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Galley NF, Greetham D, Alamán-Zárate MG, Williamson MP, Evans CA, Spittal WD, Buddle JE, Freeman J, Davis GL, Dickman MJ, Wilcox MH, Lovering AL, Fagan RP, Mesnage S. Clostridioides difficile canonical L,D-transpeptidases catalyze a novel type of peptidoglycan cross-links and are not required for beta-lactam resistance. J Biol Chem 2024; 300:105529. [PMID: 38043796 PMCID: PMC10792238 DOI: 10.1016/j.jbc.2023.105529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/19/2023] [Accepted: 11/27/2023] [Indexed: 12/05/2023] Open
Abstract
Clostridioides difficile is the leading cause of antibiotic-associated diarrhea worldwide with significant morbidity and mortality. This organism is naturally resistant to several beta-lactam antibiotics that inhibit the polymerization of peptidoglycan, an essential component of the bacteria cell envelope. Previous work has revealed that C. difficile peptidoglycan has an unusual composition. It mostly contains 3-3 cross-links, catalyzed by enzymes called L,D-transpeptidases (Ldts) that are poorly inhibited by beta-lactams. It was therefore hypothesized that peptidoglycan polymerization by these enzymes could underpin antibiotic resistance. Here, we investigated the catalytic activity of the three canonical Ldts encoded by C. difficile (LdtCd1, LdtCd2, and LdtCd3) in vitro and explored their contribution to growth and antibiotic resistance. We show that two of these enzymes catalyze the formation of novel types of peptidoglycan cross-links using meso-diaminopimelic acid both as a donor and an acceptor, also observed in peptidoglycan sacculi. We demonstrate that the simultaneous deletion of these three genes only has a minor impact on both peptidoglycan structure and resistance to beta-lactams. This unexpected result therefore implies that the formation of 3-3 peptidoglycan cross-links in C. difficile is catalyzed by as yet unidentified noncanonical Ldt enzymes.
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Affiliation(s)
- Nicola F Galley
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Darren Greetham
- School of Biosciences, University of Sheffield, Sheffield, UK
| | | | | | - Caroline A Evans
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - William D Spittal
- Department of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds Institute of Medical Research, University of Leeds, Leeds, UK; Healthcare Associated Infections Research Group, Leeds Institute of Medical Research University of Leeds, Leeds, UK
| | | | - Jane Freeman
- Department of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds Institute of Medical Research, University of Leeds, Leeds, UK; Healthcare Associated Infections Research Group, Leeds Institute of Medical Research University of Leeds, Leeds, UK
| | - Georgina L Davis
- Department of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds Institute of Medical Research, University of Leeds, Leeds, UK; Healthcare Associated Infections Research Group, Leeds Institute of Medical Research University of Leeds, Leeds, UK
| | - Mark J Dickman
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - Mark H Wilcox
- Department of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds Institute of Medical Research, University of Leeds, Leeds, UK; Healthcare Associated Infections Research Group, Leeds Institute of Medical Research University of Leeds, Leeds, UK
| | | | - Robert P Fagan
- School of Biosciences, University of Sheffield, Sheffield, UK
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2
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Phothichaisri W, Phetruen T, Chankhamhaengdecha S, Janvilisri T, Ounjai P, Fagan RP, Chanarat S. Unraveling Physical Interactions of Clostridioides difficile with Phage and Phage-Derived Proteins Using In Vitro and Whole-Cell Assays. Methods Mol Biol 2024; 2738:245-262. [PMID: 37966604 DOI: 10.1007/978-1-0716-3549-0_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
Physical interactions between bacteria and phages provide valuable insights into the mechanisms of phage infection and may provide information on the use of phages as a therapeutic approach. In this study, we employed a combination of in vitro and whole-cell assays to examine the interactions between Clostridioides difficile and phages and phage-derived proteins. These techniques can also be adapted for studying the physical interactions between other bacterial species and their associated phages.
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Affiliation(s)
- Wichuda Phothichaisri
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Tanaporn Phetruen
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
- Laboratory of Molecular Cell Biology, Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | | | - Tavan Janvilisri
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Puey Ounjai
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Robert P Fagan
- School of Biosciences, Florey Institute, University of Sheffield, Sheffield, UK
| | - Sittinan Chanarat
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand.
- Laboratory of Molecular Cell Biology, Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok, Thailand.
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3
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Abstract
Clostridioides difficile is the most common cause of nosocomial antibiotic-associated diarrhea, and is responsible for a spectrum of diseases characterized by high levels of recurrence, morbidity, and mortality. Treatment is complex, since antibiotics constitute both the main treatment and the major risk factor for infection. Worryingly, resistance to multiple antibiotics is becoming increasingly widespread, leading to the classification of this pathogen as an urgent threat to global health. As a consummate opportunist, C. difficile is well equipped for promoting disease, owing to its arsenal of virulence factors: transmission of this anaerobe is highly efficient due to the formation of robust endospores, and an array of adhesins promote gut colonization. C. difficile produces multiple toxins acting upon gut epithelia, resulting in manifestations typical of diarrheal disease, and severe inflammation in a subset of patients. This review focuses on such virulence factors, as well as the importance of antimicrobial resistance and genome plasticity in enabling pathogenesis and persistence of this important pathogen.
