1
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Cai X, He Y, Yu I, Imani A, Scholl D, Miller JF, Zhou ZH. Atomic structures of a bacteriocin targeting Gram-positive bacteria. Nat Commun 2024; 15:7057. [PMID: 39152109 PMCID: PMC11329794 DOI: 10.1038/s41467-024-51038-w] [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: 03/19/2024] [Accepted: 07/29/2024] [Indexed: 08/19/2024] Open
Abstract
Due to envelope differences between Gram-positive and Gram-negative bacteria, engineering precision bactericidal contractile nanomachines requires atomic-level understanding of their structures; however, only those killing Gram-negative bacteria are currently known. Here, we report the atomic structures of an engineered diffocin, a contractile syringe-like molecular machine that kills the Gram-positive bacterium Clostridioides difficile. Captured in one pre-contraction and two post-contraction states, each structure fashions six proteins in the bacteria-targeting baseplate, two proteins in the energy-storing trunk, and a collar linking the sheath with the membrane-penetrating tube. Compared to contractile machines targeting Gram-negative bacteria, major differences reside in the baseplate and contraction magnitude, consistent with target envelope differences. The multifunctional hub-hydrolase protein connects the tube and baseplate and is positioned to degrade peptidoglycan during penetration. The full-length tape measure protein forms a coiled-coil helix bundle homotrimer spanning the entire diffocin. Our study offers mechanical insights and principles for designing potent protein-based precision antibiotics.
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Affiliation(s)
- Xiaoying Cai
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Yao He
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Iris Yu
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Anthony Imani
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Dean Scholl
- Pylum Biosciences, San Francisco, CA, 94080, USA
| | - Jeff F Miller
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
| | - Z Hong Zhou
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
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2
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Hulme JP. Emerging Diagnostics in Clostridioides difficile Infection. Int J Mol Sci 2024; 25:8672. [PMID: 39201359 PMCID: PMC11354687 DOI: 10.3390/ijms25168672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 08/06/2024] [Accepted: 08/07/2024] [Indexed: 09/02/2024] Open
Abstract
Clostridioides difficile detection in community settings is time-intensive, resulting in delays in diagnosing and quarantining infected individuals. However, with the advent of semi-automated devices and improved algorithms in recent decades, the ability to discern CDI infection from asymptomatic carriage has significantly improved. This, in turn, has led to efficiently regulated monitoring systems, further reducing endemic risk, with recent concerns regarding a possible surge in hospital-acquired Clostridioides difficile infections post-COVID failing to materialize. This review highlights established and emerging technologies used to detect community-acquired Clostridioides difficile in research and clinical settings.
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Affiliation(s)
- John P Hulme
- Department of Bio-Nano Technology, Gachon University, Seongnam-si 13120, Republic of Korea
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3
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Wang S, Courreges MC, Xu L, Gurung B, Berryman M, Gu T. Revealing roles of S-layer protein (SlpA) in Clostridioides difficile pathogenicity by generating the first slpA gene deletion mutant. Microbiol Spectr 2024; 12:e0400523. [PMID: 38709045 PMCID: PMC11237437 DOI: 10.1128/spectrum.04005-23] [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: 11/21/2023] [Accepted: 04/16/2024] [Indexed: 05/07/2024] Open
Abstract
Clostridioides difficile infection (CDI) with high morbidity and high mortality is an urgent threat to public health, and C. difficile pathogenesis studies are eagerly required for CDI therapy. The major surface layer protein, SlpA, was supposed to play a key role in C. difficile pathogenesis; however, a lack of isogenic slpA mutants has greatly hampered analysis of SlpA functions. In this study, the whole slpA gene was successfully deleted for the first time via CRISPR-Cas9 system. Deletion of slpA in C. difficile resulted in smaller, smother-edged colonies, shorter bacterial cell size, and aggregation in suspension. For life cycle, the mutant demonstrated lower growth (changes of optical density at 600 nm, OD600) but higher cell density (colony-forming unit, CFU), decreased toxins production, and inhibited sporulation. Moreover, the mutant was more impaired in motility, more sensitive to vancomycin and Triton X-100-induced autolysis, releasing more lactate dehydrogenase. In addition, SlpA deficiency led to robust biofilm formation but weak adhesion to human host cells.IMPORTANCEClostridioides difficile infection (CDI) has been the most common hospital-acquired infection, with a high rate of antibiotic resistance and recurrence incidences, become a debilitating public health threat. It is urgently needed to study C. difficile pathogenesis for developing efficient strategies as CDI therapy. SlpA was indicated to play a key role in C. difficile pathogenesis. However, analysis of SlpA functions was hampered due to lack of isogenic slpA mutants. Surprisingly, the first slpA deletion C. difficile strain was generated in this study via CRISPR-Cas9, further negating the previous thought about slpA being essential. Results in this study will provide direct proof for roles of SlpA in C. difficile pathogenesis, which will facilitate future investigations for new targets as vaccines, new therapeutic agents, and intervention strategies in combating CDI.
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Affiliation(s)
- Shaohua Wang
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, USA
- Infectious and Tropical Disease Institute, Ohio University, Athens, Ohio, USA
| | - Maria C. Courreges
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, USA
| | - Lingjun Xu
- Department of Chemical and Biomolecular Engineering, Institute for Corrosion and Multiphase Technology, Ohio University, Athens, Ohio, USA
| | - Bijay Gurung
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, USA
| | - Mark Berryman
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, USA
| | - Tingyue Gu
- Department of Chemical and Biomolecular Engineering, Institute for Corrosion and Multiphase Technology, Ohio University, Athens, Ohio, USA
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4
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Cai X, He Y, Yu I, Imani A, Scholl D, Miller JF, Zhou ZH. Atomic structures of a bacteriocin targeting Gram-positive bacteria. RESEARCH SQUARE 2024:rs.3.rs-4007122. [PMID: 38586031 PMCID: PMC10996793 DOI: 10.21203/rs.3.rs-4007122/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Due to envelope differences between Gram-positive and Gram-negative bacteria1, engineering precision bactericidal contractile nanomachines2 requires atomic-level understanding of their structures; however, only those killing a Gram-negative bacterium are currently known3,4. Here, we report the atomic structures of an engineered diffocin, a contractile syringe-like molecular machine that kills the Gram-positive bacterium Clostridioides difficile. Captured in one pre-contraction and two post-contraction states, each structure fashions six proteins in the bacteria-targeting baseplate, two proteins in the energy-storing trunk, and a collar protein linking the sheath with the membrane-penetrating tube. Compared to contractile machines targeting Gram-negative bacteria, major differences reside in the baseplate and contraction magnitude, consistent with differences between their targeted envelopes. The multifunctional hub-hydrolase protein connects the tube and baseplate and is positioned to degrade peptidoglycan during penetration. The full-length tape measure protein forms a coiled-coil helix bundle homotrimer spanning the entire length of the diffocin. Our study offers mechanical insights and principles for designing potent protein-based precision antibiotics.
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Affiliation(s)
- Xiaoying Cai
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Yao He
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Iris Yu
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Anthony Imani
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Dean Scholl
- Pylum Biosciences, 100 Kimball Way S. San Francisco, CA 94080, USA
| | - Jeff F. Miller
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Z. Hong Zhou
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
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5
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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] [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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6
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Fettucciari K, Dini F, Marconi P, Bassotti G. Role of the Alteration in Calcium Homeostasis in Cell Death Induced by Clostridioides difficile Toxin A and Toxin B. BIOLOGY 2023; 12:1117. [PMID: 37627001 PMCID: PMC10452684 DOI: 10.3390/biology12081117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 08/05/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023]
Abstract
Clostridioides difficile (C. difficile), responsible for 15-25% of gastrointestinal infections, causes health problems mainly due to the toxic activity of toxins A and B (Tcds). These are responsible for its clinical manifestations, including diarrhea, pseudomembranous colitis, toxic megacolon and death, with a mortality of 5-30% in primary infection, that increase following relapses. Studies on Tcd-induced cell death have highlighted a key role of caspases, calpains, and cathepsins, with involvement of mitochondria and reactive oxygen species (ROS) in a complex signaling pathway network. The complex response in the execution of various types of cell death (apoptosis, necrosis, pyroptosis and pyknosis) depends on the amount of Tcd, cell types, and Tcd receptors involved, and could have as initial/precocious event the alterations in calcium homeostasis. The entities, peculiarities and cell types involved in these alterations will decide the signaling pathways activated and cell death type. Calcium homeostasis alterations can be caused by calcium influx through calcium channel activation, transient intracellular calcium oscillations, and leakage of calcium from intracellular stores. These increases in cytoplasmic calcium have important effects on all calcium-regulated molecules, which may play a direct role in several cell death types and/or activate other cell death effectors, such as caspases, calpains, ROS and proapoptotic Bcl-2 family members. Furthermore, some support for the possible role of the calcium homeostasis alteration in Tcd-induced cell death originates from the similarity with cytotoxic effects that cause pore-forming toxins, based mainly on calcium influx through plasma membrane pores.
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Affiliation(s)
- Katia Fettucciari
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy;
| | - Fabrizio Dini
- School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Matelica, Italy;
| | - Pierfrancesco Marconi
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy;
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy;
- Gastroenterology & Hepatology Unit, Santa Maria Della Misericordia Hospital, 06129 Perugia, Italy
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7
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Heuler J, Chandra H, Sun X. Mucosal Vaccination Strategies against Clostridioides difficile Infection. Vaccines (Basel) 2023; 11:vaccines11050887. [PMID: 37242991 DOI: 10.3390/vaccines11050887] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/16/2023] [Accepted: 04/18/2023] [Indexed: 05/28/2023] Open
Abstract
Clostridioides difficile infection (CDI) presents a major public health threat by causing frequently recurrent, life-threatening cases of diarrhea and intestinal inflammation. The ability of C. difficile to express antibiotic resistance and to form long-lasting spores makes the pathogen particularly challenging to eradicate from healthcare settings, raising the need for preventative measures to curb the spread of CDI. Since C. difficile utilizes the fecal-oral route of transmission, a mucosal vaccine could be a particularly promising strategy by generating strong IgA and IgG responses that prevent colonization and disease. This mini-review summarizes the progress toward mucosal vaccines against C. difficile toxins, cell-surface components, and spore proteins. By assessing the strengths and weaknesses of particular antigens, as well as methods for delivering these antigens to mucosal sites, we hope to guide future research toward an effective mucosal vaccine against CDI.
