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Furtado KL, Plott L, Markovetz M, Powers D, Wang H, Hill DB, Papin J, Allbritton NL, Tamayo R. Clostridioides difficile-mucus interactions encompass shifts in gene expression, metabolism, and biofilm formation. mSphere 2024:e0008124. [PMID: 38837404 DOI: 10.1128/msphere.00081-24] [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: 02/01/2024] [Accepted: 04/28/2024] [Indexed: 06/07/2024] Open
Abstract
In a healthy colon, the stratified mucus layer serves as a crucial innate immune barrier to protect the epithelium from microbes. Mucins are complex glycoproteins that serve as a nutrient source for resident microflora and can be exploited by pathogens. We aimed to understand how the intestinal pathogen, Clostridioides difficile, independently uses or manipulates mucus to its benefit, without contributions from members of the microbiota. Using a 2-D primary human intestinal epithelial cell model to generate physiologic mucus, we assessed C. difficile-mucus interactions through growth assays, RNA-Seq, biophysical characterization of mucus, and contextualized metabolic modeling. We found that host-derived mucus promotes C. difficile growth both in vitro and in an infection model. RNA-Seq revealed significant upregulation of genes related to central metabolism in response to mucus, including genes involved in sugar uptake, the Wood-Ljungdahl pathway, and the glycine cleavage system. In addition, we identified differential expression of genes related to sensing and transcriptional control. Analysis of mutants with deletions in highly upregulated genes reflected the complexity of C. difficile-mucus interactions, with potential interplay between sensing and growth. Mucus also stimulated biofilm formation in vitro, which may in turn alter the viscoelastic properties of mucus. Context-specific metabolic modeling confirmed differential metabolism and the predicted importance of enzymes related to serine and glycine catabolism with mucus. Subsequent growth experiments supported these findings, indicating mucus is an important source of serine. Our results better define responses of C. difficile to human gastrointestinal mucus and highlight flexibility in metabolism that may influence pathogenesis. IMPORTANCE Clostridioides difficile results in upward of 250,000 infections and 12,000 deaths annually in the United States. Community-acquired infections continue to rise, and recurrent disease is common, emphasizing a vital need to understand C. difficile pathogenesis. C. difficile undoubtedly interacts with colonic mucus, but the extent to which the pathogen can independently respond to and take advantage of this niche has not been explored extensively. Moreover, the metabolic complexity of C. difficile remains poorly understood but likely impacts its capacity to grow and persist in the host. Here, we demonstrate that C. difficile uses native colonic mucus for growth, indicating C. difficile possesses mechanisms to exploit the mucosal niche. Furthermore, mucus induces metabolic shifts and biofilm formation in C. difficile, which has potential ramifications for intestinal colonization. Overall, our work is crucial to better understand the dynamics of C. difficile-mucus interactions in the context of the human gut.
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Affiliation(s)
- Kathleen L Furtado
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
| | - Lucas Plott
- Marsico Lung Institute, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
| | - Matthew Markovetz
- Marsico Lung Institute, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
| | - Deborah Powers
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia, USA
| | - Hao Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - David B Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Physics and Astronomy, College of Arts and Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jason Papin
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia, USA
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
- Department of Medicine, Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia, USA
| | - Nancy L Allbritton
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Rita Tamayo
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
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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 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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Furtado KL, Plott L, Markovetz M, Powers D, Wang H, Hill DB, Papin J, Allbritton NL, Tamayo R. Clostridioides difficile-mucus interactions encompass shifts in gene expression, metabolism, and biofilm formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.01.578425. [PMID: 38352512 PMCID: PMC10862863 DOI: 10.1101/2024.02.01.578425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
In a healthy colon, the stratified mucus layer serves as a crucial innate immune barrier to protect the epithelium from microbes. Mucins are complex glycoproteins that serve as a nutrient source for resident microflora and can be exploited by pathogens. We aimed to understand how the intestinal pathogen, Clostridioides diffiicile, independently uses or manipulates mucus to its benefit, without contributions from members of the microbiota. Using a 2-D primary human intestinal epithelial cell model to generate physiologic mucus, we assessed C. difficile-mucus interactions through growth assays, RNA-Seq, biophysical characterization of mucus, and contextualized metabolic modeling. We found that host-derived mucus promotes C. difficile growth both in vitro and in an infection model. RNA-Seq revealed significant upregulation of genes related to central metabolism in response to mucus, including genes involved in sugar uptake, the Wood-Ljungdahl pathway, and the glycine cleavage system. In addition, we identified differential expression of genes related to sensing and transcriptional control. Analysis of mutants with deletions in highly upregulated genes reflected the complexity of C. difficile-mucus interactions, with potential interplay between sensing and growth. Mucus also stimulated biofilm formation in vitro, which may in turn alter viscoelastic properties of mucus. Context-specific metabolic modeling confirmed differential metabolism and predicted importance of enzymes related to serine and glycine catabolism with mucus. Subsequent growth experiments supported these findings, indicating mucus is an important source of serine. Our results better define responses of C. difficile to human gastrointestinal mucus and highlight a flexibility in metabolism that may influence pathogenesis.
