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Tan Z, Yang W, O'Brien NA, Pan X, Ramadan S, Marsh T, Hammer N, Cywes-Bentley C, Vinacur M, Pier GB, Gildersleeve JC, Huang X. A comprehensive synthetic library of poly-N-acetyl glucosamines enabled vaccine against lethal challenges of Staphylococcus aureus. Nat Commun 2024; 15:3420. [PMID: 38658531 PMCID: PMC11043332 DOI: 10.1038/s41467-024-47457-4] [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: 10/19/2023] [Accepted: 04/03/2024] [Indexed: 04/26/2024] Open
Abstract
Poly-β-(1-6)-N-acetylglucosamine (PNAG) is an important vaccine target, expressed on many pathogens. A critical hurdle in developing PNAG based vaccine is that the impacts of the number and the position of free amine vs N-acetylation on its antigenicity are not well understood. In this work, a divergent strategy is developed to synthesize a comprehensive library of 32 PNAG pentasaccharides. This library enables the identification of PNAG sequences with specific patterns of free amines as epitopes for vaccines against Staphylococcus aureus (S. aureus), an important human pathogen. Active vaccination with the conjugate of discovered PNAG epitope with mutant bacteriophage Qβ as a vaccine carrier as well as passive vaccination with diluted rabbit antisera provides mice with near complete protection against infections by S. aureus including methicillin-resistant S. aureus (MRSA). Thus, the comprehensive PNAG pentasaccharide library is an exciting tool to empower the design of next generation vaccines.
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Affiliation(s)
- Zibin Tan
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, MI, 48824, USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, 48824, USA
- Center for Cancer Immunology, Faculty of Pharmaceutical Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences (CAS), Shenzhen, Guangdong, 518000, China
| | - Weizhun Yang
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, MI, 48824, USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, 48824, USA
- School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, Zhejiang, 310024, China
| | - Nicholas A O'Brien
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Xingling Pan
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, MI, 48824, USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, 48824, USA
| | - Sherif Ramadan
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, MI, 48824, USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, 48824, USA
- Chemistry Department, Faculty of Science, Benha University, Benha, Qaliobiya, 13518, Egypt
| | - Terence Marsh
- Department of Microbiology, Genetics & Immunology, Michigan State University, East Lansing, MI, 48824, USA
| | - Neal Hammer
- Department of Microbiology, Genetics & Immunology, Michigan State University, East Lansing, MI, 48824, USA
| | - Colette Cywes-Bentley
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Mariana Vinacur
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Gerald B Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Jeffrey C Gildersleeve
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Xuefei Huang
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, MI, 48824, USA.
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, 48824, USA.
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, 48824, USA.
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Sereme Y, Schrimp C, Faury H, Agapoff M, Lefebvre-Wloszczowski E, Chang Marchand Y, Ageron-Ardila E, Panafieu E, Blec F, Coureuil M, Frapy E, Tsatsaris V, Bonacorsi S, Skurnik D. A live attenuated vaccine to prevent severe neonatal Escherichia coli K1 infections. Nat Commun 2024; 15:3021. [PMID: 38589401 PMCID: PMC11001983 DOI: 10.1038/s41467-024-46775-x] [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: 08/25/2023] [Accepted: 03/11/2024] [Indexed: 04/10/2024] Open
Abstract
Preterm birth is currently the leading cause of neonatal morbidity and mortality. Genetic, immunological and infectious causes are suspected. Preterm infants have a higher risk of severe bacterial neonatal infections, most of which are caused by Escherichia coli an in particular E. coli K1strains. Women with history of preterm delivery have a high risk of recurrence and therefore constitute a target population for the development of vaccine against E. coli neonatal infections. Here, we characterize the immunological, microbiological and protective properties of a live attenuated vaccine candidate in adult female mice and their pups against after a challenge by K1 and non-K1 strains of E. coli. Our results show that the E. coli K1 E11 ∆aroA vaccine induces strong immunity, driven by polyclonal bactericidal antibodies. In our model of meningitis, mothers immunized prior to mating transfer maternal antibodies to pups, which protect newborn mice against various K1 and non-K1 strains of E. coli. Given the very high mortality rate and the neurological sequalae associated with neonatal E. coli K1 meningitis, our results constitute preclinical proof of concept for the development of a live attenuated vaccine against severe E. coli infections in women at risk of preterm delivery.