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Affiliation(s)
- Jessica E Buddle
- Molecular Microbiology, School of Biosciences, University of Sheffield, Sheffield, UK
| | - Robert P Fagan
- Molecular Microbiology, School of Biosciences, University of Sheffield, Sheffield, UK
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4
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Ormsby MJ, Vaz F, Kirk JA, Barwinska-Sendra A, Hallam JC, Lanzoni-Mangutchi P, Cole J, Chaudhuri RR, Salgado PS, Fagan RP, Douce GR. An intact S-layer is advantageous to Clostridioides difficile within the host. PLoS Pathog 2023; 19:e1011015. [PMID: 37384772 PMCID: PMC10310040 DOI: 10.1371/journal.ppat.1011015] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 05/31/2023] [Indexed: 07/01/2023] Open
Abstract
Clostridioides difficile is responsible for substantial morbidity and mortality in antibiotically-treated, hospitalised, elderly patients, in which toxin production correlates with diarrhoeal disease. While the function of these toxins has been studied in detail, the contribution of other factors, including the paracrystalline surface layer (S-layer), to disease is less well understood. Here, we highlight the essentiality of the S-layer in vivo by reporting the recovery of S-layer variants, following infection with the S-layer-null strain, FM2.5. These variants carry either correction of the original point mutation, or sequence modifications which restored the reading frame, and translation of slpA. Selection of these variant clones was rapid in vivo, and independent of toxin production, with up to 90% of the recovered C. difficile population encoding modified slpA sequence within 24 h post infection. Two variants, subsequently named FM2.5varA and FM2.5varB, were selected for study in greater detail. Structural determination of SlpA from FM2.5varB indicated an alteration in the orientation of protein domains, resulting in a reorganisation of the lattice assembly, and changes in interacting interfaces, which might alter function. Interestingly, variant FM2.5varB displayed an attenuated, FM2.5-like phenotype in vivo compared to FM2.5varA, which caused disease severity more comparable to that of R20291. Comparative RNA sequencing (RNA-Seq) analysis of in vitro grown isolates revealed large changes in gene expression between R20291 and FM2.5. Downregulation of tcdA/tcdB and several genes associated with sporulation and cell wall integrity may account for the reported attenuated phenotype of FM2.5 in vivo. RNA-seq data correlated well with disease severity with the more virulent variant, FM2.5varA, showing s similar profile of gene expression to R20291 in vitro, while the attenuated FM2.5varB showed downregulation of many of the same virulence associated traits as FM2.5. Cumulatively, these data add to a growing body of evidence that the S-layer contributes to C. difficile pathogenesis and disease severity.
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Affiliation(s)
- Michael J. Ormsby
- School of Infection and Immunity, College of Medical, Veterinary & Life Sciences, University of Glasgow, Scotland, United Kingdom
| | - Filipa Vaz
- School of Infection and Immunity, College of Medical, Veterinary & Life Sciences, University of Glasgow, Scotland, United Kingdom
| | - Joseph A. Kirk
- Molecular Microbiology, School of Biosciences, University of Sheffield, England, United Kingdom
| | - Anna Barwinska-Sendra
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, England, United Kingdom
| | - Jennifer C. Hallam
- School of Infection and Immunity, College of Medical, Veterinary & Life Sciences, University of Glasgow, Scotland, United Kingdom
| | - Paola Lanzoni-Mangutchi
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, England, United Kingdom
| | - John Cole
- School of Infection and Immunity, College of Medical, Veterinary & Life Sciences, University of Glasgow, Scotland, United Kingdom
| | - Roy R. Chaudhuri
- Molecular Microbiology, School of Biosciences, University of Sheffield, England, United Kingdom
| | - Paula S. Salgado
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, England, United Kingdom
| | - Robert P. Fagan
- Molecular Microbiology, School of Biosciences, University of Sheffield, England, United Kingdom
| | - Gillian R Douce
- School of Infection and Immunity, College of Medical, Veterinary & Life Sciences, University of Glasgow, Scotland, United Kingdom
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5
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Royer ALM, Umansky AA, Allen MM, Garneau JR, Ospina-Bedoya M, Kirk JA, Govoni G, Fagan RP, Soutourina O, Fortier LC. Clostridioides difficile S-Layer Protein A (SlpA) Serves as a General Phage Receptor. Microbiol Spectr 2023; 11:e0389422. [PMID: 36790200 PMCID: PMC10100898 DOI: 10.1128/spectrum.03894-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 01/27/2023] [Indexed: 02/16/2023] Open
Abstract
Therapeutic bacteriophages (phages) are being considered as alternatives in the fight against Clostridioides difficile infections. To be efficient, phages should have a wide host range, buthe lack of knowledge about the cell receptor used by C. difficile phages hampers the rational design of phage cocktails. Recent reports suggested that the C. difficile surface layer protein A (SlpA) is an important phage receptor, but available data are still limited. Here, using the epidemic R20291 strain and its FM2.5 mutant derivative lacking a functional S-layer, we show that the absence of SlpA renders cells completely resistant to infection by ϕCD38-2, ϕCD111, and ϕCD146, which normally infect the parental strain. Complementation with 12 different S-layer cassette types (SLCTs) expressed from a plasmid revealed that SLCT-6 also allowed infection by ϕCD111 and SLCT-11 enabled infection by ϕCD38-2 and ϕCD146. Of note, the expression of SLCT-1, -6, -8, -9, -10, or -12 conferred susceptibility to infection by 5 myophages that normally do not infect the R20291 strain. Also, deletion of the D2 domain within the low-molecular-weight fragment of SlpA was found to abolish infection by ϕCD38-2 and ϕCD146 but not ϕCD111. Altogether, our data suggest that many phages use SlpA as their receptor and, most importantly, that both siphophages and myophages target SlpA despite major differences in their tail structures. Our study therefore represents an important step in understanding the interactions between C. difficile and its phages. IMPORTANCE Phage therapy represents an interesting alternative to treat Clostridioides difficile infections because, contrary to antibiotics, most phages are highly species specific, thereby sparing the beneficial gut microbes that protect from infection. However, currently available phages against C. difficile have a narrow host range and target members from only one or a few PCR ribotypes. Without a clear comprehension of the factors that define host specificity, and in particular the host receptor recognized by phages, it is hard to develop therapeutic cocktails in a rational manner. In our study, we provide clear and unambiguous experimental evidence that SlpA is a common receptor used by many siphophages and myophages. Although work is still needed to define how a particular phage receptor-binding protein binds to a specific SLCT, the identification of SlpA as a common receptor is a major keystone that will facilitate the rational design of therapeutic phage cocktails against clinically important strains.