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Affiliation(s)
- Kathleen L. Furtado
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Lucas Plott
- Marsico Lung Institute, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Matthew Markovetz
- Marsico Lung Institute, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Deborah Powers
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Hao Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - David B. Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Physics and Astronomy, College of Arts and Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jason Papin
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
- Department of Medicine, Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | | | - Rita Tamayo
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
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Molecular characterization and antibiotic resistance of Clostridioides difficile in patients with inflammatory bowel disease from two hospitals in China. J Glob Antimicrob Resist 2022; 30:252-258. [PMID: 35764214 DOI: 10.1016/j.jgar.2022.06.017] [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: 09/27/2021] [Revised: 05/27/2022] [Accepted: 06/16/2022] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE Patients with inflammatory bowel disease (IBD) are susceptible to Clostridioides difficile infection (CDI), resulting in poor outcomes and recurrence; therefore, the molecular characterization of C. difficle in IBD patients in China needs further investigation. METHODS C. difficile strains were isolated and identified from fecal samples of adult and pediatric IBD patients. Toxigenic strains were typed using multilocus sequence typing (MLST) and whole genomic sequencing (WGS) to construct the phylogenetic tree. Susceptibility to 10 antimicrobials was evaluated using the E-test. RESULTS Among the 838 IBD patients, 82 toxigenic C. difficile were identified, which comprised 46 from adults and 36 children. 90.2% (74/82) of the isolates were positive for both toxin A and toxin B genes (A+B+), while the remaining 9.8% were negative for toxin A gene, but positive for toxin B gene (A-B+). These toxigenic strains were susceptible to metronidazole and vancomycin, but highly resistant to clindamycin, erythromycin, and fluoroquinolones. All moxifloxacin-resistant isolates had mutations resulting in an amino acid substitution in gryA (T82I). The dominant types were ST-35 (20.7%), ST-2 (17.1%), ST-54 (13.4%), and ST-3 (13.4%) in all patients. CONCLUSION The incidence and molecular epidemiology of C. difficile infection in adult IBD patients resembled CDI in the general inpatient population. A higher antibiotic resistance rate was identified among the C. difficile isolates obtained from pediatric IBD patients than adult patients, and few STs accounted for most multidrug-resistant strains. However, the molecular genetic features of the same ST-type between these two groups remains highly correlated.
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Chen J, Du Y, Lu Y, Wang H, Wu Q. Recent development of small-molecular inhibitors against Clostridioides difficile infection. Bioorg Chem 2022; 125:105843. [DOI: 10.1016/j.bioorg.2022.105843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 03/02/2022] [Accepted: 04/23/2022] [Indexed: 11/29/2022]
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Polymorphisms in the genes encoding surface associated proteins of Clostridioides difficile isolates. INFECTION GENETICS AND EVOLUTION 2020; 86:104598. [PMID: 33080382 DOI: 10.1016/j.meegid.2020.104598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 10/08/2020] [Accepted: 10/13/2020] [Indexed: 11/21/2022]
Abstract
BACKGROUND Although the diversity of Clostridioides difficile toxins have been extensively studied, little is known about the variation in the surface associated proteins (SAPs) which are important in early steps of bacterial colonization and infection. Here, we examined 65C. difficile isolates to identify polymorphisms in the genes encoding SAPs. METHODS PCR was used to amplify slpA, fliC, fliD, cwp66 and cwp84 genes, followed by sequencing. In addition, the antigenicity and immunogenicity properties of different types of SlpA, FliC, FliD, Cwp66 and Cwp84 proteins were predicted in-silico by VaxiJen and BcePred online servers. RESULTS The predominant slpA sequence type was gr-01 (42.37%), followed by hr-01 (11.86%) and 078-01 (10.16%). In addition, two new slpA subtypes of smz (smz-09-Ir and smz-010-Ir) and a new slpA sequence type (Ir-01) were identified among the isolates examined. Analysis of the nucleotide sequences of fliC, fliD, cwp66 and cwp84 genes revealed 7, 5,5,3 different sequence types, respectively. Insilico analysis of antigenicity of SAPs showed that FliC had the highest level of antigenicity whereas SlpA and Cwp66 proteins had the highest level of immunogenicity. CONCLUSIONS This study pointed to the nucleotide polymorphism in SAPs of C. difficile isolates and demonstrated noticeable diversity in antigenicity and immunogenicity of these proteins which need to be taken into consideration as promising therapeutic or vaccine targets.