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Affiliation(s)
- Joshua Heuler
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Harish Chandra
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Xingmin Sun
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
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8
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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] [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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9
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Razim A, Górska S, Gamian A. Non-Toxin-Based Clostridioides difficile Vaccination Approaches. Pathogens 2023; 12:235. [PMID: 36839507 PMCID: PMC9966970 DOI: 10.3390/pathogens12020235] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/02/2023] [Accepted: 01/05/2023] [Indexed: 02/05/2023] Open
Abstract
Clostridioides difficile (CD) is a Gram-positive, anaerobic bacterium that infects mainly hospitalized and elderly people who have been treated with long-term antibiotic therapy leading to dysbiosis. The deteriorating demographic structure and the increase in the number of antibiotics used indicate that the problem of CD infections (CDI) will continue to increase. Thus far, there is no vaccine against CD on the market. Unfortunately, clinical trials conducted using the CD toxin-based antigens did not show sufficiently high efficacy, because they did not prevent colonization and transmission between patients. It seems that the vaccine should also include antigens found in the bacterium itself or its spores in order not only to fight the effects of toxins but also to prevent the colonization of the patient. This literature review summarizes the latest advances in research into vaccine antigens that do not contain CD toxins.
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Affiliation(s)
- Agnieszka Razim
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland
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10
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Cheng JKJ, Unnikrishnan M. Clostridioides difficile infection: traversing host-pathogen interactions in the gut. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36848200 DOI: 10.1099/mic.0.001306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
C. difficile is the primary cause for nosocomial infective diarrhoea. For a successful infection, C. difficile must navigate between resident gut bacteria and the harsh host environment. The perturbation of the intestinal microbiota by broad-spectrum antibiotics alters the composition and the geography of the gut microbiota, deterring colonization resistance, and enabling C. difficile to colonize. This review will discuss how C. difficile interacts with and exploits the microbiota and the host epithelium to infect and persist. We provide an overview of C. difficile virulence factors and their interactions with the gut to aid adhesion, cause epithelial damage and mediate persistence. Finally, we document the host responses to C. difficile, describing the immune cells and host pathways that are associated and triggered during C. difficile infection.
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Affiliation(s)
- Jeffrey K J Cheng
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
| | - Meera Unnikrishnan
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
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11
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Biochemical Characterizations of the Putative Endolysin Ecd09610 Catalytic Domain from Clostridioides difficile. Antibiotics (Basel) 2022; 11:antibiotics11081131. [PMID: 36010000 PMCID: PMC9405191 DOI: 10.3390/antibiotics11081131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 11/18/2022] Open
Abstract
Clostridioides difficile is the major pathogen of pseudomembranous colitis, and novel antimicrobial agents are sought after for its treatment. Phage-derived endolysins with species-specific lytic activity have potential as novel antimicrobial agents. We surveyed the genome of C. difficile strain 630 and identified an endolysin gene, Ecd09610, which has an uncharacterized domain at the N-terminus and two catalytic domains that are homologous to glucosaminidase and endopeptidase at the C-terminus. Genes containing the two catalytic domains, the glucosaminidase domain and the endopeptidase domain, were cloned and expressed in Escherichia coli as N-terminal histidine-tagged proteins. The purified domain variants showed lytic activity almost specifically for C. difficile, which has a unique peptide bridge in its peptidoglycan. This species specificity is thought to depend on substrate cleavage activity rather than binding. The domain variants were thermostable, and, notably, the glucosaminidase domain remained active up to 100 °C. In addition, we determined the optimal pH and salt concentrations of these domain variants. Their properties are suitable for formulating a bacteriolytic enzyme as an antimicrobial agent. This lytic enzyme can serve as a scaffold for the construction of high lytic activity mutants with enhanced properties.
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12
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Surface layer protein A from hypervirulent Clostridioides difficile ribotype 001 can induce autophagy process in human intestinal epithelial cells. Microb Pathog 2022; 169:105681. [PMID: 35850375 DOI: 10.1016/j.micpath.2022.105681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 05/31/2022] [Accepted: 07/12/2022] [Indexed: 11/21/2022]
Abstract
Clostridioides difficile is the leading cause of nosocomial diarrhea with high morbidity and mortality worldwide. C. difficile strains produce a crystalline surface layer protein A (SlpA), which is an absolute necessity for its pathogenesis. However, its pathogenic mechanisms and its pro-inflammatory behavior are not yet fully elucidated. Herein, we report for the first time that SlpA extracted from C. difficile can induce autophagy process in Caco-2 cells. SlpA protein was purified from two C. difficile strains (RT001 and ATCC 700075). The cell viability of Caco-2 cells after exposure with different concentrations (15, 20, 25 μg/mL) of SlpA at various time points (3, 6, 12, 24 h) was measured by MTT assay. Acridine orange staining was used to visualize the hypothetical acidic vesicular organelles. The gene expression of autophagy mediators including LC3B, Atg5, Atg16L, and Beclin-1 was determined by quantitative real-time PCR assay. Western blotting assay was used to detect the expression of LC3B protein. MTT assay showed that different concentrations of SlpA did not induce significant changes in the viability of Caco-2 cells. SlpA at concentration of 20 μg/mL enhanced the formation of acidic vesicular organelles in Caco-2 cells after 12 h of exposure. Moreover, SlpA treatment significantly increased the expression of autophagy-associated genes, and increased the expression of LC3B protein in Caco-2 cells. In conclusion, our study demonstrated that SlpA is capable to induce autophagy in intestinal epithelial cells. These findings reveal a novel mechanism for the pathogenesis of C. difficile mediated by its SLPs.
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13
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Wang M, Deng Z, Li Y, Ma Y, Wang J. Design and characterization of a novel lytic protein against Clostridium difficile. Appl Microbiol Biotechnol 2022; 106:4511-4521. [PMID: 35699735 PMCID: PMC9194777 DOI: 10.1007/s00253-022-12010-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/29/2022] [Accepted: 06/01/2022] [Indexed: 11/29/2022]
Abstract
Abstract Clostridium difficile (C. difficile) is a Gram-positive, spore-forming, toxin-producing anaerobe that can cause nosocomial antibiotic-associated intestinal disease. Autolysin is a lytic enzyme that hydrolyzes peptidoglycans of the bacterial cell wall, with a catalytic domain and cell wall–binding domains, proven to be involved in bacterial cell wall remodeling and cell division. Although autolysins in C. difficile have been reported, the autolysins have failed to yield impressive results when used as exogenous lytic agents. In this study, we expressed and characterized the binding domains (Cwp19-BD and Acd-BD) and catalytic domains (Cwp19-CD, Acd-CD, and Cwl-CD) of C. difficile autolysins, and the domains with the best binding specificity and lytic activity were selected towards C. difficile to design a novel lytic protein Cwl-CWB2. Cwl-CWB2 showed good biosafety with significantly low hemolysis and without cytotoxicity. The results of fluorescence analysis and lytic assay demonstrated that Cwl-CWB2 has higher binding specificity and stronger lytic activity with a minimum inhibitory concentration at 13.39 ± 5.80 μg/mL against living C. difficile cells, which is significantly stronger than commercial lysozyme (3333.33 ± 1443.37 μg/mL) and other reported C. difficile autolysins. Besides, Cwl-CWB2 exhibited good stability as about 75% of the lytic activity was still retained when incubated at 37 °C for 96 h, which is considered to be a potential antimicrobial agent to combat C. difficile. Key points • Several binding domains and catalytic domains, deriving from several Clostridium difficile autolysins, were expressed, purified, and functionally characterized. • A novel C. difficile lytic protein Cwl-CWB2 was designed from C. difficile autolysins. • The binding specificity and lytic activity of Cwl-CWB2 against C. difficile showed advantages compared with other reported C. difficile autolysins. • Cwl-CWB2 exhibited significantly low hemolysis and cytotoxicity against normal-derived colon mucosa 460 cell. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1007/s00253-022-12010-0.
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Affiliation(s)
- Meng Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Zifeng Deng
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Yanmei Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Yi Ma
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Jufang Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China.
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China.
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14
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Bacterial communities in home-made Doushen with and without chili pepper. Food Res Int 2022; 156:111321. [PMID: 35651075 DOI: 10.1016/j.foodres.2022.111321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 11/24/2022]
Abstract
Doushen is a traditional Chinese fermented soybean product prepared with sterilizated soybeans under open conditions. However, little is known on the bacterial community and their influence on the flavor of Doushen. In the present study, Doushen samples with and without chili pepper were collected to reveal the bacterial community and assess a correlation between bacterial community and VFCs in the two kinds of Doushen samples. We identified four phyla and 97 bacterial genera in the two kinds of Doushen samples. In addition, a total of 17 significantly different OTUs were detected by LEfSe (Line Discriminant Analysis (LDA) Effect Size). Results of Principal coordinates analysis (PCoA), unweighted pair-group method (UPGMA) and functional and phenotypes prediction showed that bacterial communities in the two kinds of Doushen were significantly different. Spearman correlation analysis showed that all the dominant genera, except Clostridium Sensu stricto 1, were significantly correlated with the characteristic VFCs. This study provides a theoretical basis for improving the flavour quality of traditional homemade Doushen.
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15
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Shen A, Tamayo R. Editorial overview: Gene regulation mechanisms governing Clostridioides difficile physiology and virulence. Curr Opin Microbiol 2022; 67:102139. [PMID: 35231749 DOI: 10.1016/j.mib.2022.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.
| | - Rita Tamayo
- Department of Microbiology and Immunology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA.