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Affiliation(s)
- Alexia L. M. Royer
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Andrew A. Umansky
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Marie-Maude Allen
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Julian R. Garneau
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Maicol Ospina-Bedoya
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Joseph A. Kirk
- Molecular Microbiology, School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | | | - Robert P. Fagan
- Molecular Microbiology, School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Olga Soutourina
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Louis-Charles Fortier
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
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6
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Phothichaisri W, Chankhamhaengdecha S, Janvilisri T, Nuadthaisong J, Phetruen T, Fagan RP, Chanarat S. Potential Role of the Host-Derived Cell-Wall Binding Domain of Endolysin CD16/50L as a Molecular Anchor in Preservation of Uninfected Clostridioides difficile for New Rounds of Phage Infection. Microbiol Spectr 2022; 10:e0236121. [PMID: 35377223 PMCID: PMC9045149 DOI: 10.1128/spectrum.02361-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 03/20/2022] [Indexed: 01/21/2023] Open
Abstract
Endolysin is a phage-encoded cell-wall hydrolase which degrades the peptidoglycan layer of the bacterial cell wall. The enzyme is often expressed at the late stage of the phage lytic cycle and is required for progeny escape. Endolysins of bacteriophage that infect Gram-positive bacteria often comprises two domains: a peptidoglycan hydrolase and a cell-wall binding domain (CBD). Although the catalytic domain of endolysin is relatively well-studied, the precise role of CBD is ambiguous and remains controversial. Here, we focus on the function of endolysin CBD from a recently isolated Clostridioides difficile phage. We found that the CBD is not required for lytic activity, which is strongly prevented by the surface layer of C. difficile. Intriguingly, hidden Markov model analysis suggested that the endolysin CBD is likely derived from the CWB2 motif of C. difficile cell-wall proteins but possesses a higher binding affinity to bacterial cell-wall polysaccharides. Moreover, the CBD forms a homodimer, formation of which is necessary for interaction with the surface saccharides. Importantly, endolysin diffusion and sequential cytolytic assays showed that CBD of endolysin is required for the enzyme to be anchored to post-lytic cell-wall remnants, suggesting its physiological roles in limiting diffusion of the enzyme, preserving neighboring host cells, and thereby enabling the phage progeny to initiate new rounds of infection. Taken together, this study provides an insight into regulation of endolysin through CBD and can potentially be applied for endolysin treatment against C. difficile infection. IMPORTANCE Endolysin is a peptidoglycan hydrolase encoded in a phage genome. The enzyme is attractive due to its potential use as antibacterial treatment. To utilize endolysin for the therapeutic propose, understanding of the fundamental role of endolysin becomes important. Here, we investigate the function of cell-wall binding domain (CBD) of an endolysin from a C. difficile phage. The domain is homologous to a cell-wall associating module of bacterial cell-wall proteins, likely acquired during phage-host coevolution. The interaction of CBD to bacterial cell walls reduces enzyme diffusion and thereby limits cell lysis of the neighboring bacteria. Our findings indicate that the endolysin is trapped to the cell-wall residuals through CBD and might serve as an advantage for phage replication. Thus, employing a CBD-less endolysin might be a feasible strategy for using endolysin for the treatment of C. difficile infection.
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Affiliation(s)
- Wichuda Phothichaisri
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
| | | | - Tavan Janvilisri
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Jirayu Nuadthaisong
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Tanaporn Phetruen
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Robert P. Fagan
- School of Biosciences, Florey Institute, University of Sheffield, Sheffield, United Kingdom
| | - Sittinan Chanarat
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
- Laboratory of Molecular Cell Biology, Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok, Thailand
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Lanzoni-Mangutchi P, Banerji O, Wilson J, Barwinska-Sendra A, Kirk JA, Vaz F, O'Beirne S, Baslé A, El Omari K, Wagner A, Fairweather NF, Douce GR, Bullough PA, Fagan RP, Salgado PS. Structure and assembly of the S-layer in C. difficile. Nat Commun 2022; 13:970. [PMID: 35217634 PMCID: PMC8881574 DOI: 10.1038/s41467-022-28196-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 01/06/2022] [Indexed: 12/13/2022] Open
Abstract
Many bacteria and archaea possess a two-dimensional protein array, or S-layer, that covers the cell surface and plays crucial roles in cell physiology. Here, we report the crystal structure of SlpA, the main S-layer protein of the bacterial pathogen Clostridioides difficile, and use electron microscopy to study S-layer organisation and assembly. The SlpA crystal lattice mimics S-layer assembly in the cell, through tiling of triangular prisms above the cell wall, interlocked by distinct ridges facing the environment. Strikingly, the array is very compact, with pores of only ~10 Å in diameter, compared to other S-layers (30-100 Å). The surface-exposed flexible ridges are partially dispensable for overall structure and assembly, although a mutant lacking this region becomes susceptible to lysozyme, an important molecule in host defence. Thus, our work gives insights into S-layer organisation and provides a basis for development of C. difficile-specific therapeutics.