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Affiliation(s)
- Youssouf Sereme
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades, Paris, France
| | - Cécile Schrimp
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades, Paris, France
| | - Helène Faury
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades, Paris, France
- Department of Microbiology, Necker Hospital, University de Paris, Paris, France
| | - Maeva Agapoff
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades, Paris, France
| | | | | | | | - Emilie Panafieu
- LEAT antenne Imagine- SFR Necker INSERM US 24, Paris, France
| | - Frank Blec
- LEAT antenne Imagine- SFR Necker INSERM US 24, Paris, France
| | - Mathieu Coureuil
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades, Paris, France
| | - Eric Frapy
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades, Paris, France
| | - Vassilis Tsatsaris
- Maternité Port-Royal, hôpital Cochin, GHU Centre Paris cité, AP-HP, Paris, France
- FHU PREMA, Maternité Port-Royal, Paris, France
| | - Stephane Bonacorsi
- IAME, UMR 1137, INSERM, Université Paris Cité, Paris, France
- Laboratoire de Microbiologie, Hôpital Robert Debré, AP-HP, Paris, France
| | - David Skurnik
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades, Paris, France.
- Department of Microbiology, Necker Hospital, University de Paris, Paris, France.
- FHU PREMA, Maternité Port-Royal, Paris, France.
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Pons S, Frapy E, Sereme Y, Gaultier C, Lebreton F, Kropec A, Danilchanka O, Schlemmer L, Schrimpf C, Allain M, Angoulvant F, Lecuyer H, Bonacorsi S, Aschard H, Sokol H, Cywes-Bentley C, Mekalanos JJ, Guillard T, Pier GB, Roux D, Skurnik D. A high-throughput sequencing approach identifies immunotherapeutic targets for bacterial meningitis in neonates. EBioMedicine 2023; 88:104439. [PMID: 36709579 PMCID: PMC9900374 DOI: 10.1016/j.ebiom.2023.104439] [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: 07/14/2022] [Revised: 12/20/2022] [Accepted: 12/23/2022] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Worldwide, Escherichia coli is the leading cause of neonatal Gram-negative bacterial meningitis, but full understanding of the pathogenesis of this disease is not yet achieved. Moreover, to date, no vaccine is available against bacterial neonatal meningitis. METHODS Here, we used Transposon Sequencing of saturated banks of mutants (TnSeq) to evaluate E. coli K1 genetic fitness in murine neonatal meningitis. We identified E. coli K1 genes encoding for factors important for systemic dissemination and brain infection, and focused on products with a likely outer-membrane or extra-cellular localization, as these are potential vaccine candidates. We used in vitro and in vivo models to study the efficacy of active and passive immunization. RESULTS We selected for further study the conserved surface polysaccharide Poly-β-(1-6)-N-Acetyl Glucosamine (PNAG), as a strong candidate for vaccine development. We found that PNAG was a virulence factor in our animal model. We showed that both passive and active immunization successfully prevented and/or treated meningitis caused by E. coli K1 in neonatal mice. We found an excellent opsonophagocytic killing activity of the antibodies to PNAG and in vitro these antibodies were also able to decrease binding, invasion and crossing of E. coli K1 through two blood brain barrier cell lines. Finally, to reinforce the potential of PNAG as a vaccine candidate in bacterial neonatal meningitis, we demonstrated that Group B Streptococcus, the main cause of neonatal meningitis in developed countries, also produced PNAG and that antibodies to PNAG could protect in vitro and in vivo against this major neonatal pathogen. INTERPRETATION Altogether, these results indicate the utility of a high-throughput DNA sequencing method to identify potential immunotherapy targets for a pathogen, including in this study a potential broad-spectrum target for prevention of neonatal bacterial infections. FUNDINGS ANR Seq-N-Vaq, Charles Hood Foundation, Hearst Foundation, and Groupe Pasteur Mutualité.