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16
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The WalRK Two-Component System Is Essential for Proper Cell Envelope Biogenesis in Clostridioides difficile. J Bacteriol 2022; 204:e0012122. [PMID: 35575581 PMCID: PMC9210968 DOI: 10.1128/jb.00121-22] [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] [Indexed: 11/20/2022] Open
Abstract
The WalR-WalK two-component regulatory system (TCS) is found in all Firmicutes, in which it regulates the expression of multiple genes required for remodeling the cell envelope during growth and division. Unlike most TCSs, WalRK is essential for viability, so it has attracted interest as a potential antibiotic target. In this study, we used overexpression of WalR and CRISPR interference to investigate the Wal system of Clostridioides difficile, a major cause of hospital-associated diarrhea in high-income countries. We confirmed that the wal operon is essential and identified morphological defects and cell lysis as the major terminal phenotypes of altered wal expression. We also used transcriptome sequencing (RNA-seq) to identify over 150 genes whose expression changes in response to WalR levels. This gene set is enriched in cell envelope genes and includes genes encoding several predicted PG hydrolases and proteins that could regulate PG hydrolase activity. A distinct feature of the C. difficile cell envelope is the presence of an S-layer, and we found that WalR affects expression of several genes which encode S-layer proteins. An unexpected finding was that some Wal-associated phenotypic defects were inverted in comparison to what has been reported for other Firmicutes. For example, downregulation of Wal signaling caused C. difficile cells to become longer rather than shorter, as in Bacillus subtilis. Likewise, downregulation of Wal rendered C. difficile more sensitive to vancomycin, whereas reduced Wal activity is linked to increased vancomycin resistance in Staphylococcus aureus. IMPORTANCE The WalRK two-component system (TCS) is essential for coordinating synthesis and turnover of peptidoglycan in Firmicutes. We investigated the WalRK TCS in Clostridioides difficile, an important bacterial pathogen with an atypical cell envelope. We confirmed that WalRK is essential and regulates cell envelope biogenesis, although several of the phenotypic changes we observed were opposite to what has been reported for other Firmicutes. We also identified over 150 genes whose expression is controlled either directly or indirectly by WalR. Overall, our findings provide a foundation for future investigations of an important regulatory system and potential antibiotic target in C. difficile.
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17
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A Novel Bacteriophage with Broad Host Range against Clostridioides difficile Ribotype 078 Supports SlpA as the Likely Phage Receptor. Microbiol Spectr 2022; 10:e0229521. [PMID: 35107319 PMCID: PMC8809339 DOI: 10.1128/spectrum.02295-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Bacteriophages represent a promising option for the treatment of Clostridioides difficile (formerly Clostridium difficile) infection (CDI), which at present relies on conventional antibiotic therapy. The specificity of bacteriophages should prevent dysbiosis of the colonic microbiota associated with antibiotic treatment of CDI. While numerous phages have been isolated, none have been characterized with broad host range activity toward PCR ribotype (RT) 078 strains, despite their relevance to medicine and agriculture. In this study, we isolated four novel C. difficile myoviruses: ΦCD08011, ΦCD418, ΦCD1801, and ΦCD2301. Their characterization revealed that each was comparable with other C. difficile phages described in the literature, with the exception of ΦCD1801, which exhibited broad host range activity toward RT 078, infecting 15/16 (93.8%) of the isolates tested. In order for wild-type phages to be exploited in the effective treatment of CDI, an optimal phage cocktail must be assembled that provides broad coverage against all C. difficile RTs. We conducted experiments to support previous findings suggesting that SlpA, a constituent of the C. difficile surface layer (S-layer) is the likely phage receptor. Through interpretation of phage-binding assays, our data suggested that ΦCD1801 could bind to an RT 012 strain only in the presence of a plasmid-borne S-layer cassette corresponding to the slpA allele found in RT 078. Armed with this information, efforts should be directed toward the isolation of phages with broad host range activity toward defined S-layer cassette types, which could form the basis of an effective phage cocktail for the treatment of CDI. IMPORTANCE Research into phage therapy has seen a resurgence in recent years owing to growing concerns regarding antimicrobial resistance. Phage research for potential therapy against Clostridioides difficile infection (CDI) is in its infancy, where an optimal “one size fits all” phage cocktail is yet to be derived. The pursuit thus far has aimed to find phages with the broadest possible host range. However, for C. difficile strains belonging to certain PCR ribotypes (RTs), in particular RT 078, phages with broad host range activity are yet to be discovered. In this study, we isolate four novel myoviruses, including ΦCD1801, which exerts the broadest host range activity toward RT 078 reported in the literature. Through the application of ΦCD1801 to phage-binding assays, we provide data to support the prior notion that SlpA represents the likely phage receptor on the bacterial cell surface. Our finding directs research attention toward the isolation of phages with activity toward strains possessing defined S-layer cassette types.
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18
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Nibbering B, Gerding DN, Kuijper EJ, Zwittink RD, Smits WK. Host Immune Responses to Clostridioides difficile: Toxins and Beyond. Front Microbiol 2022; 12:804949. [PMID: 34992590 PMCID: PMC8724541 DOI: 10.3389/fmicb.2021.804949] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/22/2021] [Indexed: 12/17/2022] Open
Abstract
Clostridioides difficile is often resistant to the actions of antibiotics to treat other bacterial infections and the resulting C. difficile infection (CDI) is among the leading causes of nosocomial infectious diarrhea worldwide. The primary virulence mechanism contributing to CDI is the production of toxins. Treatment failures and recurrence of CDI have urged the medical community to search for novel treatment options. Strains that do not produce toxins, so called non-toxigenic C. difficile, have been known to colonize the colon and protect the host against CDI. In this review, a comprehensive description and comparison of the immune responses to toxigenic C. difficile and non-toxigenic adherence, and colonization factors, here called non-toxin proteins, is provided. This revealed a number of similarities between the host immune responses to toxigenic C. difficile and non-toxin proteins, such as the influx of granulocytes and the type of T-cell response. Differences may reflect genuine variation between the responses to toxigenic or non-toxigenic C. difficile or gaps in the current knowledge with respect to the immune response toward non-toxigenic C. difficile. Toxin-based and non-toxin-based immunization studies have been evaluated to further explore the role of B cells and reveal that plasma cells are important in protection against CDI. Since the success of toxin-based interventions in humans to date is limited, it is vital that future research will focus on the immune responses to non-toxin proteins and in particular non-toxigenic strains.
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Affiliation(s)
- Britt Nibbering
- Center for Microbiome Analyses and Therapeutics, Leiden University Medical Center, Leiden, Netherlands.,Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - Dale N Gerding
- Department of Veterans Affairs, Research Service, Edward Hines Jr. VA Hospital, Hines, IL, United States
| | - Ed J Kuijper
- Center for Microbiome Analyses and Therapeutics, Leiden University Medical Center, Leiden, Netherlands.,Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - Romy D Zwittink
- Center for Microbiome Analyses and Therapeutics, Leiden University Medical Center, Leiden, Netherlands.,Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - Wiep Klaas Smits
- Center for Microbiome Analyses and Therapeutics, Leiden University Medical Center, Leiden, Netherlands.,Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
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19
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Inhibitors of Sortases of Gram-Positive Bacteria and their Role in the Treatment of Infectious Diseases (Review). Pharm Chem J 2021. [DOI: 10.1007/s11094-021-02488-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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20
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Planas A. Peptidoglycan Deacetylases in Bacterial Cell Wall Remodeling and Pathogenesis. Curr Med Chem 2021; 29:1293-1312. [PMID: 34525907 DOI: 10.2174/0929867328666210915113723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/24/2021] [Accepted: 07/26/2021] [Indexed: 11/22/2022]
Abstract
The bacterial cell wall peptidoglycan (PG) is a dynamic structure that is constantly synthesized, re-modeled and degraded during bacterial division and growth. Post-synthetic modifications modulate the action of endogenous autolysis during PG lysis and remodeling for growth and sporulation, but also they are a mechanism used by pathogenic bacteria to evade the host innate immune system. Modifica-tions of the glycan backbone are limited to the C-2 amine and the C-6 hydroxyl moieties of either Glc-NAc or MurNAc residues. This paper reviews the functional roles and properties of peptidoglycan de-N-acetylases (distinct PG GlcNAc and MurNAc deacetylases) and recent progress through genetic stud-ies and biochemical characterization to elucidate their mechanism of action, 3D structures, substrate specificities and biological functions. Since they are virulence factors in pathogenic bacteria, peptidogly-can deacetylases are potential targets for the design of novel antimicrobial agents.
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Affiliation(s)
- Antoni Planas
- Laboratory of Biochemistry, Institut Químic de Sarrià. University Ramon Llull, 08017 Barcelona. Spain
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21
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Abstract
Clostridiodes difficile (C. difficile) was ranked an “urgent threat” by the Centers for Disease Control and Prevention (CDC) in 2019. C. difficile infection (CDI) is the most common healthcare-associated infection (HAI) in the United States of America as well as the leading cause of antibiotic-associated gastrointestinal disease. C. difficile is a gram-positive, rod-shaped, spore-forming, anaerobic bacterium that causes infection of the epithelial lining of the gut. CDI occurs most commonly after disruption of the human gut microflora following the prolonged use of broad-spectrum antibiotics. However, the recurrent nature of this disease has led to the hypothesis that biofilm formation may play a role in its pathogenesis. Biofilms are sessile communities of bacteria protected from extracellular stresses by a matrix of self-produced proteins, polysaccharides, and extracellular DNA. Biofilm regulation in C. difficile is still incompletely understood, and its role in disease recurrence has yet to be fully elucidated. However, many factors have been found to influence biofilm formation in C. difficile, including motility, adhesion, and hydrophobicity of the bacterial cells. Small changes in one of these systems can greatly influence biofilm formation. Therefore, the biofilm regulatory system would need to coordinate all these systems to create optimal biofilm-forming physiology under appropriate environmental conditions. The coordination of these systems is complex and multifactorial, and any analysis must take into consideration the influences of the stress response, quorum sensing (QS), and gene regulation by second messenger molecule cyclic diguanosine monophosphate (c-di-GMP). However, the differences in biofilm-forming ability between C. difficile strains such as 630 and the “hypervirulent” strain, R20291, make it difficult to assign a “one size fits all” mechanism to biofilm regulation in C. difficile. This review seeks to consolidate published data regarding the regulation of C. difficile biofilms in order to identify gaps in knowledge and propose directions for future study. Clostridioides difficile (C. difficile) is an opportunistic bacterial pathogen that causes infection of the human gut epithelium following disruption of the normal gut microflora, usually by broad-spectrum antibiotics. C. difficile infection (CDI) is recurrent in 20% to 30% of cases and can lead to significant health-related complications such as pseudomembranous colitis and, in severe cases, death. The impact and cost of this pathogen on healthcare systems are significant, and some aspects of the pathogen’s lifestyle in the host are, as yet, unknown. It is hypothesised that C. difficile exists in the gut as a biofilm due to the infection’s severity and recurrent nature. The biofilm mode of bacterial growth can protect the cells from external factors such as antibiotic treatment, physiological processes, and the immune system. However, biofilm regulation in C. difficile is not yet fully characterised, and in this review, we consolidate published primary research on C. difficile biofilm regulation to gain a comprehensive overview of the factors involved and how they may interact to enable biofilm development within a host.