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Affiliation(s)
- Paola Lanzoni-Mangutchi
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Oishik Banerji
- Krebs Institute, School of Biosciences, University of Sheffield, Sheffield, UK
- Royal Society of Chemistry, Burlington House, Piccadilly, London, UK
| | - Jason Wilson
- Krebs Institute, School of Biosciences, University of Sheffield, Sheffield, UK
| | - Anna Barwinska-Sendra
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Joseph A Kirk
- Krebs Institute, School of Biosciences, University of Sheffield, Sheffield, UK
- Florey Institute, School of Biosciences, University of Sheffield, Sheffield, UK
| | - Filipa Vaz
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Department of Immunology, Oslo University Hospital, Oslo, Norway
| | - Shauna O'Beirne
- Krebs Institute, School of Biosciences, University of Sheffield, Sheffield, UK
- Florey Institute, School of Biosciences, University of Sheffield, Sheffield, UK
| | - Arnaud Baslé
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | | | | | | | - Gillian R Douce
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Per A Bullough
- Krebs Institute, School of Biosciences, University of Sheffield, Sheffield, UK.
| | - Robert P Fagan
- Krebs Institute, School of Biosciences, University of Sheffield, Sheffield, UK.
- Florey Institute, School of Biosciences, University of Sheffield, Sheffield, UK.
| | - Paula S Salgado
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.
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8
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9
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Kirk JA, Gebhart D, Buckley AM, Lok S, Scholl D, Douce GR, Govoni GR, Fagan RP. New class of precision antimicrobials redefines role of Clostridium difficile S-layer in virulence and viability. Sci Transl Med 2018; 9:9/406/eaah6813. [PMID: 28878013 DOI: 10.1126/scitranslmed.aah6813] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 02/06/2017] [Accepted: 04/13/2017] [Indexed: 12/16/2022]
Abstract
There is a medical need for antibacterial agents that do not damage the resident gut microbiota or promote the spread of antibiotic resistance. We recently described a prototypic precision bactericidal agent, Av-CD291.2, which selectively kills specific Clostridium difficile strains and prevents them from colonizing mice. We have since selected two Av-CD291.2-resistant mutants that have a surface (S)-layer-null phenotype due to distinct point mutations in the slpA gene. Using newly identified bacteriophage receptor binding proteins for targeting, we constructed a panel of Avidocin-CDs that kills diverse C. difficile isolates in an S-layer sequence-dependent manner. In addition to bacteriophage receptor recognition, characterization of the mutants also uncovered important roles for S-layer protein A (SlpA) in sporulation, resistance to innate immunity effectors, and toxin production. Surprisingly, S-layer-null mutants were found to persist in the hamster gut despite a complete attenuation of virulence. These findings suggest antimicrobials targeting virulence factors dispensable for fitness in the host force pathogens to trade virulence for viability and would have clear clinical advantages should resistance emerge. Given their exquisite specificity for the pathogen, Avidocin-CDs have substantial therapeutic potential for the treatment and prevention of C. difficile infections.
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Affiliation(s)
- Joseph A Kirk
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Dana Gebhart
- AvidBiotics Corp., South San Francisco, CA 94080, USA
| | - Anthony M Buckley
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Stephen Lok
- AvidBiotics Corp., South San Francisco, CA 94080, USA
| | - Dean Scholl
- AvidBiotics Corp., South San Francisco, CA 94080, USA
| | - Gillian R Douce
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | | | - Robert P Fagan
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
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10
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Vallabhaneni S, Kallen A, Tsay S, Chow N, Welsh R, Kerins J, Kemble SK, Pacilli M, Black SR, Landon E, Ridgway J, Palmore TN, Zelzany A, Adams EH, Quinn M, Chaturvedi S, Greenko J, Fernandez R, Southwick K, Furuya EY, Calfee DP, Hamula C, Patel G, Barrett P, Lafaro P, Berkow EL, Moulton-Meissner H, Noble-Wang J, Fagan RP, Jackson BR, Lockhart SR, Litvintseva AP, Chiller TM. Investigation of the First Seven Reported Cases of Candida auris, a Globally Emerging Invasive, Multidrug-Resistant Fungus-United States, May 2013-August 2016. Am J Transplant 2017; 17:296-299. [PMID: 28029734 DOI: 10.1111/ajt.14121] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
November 11, 2016/65(44);1234-1237. What is already known about this topic? Candida auris is an emerging pathogenic fungus that has been reported from at least a dozen countries on four continents during 2009-2015. The organism is difficult to identify using traditional biochemical methods, some isolates have been found to be resistant to all three major classes of antifungal medications, and C. auris has caused health care-associated outbreaks. What is added by this report? This is the first description of C. auris cases in the United States. C. auris appears to have emerged in the United States only in the last few years, and U.S. isolates are related to isolates from South America and South Asia. Evidence from U.S. case investigations suggests likely transmission of the organism occurred in health care settings. What are the implications for public health practice? It is important that U.S. laboratories accurately identify C. auris and for health care facilities to implement recommended infection control practices to prevent the spread of C. auris. Local and state health departments and CDC should be notified of possible cases of C. auris and of isolates of C. haemulonii and Candida spp. that cannot be identified after routine testing.