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Affiliation(s)
- Stéphanie Pons
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA,Department of Anesthesiology and Critical Care, Sorbonne University, GRC 29, AP-HP, DMU DREAM, Pitié-Salpêtrière, Paris, France
| | - Eric Frapy
- CNRS, INSERM, Institut Necker Enfants Malades-INEM, F-75015 Paris, France,Faculté de Médecine, University of Paris City, Paris, France
| | - Youssouf Sereme
- CNRS, INSERM, Institut Necker Enfants Malades-INEM, F-75015 Paris, France,Faculté de Médecine, University of Paris City, Paris, France
| | - Charlotte Gaultier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - François Lebreton
- Department of Ophthalmology and Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02114, USA
| | - Andrea Kropec
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Olga Danilchanka
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Laura Schlemmer
- CNRS, INSERM, Institut Necker Enfants Malades-INEM, F-75015 Paris, France
| | - Cécile Schrimpf
- CNRS, INSERM, Institut Necker Enfants Malades-INEM, F-75015 Paris, France
| | - Margaux Allain
- CNRS, INSERM, Institut Necker Enfants Malades-INEM, F-75015 Paris, France
| | - François Angoulvant
- Assistance Publique - Hôpitaux de Paris, Pediatric Emergency Department, Necker-Enfants Malades University Hospital, University of Paris City, Paris, France,INSERM, Centre de Recherche des Cordeliers, UMRS 1138, Sorbonne Université, Université de Paris, Paris, France
| | - Hervé Lecuyer
- CNRS, INSERM, Institut Necker Enfants Malades-INEM, F-75015 Paris, France,Faculté de Médecine, University of Paris City, Paris, France,Department of Clinical Microbiology, Fédération Hospitalo-Universitaire Prématurité (FHU PREMA), Necker-Enfants Malades University Hospital, University of Paris City, Paris, France
| | - Stéphane Bonacorsi
- E IAME, UMR 1137, INSERM, Université de Paris, AP-HP, Paris, France,Laboratoire de Microbiologie, Hôpital Robert Debré, AP-HP, Paris, France
| | - Hugues Aschard
- Centre de Bioinformatique, Biostatistique et Biologie Intégrative (C3BI), Institut Pasteur, Paris, France,Department of Epidemiology, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Harry Sokol
- Gastroenterology Department, Sorbonne University, INSERM, Centre de Recherche Saint-Antoine, CRSA, AP-HP, Saint Antoine Hospital, F-75012 Paris, France,INRA, UMR1319 Micalis & AgroParisTech, Jouy en Josas, France,Paris Centre for Microbiome Medicine FHU, Paris, France
| | - Colette Cywes-Bentley
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - John J. Mekalanos
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Thomas Guillard
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA,Université de Reims Champagne-Ardenne, SFR CAP-Santé, Inserm UMR-S 1250 P3Cell, Reims, France,Laboratoire de Bactériologie-Virologie-Hygiène Hospitalière-Parasitologie-Mycologie, CHU, Reims, France
| | - Gerald B. Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Damien Roux
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA,Université de Paris, INSERM, UMR 1137 IAME, F-75018 Paris, France,AP-HP, Médecine Intensive Réanimation, Hôpital Louis Mourier, F-92700 Colombes, France
| | - David Skurnik
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; CNRS, INSERM, Institut Necker Enfants Malades-INEM, F-75015 Paris, France; Faculté de Médecine, University of Paris City, Paris, France; Department of Clinical Microbiology, Fédération Hospitalo-Universitaire Prématurité (FHU PREMA), Necker-Enfants Malades University Hospital, University of Paris City, Paris, France.
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Molecular Lipopolysaccharide Di-Vaccine Protects from Shiga-Toxin Producing Epidemic Strains of Escherichia coli O157:H7 and O104:H4. Vaccines (Basel) 2022; 10:vaccines10111854. [DOI: 10.3390/vaccines10111854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/25/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022] Open
Abstract
Background: Shiga toxin-producing Escherichia coli (STEC) O157:H7 and O104:H4 strains are important causative agents of food-borne diseases such as hemorrhagic colitis and hemolytic–uremic syndrome, which is the leading cause of kidney failure and death in children under 5 years as well as in the elderly. Methods: the native E. coli O157:H7 and O104:H4 lipopolysaccharides (LPS) were partially deacylated under alkaline conditions to obtain apyrogenic S-LPS with domination of tri-acylated lipid A species—Ac3-S-LPS. Results: intraperitoneal immunization of BALB/c mice with Ac3-S-LPS antigens from E. coli O157:H7 and O104:H4 or combination thereof (di-vaccine) at single doses ranging from 25 to 250 µg induced high titers of serum O-specific IgG (mainly IgG1), protected animals against intraperitoneal challenge with lethal doses of homologous STEC strains (60–100% survival rate) and reduced the E. coli O157:H7 and O104:H4 intestinal colonization under an in vivo murine model (6–8-fold for monovalent Ac3-S-LPS and 10-fold for di-vaccine). Conclusions: Di-vaccine induced both systemic and intestinal anti-colonization immunity in mice simultaneously against two highly virulent human STEC strains. The possibility of creating a multivalent STEC vaccine based on safe Ac3-S-LPS seems to be especially promising due to a vast serotype diversity of pathogenic E. coli.
