, Durif C, Roussel C, Sivignon A, Chalancon S, Uriot O, Van Herreweghen F, Van de Wiele T, Etienne-Mesmin L, Blanquet-Diot S. Role of mucus-bacteria interactions in Enterotoxigenic Escherichia coli (ETEC) H10407 virulence and interplay with human microbiome. NPJ Biofilms Microbiomes 2022; 8:86. [PMID: 36266277 PMCID: PMC9584927 DOI: 10.1038/s41522-022-00344-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 10/04/2022] [Indexed: 11/09/2022] Open
Abstract
The intestinal mucus layer has a dual role in human health constituting a well-known microbial niche that supports gut microbiota maintenance but also acting as a physical barrier against enteric pathogens. Enterotoxigenic Escherichia coli (ETEC), the major agent responsible for traveler's diarrhea, is able to bind and degrade intestinal mucins, representing an important but understudied virulent trait of the pathogen. Using a set of complementary in vitro approaches simulating the human digestive environment, this study aimed to describe how the mucus microenvironment could shape different aspects of the human ETEC strain H10407 pathophysiology, namely its survival, adhesion, virulence gene expression, interleukin-8 induction and interactions with human fecal microbiota. Using the TNO gastrointestinal model (TIM-1) simulating the physicochemical conditions of the human upper gastrointestinal (GI) tract, we reported that mucus secretion and physical surface sustained ETEC survival, probably by helping it to face GI stresses. When integrating the host part in Caco2/HT29-MTX co-culture model, we demonstrated that mucus secreting-cells favored ETEC adhesion and virulence gene expression, but did not impede ETEC Interleukin-8 (IL-8) induction. Furthermore, we proved that mucosal surface did not favor ETEC colonization in a complex gut microbial background simulated in batch fecal experiments. However, the mucus-specific microbiota was widely modified upon the ETEC challenge suggesting its role in the pathogen infectious cycle. Using multi-targeted in vitro approaches, this study supports the major role played by mucus in ETEC pathophysiology, opening avenues in the design of new treatment strategies.
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Affiliation(s)
- Thomas Sauvaitre
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France.,Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Josefien Van Landuyt
- Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Claude Durif
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Charlène Roussel
- Université Laval, Nutrition and Functional Foods Institute (INAF), 2440 Bd Hochelaga Suite 1710, Québec, QC, G1V 0A6, Canada
| | - Adeline Sivignon
- Université Clermont Auvergne, UMR 1071 Inserm, USC-INRAE 2018, Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte (M2iSH), 63000, Clermont-Ferrand, France
| | - Sandrine Chalancon
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Ophélie Uriot
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Florence Van Herreweghen
- Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Tom Van de Wiele
- Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Lucie Etienne-Mesmin
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Stéphanie Blanquet-Diot
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France.
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Kim K, Song M, Liu Y, Ji P. Enterotoxigenic Escherichia coli infection of weaned pigs: Intestinal challenges and nutritional intervention to enhance disease resistance. Front Immunol 2022; 13:885253. [PMID: 35990617 PMCID: PMC9389069 DOI: 10.3389/fimmu.2022.885253] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) infection induced post-weaning diarrhea is one of the leading causes of morbidity and mortality in newly weaned pigs and one of the significant drivers for antimicrobial use in swine production. ETEC attachment to the small intestine initiates ETEC colonization and infection. The secretion of enterotoxins further disrupts intestinal barrier function and induces intestinal inflammation in weaned pigs. ETEC infection can also aggravate the intestinal microbiota dysbiosis due to weaning stress and increase the susceptibility of weaned pigs to other enteric infectious diseases, which may result in diarrhea or sudden death. Therefore, the amount of antimicrobial drugs for medical treatment purposes in major food-producing animal species is still significant. The alternative practices that may help reduce the reliance on such antimicrobial drugs and address animal health requirements are needed. Nutritional intervention in order to enhance intestinal health and the overall performance of weaned pigs is one of the most powerful practices in the antibiotic-free production system. This review summarizes the utilization of several categories of feed additives or supplements, such as direct-fed microbials, prebiotics, phytochemicals, lysozyme, and micro minerals in newly weaned pigs. The current understanding of these candidates on intestinal health and disease resistance of pigs under ETEC infection are particularly discussed, which may inspire more research on the development of alternative practices to support food-producing animals.