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Affiliation(s)
- S Vallabhaneni
- Mycotic Diseases Branch, Division of Food Water and Environmental Diseases, CDC, Atlanta, GA
| | - A Kallen
- Division of Healthcare Quality Promotion, CDC, Atlanta, GA
| | - S Tsay
- Mycotic Diseases Branch, Division of Food Water and Environmental Diseases, CDC, Atlanta, GA.,Epidemic Intelligence Service, Center for Surveillance, Epidemiology and Laboratory Services, CDC, Atlanta, GA
| | - N Chow
- Mycotic Diseases Branch, Division of Food Water and Environmental Diseases, CDC, Atlanta, GA
| | - R Welsh
- Mycotic Diseases Branch, Division of Food Water and Environmental Diseases, CDC, Atlanta, GA
| | - J Kerins
- Epidemic Intelligence Service, Center for Surveillance, Epidemiology and Laboratory Services, CDC, Atlanta, GA.,Chicago Department of Public Health, Chicago, IL
| | - S K Kemble
- Chicago Department of Public Health, Chicago, IL
| | - M Pacilli
- Chicago Department of Public Health, Chicago, IL
| | - S R Black
- Chicago Department of Public Health, Chicago, IL
| | - E Landon
- University of Chicago, Chicago, IL
| | | | - T N Palmore
- National Institutes of Health Clinical Center, Bethesda, MD
| | - A Zelzany
- National Institutes of Health Clinical Center, Bethesda, MD
| | - E H Adams
- New York State Department of Health, New York, NY
| | - M Quinn
- New York State Department of Health, New York, NY
| | - S Chaturvedi
- New York State Department of Health, New York, NY
| | - J Greenko
- New York State Department of Health, New York, NY
| | - R Fernandez
- New York State Department of Health, New York, NY
| | - K Southwick
- New York State Department of Health, New York, NY
| | - E Y Furuya
- Columbia University College of Physicians & Surgeons, New York, NY
| | | | - C Hamula
- Mount Sinai Health System/Icahn School of Medicine at Mount Sinai, New York, NY
| | - G Patel
- Mount Sinai Health System/Icahn School of Medicine at Mount Sinai, New York, NY
| | - P Barrett
- New Jersey Department of Health, Trenton, NJ
| | - P Lafaro
- Robert Wood Johnson University Hospital, New Brunswick, NJ
| | - E L Berkow
- Mycotic Diseases Branch, Division of Food Water and Environmental Diseases, CDC, Atlanta, GA
| | | | - J Noble-Wang
- Division of Healthcare Quality Promotion, CDC, Atlanta, GA
| | - R P Fagan
- Division of Healthcare Quality Promotion, CDC, Atlanta, GA
| | - B R Jackson
- Mycotic Diseases Branch, Division of Food Water and Environmental Diseases, CDC, Atlanta, GA
| | - S R Lockhart
- Mycotic Diseases Branch, Division of Food Water and Environmental Diseases, CDC, Atlanta, GA
| | - A P Litvintseva
- Mycotic Diseases Branch, Division of Food Water and Environmental Diseases, CDC, Atlanta, GA
| | - T M Chiller
- Mycotic Diseases Branch, Division of Food Water and Environmental Diseases, CDC, Atlanta, GA
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11
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Abstract
Clostridium difficile infection has increased in incidence and severity over the past decade, and poses a unique threat to human health. However, genetic manipulation of C. difficile remains in its infancy and the bacterium remains relatively poorly characterised. Low-efficiency conjugation is currently the only available method for transfer of plasmid DNA into C. difficile. This is practically limiting and has slowed progress in understanding this important pathogen. Conjugation efficiency varies widely between strains, with important clinically relevant strains such as R20291 being particularly refractory to plasmid transfer. Here we present an optimised conjugation method in which the recipient C. difficile is heat treated prior to conjugation. This significantly improves conjugation efficiency in all C. difficile strains tested including R20291. Conjugation efficiency was also affected by the choice of media on which conjugations were performed, with standard BHI media giving most transconjugant recovery. Using our optimised method greatly increased the ease with which the chromosome of R20291 could be precisely manipulated by homologous recombination. Our method improves on current conjugation protocols and will help speed genetic manipulation of strains otherwise difficult to work with. Conjugation efficiency in Clostridium difficile can be increased through heat treatment of recipient C. difficile. Conjugation efficiency using an optimised heat treatment conjugation protocol is affected by media choice. Conjugation efficiency is improved when a heat treatment step is included, using a plasmid with a pBP1 replicon. Heat treatment improves conjugation efficiency in all C. difficile strains tested.
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Affiliation(s)
- Joseph A Kirk
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
| | - Robert P Fagan
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
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12
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Kirk JA, Banerji O, Fagan RP. Characteristics of the Clostridium difficile cell envelope and its importance in therapeutics. Microb Biotechnol 2016; 10:76-90. [PMID: 27311697 PMCID: PMC5270738 DOI: 10.1111/1751-7915.12372] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 05/26/2016] [Accepted: 05/30/2016] [Indexed: 01/08/2023] Open
Abstract
Clostridium difficile infection (CDI) is a challenging threat to human health. Infections occur after disruption of the normal microbiota, most commonly through the use of antibiotics. Current treatment for CDI largely relies on the broad‐spectrum antibiotics vancomycin and metronidazole that further disrupt the microbiota resulting in frequent recurrence, highlighting the need for C. difficile‐specific antimicrobials. The cell surface of C. difficile represents a promising target for the development of new drugs. C. difficile possesses a highly deacetylated peptidoglycan cell wall containing unique secondary cell wall polymers. Bound to the cell wall is an essential S‐layer, formed of SlpA and decorated with an additional 28 related proteins. In addition to the S‐layer, many other cell surface proteins have been identified, including several with roles in host colonization. This review aims to summarize our current understanding of these different C. difficile cell surface components and their viability as therapeutic targets.
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Affiliation(s)
- Joseph A Kirk
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Oishik Banerji
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Robert P Fagan
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
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13
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Willing SE, Candela T, Shaw HA, Seager Z, Mesnage S, Fagan RP, Fairweather NF. Clostridium difficile surface proteins are anchored to the cell wall using CWB2 motifs that recognise the anionic polymer PSII. Mol Microbiol 2015; 96:596-608. [PMID: 25649385 PMCID: PMC4973711 DOI: 10.1111/mmi.12958] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2015] [Indexed: 01/05/2023]
Abstract
Gram‐positive surface proteins can be covalently or non‐covalently anchored to the cell wall and can impart important properties on the bacterium in respect of cell envelope organisation and interaction with the environment. We describe here a mechanism of protein anchoring involving tandem CWB2 motifs found in a large number of cell wall proteins in the Firmicutes. In the Clostridium difficile cell wall protein family, we show the three tandem repeats of the CWB2 motif are essential for correct anchoring to the cell wall. CWB2 repeats are non‐identical and cannot substitute for each other, as shown by the secretion into the culture supernatant of proteins containing variations in the patterns of repeats. A conserved Ile Leu Leu sequence within the CWB2 repeats is essential for correct anchoring, although a preceding proline residue is dispensable. We propose a likely genetic locus encoding synthesis of the anionic polymer PSII and, using RNA knock‐down of key genes, reveal subtle effects on cell wall composition. We show that the anionic polymer PSII binds two cell wall proteins, SlpA and Cwp2, and these interactions require the CWB2 repeats, defining a new mechanism of protein anchoring in Gram‐positive bacteria.