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Virulence Factors of Clostridioides ( Clostridium) difficile Linked to Recurrent Infections. CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY 2019; 2019:7127850. [PMID: 31933709 PMCID: PMC6942709 DOI: 10.1155/2019/7127850] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 12/02/2019] [Accepted: 12/07/2019] [Indexed: 12/18/2022]
Abstract
From 20 to 30% of Clostridioides (Clostridium) difficile infection (CDI), patients might develop recurrence of the infection (RCDI) and, after the first recurrence, the risk of further episodes increases up to 60%. Several bacterial virulence factors have been associated with RCDI, including the elevated production of toxins A and B, the presence of a binary toxin CDT, and mutations in the negative regulator of toxin expression, tcdC. Additional factors have shown to regulate toxin production and virulence in C. difficile in RCDI, including the accessory-gene regulator agr, which acts as a positive switch for toxin transcription. Furthermore, adhesion and motility-associated factors, such as Cwp84, SlpA, and flagella, have shown to increase the adhesion efficiency to host epithelia, cell internalization, and the formation of biofilm. Finally, biofilm confers to C. difficile protection from antibiotics and acts as a reservoir for spores that allow the persistence of the infection in the host. In this review, we describe the key virulence factors of C. difficile that have been associated with recurrent infections.
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Pantaléon V, Monot M, Eckert C, Hoys S, Collignon A, Janoir C, Candela T. Clostridium difficile forms variable biofilms on abiotic surface. Anaerobe 2018; 53:34-37. [PMID: 29859742 DOI: 10.1016/j.anaerobe.2018.05.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 05/14/2018] [Accepted: 05/18/2018] [Indexed: 01/06/2023]
Abstract
Clostridium difficile can form biofilms. Thirty-seven strains were characterized for their ability to form a biofilm, adhesion on an inert surface and hydrophobicity. No correlation between the ability to form a biofilm and the strain virulence was highlighted. However, non-motile strains were not able to form a high biofilm.
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Affiliation(s)
- V Pantaléon
- EA4043 Unité Bactéries Pathogènes et Santé (UBaPS), Université Paris-Sud, Université Paris-Saclay, 92290 Châtenay-Malabry, France
| | - M Monot
- Département de Microbiologie, Institut Pasteur, Laboratoire Pathogenèse des Bactéries Anaérobies, Paris, France; Département de Microbiologie et d'infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada; Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - C Eckert
- National Reference Laboratory for C. difficile, Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Paris, France; Sorbonne Université, Centre d'immunologie et des Maladies Infectieuses-Paris, Cimi-Paris, Département de Bactériologie, AP-HP, Hôpitaux Universitaires de l'Est Parisien, F-75012 Paris, France
| | - S Hoys
- EA4043 Unité Bactéries Pathogènes et Santé (UBaPS), Université Paris-Sud, Université Paris-Saclay, 92290 Châtenay-Malabry, France
| | - A Collignon
- EA4043 Unité Bactéries Pathogènes et Santé (UBaPS), Université Paris-Sud, Université Paris-Saclay, 92290 Châtenay-Malabry, France
| | - C Janoir
- EA4043 Unité Bactéries Pathogènes et Santé (UBaPS), Université Paris-Sud, Université Paris-Saclay, 92290 Châtenay-Malabry, France
| | - T Candela
- EA4043 Unité Bactéries Pathogènes et Santé (UBaPS), Université Paris-Sud, Université Paris-Saclay, 92290 Châtenay-Malabry, France.
