1
|
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.
Collapse
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
| |
Collapse
|
4
|
Midgett CR, Talbot KM, Day JL, Munson GP, Kull FJ. Structure of the master regulator Rns reveals an inhibitor of enterotoxigenic Escherichia coli virulence regulons. Sci Rep 2021; 11:15663. [PMID: 34341412 PMCID: PMC8329261 DOI: 10.1038/s41598-021-95123-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 07/14/2021] [Indexed: 02/07/2023] Open
Abstract
Enteric infections caused by the gram-negative bacteria enterotoxigenic Escherichia coli (ETEC), Vibrio cholerae, Shigella flexneri, and Salmonella enterica are among the most common and affect billions of people each year. These bacteria control expression of virulence factors using a network of transcriptional regulators, some of which are modulated by small molecules as has been shown for ToxT, an AraC family member from V. cholerae. In ETEC the expression of many types of adhesive pili is dependent upon the AraC family member Rns. We present here the 3 Å crystal structure of Rns and show it closely resembles ToxT. Rns crystallized as a dimer via an interface similar to that observed in other dimeric AraC's. Furthermore, the structure of Rns revealed the presence of a ligand, decanoic acid, that inhibits its activity in a manner similar to the fatty acid mediated inhibition observed for ToxT and the S. enterica homologue HilD. Together, these results support our hypothesis that fatty acids regulate virulence controlling AraC family members in a common manner across a number of enteric pathogens. Furthermore, for the first time this work identifies a small molecule capable of inhibiting the ETEC Rns regulon, providing a basis for development of therapeutics against this deadly human pathogen.
Collapse
Affiliation(s)
| | - Kacey Marie Talbot
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Jessica L Day
- Department of Chemistry, Dartmouth College, Hanover, NH, USA
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - George P Munson
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - F Jon Kull
- Department of Chemistry, Dartmouth College, Hanover, NH, USA.
| |
Collapse
|
6
|
Vidal RM, Muhsen K, Tennant SM, Svennerholm AM, Sow SO, Sur D, Zaidi AKM, Faruque ASG, Saha D, Adegbola R, Hossain MJ, Alonso PL, Breiman RF, Bassat Q, Tamboura B, Sanogo D, Onwuchekwa U, Manna B, Ramamurthy T, Kanungo S, Ahmed S, Qureshi S, Quadri F, Hossain A, Das SK, Antonio M, Mandomando I, Nhampossa T, Acácio S, Omore R, Ochieng JB, Oundo JO, Mintz ED, O’Reilly CE, Berkeley LY, Livio S, Panchalingam S, Nasrin D, Farag TH, Wu Y, Sommerfelt H, Robins-Browne RM, Del Canto F, Hazen TH, Rasko DA, Kotloff KL, Nataro JP, Levine MM. Colonization factors among enterotoxigenic Escherichia coli isolates from children with moderate-to-severe diarrhea and from matched controls in the Global Enteric Multicenter Study (GEMS). PLoS Negl Trop Dis 2019; 13:e0007037. [PMID: 30608930 PMCID: PMC6343939 DOI: 10.1371/journal.pntd.0007037] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/23/2019] [Accepted: 11/28/2018] [Indexed: 12/29/2022] Open
Abstract
Background Enterotoxigenic Escherichia coli (ETEC) encoding heat-stable enterotoxin (ST) alone or with heat-labile enterotoxin (LT) cause moderate-to-severe diarrhea (MSD) in developing country children. The Global Enteric Multicenter Study (GEMS) identified ETEC encoding ST among the top four enteropathogens. Since the GEMS objective was to provide evidence to guide development and implementation of enteric vaccines and other interventions to diminish diarrheal disease morbidity and mortality, we examined colonization factor (CF) prevalence among ETEC isolates from children age <5 years with MSD and from matched controls in four African and three Asian sites. We also assessed strength of association of specific CFs with MSD. Methodology/Principal findings MSD cases enrolled at healthcare facilities over three years and matched controls were tested in a standardized manner for many enteropathogens. To identify ETEC, three E. coli colonies per child were tested by polymerase chain reaction (PCR) to detect genes encoding LT, ST; confirmed ETEC were examined by PCR for major CFs (Colonization Factor Antigen I [CFA/I] or Coli Surface [CS] antigens CS1-CS6) and minor CFs (CS7, CS12, CS13, CS14, CS17, CS18, CS19, CS20, CS21, CS30). ETEC from 806 cases had a single toxin/CF profile in three tested strains per child. Major CFs, components of multiple ETEC vaccine