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Gening ML, Pier GB, Nifantiev NE. Broadly protective semi-synthetic glycoconjugate vaccine against pathogens capable of producing poly-β-(1→6)-N-acetyl-d-glucosamine exopolysaccharide. DRUG DISCOVERY TODAY. TECHNOLOGIES 2020; 35-36:13-21. [PMID: 33388124 DOI: 10.1016/j.ddtec.2020.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/12/2020] [Accepted: 09/14/2020] [Indexed: 11/15/2022]
Abstract
Poly-β-(1→6)-N-acetylglucosamine (PNAG) was first discovered as a major component of biofilms formed by Staphylococcus aureus and some other staphylococci but later this exopolysaccharide was also found to be produced by pathogens of various nature. This common antigen is considered as a promising target for construction of a broadly protective vaccine. Extensive studies of PNAG, its de-N-acetylated derivative (dPNAG, containing around 15% of residual N-acetates) and their conjugates with Tetanus Toxoid (TT) revealed the crucial role of de-N-acetylated glucosamine units for the induction of protective immunity. Conjugates of synthetic penta- (5GlcNH2) and nona-β-(1→6)-d-glucosamines (9GlcNH2) were tested in vitro and in different animal models and proved to be effective in passive and active protection against different microbial pathogens. Presently conjugate 5GlcNH2-TT is being produced under GMP conditions and undergoes safety and effectiveness evaluation in humans and economically important animals. Current review summarizes all stages of this long-termed study.
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Affiliation(s)
- Marina L Gening
- Laboratory of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia
| | - Gerald B Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital/Harvard Medical School, Boston, MA 02115, USA.
| | - Nikolay E Nifantiev
- Laboratory of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia.
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D'Gama JD, Ma Z, Zhang H, Liu X, Fan H, Morris ERA, Cohen ND, Cywes-Bentley C, Pier GB, Waldor MK. A Conserved Streptococcal Virulence Regulator Controls the Expression of a Distinct Class of M-Like Proteins. mBio 2019; 10:e02500-19. [PMID: 31641092 PMCID: PMC6805998 DOI: 10.1128/mbio.02500-19] [Citation(s) in RCA: 5] [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: 09/19/2019] [Accepted: 09/23/2019] [Indexed: 12/16/2022] Open
Abstract
Streptococcus equi subspecies zooepidemicus (SEZ) are group C streptococci that are important pathogens of economically valuable animals such as horses and pigs. Here, we found that many SEZ isolates bind to a monoclonal antibody that recognizes poly-N-acetylglucosamine (PNAG), a polymer that is found as a surface capsule-like structure on diverse microbes. A fluorescence-activated cell sorting-based transposon insertion sequencing (Tn-seq) screen, coupled with whole-genome sequencing, was used to search for genes for PNAG biosynthesis. Surprisingly, mutations in a gene encoding an M-like protein, szM, and the adjacent transcription factor, designated sezV, rendered strains PNAG negative. SezV was required for szM expression and transcriptome analysis showed that SezV has a small regulon. SEZ strains with inactivating mutations in either sezV or szM were highly attenuated in a mouse model of infection. Comparative genomic analyses revealed that linked sezV and szM homologues are present in all SEZ, S. equi subspecies equi (SEE), and M18 group A streptococcal (GAS) genomes in the database, but not in other streptococci. The antibody to PNAG bound to a wide range of SEZ, SEE, and M18 GAS strains. Immunochemical studies suggest that the SzM protein may be decorated with a PNAG-like oligosaccharide although an intact oligosaccharide substituent could not be isolated. Collectively, our findings suggest that the szM and sezV loci define a subtype of virulent streptococci and that an antibody to PNAG may have therapeutic applications in animal and human diseases caused by streptococci bearing SzM-like proteins.IMPORTANCE M proteins are surface-anchored virulence factors in group A streptococci, human pathogens. Here, we identified an M-like protein, SzM, and its positive regulator, SezV, in Streptococcus equi subspecies zooepidemicus (SEZ), an important group of pathogens for domesticated animals, including horses and pigs. SzM and SezV homologues were found in the genomes of all SEZ and S. equi subspecies equi and M18 group A streptococcal strains analyzed but not in other streptococci. Mutant SEZ strains lacking either sezV or szM were highly attenuated in a mouse model of infection. Collectively, our findings suggest that SezV-related regulators and the linked SzM family of M-like proteins define a new subset of virulent streptococci.