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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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Antibiotic Treatments for Clostridium difficile Infection Are Associated with Distinct Bacterial and Fungal Community Structures. mSphere 2018; 3:mSphere00572-17. [PMID: 29359185 PMCID: PMC5760750 DOI: 10.1128/msphere.00572-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 12/15/2017] [Indexed: 01/19/2023] Open
Abstract
Clostridium difficile infection (CDI) is the most common nosocomial infection in the United States, being associated with high recurrence and persistence rates. Though the relationship between intestinal dysbiosis and CDI is well known, it is unclear whether different forms of dysbiosis may potentially affect the course of CDI. How this is further influenced by C. difficile-directed antibiotics is virtually uninvestigated. In this study, diarrheal stool samples were collected from 20 hospitalized patients, half of whom were confirmed to have CDI. Analyzing tissue ex vivo and in duplicate, CDI and non-CDI fecal samples (n = 176) were either not antibiotic treated or treated with metronidazole, vancomycin, or fidaxomicin, the three most common CDI therapies. The microbial community composition, interactions, and predicted metabolic functions were assessed by 16S rRNA gene and internal transcribed spacer sequencing, bipartite network analysis, and phylogenetic investigation of communities by reconstruction of unobserved states. Our results demonstrate that while all C. difficile-directed antibiotics were associated with similar reductions in alpha diversity, beta diversity significantly differed on the basis of the particular antibiotic, with differentiating relative abundances of bacterial and fungal assemblages. With the exception of fidaxomicin, each antibiotic was associated with the emergence of potentially pathogenic fungal operational taxonomic units, with predicted bacterial functions enriched for xenobiotic metabolism that could perpetuate the dysbiosis driving CDI. Toxin-independent mechanisms of colitis related to the relative abundance of pathogenic bacteria and fungi were also noted. This study suggests that a transkingdom interaction between fungi and bacteria may be important in CDI pathophysiology, including being a factor in the historically high persistence and recurrence rates associated with this disease. IMPORTANCE Using human fecal samples and including sequencing for both bacterial and fungal taxa, this study compared the conventional antibiotics used to treat C. difficile infection (CDI) from the perspective of the microbiome, which is particularly relevant, given the relationship between dysbiotic states and the development of CDI. Sequencing and imputed functional analyses suggest that C. difficile-directed antibiotics are associated with distinct forms of dysbiosis that may be influential in the course of CDI. Further, a role for fungal organisms in the perpetuation of the causal dysbiosis of CDI is discussed, suggesting a previously unappreciated, clinically relevant transkingdom interaction that warrants further study.
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12
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Soavelomandroso AP, Gaudin F, Hoys S, Nicolas V, Vedantam G, Janoir C, Bouttier S. Biofilm Structures in a Mono-Associated Mouse Model of Clostridium difficile Infection. Front Microbiol 2017; 8:2086. [PMID: 29118745 PMCID: PMC5661025 DOI: 10.3389/fmicb.2017.02086] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 10/11/2017] [Indexed: 12/31/2022] Open
Abstract
Clostridium difficile infection (CDI) is a major healthcare-associated disease with high recurrence rates. Host colonization is critical for the infectious process, both in first episodes and in recurrent disease, with biofilm formation playing a key role. The ability of C. difficile to form a biofilm on abiotic surfaces is established, but has not yet been confirmed in the intestinal tract. Here, four different isolates of C. difficile, which are in vitro biofilm producers, were studied for their ability to colonize germ-free mice. The level of colonization achieved was similar for all isolates in the different parts of the murine gastrointestinal tract, but pathogen burden was higher in the cecum and colon. Confocal laser scanning microscopy revealed that C. difficile bacteria were distributed heterogeneously over the intestinal tissue, without contact with epithelial cells. The R20291 strain, which belongs to the Ribotype 027 lineage, displayed a unique behavior compared to the other strains by forming numerous aggregates. By immunochemistry analyses, we showed that bacteria were localized inside and outside the mucus layer, irrespective of the strains tested. Most bacteria were entrapped in 3-D structures overlaying the mucus layer. For the R20291 strain, the cell-wall associated polysaccharide PS-II was detected in large amounts in the 3-D structure. As this component has been detected in the extrapolymeric matrix of in vitro C. difficile biofilms, our data suggest strongly that at least the R20291 strain is organized in the mono-associated mouse model in glycan-rich biofilm architecture, which sustainably maintains bacteria outside the mucus layer.