candidates, were detected in 66.0% of LT/ST and ST-only cases and were associated with MSD versus matched controls by conditional logistic regression (p≤0.006); major CFs detected in only 25.0% of LT-only cases weren’t associated with MSD. ETEC encoding exclusively CS14, identified among 19.9% of 291 ST-only and 1.5% of 259 LT/ST strains, were associated with MSD (p = 0.0011). No other minor CF exhibited prevalence ≥5% and significant association with MSD. Conclusions/Significance Major CF-based efficacious ETEC vaccines could potentially prevent up to 66% of pediatric MSD cases due to ST-encoding ETEC in developing countries; adding CS14 extends coverage to ~77%. Enterotoxigenic Escherichia coli (“ETEC”) were found to be one of the four most consistently important agents that cause moderate-to-severe diarrhea among children <5 years of age in a large case-control study, the Global Enteric Multicenter Study, performed in four countries in sub-Saharan Africa and three in South Asia. ETEC attach to the lining of the human small intestine by means of protein colonization factors (CFs), after which bacterial toxins stimulate intestinal secretion resulting in diarrhea. Moderate-to-severe diarrhea in young children in developing countries can lead to malnutrition and death. Vaccines are being developed to prevent ETEC diarrhea and its consequences. Several ETEC vaccines aim to stimulate antibodies (protective proteins) that will bind CFs and prevent the bacteria from attaching to intestinal cells, which should, in turn, prevent ETEC diarrhea. Different types of CFs exist. To guide the development of vaccines intending to provide broad protection against ETEC, one must know the frequency with which the different major CFs are produced by ETEC. This paper reports an extensive systematic survey of ETEC CFs and provides helpful information to guide the development of ETEC vaccines.
Collapse
Affiliation(s)
- Roberto M. Vidal
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Khitam Muhsen
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Sharon M. Tennant
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology at Institute of Biomedicine, University of Göteborg, Göteborg, Sweden
| | - Samba O. Sow
- Centre pour le Développement des Vaccins du Mali (CVD-Mali), Bamako, Mali
| | - Dipika Sur
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Anita K. M. Zaidi
- Department of Paediatrics and Child Health, the Aga Khan University, Karachi, Pakistan
| | - Abu S. G. Faruque
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Debasish Saha
- Medical Research Council (United Kingdom) Unit, Fajara, The Gambia
| | - Richard Adegbola
- Medical Research Council (United Kingdom) Unit, Fajara, The Gambia
| | | | - Pedro L. Alonso
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
- ISGlobal, Barcelona Ctr. Int. Health Res. Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
| | - Robert F. Breiman
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
- Global Disease Detection Division, Kenya Office of the US Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Quique Bassat
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
- ISGlobal, Barcelona Ctr. Int. Health Res. Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
| | - Boubou Tamboura
- Centre pour le Développement des Vaccins du Mali (CVD-Mali), Bamako, Mali
| | - Doh Sanogo
- Centre pour le Développement des Vaccins du Mali (CVD-Mali), Bamako, Mali
| | - Uma Onwuchekwa
- Centre pour le Développement des Vaccins du Mali (CVD-Mali), Bamako, Mali
| | - Byomkesh Manna
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | | | - Suman Kanungo
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shahnawaz Ahmed
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Shahida Qureshi
- Department of Paediatrics and Child Health, the Aga Khan University, Karachi, Pakistan
| | - Farheen Quadri
- Department of Paediatrics and Child Health, the Aga Khan University, Karachi, Pakistan
| | - Anowar Hossain
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Sumon K. Das
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Martin Antonio
- Medical Research Council (United Kingdom) Unit, Fajara, The Gambia
| | | | | | - Sozinho Acácio
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
| | - Richard Omore
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - John B. Ochieng
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Joseph O. Oundo
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Eric D. Mintz
- Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Ciara E. O’Reilly
- Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Lynette Y. Berkeley
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Sofie Livio
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Sandra Panchalingam
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Dilruba Nasrin
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Tamer H. Farag
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Yukun Wu
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Halvor Sommerfelt
- Centre of Intervention Science in Maternal and Child Health, Centre for International Health, Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
- Norwegian Institute of Public Health, Oslo, Norway
| | - Roy M. Robins-Browne
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Victoria, Australia
| | - Felipe Del Canto
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Tracy H. Hazen
- The Institute of Genomic Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - David A. Rasko
- The Institute of Genomic Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Karen L. Kotloff
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - James P. Nataro
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Myron M. Levine
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
- * E-mail:
| |
Collapse
|
7
|
Hodson C, Yang J, Hocking DM, Azzopardi K, Chen Q, Holien JK, Parker MW, Tauschek M, Robins-Browne RM. Control of Virulence Gene Expression by the Master Regulator, CfaD, in the Prototypical Enterotoxigenic Escherichia coli Strain, H10407. Front Microbiol 2017; 8:1525. [PMID: 28848532 PMCID: PMC5554520 DOI: 10.3389/fmicb.2017.01525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/28/2017] [Indexed: 12/24/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is the most common bacterial cause of diarrhea in children in developing countries, as well as in travelers to these countries. To cause disease, ETEC needs to produce a series of virulence proteins including enterotoxins, colonization factors and secretion pathways, which enable this pathogen to colonize the human small intestine and deliver enterotoxins to epithelial cells. Previously, a number of studies have demonstrated that CfaD, an AraC-like transcriptional regulator, plays a key role in virulence gene expression by ETEC. In this study, we carried out a transcriptomic analysis of ETEC strain, H10407, grown under different conditions, and determined the complete set of genes that are regulated by CfaD. In this way, we identified a number of new target genes, including rnr-1, rnr-2, etpBAC, agn43, flu, traM and ETEC_3214, whose expression is strongly activated by CfaD. Using promoter-lacZ reporters, primer extension and electrophoretic mobility shift assays, we characterized the CfaD-mediated activation of several selected target promoters. We also showed that the gut-associated environmental signal, sodium bicarbonate, stimulates CfaD-mediated upregulation of its virulence target operons. Finally, we screened a commercial small molecule library and identified a compound (CH-1) that specifically inhibited the regulatory function of CfaD, and by 2-D analoging, we identified a second inhibitor (CH-2) with greater potency.
Collapse
Affiliation(s)
- Carla Hodson
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, ParkvilleVIC, Australia
| | - Ji Yang
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, ParkvilleVIC, Australia
| | - Dianna M Hocking
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, ParkvilleVIC, Australia
| | - Kristy Azzopardi
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, ParkvilleVIC, Australia.,Murdoch Childrens Research Institute, The Royal Children's Hospital, ParkvilleVIC, Australia
| | - Qianyu Chen
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, ParkvilleVIC, Australia
| | - Jessica K Holien
- Australian Cancer Research Foundation Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, FitzroyVIC, Australia
| | - Michael W Parker
- Australian Cancer Research Foundation Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, FitzroyVIC, Australia.,Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, ParkvilleVIC, Australia
| | - Marija Tauschek
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, ParkvilleVIC, Australia
| | - Roy M Robins-Browne
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, ParkvilleVIC, Australia.,Murdoch Childrens Research Institute, The Royal Children's Hospital, ParkvilleVIC, Australia
| |
Collapse
|