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Affiliation(s)
- Jonathan D D'Gama
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Zhe Ma
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
| | - Hailong Zhang
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Xu Liu
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Hongjie Fan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
| | - Ellen Ruth A Morris
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, College Station, Texas, USA
| | - Noah D Cohen
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, College Station, Texas, USA
| | - Colette Cywes-Bentley
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Gerald B Pier
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Matthew K Waldor
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Boston, Massachusetts, USA
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Immunization against poly- N-acetylglucosamine reduces neutrophil activation and GVHD while sparing microbial diversity. Proc Natl Acad Sci U S A 2019; 116:20700-20706. [PMID: 31527267 DOI: 10.1073/pnas.1908549116] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Microbial invasion into the intestinal mucosa after allogeneic hematopoietic cell transplantation (allo-HCT) triggers neutrophil activation and requires antibiotic interventions to prevent sepsis. However, antibiotics lead to a loss of microbiota diversity, which is connected to a higher incidence of acute graft-versus-host disease (aGVHD). Antimicrobial therapies that eliminate invading bacteria and reduce neutrophil-mediated damage without reducing the diversity of the microbiota are therefore highly desirable. A potential solution would be the use of antimicrobial antibodies that target invading pathogens, ultimately leading to their elimination by innate immune cells. In a mouse model of aGVHD, we investigated the potency of active and passive immunization against the conserved microbial surface polysaccharide poly-N-acetylglucosamine (PNAG) that is expressed on numerous pathogens. Treatment with monoclonal or polyclonal antibodies to PNAG (anti-PNAG) or vaccination against PNAG reduced aGVHD-related mortality. Anti-PNAG treatment did not change the intestinal microbial diversity as determined by 16S ribosomal DNA sequencing. Anti-PNAG treatment reduced myeloperoxidase activation and proliferation of neutrophil granulocytes (neutrophils) in the ileum of mice developing GVHD. In vitro, anti-PNAG treatment showed high antimicrobial activity. The functional role of neutrophils was confirmed by using neutrophil-deficient LysM cre Mcl1 fl/fl mice that had no survival advantage under anti-PNAG treatment. In summary, the control of invading bacteria by anti-PNAG treatment could be a novel approach to reduce the uncontrolled neutrophil activation that promotes early GVHD and opens a new avenue to interfere with aGVHD without affecting commensal intestinal microbial diversity.
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8
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Khanifar J, Salmanian AH, Haji Hosseini R, Amani J, Kazemi R. Chitosan nano-structure loaded with recombinant E. coli O157:H7 antigens as a vaccine candidate can effectively increase immunization capacity. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2019; 47:2593-2604. [DOI: 10.1080/21691401.2019.1629947] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Jaleh Khanifar
- Department of Biology, Payame Noor University, Tehran, Iran
| | - Ali Hatef Salmanian
- Department of Agricultural Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | | | - Jafar Amani
- Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Rohoallah Kazemi
- Department of Molecular Biology, Green Gene Company, Tehran, Iran
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9
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Labor therapeutics and BMI as risk factors for postpartum preeclampsia: A case-control study. Pregnancy Hypertens 2017; 10:177-181. [PMID: 29153674 DOI: 10.1016/j.preghy.2017.07.142] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 07/14/2017] [Accepted: 07/23/2017] [Indexed: 11/23/2022]
Abstract
OBJECTIVES This study aims at identifying associations between therapeutics used during labor and the occurrence of postpartum preeclampsia (PPPE), a poorly understood entity. STUDY DESIGN AND MAIN OUTCOME MEASURES This is a case-control study of women who received an ICD-9 code for PPPE (cases) during the years 2009-2011, compared to women with a normotensive term pregnancy, delivery and postpartum period until discharge (controls), matched on age (±1year) and delivery date (±3months). Cases were defined as women having a normotensive term pregnancy, delivery and initial postpartum period (48h post-delivery) but developing hypertension between 48h and 6weeks postpartum. Single variable and multiple variable models were used to determine significant risk factors. RESULTS Forty-three women with PPPE were compared to 86 controls. Use of vasopressors and oxytocin did not differ between cases and controls, but rate of fluids administered during labor (OR=1.68 per 100cc/h; 95% CI: 1.09-2.59, p=0.02) and an elevated pre-pregnancy/first trimester BMI (OR=1.18 per kg/m2, 95% CI: 1.07-1.3, p=0.001) were identified as significant risk factors in multivariate analysis. CONCLUSIONS We identified two potentially modifiable risk factors for PPPE; further studies are needed to better define the role of these two variables in the development of PPPE.