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Affiliation(s)
- Anna P Soavelomandroso
- EA4043, Unité Bactéries Pathogènes et Santé (UBaPS), Univ. Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Françoise Gaudin
- Institut Paris Saclay d'Innovation Thérapeutique (IPSIT), UMS IPSIT Université Paris-Sud - US 31 INSERM - UMS 3679 CNRS, Plateforme d'Histologie souris Immunopathologie de Clamart - PHIC, Clamart, France
| | - Sandra Hoys
- EA4043, Unité Bactéries Pathogènes et Santé (UBaPS), Univ. Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Valérie Nicolas
- Institut Paris Saclay d'Innovation Thérapeutique (IPSIT), UMS IPSIT Université Paris-Sud - US 31 INSERM - UMS 3679 CNRS, Plateforme d'Imagerie cellulaire - MIPSIT, Châtenay-Malabry, France
| | - Gayatri Vedantam
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, United States
| | - Claire Janoir
- EA4043, Unité Bactéries Pathogènes et Santé (UBaPS), Univ. Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Sylvie Bouttier
- EA4043, Unité Bactéries Pathogènes et Santé (UBaPS), Univ. Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
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13
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Zarandi ER, Mansouri S, Nakhaee N, Sarafzadeh F, Moradi M. Effect of sub-MIC of vancomycin and clindamycin alone and in combination with ceftazidime on Clostridium difficile surface layer protein A (slpA) gene expression. Microb Pathog 2017; 111:163-167. [PMID: 28867619 DOI: 10.1016/j.micpath.2017.08.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 08/30/2017] [Accepted: 08/30/2017] [Indexed: 11/15/2022]
Abstract
Clostridium difficile (C.difficile) infection is often established in the presence of antibiotics and probably antibiotics can influence surface layer protein A (slpA) expression as a colonization factor. The aim of this study is to evaluate the effect of vancomycin (VAN), clindamycin (CLI) alone and in combination with ceftazidime (CAZ) on slpA gene expression to determine whether such antibiotics can have any effect on slpA expression. About ∼106 CFU/mL was inoculated to medium containing an appropriate concentration of antibiotics alone and in combination. After 24 and 48 h incubation under anaerobic condition, 3 mL of culture was excluded and centrifuged in 8000 × g per 3 min. The pellet was washed and used for RNA extraction. The RNA extraction, Dnase I treatment and cDNA synthesis was performed by RNA extraction, Dnase I, and cDNA synthesis kits, respectively. The real-time PCR were carried out by sybrGreen methods and data were analyzed based on comparative ΔΔCT. All antibiotics alone and in combination, except VAN/CAZ in clinical isolate, decreased the level of slpA gene expression in the 24-h incubation. While the expression profile of slpA was different in the 48-h incubation period. The VAN and CLI decreased the slpA expression, although the template of expression is closed to control medium. CAZ alone and in combination increased slpA expression. C. difficile may down-regulate slpA expression in the early stages of growth in sub-inhibitory concentration of antibiotics. But, over time C. difficile increases or over expresses the slpA expression level. Consequently C. difficile binds strongly to epithelial cells and continues to survive in the presence of sub-MIC concentration of antibiotics. This effect is observed especially with regard to CAZ and probably other third generation cephalosporins or in combination therapy with VAN or CLI, which are prescribed in the clinic. CAZ can interfere with the anti-down regulatory feature of VAN, CLI, and maybe other antibiotics.