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22
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Noori M, Ghalavand Z, Azimirad M, Yadegar A, Eslami G, Krutova M, Brajerova M, Goudarzi M, Zali MR. Genetic diversity and phylogenetic analysis of the surface layer protein A gene (slpA) among Clostridioides difficile clinical isolates from Tehran, Iran. Anaerobe 2021; 70:102403. [PMID: 34111549 DOI: 10.1016/j.anaerobe.2021.102403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 05/24/2021] [Accepted: 06/04/2021] [Indexed: 12/15/2022]
Abstract
Clostridioides difficile is the most common causative agent of healthcare-associated diarrhea. C. difficile strains produce a crystalline surface layer protein (SlpA), encoded by the slpA gene. Previous studies have shown that SlpA varies among C. difficile strains. In this study, we used the SlpA sequence-based typing system (SlpAST) for the molecular genotyping of C. difficile clinical isolates identified in Iran; the PCR ribotypes (RTs) and toxin profiles of the isolates were also characterized. Forty-eight C. difficile isolates were obtained from diarrheal patients, and characterized by capillary electrophoresis (CE) PCR ribotyping and the detection of toxin genes. In addition, the genetic diversity of the slpA gene was investigated by Sanger sequencing. The most common RTs were RT126 (20.8%), followed by RT001 (12.5%) and RT084 (10.4%). The intact PaLoc arrangement representing cdu2+/tcdR+/tcdB+/tcdE+/tcdA+/tcdC+/cdd3+ profile was the predominant pattern and cdtA and cdtB genes were found in one-third of the isolates. Using the SlpA genotyping, 12 main genotypes and 16 subtypes were identified. The SlpA type 078-1 was the most prevalent genotype (20.8%), and identified within the isolates of RT126. The yok-1, gr-1, cr-1 and kr-3 genotypes were detected in 14.5%, 12.5%, 12.5% and 8.3% of isolates, respectively. Almost all the isolates with the same RT were clustered in similar SlpA sequence types. In comparison to PCR ribotyping, SlpAST, as a simple and highly reproducible sequenced-based technique, can discriminate well between C. difficile isolates. This typing method appears to be a valuable tool for the epidemiological study of C. difficile isolates worldwide.
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Affiliation(s)
- Maryam Noori
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zohreh Ghalavand
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Masoumeh Azimirad
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbas Yadegar
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Gita Eslami
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Marcela Krutova
- Department of Medical Microbiology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
| | - Marie Brajerova
- Department of Medical Microbiology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
| | - Mehdi Goudarzi
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Zali
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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23
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In silico designing of vaccine candidate against Clostridium difficile. Sci Rep 2021; 11:14215. [PMID: 34244557 PMCID: PMC8271013 DOI: 10.1038/s41598-021-93305-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/21/2021] [Indexed: 12/19/2022] Open
Abstract
Clostridium difficile is a spore-forming gram-positive bacterium, recognized as the primary cause of antibiotic-associated nosocomial diarrhoea. Clostridium difficile infection (CDI) has emerged as a major health-associated infection with increased incidence and hospitalization over the years with high mortality rates. Contamination and infection occur after ingestion of vegetative spores, which germinate in the gastro-intestinal tract. The surface layer protein and flagellar proteins are responsible for the bacterial colonization while the spore coat protein, is associated with spore colonization. Both these factors are the main concern of the recurrence of CDI in hospitalized patients. In this study, the CotE, SlpA and FliC proteins are chosen to form a multivalent, multi-epitopic, chimeric vaccine candidate using the immunoinformatics approach. The overall reliability of the candidate vaccine was validated in silico and the molecular dynamics simulation verified the stability of the vaccine designed. Docking studies showed stable vaccine interactions with Toll‐Like Receptors of innate immune cells and MHC receptors. In silico codon optimization of the vaccine and its insertion in the cloning vector indicates a competent expression of the modelled vaccine in E. coli expression system. An in silico immune simulation system evaluated the effectiveness of the candidate vaccine to trigger a protective immune response.
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24
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Brauer M, Lassek C, Hinze C, Hoyer J, Becher D, Jahn D, Sievers S, Riedel K. What's a Biofilm?-How the Choice of the Biofilm Model Impacts the Protein Inventory of Clostridioides difficile. Front Microbiol 2021; 12:682111. [PMID: 34177868 PMCID: PMC8225356 DOI: 10.3389/fmicb.2021.682111] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/12/2021] [Indexed: 12/18/2022] Open
Abstract
The anaerobic pathogen Clostridioides difficile is perfectly equipped to survive and persist inside the mammalian intestine. When facing unfavorable conditions C. difficile is able to form highly resistant endospores. Likewise, biofilms are currently discussed as form of persistence. Here a comprehensive proteomics approach was applied to investigate the molecular processes of C. difficile strain 630Δerm underlying biofilm formation. The comparison of the proteome from two different forms of biofilm-like growth, namely aggregate biofilms and colonies on agar plates, revealed major differences in the formation of cell surface proteins, as well as enzymes of its energy and stress metabolism. For instance, while the obtained data suggest that aggregate biofilm cells express both flagella, type IV pili and enzymes required for biosynthesis of cell-surface polysaccharides, the S-layer protein SlpA and most cell wall proteins (CWPs) encoded adjacent to SlpA were detected in significantly lower amounts in aggregate biofilm cells than in colony biofilms. Moreover, the obtained data suggested that aggregate biofilm cells are rather actively growing cells while colony biofilm cells most likely severely suffer from a lack of reductive equivalents what requires induction of the Wood-Ljungdahl pathway and C. difficile’s V-type ATPase to maintain cell homeostasis. In agreement with this, aggregate biofilm cells, in contrast to colony biofilm cells, neither induced toxin nor spore production. Finally, the data revealed that the sigma factor SigL/RpoN and its dependent regulators are noticeably induced in aggregate biofilms suggesting an important role of SigL/RpoN in aggregate biofilm formation.
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Affiliation(s)
- Madita Brauer
- Department for Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Christian Lassek
- Department for Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Christian Hinze
- Department for Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Juliane Hoyer
- Department for Microbial Proteomics, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Dörte Becher
- Department for Microbial Proteomics, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Dieter Jahn
- Braunschweig Integrated Centre of Systems Biology (BRICS), Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Susanne Sievers
- Department for Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Katharina Riedel
- Department for Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, Greifswald, Germany
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25
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Sekiya H, Tamai E, Kawasaki J, Murakami K, Kamitori S. Structural and biochemical characterizations of the novel autolysin Acd24020 from Clostridioides difficile and its full-function catalytic domain as a lytic enzyme. Mol Microbiol 2020; 115:684-698. [PMID: 33140473 DOI: 10.1111/mmi.14636] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 10/13/2020] [Accepted: 10/28/2020] [Indexed: 12/17/2022]
Abstract
Autolysin is a lytic enzyme that hydrolyzes peptidoglycans of the bacterial cell wall, with a catalytic domain and cell wall-binding (CWB) domains, to be involved in different physiological functions that require bacterial cell wall remodeling. We identified a novel autolysin, Acd24020, from Clostridioides (Clostridium) difficile (C. difficile), with an endopeptidase catalytic domain belonging to the NlpC/P60 family and three bacterial Src-homology 3 domains as CWB domains. The catalytic domain of Acd24020 (Acd24020-CD) exhibited C. difficile-specific lytic activity equivalent to Acd24020, indicating that Acd24020-CD has full-function as a lytic enzyme by itself. To elucidate the specific peptidoglycan-recognition and catalytic reaction mechanisms of Acd24020-CD, biochemical characterization, X-ray structure determination, a modeling study of the enzyme/substrate complex, and mutagenesis analysis were performed. Acd24020-CD has an hourglass-shaped substrate-binding groove across the molecule, which is responsible for recognizing the direct 3-4 cross-linking structure unique to C. difficile peptidoglycan. Based on the X-ray structure and modeling study, we propose a dynamic Cys/His catalyzing mechanism, in which the catalytic Cys299 and His354 residues dynamically change their conformations to complement each step of the enzyme catalytic reaction.
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Affiliation(s)
- Hiroshi Sekiya
- Department of Infectious Disease, College of Pharmaceutical Science, Matsuyama University, Matsuyama, Japan
| | - Eiji Tamai
- Department of Infectious Disease, College of Pharmaceutical Science, Matsuyama University, Matsuyama, Japan.,Life Science Research Center and Faculty of Medicine, Kagawa University, Miki-cho, Kita-gun, Japan
| | - Jurina Kawasaki
- Department of Infectious Disease, College of Pharmaceutical Science, Matsuyama University, Matsuyama, Japan
| | - Kaho Murakami
- Department of Infectious Disease, College of Pharmaceutical Science, Matsuyama University, Matsuyama, Japan
| | - Shigehiro Kamitori
- Life Science Research Center and Faculty of Medicine, Kagawa University, Miki-cho, Kita-gun, Japan
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Kaus GM, Snyder LF, Müh U, Flores MJ, Popham DL, Ellermeier CD. Lysozyme Resistance in Clostridioides difficile Is Dependent on Two Peptidoglycan Deacetylases. J Bacteriol 2020; 202:e00421-20. [PMID: 32868404 PMCID: PMC7585060 DOI: 10.1128/jb.00421-20] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 08/25/2020] [Indexed: 12/18/2022] Open
Abstract
Clostridioides (Clostridium) difficile is a major cause of hospital-acquired infections leading to antibiotic-associated diarrhea. C. difficile exhibits a very high level of resistance to lysozyme. Bacteria commonly resist lysozyme through modification of the cell wall. In C. difficile, σV is required for lysozyme resistance, and σV is activated in response to lysozyme. Once activated, σV, encoded by csfV, directs transcription of genes necessary for lysozyme resistance. Here, we analyze the contribution of individual genes in the σV regulon to lysozyme resistance. Using CRISPR-Cas9-mediated mutagenesis we constructed in-frame deletions of single genes in the csfV operon. We find that pdaV, which encodes a peptidoglycan deacetylase, is partially responsible for lysozyme resistance. We then performed CRISPR inhibition (CRISPRi) to identify a second peptidoglycan deacetylase, encoded by pgdA, that is important for lysozyme resistance. Deletion of either pgdA or pdaV resulted in modest decreases in lysozyme resistance. However, deletion of both pgdA and pdaV resulted in a 1,000-fold decrease in lysozyme resistance. Further, muropeptide analysis revealed that loss of either PgdA or PdaV had modest effects on peptidoglycan deacetylation but that loss of both PgdA and PdaV resulted in almost complete loss of peptidoglycan deacetylation. This suggests that PgdA and PdaV are redundant peptidoglycan deacetylases. We also used CRISPRi to compare other lysozyme resistance mechanisms and conclude that peptidoglycan deacetylation is the major mechanism of lysozyme resistance in C. difficileIMPORTANCEClostridioides difficile is the leading cause of hospital-acquired diarrhea. C. difficile is highly resistant to lysozyme. We previously showed that the csfV operon is required for lysozyme resistance. Here, we used CRISPR-Cas9 mediated mutagenesis and CRISPRi knockdown to show that peptidoglycan deacetylation is necessary for lysozyme resistance and is the major lysozyme resistance mechanism in C. difficile We show that two peptidoglycan deacetylases in C. difficile are partially redundant and are required for lysozyme resistance. PgdA provides an intrinsic level of deacetylation, and PdaV, encoded by a part of the csfV operon, provides lysozyme-induced peptidoglycan deacetylation.