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Bröker M, Berti F, Schneider J, Vojtek I. Polysaccharide conjugate vaccine protein carriers as a "neglected valency" - Potential and limitations. Vaccine 2017; 35:3286-3294. [PMID: 28487056 DOI: 10.1016/j.vaccine.2017.04.078] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 04/20/2017] [Accepted: 04/26/2017] [Indexed: 12/01/2022]
Abstract
The development of vaccines against polysaccharide-encapsulated pathogens (e.g. Haemophilus influenzae type b, pneumococci, meningococci) is challenging because polysaccharides do not elicit a strong and long-lasting immune response (i.e. T-cell independent). This can be overcome by conjugating the polysaccharide to a protein carrier (e.g. tetanus toxoid, cross-reacting material 197 [CRM]), which vastly improves the immune response and induces memory to the polysaccharide (T-cell dependent). Although it is well documented that protein carriers additionally induce an immune response against themselves, this potential "additional valency" has so far not been recognized. The only exception is for the protein D carrier (derived from non-typeable Haemophilus influenzae [NTHi]) used in a pneumococcal conjugate vaccine, which may have a beneficial impact on NTHi acute otitis media. In this review, we describe the immunogenicity of various protein carriers and discuss their potential dual function: as providers of T-cell helper epitopes and as protective antigens. If this "additional valency" could be proven to be protective, it may be possible to consider its potential effect on the number of required immunizations. We also describe the potential for positive or negative interference between conjugate vaccines using the same protein carriers, the resulting desire for novel carriers, and information on potential new carriers. The range of conjugate vaccines is ever expanding, with different carriers and methods of conjugation. We propose that new conjugate vaccine trials should assess immunogenicity to both the polysaccharide and carrier. Ultimately, this so-far "neglected valency" could be an exploitable characteristic of polysaccharide conjugate vaccines.
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Affiliation(s)
- Michael Bröker
- GSK Vaccines GmbH, Emil-von-Behring-Str. 76, 35041 Marburg, Germany.
| | | | - Joerg Schneider
- LimmaTech Biologics AG, Grabenstrasse 3, 8952 Schlieren, Switzerland.
| | - Ivo Vojtek
- GSK Vaccines, Avenue Fleming 20, 1300 Wavre, Belgium.
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11
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Khatun F, Stephenson RJ, Toth I. An Overview of Structural Features of Antibacterial Glycoconjugate Vaccines That Influence Their Immunogenicity. Chemistry 2017; 23:4233-4254. [PMID: 28097690 DOI: 10.1002/chem.201603599] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Indexed: 12/13/2022]
Abstract
Bacterial cell-surface-derived or mimicked carbohydrate moieties that act as protective antigens are used in the development of antibacterial glycoconjugate vaccines. The carbohydrate antigen must have a minimum length or size to maintain the conformational structure of the antigenic epitope(s). The presence or absence of O-acetate, phosphate, glycerol phosphate and pyruvate ketal plays a vital role in defining the immunogenicity of the carbohydrate antigen. The nature of the carrier protein, spacer and conjugation pattern used to develop the glycoconjugate vaccine also defines its overall spatial orientation which in turn affects its avidity and selectivity of interaction with the desired target(s). In addition, the ratio of carbohydrate to protein in glycoconjugate vaccines also makes an important contribution in determining the optimum immunological response. This Review article presents the importance of these variables in the development of antibacterial glycoconjugate vaccines and their effects on immune efficacy.
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Affiliation(s)
- Farjana Khatun
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Rachel J Stephenson
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia.,School of Pharmacy, Woolloongabba, The University of Queensland, QLD, Australia.,Institute for Molecular Bioscience, St. Lucia, The University of Queensland, QLD, Australia
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12
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Saeedi P, Yazdanparast M, Behzadi E, Salmanian AH, Mousavi SL, Nazarian S, Amani J. A review on strategies for decreasing E. coli O157:H7 risk in animals. Microb Pathog 2017; 103:186-195. [PMID: 28062285 DOI: 10.1016/j.micpath.2017.01.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 12/25/2016] [Accepted: 01/02/2017] [Indexed: 11/17/2022]
Abstract
Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is a food-borne pathogen that younger children are most prone to this microorganism. Hemolytic Uremic Syndrome (HUS) caused by EHEC, leads to the destruction of red blood cells and kidney failure. The virulence of E.coli O157:H7 is attributed to fimbriae, that facilitate colonization of bacteria within the colon and verotoxins (VT) or Shiga toxins (Stx) that are released into the blood. Although, in most cases, the infection is self-limitedin young children and aged population, it may cause HUS. Therefore, several investigations are performed in order to offer effective therapies and vaccines, which can prevent and treat the infection in appropriate time. As the pathogenesis of this infection is complicated, a multi-targeted strategy is required. Since cattle are the most important reservoir of EHEC and the root of contamination, reducing E. coli O157:H7 at the farm level should decrease the risk of human illness. Several vaccine approaches have been employed with different proper outcomes in animal models, including recombinant proteins (virulence factors such as; Stx1/2, intimin, EspA, fusion proteins of A and B Stx subunits), avirulent ghost cells of EHEC O157:H7, live attenuated bacteria expressing recombinant proteins, recombinant fimbrial proteins. In addition to protein-based vaccines, DNA vaccines have provided proper prevention in the laboratory animal model. This review paper summarizes the previous studies, current status and future perspective of different immunization strategies for eradicating Enterohemorrhagic Escherichia coli O157:H7.