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Affiliation(s)
- Stephanie E Willing
- Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
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14
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Pettit LJ, Browne HP, Yu L, Smits WK, Fagan RP, Barquist L, Martin MJ, Goulding D, Duncan SH, Flint HJ, Dougan G, Choudhary JS, Lawley TD. Functional genomics reveals that Clostridium difficile Spo0A coordinates sporulation, virulence and metabolism. BMC Genomics 2014; 15:160. [PMID: 24568651 PMCID: PMC4028888 DOI: 10.1186/1471-2164-15-160] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 02/14/2014] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Clostridium difficile is an anaerobic, Gram-positive bacterium that can reside as a commensal within the intestinal microbiota of healthy individuals or cause life-threatening antibiotic-associated diarrhea in immunocompromised hosts. C. difficile can also form highly resistant spores that are excreted facilitating host-to-host transmission. The C. difficile spo0A gene encodes a highly conserved transcriptional regulator of sporulation that is required for relapsing disease and transmission in mice. RESULTS Here we describe a genome-wide approach using a combined transcriptomic and proteomic analysis to identify Spo0A regulated genes. Our results validate Spo0A as a positive regulator of putative and novel sporulation genes as well as components of the mature spore proteome. We also show that Spo0A regulates a number of virulence-associated factors such as flagella and metabolic pathways including glucose fermentation leading to butyrate production. CONCLUSIONS The C. difficile spo0A gene is a global transcriptional regulator that controls diverse sporulation, virulence and metabolic phenotypes coordinating pathogen adaptation to a wide range of host interactions. Additionally, the rich breadth of functional data allowed us to significantly update the annotation of the C. difficile 630 reference genome which will facilitate basic and applied research on this emerging pathogen.
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15
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Abstract
Here we show that the Rns regulator of Escherichia coli dimerises in vivo and in vitro. Furthermore, we demonstrate that Rns forms aggregates in vitro and describe a methodology to ameliorate aggregation thus permitting the analysis of Rns by cross-linking.
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Affiliation(s)
- Vivienne Mahon
- Department of Clinical Microbiology, School of Medicine, Trinity College Dublin, St. James's Hospital, Dublin, Ireland
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16
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Tam Dang TH, Fagan RP, Fairweather NF, Tate EW. Novel inhibitors of surface layer processing in Clostridium difficile. Bioorg Med Chem 2011; 20:614-21. [PMID: 21752656 DOI: 10.1016/j.bmc.2011.06.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 04/20/2011] [Accepted: 06/14/2011] [Indexed: 01/05/2023]
Abstract
Clostridium difficile, a leading cause of hospital-acquired bacterial infection, is coated in a dense surface layer (S-layer) that is thought to provide both physicochemical protection and a scaffold for host-pathogen interactions. The key structural components of the S-layer are two proteins derived from a polypeptide precursor, SlpA, via proteolytic cleavage by the protease Cwp84. Here, we report the design, synthesis and in vivo characterization of a panel of protease inhibitors and activity-based probes (ABPs) designed to target S-layer processing in live C. difficile cells. Inhibitors based on substrate-mimetic peptides bearing a C-terminal Michael acceptor warhead were found to be promising candidates for further development.
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Affiliation(s)
- T H Tam Dang
- Department of Chemistry, Imperial College London, London SW72AZ, United Kingdom
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17
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Abstract
Protein translocation across the cytoplasmic membrane is an essential process in all bacteria. The Sec system, comprising at its core an ATPase, SecA, and a membrane channel, SecYEG, is responsible for the majority of this protein transport. Recently, a second parallel Sec system has been described in a number of gram-positive species. This accessory Sec system is characterized by the presence of a second copy of the energizing ATPase, SecA2; where it has been studied, SecA2 is responsible for the translocation of a subset of Sec substrates. In common with many pathogenic gram-positive species, Clostridium difficile possesses two copies of SecA. Here, we describe the first characterization of the C. difficile accessory Sec system and the identification of its major substrates. Using inducible antisense RNA expression and dominant-negative alleles of secA1 and secA2, we demonstrate that export of the S-layer proteins (SLPs) and an additional cell wall protein (CwpV) is dependent on SecA2. Accumulation of the cytoplasmic precursor of the SLPs SlpA and other cell wall proteins was observed in cells expressing dominant-negative secA1 or secA2 alleles, concomitant with a decrease in the levels of mature SLPs in the cell wall. Furthermore, expression of either dominant-negative allele or antisense RNA knockdown of SecA1 or SecA2 dramatically impaired growth, indicating that both Sec systems are essential in C. difficile.
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Affiliation(s)
- Robert P Fagan
- Division of Cell and Molecular Biology, Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, United Kingdom.