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Affiliation(s)
- Gabriela M Kaus
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Lindsey F Snyder
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, Iowa, USA
| | - Ute Müh
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Matthew J Flores
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - David L Popham
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Craig D Ellermeier
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, Iowa, USA
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27
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Chen Y, Huang K, Chen LK, Wu HY, Hsu CY, Tsai YS, Ko WC, Tsai PJ. Membrane Cholesterol Is Crucial for Clostridium difficile Surface Layer Protein Binding and Triggering Inflammasome Activation. Front Immunol 2020; 11:1675. [PMID: 32849582 PMCID: PMC7411348 DOI: 10.3389/fimmu.2020.01675] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/23/2020] [Indexed: 12/12/2022] Open
Abstract
Clostridium difficile, an obligate anaerobic gram-positive bacillus, generates spores and is commonly found colonizing the human gut. Patients with C. difficile infection (CDI) often exhibit clinical manifestations of pseudomembranous colitis or antibiotic-associated diarrhea. Surface layer proteins (SLPs) are the most abundant proteins in the C. difficile cell wall, suggesting that they might involve in immune recognition. Our previous results demonstrated that C. difficile triggers inflammasome activation. Here, we found SLPs as well as C. difficile induced inflammasome activation, and in a dose-dependent manner. In addition, the cholesterol-rich microdomains on the cell membrane (also referred to as lipid rafts) are thought to be crucial for bacterial adhesion and signal transduction. We demonstrated that lipid rafts participated in C. difficile SLPs binding to the cell membrane. Fluorescence microscopy showed that membrane cholesterol depletion by methyl-β-cyclodextrin (MβCD) reduced the association of SLPs with the cell surface. The coalescence of SLPs in the cholesterol-rich microdomains was confirmed in C. difficile-infected cells. Furthermore, the inflammasome activations induced by SLPs or C. difficile were abrogated by MβCD. Our results demonstrate that SLPs recruit the lipid rafts, which may be a key step for C. difficile colonization and inducing inflammasome activation.
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Affiliation(s)
- Yu Chen
- Department of Laboratory Medicine, Mackay Memorial Hospital, New Taipei, Taiwan
| | - Kai Huang
- Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan, Taiwan
| | - Liang-Kuei Chen
- Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan, Taiwan.,Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan
| | - Hui-Yu Wu
- Department of Laboratory Medicine, Mackay Memorial Hospital, New Taipei, Taiwan
| | - Chih-Yu Hsu
- Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan, Taiwan
| | - Yau-Sheng Tsai
- Institute of Clinical Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wen-Chien Ko
- Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan
| | - Pei-Jane Tsai
- Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan, Taiwan.,Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan.,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan
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28
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Shaw HA, Preston MD, Vendrik KEW, Cairns MD, Browne HP, Stabler RA, Crobach MJT, Corver J, Pituch H, Ingebretsen A, Pirmohamed M, Faulds-Pain A, Valiente E, Lawley TD, Fairweather NF, Kuijper EJ, Wren BW. The recent emergence of a highly related virulent Clostridium difficile clade with unique characteristics. Clin Microbiol Infect 2020; 26:492-498. [PMID: 31525517 PMCID: PMC7167513 DOI: 10.1016/j.cmi.2019.09.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 01/06/2023]
Abstract
OBJECTIVES Clostridium difficile is a major global human pathogen divided into five clades, of which clade 3 is the least characterized and consists predominantly of PCR ribotype (RT) 023 strains. Our aim was to analyse and characterize this clade. METHODS In this cohort study the clinical presentation of C. difficile RT023 infections was analysed in comparison with known 'hypervirulent' and non-hypervirulent strains, using data from the Netherlands national C. difficile surveillance programme. European RT023 strains of diverse origin were collected and whole-genome sequenced to determine the genetic similarity between isolates. Distinctive features were investigated and characterized. RESULTS Clinical presentation of C. difficile RT023 infections show severe infections akin to those seen with 'hypervirulent' strains from clades 2 (RT027) and 5 (RT078) (35%, 29% and 27% severe CDI, respectively), particularly with significantly more bloody diarrhoea than RT078 and non-hypervirulent strains (RT023 8%, other RTs 4%, p 0.036). The full genome sequence of strain CD305 is presented as a robust reference. Phylogenetic comparison of CD305 and a further 79 previously uncharacterized European RT023 strains of diverse origin revealed minor genetic divergence with >99.8% pairwise identity between strains. Analyses revealed distinctive features among clade 3 strains, including conserved pathogenicity locus, binary toxin and phage insertion toxin genotypes, glycosylation of S-layer proteins, presence of the RT078 four-gene trehalose cluster and an esculinase-negative genotype. CONCLUSIONS Given their recent emergence, virulence and genomic characteristics, the surveillance of clade 3 strains should be more highly prioritized.
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Affiliation(s)
- H A Shaw
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK; Division of Bacteriology, National Institute for Biological Standards and Controls, South Mimms, Potters Bar, UK
| | - M D Preston
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK; Analytical Biological Service Division, National Institute for Biological Standards and Controls, Potters Bar, UK
| | - K E W Vendrik
- National Reference Laboratory for CDI Surveillance, Department of Medical Microbiology and RIVM, Leiden University Medical Centre, Leiden, the Netherlands
| | - M D Cairns
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK; Public Health Laboratory London, Division of Infection, The Royal London Hospital, London, UK
| | - H P Browne
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK
| | - R A Stabler
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - M J T Crobach
- National Reference Laboratory for CDI Surveillance, Department of Medical Microbiology and RIVM, Leiden University Medical Centre, Leiden, the Netherlands
| | - J Corver
- National Reference Laboratory for CDI Surveillance, Department of Medical Microbiology and RIVM, Leiden University Medical Centre, Leiden, the Netherlands
| | - H Pituch
- Department of Medical Microbiology, Medical University of Warsaw, Warsaw, Poland
| | - A Ingebretsen
- Department of Microbiology, Oslo University Hospital, Oslo, Norway; Department of Infection Prevention, Oslo University Hospital, Oslo, Norway
| | - M Pirmohamed
- Department of Molecular and Clinical Pharmacology, The University of Liverpool, Liverpool, UK
| | - A Faulds-Pain
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - E Valiente
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - T D Lawley
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK
| | | | - E J Kuijper
- National Reference Laboratory for CDI Surveillance, Department of Medical Microbiology and RIVM, Leiden University Medical Centre, Leiden, the Netherlands
| | - B W Wren
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK.
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29
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Clostridium difficile clade 3 (RT023) have a modified cell surface and contain a large transposable island with novel cargo. Sci Rep 2019; 9:15330. [PMID: 31653906 PMCID: PMC6814731 DOI: 10.1038/s41598-019-51628-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 10/02/2019] [Indexed: 12/16/2022] Open
Abstract
The major global pathogen Clostridium difficile (recently renamed Clostridioides difficile) has large genetic diversity including multiple mobile genetic elements. In this study, whole genome sequencing of 86 strains from the poorly characterised clade 3, predominantly PCR ribotype (RT)023, of C. difficile revealed distinctive surface architecture characteristics and a large mobile genetic island. These strains have a unique sortase substrate phenotype compared with well-characterised strains of C. difficile, and loss of the phage protection protein CwpV. A large genetic insertion (023_CTnT) comprised of three smaller elements (023_CTn1-3) is present in 80/86 strains analysed in this study, with genes common among other bacterial strains in the gut microbiome. Novel cargo regions of 023_CTnT include genes encoding a sortase, putative sortase substrates, lantibiotic ABC transporters and a putative siderophore biosynthetic cluster. We demonstrate the excision of 023_CTnT and sub-elements 023_CTn2 and 023_CTn3 from the genome of RT023 reference strain CD305 and the transfer of 023_CTn3 to a non-toxigenic C. difficile strain, which may have implications for the use of non-toxigenic C. difficile strains as live attenuated vaccines. Finally, we show that the genes within the island are expressed in a regulated manner in C. difficile RT023 strains conferring a distinct "niche adaptation".
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30
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Bradshaw WJ, Bruxelle JF, Kovacs-Simon A, Harmer NJ, Janoir C, Péchiné S, Acharya KR, Michell SL. Molecular features of lipoprotein CD0873: A potential vaccine against the human pathogen Clostridioides difficile. J Biol Chem 2019; 294:15850-15861. [PMID: 31420448 PMCID: PMC6816091 DOI: 10.1074/jbc.ra119.010120] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/15/2019] [Indexed: 01/10/2023] Open
Abstract
Clostridioides difficile is the primary cause of antibiotic-associated diarrhea and colitis, a healthcare-associated intestinal disease resulting in a significant fatality rate. Colonization of the gut is critical for C. difficile pathogenesis. The bacterial molecules essential for efficient colonization therefore offer great potential as vaccine candidates. Here we present findings demonstrating that the C. difficile immunogenic lipoprotein CD0873 plays a critical role in pathogen success in vivo. We found that in a dixenic colonization model, a CD0873-positive strain of C. difficile significantly outcompeted a CD0873-negative strain. Immunization of mice with recombinant CD0873 prevented long-term gut colonization and was correlated with a strong secretory IgA immune response. We further present high-resolution crystal structures of CD0873, at 1.35–2.50 Å resolutions, offering a first view of the ligand-binding pocket of CD0873 and provide evidence that this lipoprotein adhesin is part of a tyrosine import system, an amino acid key in C. difficile infection. These findings suggest that CD0873 could serve as an effective component in a vaccine against C. difficile.