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Affiliation(s)
- Kwangwook Kim
- Department of Animal Science, University of California, Davis, Davis, CA, United States
| | - Minho Song
- Division of Animal and Dairy Science, Chungnam National University, Daejeon, South Korea
| | - Yanhong Liu
- Department of Animal Science, University of California, Davis, Davis, CA, United States
- *Correspondence: Yanhong Liu, ; Peng Ji,
| | - Peng Ji
- Department of Nutrition, University of California, Davis, Davis, CA, United States
- *Correspondence: Yanhong Liu, ; Peng Ji,
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Smith EM, Grassel CL, Papadimas A, Foulke-Abel J, Barry EM. The role of CFA/I in adherence and toxin delivery by ETEC expressing multiple colonization factors in the human enteroid model. PLoS Negl Trop Dis 2022; 16:e0010638. [PMID: 35881640 PMCID: PMC9355178 DOI: 10.1371/journal.pntd.0010638] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 08/05/2022] [Accepted: 07/07/2022] [Indexed: 01/10/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a primary causative agent of diarrhea in travelers and young children in low-to-middle-income countries (LMICs). ETEC adhere to intestinal epithelia via colonization factors (CFs) and secrete heat-stable toxin (ST) and/or heat-labile toxin (LT), causing dysregulated cellular ion transport and water secretion. ETEC isolates often harbor genes encoding more than one CF that are targets as vaccine antigens. CFA/I is a major CF that is associated with ETEC that causes moderate-to-severe diarrhea and plays an important role in pathogenesis. The Global Enteric Multicenter Study finding that 78% of CFA/I-expressing ETEC also encode the minor CF CS21 prompted investigation of the combined role of these two CFs. Western blots and electron microscopy demonstrated growth media-dependent and strain-dependent differences in CFA/I and CS21 expression. The critical role of CFA/I in adherence by ETEC strains expressing CFA/I and CS21 was demonstrated using the human enteroid model and a series of CFA/I- and CS21-specific mutants. Furthermore, only anti-CFA/I antibodies inhibited adherence by global ETEC isolates expressing CFA/I and CS21. Delivery of ST and resulting cGMP secretion was measured in supernatants from infected enteroid monolayers, and strain-specific ST delivery and time-dependent cGMP production was observed. Interestingly, cGMP levels were similar across wildtype and CF-deficient strains, reflecting a limitation of this static aerobic infection model. Despite adherence by ETEC and delivery of ST, the enteroid monolayer integrity was not disrupted, as shown by the lack of decrease in transepithelial electrical resistance and the lack of IL-8 cytokines produced during infection. Taken together, these data demonstrate that targeting CFA/I in global clinical CFA/I-CS21 strains is sufficient for adherence inhibition, supporting a vaccine strategy that focuses on blocking major CFs. In addition, the human enteroid model has significant utility for the study of ETEC pathogenesis and evaluation of vaccine-induced functional antibody responses.
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Affiliation(s)
- Emily M. Smith
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Christen L. Grassel
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Antonia Papadimas
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jennifer Foulke-Abel
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Eileen M. Barry
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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Intestinal Epithelial Cells Modulate the Production of Enterotoxins by Porcine Enterotoxigenic E. coli Strains. Int J Mol Sci 2022; 23:ijms23126589. [PMID: 35743033 PMCID: PMC9223395 DOI: 10.3390/ijms23126589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/03/2022] [Accepted: 06/12/2022] [Indexed: 01/23/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains are one of the most common etiological agents of diarrhea in both human and farm animals. In addition to encoding toxins that cause diarrhea, ETEC have evolved numerous strategies to interfere with host defenses. These strategies most likely depend on the sensing of host factors, such as molecules secreted by gut epithelial cells. The present study tested whether the exposure of ETEC to factors secreted by polarized IPEC-J2 cells resulted in transcriptional changes of ETEC-derived virulence factors. Following the addition of host-derived epithelial factors, genes encoding enterotoxins, secretion-system-associated proteins, and the key regulatory molecule cyclic AMP (cAMP) receptor protein (CRP) were substantially modulated, suggesting that ETEC recognize and respond to factors produced by gut epithelial cells. To determine whether these factors were heat sensitive, the IEC-conditioned medium was incubated at 56 °C for 30 min. In most ETEC strains, heat treatment of the IEC-conditioned medium resulted in a loss of transcriptional modulation. Taken together, these data suggest that secreted epithelial factors play a role in bacterial pathogenesis by modulating the transcription of genes encoding key ETEC virulence factors. Further research is warranted to identify these secreted epithelial factors and how ETEC sense these molecules to gain a competitive advantage in the early engagement of the gut epithelium.
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N-Acetylglucosamine Sensing and Metabolic Engineering for Attenuating Human and Plant Pathogens. Bioengineering (Basel) 2022; 9:bioengineering9020064. [PMID: 35200417 PMCID: PMC8869657 DOI: 10.3390/bioengineering9020064] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/22/2022] [Accepted: 02/03/2022] [Indexed: 11/17/2022] Open
Abstract
During evolution, both human and plant pathogens have evolved to utilize a diverse range of carbon sources. N-acetylglucosamine (GlcNAc), an amino sugar, is one of the major carbon sources utilized by several human and phytopathogens. GlcNAc regulates the expression of many virulence genes of pathogens. In fact, GlcNAc catabolism is also involved in the regulation of virulence and pathogenesis of various human pathogens, including Candida albicans, Vibrio cholerae, Leishmania donovani, Mycobacterium, and phytopathogens such as Magnaporthe oryzae. Moreover, GlcNAc is also a well-known structural component of many bacterial and fungal pathogen cell walls, suggesting its possible role in cell signaling. Over the last few decades, many studies have been performed to study GlcNAc sensing, signaling, and metabolism to better understand the GlcNAc roles in pathogenesis in order to identify new drug targets. In this review, we provide recent insights into GlcNAc-mediated cell signaling and pathogenesis. Further, we describe how the GlcNAc metabolic pathway can be targeted to reduce the pathogens’ virulence in order to control the disease prevalence and crop productivity.
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