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18
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Jackson KA, Biggerstaff M, Tobin-D'Angelo M, Sweat D, Klos R, Nosari J, Garrison O, Boothe E, Saathoff-Huber L, Hainstock L, Fagan RP. Multistate outbreak of Listeria monocytogenes associated with Mexican-style cheese made from pasteurized milk among pregnant, Hispanic women. J Food Prot 2011; 74:949-53. [PMID: 21669072 DOI: 10.4315/0362-028x.jfp-10-536] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Listeriosis is a severe infection caused by Listeria monocytogenes. Since 2004, the Centers for Disease Control and Prevention has requested that listeriosis patients be interviewed using a standardized Listeria Initiative (LI) questionnaire. In January 2009, states and the Centers for Disease Control and Prevention began investigating a multistate outbreak of listeriosis among pregnant, Hispanic women. We defined a case as an illness occurring between October 2008 and March 2009 with an L. monocytogenes isolate indistinguishable from the outbreak strain by pulsed-field gel electrophoresis. We conducted a multistate case-control study using controls that were selected from L. monocytogenes illnesses in non-outbreak-related pregnant, Hispanic women that were reported to the LI during 2004 to 2008. Eight cases in five states were identified. Seven of these were pregnant, Hispanic females aged 21 to 43 years, and one was a 3-year-old Hispanic girl, who was excluded from the study. Seven (100%) cases but only 26 (60%) of 43 controls had consumed Mexican-style cheese in the month before illness (odds ratio, 5.89; 95% confidence interval, 1.07 to ∞; P = 0.04). Cultures of asadero cheese made from pasteurized milk collected at a manufacturing facility during routine sampling by the Michigan Department of Agriculture on 23 February 2009 yielded the outbreak strain, leading to a recall of cheeses produced in the plant. Recalled product was traced to stores where at least three of the women had purchased cheese. This investigation highlights the usefulness of routine product sampling for identifying contaminated foods, of pulsed-field gel electrophoresis analysis to detect multistate outbreaks, and of the LI for providing timely exposure information for case-control analyses. Recalls of contaminated cheeses likely prevented additional illnesses.
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Affiliation(s)
- K A Jackson
- Enteric Diseases Epidemiology Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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19
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Reynolds CB, Emerson JE, de la Riva L, Fagan RP, Fairweather NF. The Clostridium difficile cell wall protein CwpV is antigenically variable between strains, but exhibits conserved aggregation-promoting function. PLoS Pathog 2011; 7:e1002024. [PMID: 21533071 PMCID: PMC3080850 DOI: 10.1371/journal.ppat.1002024] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 02/21/2011] [Indexed: 12/20/2022] Open
Abstract
Clostridium difficile is the main cause of antibiotic-associated
diarrhea, leading to significant morbidity and mortality and putting
considerable economic pressure on healthcare systems. Current knowledge of the
molecular basis of pathogenesis is limited primarily to the activities and
regulation of two major toxins. In contrast, little is known of mechanisms used
in colonization of the enteric system. C. difficile expresses a
proteinaceous array on its cell surface known as the S-layer, consisting
primarily of the major S-layer protein SlpA and a family of SlpA homologues, the
cell wall protein (CWP) family. CwpV is the largest member of this family and is
expressed in a phase variable manner. Here we show CwpV promotes C.
difficile aggregation, mediated by the C-terminal repetitive
domain. This domain varies markedly between strains; five distinct repeat types
were identified and were shown to be antigenically distinct. Other aspects of
CwpV are, however, conserved. All CwpV types are expressed in a phase variable
manner. Using targeted gene knock-out, we show that a single site-specific
recombinase RecV is required for CwpV phase variation. CwpV is
post-translationally cleaved at a conserved site leading to formation of a
complex of cleavage products. The highly conserved N-terminus anchors the CwpV
complex to the cell surface. Therefore CwpV function, regulation and processing
are highly conserved across C. difficile strains, whilst the
functional domain exists in at least five antigenically distinct forms. This
hints at a complex evolutionary history for CwpV. Clostridium difficile is a bacterial pathogen that causes
antibiotic-associated diarrhea, which can be fatal. Infections often occur in
healthcare facilities, where there is a high population density of susceptible
patients with many possible routes of transmission. We currently do not know the
functions of molecules found on the surface of C. difficile,
which are likely to facilitate colonization of the host. In this study we
characterize a protein called CwpV that is found on the surface of C.
difficile. We show that bacteria isolated from different patients
have different versions of CwpV and that the immune system's weapons
(antibodies) against one version are useless against the others. This suggests
that CwpV may help C. difficile to escape from our natural
defenses. We have also found that CwpV promotes aggregation of C.
difficile, which may be important for host colonization. To test
these hypotheses in the future we will use animal models to compare genetically
modified C. difficile expressing different levels of CwpV to
see if they behave differently during infection. We hope that knowing more about
CwpV will help guide improvements in the prevention and treatment of C.
difficile.
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Affiliation(s)
- Catherine B. Reynolds
- Division of Cell and Molecular Biology, Centre for Molecular Microbiology
and Infection, Imperial College London, London, United Kingdom
| | - Jenny E. Emerson
- Division of Cell and Molecular Biology, Centre for Molecular Microbiology
and Infection, Imperial College London, London, United Kingdom
| | - Lucia de la Riva
- Division of Cell and Molecular Biology, Centre for Molecular Microbiology
and Infection, Imperial College London, London, United Kingdom
| | - Robert P. Fagan
- Division of Cell and Molecular Biology, Centre for Molecular Microbiology
and Infection, Imperial College London, London, United Kingdom
| | - Neil F. Fairweather
- Division of Cell and Molecular Biology, Centre for Molecular Microbiology
and Infection, Imperial College London, London, United Kingdom
- * E-mail:
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20
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Fagan RP, Janoir C, Collignon A, Mastrantonio P, Poxton IR, Fairweather NF. A proposed nomenclature for cell wall proteins of Clostridium difficile. J Med Microbiol 2011; 60:1225-1228. [PMID: 21252271 DOI: 10.1099/jmm.0.028472-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Strains of Clostridium difficile produce a number of surface-localized proteins, including the S-layer proteins (SLPs) and other proteins that have suspected roles in pathogenesis. During the Third International C. difficile Symposium (Bled, Slovenia, September 2010) discussions were held on standardization of nomenclature. Gene designations were proposed for the large family of cell wall proteins that are paralogues of the SLP and contain putative cell wall binding motifs. This paper summarizes the agreed nomenclature, which we hope will be used by research groups currently active in the field.