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Affiliation(s)
- William J Bradshaw
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Jean-François Bruxelle
- EA4043 Unité Bactéries Pathogènes et Santé (UBaPS), University Paris-Sud, Université Paris-Saclay, Châtenay-Malabry Cedex, France
| | - Andrea Kovacs-Simon
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Nicholas J Harmer
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom.,Living Systems Institute, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Claire Janoir
- EA4043 Unité Bactéries Pathogènes et Santé (UBaPS), University Paris-Sud, Université Paris-Saclay, Châtenay-Malabry Cedex, France
| | - Severine Péchiné
- EA4043 Unité Bactéries Pathogènes et Santé (UBaPS), University Paris-Sud, Université Paris-Saclay, Châtenay-Malabry Cedex, France
| | - K Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Stephen L Michell
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom
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31
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The Ser/Thr Kinase PrkC Participates in Cell Wall Homeostasis and Antimicrobial Resistance in Clostridium difficile. Infect Immun 2019; 87:IAI.00005-19. [PMID: 31085703 DOI: 10.1128/iai.00005-19] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/26/2019] [Indexed: 12/15/2022] Open
Abstract
Clostridium difficile is the leading cause of antibiotic-associated diarrhea in adults. During infection, C. difficile must detect the host environment and induce an appropriate survival strategy. Signal transduction networks involving serine/threonine kinases (STKs) play key roles in adaptation, as they regulate numerous physiological processes. PrkC of C. difficile is an STK with two PASTA domains. We showed that PrkC is membrane associated and is found at the septum. We observed that deletion of prkC affects cell morphology with an increase in mean size, cell length heterogeneity, and presence of abnormal septa. A ΔprkC mutant was able to sporulate and germinate but was less motile and formed more biofilm than the wild-type strain. Moreover, a ΔprkC mutant was more sensitive to antimicrobial compounds that target the cell envelope, such as the secondary bile salt deoxycholate, cephalosporins, cationic antimicrobial peptides, and lysozyme. This increased susceptibility was not associated with differences in peptidoglycan or polysaccharide II composition. However, the ΔprkC mutant had less peptidoglycan and released more polysaccharide II into the supernatant. A proteomic analysis showed that the majority of C. difficile proteins associated with the cell wall were less abundant in the ΔprkC mutant than the wild-type strain. Finally, in a hamster model of infection, the ΔprkC mutant had a colonization delay that did not significantly affect overall virulence.
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32
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Topologically-guided continuous protein crystallization controls bacterial surface layer self-assembly. Nat Commun 2019; 10:2731. [PMID: 31227690 PMCID: PMC6588578 DOI: 10.1038/s41467-019-10650-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 05/16/2019] [Indexed: 12/22/2022] Open
Abstract
Many bacteria and most archaea possess a crystalline protein surface layer (S-layer), which surrounds their growing and topologically complicated outer surface. Constructing a macromolecular structure of this scale generally requires localized enzymatic machinery, but a regulatory framework for S-layer assembly has not been identified. By labeling, superresolution imaging, and tracking the S-layer protein (SLP) from C. crescentus, we show that 2D protein self-assembly is sufficient to build and maintain the S-layer in living cells by efficient protein crystal nucleation and growth. We propose a model supported by single-molecule tracking whereby randomly secreted SLP monomers diffuse on the lipopolysaccharide (LPS) outer membrane until incorporated at the edges of growing 2D S-layer crystals. Surface topology creates crystal defects and boundaries, thereby guiding S-layer assembly. Unsupervised assembly poses challenges for therapeutics targeting S-layers. However, protein crystallization as an evolutionary driver rationalizes S-layer diversity and raises the potential for biologically inspired self-assembling macromolecular nanomaterials. Bacteria assemble the surface layer (S-layer), a crystalline protein coat surrounding the curved surface, using protein self-assembly. Here authors image native and purified RsaA, the S-layer protein from C. crescentus, and show that protein crystallization alone is sufficient to assemble and maintain the S-layer in vivo.
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33
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Giau VV, Lee H, An SSA, Hulme J. Recent advances in the treatment of C. difficile using biotherapeutic agents. Infect Drug Resist 2019; 12:1597-1615. [PMID: 31354309 PMCID: PMC6579870 DOI: 10.2147/idr.s207572] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/03/2019] [Indexed: 12/12/2022] Open
Abstract
Clostridium difficile (C. difficile) is rapidly becoming one of the most prevalent health care–associated bacterial infections in the developed world. The emergence of new, more virulent strains has led to greater morbidity and resistance to standard therapies. The bacterium is readily transmitted between people where it can asymptomatically colonize the gut environment, and clinical manifestations ranging from frequent watery diarrhea to toxic megacolon can arise depending on the age of the individual or their state of gut dysbiosis. Several inexpensive approaches are shown to be effective against virulent C. difficile in research settings such as probiotics, fecal microbiota transfer and immunotherapies. This review aims to highlight the current advantages and limitations of the aforementioned approaches with an emphasis on recent studies.
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Affiliation(s)
- Vo Van Giau
- Department of BioNano Technology, Gachon University, Seongnam-si 461-701, Republic of Korea
| | - Hyon Lee
- Department of Neurology, Gachon University Gil Medical Center, Incheon, South Korea
| | - Seong Soo A An
- Department of BioNano Technology, Gachon University, Seongnam-si 461-701, Republic of Korea
| | - John Hulme
- Department of BioNano Technology, Gachon University, Seongnam-si 461-701, Republic of Korea
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34
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Richards E, Bouché L, Panico M, Arbeloa A, Vinogradov E, Morris H, Wren B, Logan SM, Dell A, Fairweather NF. The S-layer protein of a Clostridium difficile SLCT-11 strain displays a complex glycan required for normal cell growth and morphology. J Biol Chem 2018; 293:18123-18137. [PMID: 30275012 PMCID: PMC6254364 DOI: 10.1074/jbc.ra118.004530] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/27/2018] [Indexed: 12/16/2022] Open
Abstract
Clostridium difficile is a bacterial pathogen that causes major health challenges worldwide. It has a well-characterized surface (S)-layer, a para-crystalline proteinaceous layer surrounding the cell wall. In many bacterial and archaeal species, the S-layer is glycosylated, but no such modifications have been demonstrated in C. difficile. Here, we show that a C. difficile strain of S-layer cassette type 11, Ox247, has a complex glycan attached via an O-linkage to Thr-38 of the S-layer low-molecular-weight subunit. Using MS and NMR, we fully characterized this glycan. We present evidence that it is composed of three domains: (i) a core peptide-linked tetrasaccharide with the sequence -4-α-Rha-3-α-Rha-3-α-Rha-3-β-Gal-peptide; (ii) a repeating pentasaccharide with the sequence -4-β-Rha-4-α-Glc-3-β-Rha-4-(α-Rib-3-)β-Rha-; and (iii) a nonreducing end-terminal 2,3 cyclophosphoryl-rhamnose attached to a ribose-branched sub-terminal rhamnose residue. The Ox247 genome contains a 24-kb locus containing genes for synthesis and protein attachment of this glycan. Mutations in genes within this locus altered or completely abrogated formation of this glycan, and their phenotypes suggested that this S-layer modification may affect sporulation, cell length, and biofilm formation of C. difficile In summary, our findings indicate that the S-layer protein of SLCT-11 strains displays a complex glycan and suggest that this glycan is required for C. difficile sporulation and control of cell shape, a discovery with implications for the development of antimicrobials targeting the S-layer.
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Affiliation(s)
- Emma Richards
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom
| | - Laura Bouché
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom
| | - Maria Panico
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom
| | - Ana Arbeloa
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom
| | - Evgeny Vinogradov
- the Vaccine Program, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Howard Morris
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom,; Biopharmaspec, Suite 3.1, Lido Medical Centre, St. Saviours Road, JE2 7LA Jersey, United Kingdom, and
| | - Brendan Wren
- the London School of Hygiene and Tropical Medicine, WC1E 7HT, London, United Kingdom
| | - Susan M Logan
- the Vaccine Program, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Anne Dell
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom,.
| | - Neil F Fairweather
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom,.
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35
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Lawry BM, Johnson CL, Flanagan K, Spoors JA, McNeil CJ, Wipat A, Keegan N. Species-Specific Detection of C. difficile Using Targeted Antibody Design. Anal Chem 2018; 90:13475-13482. [DOI: 10.1021/acs.analchem.8b03349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- B. M. Lawry
- School of Biomedical Sciences, Faculty of Medical Sciences, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, United Kingdom
| | - C. L. Johnson
- Diagnostic and Therapeutic Technologies, Institute of Cellular Medicine, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, United Kingdom
| | - K. Flanagan
- School of Computing, Urban Sciences Building, Newcastle University, Newcastle-Upon-Tyne, NE4 5TG, United Kingdom
| | - J. A. Spoors
- Diagnostic and Therapeutic Technologies, Institute of Cellular Medicine, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, United Kingdom
| | - C. J. McNeil
- Diagnostic and Therapeutic Technologies, Institute of Cellular Medicine, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, United Kingdom
| | - A. Wipat
- School of Computing, Urban Sciences Building, Newcastle University, Newcastle-Upon-Tyne, NE4 5TG, United Kingdom
| | - N. Keegan
- Diagnostic and Therapeutic Technologies, Institute of Cellular Medicine, Newcastle University, Newcastle-Upon-Tyne, NE2 4HH, United Kingdom
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36
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Ghazaei C, Line El Helou M. Beyond proteostasis: Roles of type I chaperonins in bacterial pathogenesis. J Med Microbiol 2018; 67:1203-1211. [PMID: 30074472 DOI: 10.1099/jmm.0.000811] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nearly all bacterial species express two or more chaperonin genes. Recent data indicate that type I chaperonins may be key players in bacterial infections. This is partly due to the well-known contribution of chaperonins in cellular proteostasis, the latter being compromised during bacterial host infection. In addition to their protein-folding activity, it has been revealed that certain chaperonins also exhibit moonlighting functions that can contribute in different ways to bacterial pathogenicity. Examples range from inducing adhesion molecules in Chlamydophila pneumoniae to supporting intracellular survival in Mycobacterium tuberculosis and Leishmania donovani, to inducing cytokines in Helicobacter pylori to promoting antimicrobial resistance in Escherichia coli, amongst others. This article provides a thorough reviews of our current understanding of the different mechanisms involving type I chaperonins during bacteria-host interactions, and suggests new areas to be explored and the potential of finding new targets for fighting bacterial infections.