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Affiliation(s)
- Pardis Saeedi
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Maryam Yazdanparast
- Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
| | - Elham Behzadi
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Ali Hatef Salmanian
- Plant Bioproducts Department, Institute of Agricultural Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Seyed Latif Mousavi
- Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
| | - Shahram Nazarian
- Department of Biology, Faculty of Science, Imam Hossein University, Tehran, Iran
| | - Jafar Amani
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
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13
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Skurnik D, Cywes-Bentley C, Pier GB. The exceptionally broad-based potential of active and passive vaccination targeting the conserved microbial surface polysaccharide PNAG. Expert Rev Vaccines 2016; 15:1041-53. [PMID: 26918288 PMCID: PMC4985264 DOI: 10.1586/14760584.2016.1159135] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/24/2016] [Indexed: 11/08/2022]
Abstract
A challenging component of vaccine development is the large serologic diversity of protective antigens. Remarkably, there is a conserved surface/capsular polysaccharide, one of the most effective vaccine targets, expressed by a large number of bacterial, fungal and eukaryotic pathogens: poly-N-acetyl glucosamine (PNAG). Natural antibodies to PNAG are poorly effective at mediating in vitro microbial killing or in vivo protection. Removing most of the acetate substituents to produce a deacetylated glycoform, or using synthetic oligosaccharides of poly-β-1-6-linked glucosamine conjugated to carrier proteins, results in vaccines that elicit high levels of broad-based immunity. A fully human monoclonal antibody is highly active in laboratory and preclinical studies and has been successfully tested in a phase-I setting. Both the synthetic oligosaccharide conjugate vaccine and MAb will be further tested in humans starting in 2016; but, even if effective against only a fraction of the PNAG-producing pathogens, a major advance in vaccine-preventable diseases will occur.
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Affiliation(s)
- David Skurnik
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 181 Longwood Ave., Boston, MA 02115, Phone: 617-525-2269; FAX: 617-525-2510
| | - Colette Cywes-Bentley
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 181 Longwood Ave., Boston, MA 02115, Phone: 617-525-2269; FAX: 617-525-2510
| | - Gerald B. Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 181 Longwood Ave., Boston, MA 02115, Phone: 617-525-2269; FAX: 617-525-2510
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14
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In silico analysis and recombinant expression of BamA protein as a universal vaccine against Escherichia coli in mice. Appl Microbiol Biotechnol 2016; 100:5089-98. [DOI: 10.1007/s00253-016-7467-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/07/2016] [Accepted: 03/10/2016] [Indexed: 02/05/2023]
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15
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Wang Y, Andole Pannuri A, Ni D, Zhou H, Cao X, Lu X, Romeo T, Huang Y. Structural Basis for Translocation of a Biofilm-supporting Exopolysaccharide across the Bacterial Outer Membrane. J Biol Chem 2016; 291:10046-57. [PMID: 26957546 DOI: 10.1074/jbc.m115.711762] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Indexed: 12/14/2022] Open
Abstract
The partially de-N-acetylated poly-β-1,6-N-acetyl-d-glucosamine (dPNAG) polymer serves as an intercellular biofilm adhesin that plays an essential role for the development and maintenance of integrity of biofilms of diverse bacterial species. Translocation of dPNAG across the bacterial outer membrane is mediated by a tetratricopeptide repeat-containing outer membrane protein, PgaA. To understand the molecular basis of dPNAG translocation, we determined the crystal structure of the C-terminal transmembrane domain of PgaA (residues 513-807). The structure reveals that PgaA forms a 16-strand transmembrane β-barrel, closed by four loops on the extracellular surface. Half of the interior surface of the barrel that lies parallel to the translocation pathway is electronegative, suggesting that the corresponding negatively charged residues may assist the secretion of the positively charged dPNAG polymer. In vivo complementation assays in a pgaA deletion bacterial strain showed that a cluster of negatively charged residues proximal to the periplasm is necessary for biofilm formation. Biochemical analyses further revealed that the tetratricopeptide repeat domain of PgaA binds directly to the N-deacetylase PgaB and is critical for biofilm formation. Our studies support a model in which the positively charged PgaB-bound dPNAG polymer is delivered to PgaA through the PgaA-PgaB interaction and is further targeted to the β-barrel lumen of PgaA potentially via a charge complementarity mechanism, thus priming the translocation of dPNAG across the bacterial outer membrane.