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Affiliation(s)
- Robert P Fagan
- Division of Cell and Molecular Biology, Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Claire Janoir
- Université de Paris-Sud XI, USC INRA EA 4043, Faculté de Pharmacie, Châtenay-Malabry Cedex, France
| | - Anne Collignon
- Université de Paris-Sud XI, USC INRA EA 4043, Faculté de Pharmacie, Châtenay-Malabry Cedex, France
| | - Paola Mastrantonio
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Ian R Poxton
- Medical Microbiology, Centre for Infectious Diseases, University of Edinburgh College of Medicine and Veterinary Medicine, Edinburgh EH16 4SB, UK
| | - Neil F Fairweather
- Division of Cell and Molecular Biology, Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, UK
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21
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Dang THT, Riva LDL, Fagan RP, Storck EM, Heal WP, Janoir C, Fairweather NF, Tate EW. Chemical probes of surface layer biogenesis in Clostridium difficile. ACS Chem Biol 2010; 5:279-85. [PMID: 20067320 DOI: 10.1021/cb9002859] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Clostridium difficile, a leading cause of hospital-acquired infection, possesses a dense surface layer (S-layer) that mediates host-pathogen interactions. The key structural components of the S-layer result from proteolytic cleavage of a precursor protein, SlpA, into high- and low-molecular-weight components. Here we report the discovery and optimization of the first inhibitors of this process in live bacteria and their application for probing S-layer processing. We also describe the design and in vivo application of activity-based probes that identify the protein Cwp84 as the cysteine protease that mediates SlpA cleavage. This work provides novel chemical tools for the analysis of S-layer biogenesis and for the potential identification of novel drug targets within clostridia and related bacterial pathogens.
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Affiliation(s)
| | - Lucia de la Riva
- Department of Chemistry
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College London, Exhibition Rd., London SW7 2AZ, U.K
| | - Robert P. Fagan
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College London, Exhibition Rd., London SW7 2AZ, U.K
| | | | | | - Claire Janoir
- EA 4043, Université Paris-Sud 11, Faculté de Pharmacie, 92296 Châtenay-Malabry, France
| | - Neil F. Fairweather
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College London, Exhibition Rd., London SW7 2AZ, U.K
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22
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Emerson JE, Reynolds CB, Fagan RP, Shaw HA, Goulding D, Fairweather NF. A novel genetic switch controls phase variable expression of CwpV, a Clostridium difficile cell wall protein. Mol Microbiol 2009; 74:541-56. [PMID: 19656296 PMCID: PMC2784873 DOI: 10.1111/j.1365-2958.2009.06812.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Clostridium difficile is a nosocomial pathogen that can cause severe gastrointestinal infections. C. difficile encodes a family of cell wall proteins, some of which are implicated in pathogenesis. Here we have characterized CwpV, the largest member of this family. CwpV is surface expressed and post-translationally processed in a manner analogous to the major S-layer protein SlpA. Expression of cwpV is phase variable, with approximately 5% of cells in a population expressing the protein under standard laboratory growth conditions. Upstream of cwpV, inverted repeats flank a 195 bp sequence which undergoes DNA inversion. Use of a gusA transcriptional reporter demonstrated that phase variation is mediated by DNA inversion; in one orientation cwpV is expressed while in the opposite orientation the gene is silent. The inversion region contains neither the promoter nor any of the open reading frame, therefore this system differs from previously described phase variation mechanisms. The cwpV promoter is located upstream of the inversion region and we propose a model of phase variation based on intrinsic terminator formation in the OFF transcript. A C. difficile site-specific recombinase able to catalyse the inversion has been identified.
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Affiliation(s)
- Jenny E Emerson
- Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, UK
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23
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Fagan RP, Albesa-Jové D, Qazi O, Svergun DI, Brown KA, Fairweather NF. Structural insights into the molecular organization of the S-layer fromClostridium difficile. Mol Microbiol 2009; 71:1308-22. [DOI: 10.1111/j.1365-2958.2009.06603.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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24
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Abstract
The OmpA outer membrane protein of Escherichia coli and other enterobacteria is a multifaceted protein. This protein is expressed to very high levels and ompA is tightly regulated at the posttranscriptional level. It can function as an adhesin and invasin, participate in biofilm formation, act as both an immune target and evasin, and serves as a receptor for several bacteriophages. Many of these properties are due to four short protein loops that emanate from the protein to the outside of the cell. Herein it is described how the structure of this protein relates to its many functions.
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Affiliation(s)
- Stephen G J Smith
- Department of Clinical Microbiology, Trinity College Dublin, St James's Hospital, Dublin, Ireland.
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25
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Abstract
Escherichia coli is the principal gram-negative causative agent of sepsis and meningitis in neonates. The pathogenesis of meningitis due to E. coli K1 involves mucosal colonization, transcytosis of epithelial cells, survival in the blood stream and eventually invasion of the meninges. The latter two aspects have been well characterized at a molecular level in the last decade. Less is known about the early stages of pathogenesis, i.e. adhesion to and invasion of gastrointestinal cells. Here, the characterization of the Hek protein is reported, which is expressed by neonatal meningitic E. coli (NMEC) and is localized to the outer membrane. It is demonstrated that this protein can cause agglutination of red blood cells and can mediate autoaggregation. Escherichia coli expressing this protein can adhere to and invade epithelial cells. So far, this is the first outer membrane protein in NMEC to be directly implicated in epithelial cell invasion.
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Affiliation(s)
- Robert P Fagan
- Department of Microbiology, Moyne Institute, Trinity College Dublin, Dublin, Ireland
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