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Affiliation(s)
- Ciamak Ghazaei
- 1Department of Microbiology, University of Mohaghegh Ardabili, Ardabil, Iran
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37
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Brown AWW, Wilson RB. Clostridium difficile colitis and zoonotic origins-a narrative review. Gastroenterol Rep (Oxf) 2018; 6:157-166. [PMID: 30151199 PMCID: PMC6101521 DOI: 10.1093/gastro/goy016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 02/26/2018] [Accepted: 04/24/2018] [Indexed: 12/18/2022] Open
Abstract
Clostridium difficile is a major cause of hospital-associated diarrhoea, and in severe cases leads to pseudomembranous colitis and toxic megacolon. The frequency of C. difficile infection (CDI) has increased in recent decades, with 453 000 cases identified in 2011 in the USA. This is related to antibiotic-selection pressure, disruption of normal host intestinal microbiota and emergence of antibiotic-resistant C. difficile strains. The burden of community-acquired CDI has been increasingly appreciated, with disease identified in patients previously considered low-risk, such as young women or patients with no prior antibiotic exposure. C. difficile has been identified in livestock animals, meat products, seafood and salads. It has been postulated that the pool of C. difficile in the agricultural industry may contribute to human CDI. There is widespread environmental dispersal of C. difficile spores. Domestic households, turf lawns and public spaces are extensively contaminated, providing a potential reservoir for community-acquired CDI. In Australia, this is particularly associated with porcine-derived C. difficile UK PCR ribotype 014/020. In this article, the epidemiological differences between hospital- and community-acquired CDI are discussed, including some emerging evidence for community-acquired CDI being a possible zoonosis.
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Affiliation(s)
- Alexander W W Brown
- General Surgery Department, Liverpool Hospital, Elizabeth St, Liverpool, NSW, Australia
| | - Robert B Wilson
- General Surgery Department, Liverpool Hospital, Elizabeth St, Liverpool, NSW, Australia
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Klychnikov OI, Shamorkina TM, Weeks SD, van Leeuwen HC, Corver J, Drijfhout JW, van Veelen PA, Sluchanko NN, Strelkov SV, Hensbergen PJ. Discovery of a new Pro-Pro endopeptidase, PPEP-2, provides mechanistic insights into the differences in substrate specificity within the PPEP family. J Biol Chem 2018; 293:11154-11165. [PMID: 29794027 DOI: 10.1074/jbc.ra118.003244] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/22/2018] [Indexed: 12/20/2022] Open
Abstract
Pro-Pro endopeptidases (PPEPs) belong to a recently discovered family of proteases capable of hydrolyzing a Pro-Pro bond. The first member from the bacterial pathogen Clostridium difficile (PPEP-1) cleaves two C. difficile cell-surface proteins involved in adhesion, one of which is encoded by the gene adjacent to the ppep-1 gene. However, related PPEPs may exist in other bacteria and may shed light on substrate specificity in this enzyme family. Here, we report on the homolog of PPEP-1 in Paenibacillus alvei, which we denoted PPEP-2. We found that PPEP-2 is a secreted metalloprotease, which likewise cleaved a cell-surface protein encoded by an adjacent gene. However, the cleavage motif of PPEP-2, PLP↓PVP, is distinct from that of PPEP-1 (VNP↓PVP). As a result, an optimal substrate peptide for PPEP-2 was not cleaved by PPEP-1 and vice versa. To gain insight into the specificity mechanism of PPEP-2, we determined its crystal structure at 1.75 Å resolution and further confirmed the structure in solution using small-angle X-ray scattering (SAXS). We show that a four-amino-acid loop, which is distinct in PPEP-1 and -2 (GGST in PPEP-1 and SERV in PPEP-2), plays a crucial role in substrate specificity. A PPEP-2 variant, in which the four loop residues had been swapped for those from PPEP-1, displayed a shift in substrate specificity toward PPEP-1 substrates. Our results provide detailed insights into the PPEP-2 structure and the structural determinants of substrate specificity in this new family of PPEP proteases.
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Affiliation(s)
- Oleg I Klychnikov
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | | | - Stephen D Weeks
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | | | | | - Jan W Drijfhout
- Immunohematology and Blood Transfusion, Leiden University Medical Center, 2300 Leiden, The Netherlands
| | | | - Nikolai N Sluchanko
- the A. N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia, and.,the Department of Biophysics, Faculty of Biology, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Sergei V Strelkov
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
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Mori N, Takahashi T. Characteristics and Immunological Roles of Surface Layer Proteins in Clostridium difficile. Ann Lab Med 2018; 38:189-195. [PMID: 29401552 PMCID: PMC5820062 DOI: 10.3343/alm.2018.38.3.189] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/07/2017] [Accepted: 12/28/2017] [Indexed: 12/18/2022] Open
Abstract
Clostridium difficile is a major causative agent of antibiotic-associated diarrhea and has become the most common pathogen of healthcare-associated infection worldwide. The pathogenesis of C. difficile infection (CDI) is mediated by many factors such as colonization involving attachment to host intestinal epithelial cells, sporulation, germination, and toxin production. Bacterial cell surface components are crucial for the interaction between the bacterium and host cells. C. difficile has two distinct surface layer proteins (SLPs): a conserved high-molecular-weight SLP and a highly variable low-molecular-weight SLP. Recent studies have shown that C. difficile SLPs play roles not only in growth and survival, but also in adhesion to host epithelial cells and induction of cytokine production. Sequence typing of the variable region of the slpA gene, which encodes SLPs, is one of the methods currently used for typing C. difficile. SLPs have received much attention in recent years as vaccine candidates and new therapeutic agents in the treatment of C. difficile-associated diseases. Gaining mechanistic insights into the molecular functions of C. difficile SLPs will help advance our understanding of CDI pathogenesis and the development of vaccines and new therapeutic approaches. In this review, we summarize the characteristics and immunological roles of SLPs in C. difficile.
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Affiliation(s)
- Nobuaki Mori
- Department of General Internal Medicine, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences and Kitasato Institute for Life Sciences, Kitasato University, Minato-ku, Tokyo, Japan.
| | - Takashi Takahashi
- Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences and Kitasato Institute for Life Sciences, Kitasato University, Minato-ku, Tokyo, Japan
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40
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Comparative genomics analysis of Clostridium difficile epidemic strain DH/NAP11/106. Microbes Infect 2018; 20:245-253. [PMID: 29391259 DOI: 10.1016/j.micinf.2018.01.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/06/2018] [Accepted: 01/08/2018] [Indexed: 02/05/2023]
Abstract
Clostridium difficile PCR ribotype 106 (also identified as restriction endonuclease analysis [REA] group DH) recently emerged as the most common strain causing C. difficile infection (CDI) among US adults. We previously identified this strain predominating our pediatric cohort. Pediatric clinical CDI isolates previously characterized by REA underwent antibiotic resistance testing and whole genome sequencing. Of 134 isolates collected from children, 31 (23%) were REA group DH. We performed a comparative genomics analysis to identify DH-associated accessory genes. We identified five DH-associated genes that are associated with virulence in other bacterial species but not previously known to contribute to CDI. These genes are associated with intestinal mucosal adhesion (collagen-binding surface protein), sporulation (sporulation integral membrane protein YtvI), and protection from oxidative stress and foreign DNA (DNA phosphorothioation-dependent restriction proteins, sulfurtransferase, and DNA sulfur modification proteins). The association of these genes was validated in a cohort of 623 publicly available C. difficile sequences, 10 (1.6%) of which were monophyletic to REA group DH through in silico multilocus sequence typing and core genome phylogenetic analysis. Further investigation is required to determine the contribution of these genes to the emergence and virulence of this epidemic strain.
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41
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Corver J, Cordo' V, van Leeuwen HC, Klychnikov OI, Hensbergen PJ. Covalent attachment and Pro-Pro endopeptidase (PPEP-1)-mediated release of Clostridium difficile cell surface proteins involved in adhesion. Mol Microbiol 2017. [PMID: 28636257 DOI: 10.1111/mmi.13736] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In the past decade, Clostridium difficile has emerged as an important gut pathogen. This anaerobic, Gram-positive bacterium is the main cause of infectious nosocomial diarrhea. Whereas much is known about the mechanism through which the C. difficile toxins cause diarrhea, relatively little is known about the dynamics of adhesion and motility, which is mediated by cell surface proteins. This review will discuss the recent advances in our understanding of the sortase-mediated covalent attachment of cell surface (adhesion) proteins to the peptidoglycan layer of C. difficile and their release through the action of a highly specific secreted metalloprotease (Pro-Pro endopeptidase 1, PPEP-1). Specific emphasis will be on a model in which PPEP-1 and its substrates control the switch from a sessile to motile phenotype in C. difficile, and how this is regulated by the cyclic dinucleotide c-di-GMP (3'-5' cyclic dimeric guanosine monophosphate).
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Affiliation(s)
- Jeroen Corver
- Department of Medical Microbiology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Valentina Cordo'
- Center for Proteomics and Metabolomics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Hans C van Leeuwen
- Department of Medical Microbiology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Oleg I Klychnikov
- Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Paul J Hensbergen
- Center for Proteomics and Metabolomics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
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42
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Udaondo Z, Duque E, Ramos JL. The pangenome of the genus Clostridium. Environ Microbiol 2017; 19:2588-2603. [PMID: 28321969 DOI: 10.1111/1462-2920.13732] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 03/15/2017] [Accepted: 03/15/2017] [Indexed: 11/26/2022]
Abstract
The pangenome for the genus Clostridium sensu stricto, which was obtained using highly curated and annotated genomes from 16 species is presented; some of these cause disease, while others are used for the production of added-value chemicals. Multilocus sequencing analysis revealed that species of this genus group into at least two clades that include non-pathogenic and pathogenic strains, suggesting that pathogenicity is dispersed across the phylogenetic tree. The core genome of the genus includes 546 protein families, which mainly comprise those involved in protein translation and DNA repair. The GS-GOGAT may represent the central pathway for generating organic nitrogen from inorganic nitrogen sources. Glycerol and glucose metabolism genes are well represented in the core genome together with a set of energy conservation systems. A metabolic network comprising proteins/enzymes, RNAs and metabolites, whose topological structure is a non-random and scale-free network with hierarchically structured modules was built. These modules shed light on the interactions between RNAs, proteins and metabolites, revealing biological features of transcription and translation, cell wall biosynthesis, C1 metabolism and N metabolism. Network analysis identified four nodes that function as hubs and bottlenecks, namely, coenzyme A, HPr kinases, S-adenosylmethionine and the ribonuclease P-protein, suggesting pivotal roles for them in Clostridium.