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Affiliation(s)
- Yan Wang
- From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Archana Andole Pannuri
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611-0700
| | - Dongchun Ni
- Department of Cardiovascular Diseases, Tianjin Xiqing Hospital, Tianjin 300380, China
| | - Haizhen Zhou
- From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiou Cao
- School of Life Sciences, Peking University, Beijing 100871, China, and
| | - Xiaomei Lu
- Dongguan Institute of Pediatrics, the Eighth People's Hospital of Dongguan, Dongguan 523325, Guangdong Province, China
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611-0700,
| | - Yihua Huang
- From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China,
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16
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Roux D, Cywes-Bentley C, Zhang YF, Pons S, Konkol M, Kearns DB, Little DJ, Howell PL, Skurnik D, Pier GB. Identification of Poly-N-acetylglucosamine as a Major Polysaccharide Component of the Bacillus subtilis Biofilm Matrix. J Biol Chem 2015; 290:19261-72. [PMID: 26078454 DOI: 10.1074/jbc.m115.648709] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 12/22/2022] Open
Abstract
Bacillus subtilis is intensively studied as a model organism for the development of bacterial biofilms or pellicles. A key component is currently undefined exopolysaccharides produced from proteins encoded by genes within the eps locus. Within this locus are four genes, epsHIJK, known to be essential for pellicle formation. We show they encode proteins synthesizing the broadly expressed microbial carbohydrate poly-N-acetylglucosamine (PNAG). PNAG was present in both pellicle and planktonic wild-type B. subtilis cells and in strains with deletions in the epsA-G and -L-O genes but not in strains deleted for epsH-K. Cloning of the B. subtilis epsH-K genes into Escherichia coli with in-frame deletions in the PNAG biosynthetic genes pgaA-D, respectively, restored PNAG production in E. coli. Cloning the entire B. subtilis epsHIJK locus into pga-deleted E. coli, Klebsiella pneumoniae, or alginate-negative Pseudomonas aeruginosa restored or conferred PNAG production. Bioinformatic and structural predictions of the EpsHIJK proteins suggest EpsH and EpsJ are glycosyltransferases (GT) with a GT-A fold; EpsI is a GT with a GT-B fold, and EpsK is an α-helical membrane transporter. B. subtilis, E. coli, and pga-deleted E. coli carrying the epsHIJK genes on a plasmid were all susceptible to opsonic killing by antibodies to PNAG. The immunochemical and genetic data identify the genes and proteins used by B. subtilis to produce PNAG as a significant carbohydrate factor essential for pellicle formation.
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Affiliation(s)
- Damien Roux
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and
| | - Colette Cywes-Bentley
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and
| | - Yi-Fan Zhang
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and Harvard School of Dental Medicine, Boston, Massachusetts 02115
| | - Stephanie Pons
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and
| | - Melissa Konkol
- the Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Daniel B Kearns
- the Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Dustin J Little
- the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada, and the Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - P Lynne Howell
- the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada, and the Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - David Skurnik
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and
| | - Gerald B Pier
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and
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17
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Rahal EA, Fadlallah SM, Nassar FJ, Kazzi N, Matar GM. Approaches to treatment of emerging Shiga toxin-producing Escherichia coli infections highlighting the O104:H4 serotype. Front Cell Infect Microbiol 2015; 5:24. [PMID: 25853096 PMCID: PMC4364364 DOI: 10.3389/fcimb.2015.00024] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 03/04/2015] [Indexed: 11/13/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) are a group of diarrheagenic bacteria associated with foodborne outbreaks. Infection with these agents may result in grave sequelae that include fatality. A large number of STEC serotypes has been identified to date. E. coli serotype O104:H4 is an emerging pathogen responsible for a 2011 outbreak in Europe that resulted in over 4000 infections and 50 deaths. STEC pathogenicity is highly reliant on the production of one or more Shiga toxins that can inhibit protein synthesis in host cells resulting in a cytotoxicity that may affect various organ systems. Antimicrobials are usually avoided in the treatment of STEC infections since they are believed to induce bacterial cell lysis and the release of stored toxins. Some antimicrobials have also been reported to enhance toxin synthesis and production from these organisms. Various groups have attempted alternative treatment approaches including the administration of toxin-directed antibodies, toxin-adsorbing polymers, probiotic agents and natural remedies. The utility of antibiotics in treating STEC infections has also been reconsidered in recent years with certain modalities showing promise.
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Affiliation(s)
- Elias A Rahal
- Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut Beirut, Lebanon
| | - Sukayna M Fadlallah
- Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut Beirut, Lebanon
| | - Farah J Nassar
- Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut Beirut, Lebanon
| | - Natalie Kazzi
- Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut Beirut, Lebanon
| | - Ghassan M Matar
- Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut Beirut, Lebanon
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