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Affiliation(s)
- Zulema Udaondo
- Calle Energía Solar 1, Building D, Campus Palmas Altas, Abengoa Research, Biotechnology Technological Area, Sevilla, 41014, Spain.,Consejo Superior de Investigaciones Científicas, EEZ, Environmental Protection Department, C/Profesor Albareda 1, Granada, 18008, Spain
| | - Estrella Duque
- Calle Energía Solar 1, Building D, Campus Palmas Altas, Abengoa Research, Biotechnology Technological Area, Sevilla, 41014, Spain.,Consejo Superior de Investigaciones Científicas, EEZ, Environmental Protection Department, C/Profesor Albareda 1, Granada, 18008, Spain
| | - Juan-Luis Ramos
- Calle Energía Solar 1, Building D, Campus Palmas Altas, Abengoa Research, Biotechnology Technological Area, Sevilla, 41014, Spain.,Consejo Superior de Investigaciones Científicas, EEZ, Environmental Protection Department, C/Profesor Albareda 1, Granada, 18008, Spain
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43
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Herrmann J, Jabbarpour F, Bargar PG, Nomellini JF, Li PN, Lane TJ, Weiss TM, Smit J, Shapiro L, Wakatsuki S. Environmental Calcium Controls Alternate Physical States of the Caulobacter Surface Layer. Biophys J 2017; 112:1841-1851. [PMID: 28494955 PMCID: PMC5425405 DOI: 10.1016/j.bpj.2017.04.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/28/2017] [Accepted: 04/06/2017] [Indexed: 11/23/2022] Open
Abstract
Surface layers (S-layers) are paracrystalline, proteinaceous structures found in most archaea and many bacteria. Often the outermost cell envelope component, S-layers serve diverse functions including aiding pathogenicity and protecting against predators. We report that the S-layer of Caulobacter crescentus exhibits calcium-mediated structural plasticity, switching irreversibly between an amorphous aggregate state and the crystalline state. This finding invalidates the common assumption that S-layers serve only as static wall-like structures. In vitro, the Caulobacter S-layer protein, RsaA, enters the aggregate state at physiological temperatures and low divalent calcium ion concentrations. At higher concentrations, calcium ions stabilize monomeric RsaA, which can then transition to the two-dimensional crystalline state. Caulobacter requires micromolar concentrations of calcium for normal growth and development. Without an S-layer, Caulobacter is even more sensitive to changes in environmental calcium concentration. Therefore, this structurally dynamic S-layer responds to environmental conditions as an ion sensor and protects Caulobacter from calcium deficiency stress, a unique mechanism of bacterial adaptation. These findings provide a biochemical and physiological basis for RsaA's calcium-binding behavior, which extends far beyond calcium's commonly accepted role in aiding S-layer biogenesis or oligomerization and demonstrates a connection to cellular fitness.
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Affiliation(s)
- Jonathan Herrmann
- Department of Structural Biology, Stanford University, Stanford, California; Bioscience Division, SLAC National Accelerator Laboratory, Menlo Park, California.
| | - Fatemeh Jabbarpour
- Department of Structural Biology, Stanford University, Stanford, California
| | | | - John F Nomellini
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Po-Nan Li
- Department of Electrical Engineering, Stanford University, Stanford, California
| | - Thomas J Lane
- Bioscience Division, SLAC National Accelerator Laboratory, Menlo Park, California
| | - Thomas M Weiss
- Bioscience Division, SLAC National Accelerator Laboratory, Menlo Park, California
| | - John Smit
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lucy Shapiro
- Department of Developmental Biology, Stanford University, Stanford, California.
| | - Soichi Wakatsuki
- Department of Structural Biology, Stanford University, Stanford, California; Bioscience Division, SLAC National Accelerator Laboratory, Menlo Park, California.
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44
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Ferreira TG, Moura H, Barr JR, Pilotto Domingues RMC, Ferreira EDO. Ribotypes associated with Clostridium difficile outbreaks in Brazil display distinct surface protein profiles. Anaerobe 2017; 45:120-128. [PMID: 28435010 DOI: 10.1016/j.anaerobe.2017.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/28/2017] [Accepted: 04/01/2017] [Indexed: 11/18/2022]
Abstract
Clostridium difficile is a spore-forming anaerobic intestinal pathogen that causes Clostridium difficile infection (CDI). C. difficile is the leading cause of toxin-mediated nosocomial antibiotic-associated diarrhea. The pathogenesis of CDI is attributed to two major virulence factors, TcdA and TcdB toxins, that cause the symptomatic infection. C. difficile also expresses a number of key proteins, including cell wall proteins (CWPs). S-layer proteins (SLPs) are CWPs that form a paracrystalline surface array that coats the surface of the bacterium. SLPs have a role in C. difficile binding to the gastrointestinal tract, but their importance in virulence need to be better elucidated. Here, we describe bottom-up proteomics analysis of surface-enriched proteins fractions obtained through glycine extraction of five C. difficile clinical isolates from Brazil using gel-based and gel-free approaches. We were able to identify approximately 250 proteins for each strain, among them SlpA, Cwp2, Cwp6, CwpV and Cwp84. Identified CWPs presented different amino acid coverage, which might suggest differences in post-translational modifications. Proteomic analysis of SLPs from ribotype 133, agent of C. difficile outbreaks in Brazil, revealed unique proteins and provided additional information towards in depth characterization of the strains causing CDI in Brazil.
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Affiliation(s)
- Thais Gonçalves Ferreira
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Laboratório de Biologia de Anaeróbios, Rio de Janeiro, Brazil
| | - Hercules Moura
- Centers for Disease Control and Prevention - CDC, Division of Laboratory Sciences, Atlanta, GA, USA
| | - John R Barr
- Centers for Disease Control and Prevention - CDC, Division of Laboratory Sciences, Atlanta, GA, USA
| | - Regina M C Pilotto Domingues
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Laboratório de Biologia de Anaeróbios, Rio de Janeiro, Brazil.
| | - Eliane de Oliveira Ferreira
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Laboratório de Biologia de Anaeróbios, Rio de Janeiro, Brazil; Universidade Federal do Rio de Janeiro - Polo Xerém, Rio de Janeiro, Brazil
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45
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Bharat TA, Kureisaite-Ciziene D, Hardy GG, Yu EW, Devant JM, Hagen WJ, Brun YV, Briggs JA, Löwe J. Structure of the hexagonal surface layer on Caulobacter crescentus cells. Nat Microbiol 2017; 2:17059. [PMID: 28418382 PMCID: PMC5699643 DOI: 10.1038/nmicrobiol.2017.59] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 03/24/2017] [Indexed: 12/12/2022]
Abstract
Many prokaryotic cells are encapsulated by a surface layer (S-layer) consisting of repeating units of S-layer proteins. S-layer proteins are a diverse class of molecules found in Gram-positive and Gram-negative bacteria and most archaea1-5. S-layers protect cells from the outside, provide mechanical stability and also play roles in pathogenicity. In situ structural information about this highly abundant class of proteins is scarce, so atomic details of how S-layers are arranged on the surface of cells have remained elusive. Here, using purified Caulobacter crescentus' sole S-layer protein RsaA, we obtained a 2.7 Å X-ray structure that shows the hexameric S-layer lattice. We also solved a 7.4 Å structure of the S-layer through electron cryotomography and sub-tomogram averaging of cell stalks. The X-ray structure was docked unambiguously into the electron cryotomography map, resulting in a pseudo-atomic-level description of the in vivo S-layer, which agrees completely with the atomic X-ray lattice model. The cellular S-layer atomic structure shows that the S-layer is porous, with a largest gap dimension of 27 Å, and is stabilized by multiple Ca2+ ions bound near the interfaces. This study spans different spatial scales from atoms to cells by combining X-ray crystallography with electron cryotomography and sub-nanometre-resolution sub-tomogram averaging.
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Affiliation(s)
- Tanmay A.M. Bharat
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | | | - Gail G. Hardy
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Ellen W. Yu
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Jessica M. Devant
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Wim J.H. Hagen
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstr. 1, Heidelberg 69117, Germany
| | - Yves V. Brun
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - John A.G. Briggs
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstr. 1, Heidelberg 69117, Germany
| | - Jan Löwe
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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46
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Péchiné S, Janoir C, Collignon A. Emerging monoclonal antibodies against Clostridium difficile infection. Expert Opin Biol Ther 2017; 17:415-427. [PMID: 28274145 DOI: 10.1080/14712598.2017.1300655] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Clostridium difficile infections are characterized by a high recurrence rate despite antibiotic treatments and there is an urgent need to develop new treatments such as fecal transplantation and immonotherapy. Besides active immunotherapy with vaccines, passive immunotherapy has shown promise, especially with monoclonal antibodies. Areas covered: Herein, the authors review the different assays performed with monoclonal antibodies against C. difficile toxins and surface proteins to treat or prevent primary or recurrent episodes of C. difficile infection in animal models and in clinical trials as well. Notably, the authors lay emphasis on the phase III clinical trial (MODIFY II), which allowed bezlotoxumab to be approved by the Food and Drug Administration and the European Medicines Agency. They also review new strategies for producing single domain antibodies and nanobodies against C. difficile and new approaches to deliver them in the digestive tract. Expert opinion: Only two human Mabs against TcdA and TcdB have been tested alone or in combination in clinical trials. However, many animal model studies have provided rationale for the use of Mabs and nanobodies in C. difficile infection and pave the way for further clinical investigation.
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Affiliation(s)
- Séverine Péchiné
- a EA4043 Faculté de Pharmacie , Univ Paris-Sud, Université Paris-Saclay , Chatenay-Malabry , France
| | - Claire Janoir
- a EA4043 Faculté de Pharmacie , Univ Paris-Sud, Université Paris-Saclay , Chatenay-Malabry , France
| | - Anne Collignon
- a EA4043 Faculté de Pharmacie , Univ Paris-Sud, Université Paris-Saclay , Chatenay-Malabry , France
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47
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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] [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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