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Affiliation(s)
- Ebrahim Rezazadeh Zarandi
- Department of Microbiology and Virology, Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Shahla Mansouri
- Department of Microbiology and Virology, Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Nouzar Nakhaee
- Department of Community Medicine, Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Farhad Sarafzadeh
- Department of Infectious Diseases, Afzalipour Hospital, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Moradi
- Department of Microbiology and Virology, Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
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14
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Kint N, Janoir C, Monot M, Hoys S, Soutourina O, Dupuy B, Martin-Verstraete I. The alternative sigma factor σ B plays a crucial role in adaptive strategies of Clostridium difficile during gut infection. Environ Microbiol 2017; 19:1933-1958. [PMID: 28198085 DOI: 10.1111/1462-2920.13696] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/19/2017] [Accepted: 01/22/2017] [Indexed: 12/29/2022]
Abstract
Clostridium difficile is a major cause of diarrhoea associated with antibiotherapy. Exposed to stresses in the gut, C. difficile can survive by inducing protection, detoxification and repair systems. In several firmicutes, most of these systems are controlled by the general stress response involving σB . In this work, we studied the role of σB in the physiopathology of C. difficile. We showed that the survival of the sigB mutant during the stationary phase was reduced. Using a transcriptome analysis, we showed that σB controls the expression of ∼25% of genes including genes involved in sporulation, metabolism, cell surface biogenesis and the management of stresses. By contrast, σB does not control toxin gene expression. In agreement with the up-regulation of sporulation genes, the sporulation efficiency is higher in the sigB mutant than in the wild-type strain. sigB inactivation also led to increased sensitivity to acidification, cationic antimicrobial peptides, nitric oxide and ROS. In addition, we showed for the first time that σB also plays a crucial role in oxygen tolerance in this strict anaerobe. Finally, we demonstrated that the fitness of colonisation by the sigB mutant is greatly affected in a dixenic mouse model of colonisation when compared to the wild-type strain.
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Affiliation(s)
- Nicolas Kint
- Laboratoire Pathogénese des Bactéries Anaérobies, Institut Pasteur, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Claire Janoir
- EA 4043, Unité Bactéries Pathogènes et Santé (UBaPS), Université Paris-Sud, Université Paris-Saclay, 92290, Châtenay-Malabry, France
| | - Marc Monot
- Laboratoire Pathogénese des Bactéries Anaérobies, Institut Pasteur, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Sandra Hoys
- EA 4043, Unité Bactéries Pathogènes et Santé (UBaPS), Université Paris-Sud, Université Paris-Saclay, 92290, Châtenay-Malabry, France
| | - Olga Soutourina
- Laboratoire Pathogénese des Bactéries Anaérobies, Institut Pasteur, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Bruno Dupuy
- Laboratoire Pathogénese des Bactéries Anaérobies, Institut Pasteur, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Isabelle Martin-Verstraete
- Laboratoire Pathogénese des Bactéries Anaérobies, Institut Pasteur, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
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15
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Oliveira Paiva AM, Friggen AH, Hossein-Javaheri S, Smits WK. The Signal Sequence of the Abundant Extracellular Metalloprotease PPEP-1 Can Be Used to Secrete Synthetic Reporter Proteins in Clostridium difficile. ACS Synth Biol 2016; 5:1376-1382. [PMID: 27333161 DOI: 10.1021/acssynbio.6b00104] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Clostridium difficile is an opportunistic pathogen and the main cause of antibiotic-associated diarrhea. Adherence of C. difficile to host cells is modulated by proteins present on the bacterial cell surface or secreted into the environment. Cleavage of collagen-binding proteins is mediated by the zinc metalloprotease PPEP-1, which was identified as one of the most abundant secreted proteins of C. difficile. Here, we exploit the PPEP-1 signal sequence to produce novel secreted enzymes. We have constructed two functional secreted reporters, AmyEopt and sLucopt for gene expression analysis in C. difficile. AmyEopt extracellular activity results in starch degradation and can be exploited to demonstrate promoter activity in liquid or plate-based assays. sLucopt activity could reliably be detected in culture supernatant when produced from an inducible or native promoter. The secreted reporters can be easily assessed under aerobic conditions, without the need of complex sample processing.
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Affiliation(s)
- Ana M. Oliveira Paiva
- Department
of Medical Microbiology,
Section Experimental Microbiology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Annemieke H. Friggen
- Department
of Medical Microbiology,
Section Experimental Microbiology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Shabnam Hossein-Javaheri
- Department
of Medical Microbiology,
Section Experimental Microbiology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Wiep Klaas Smits
- Department
of Medical Microbiology,
Section Experimental Microbiology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
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16
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Barbanti F, Spigaglia P. Characterization of Clostridium difficile PCR-ribotype 018: A problematic emerging type. Anaerobe 2016; 42:123-129. [PMID: 27725230 DOI: 10.1016/j.anaerobe.2016.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 09/20/2016] [Accepted: 10/06/2016] [Indexed: 10/20/2022]
Abstract
Recent surveys indicate that the majority of toxigenic Clostridium difficile strains isolated in European hospitals belonged to PCR-ribotypes (RTs) different from RT 027 or RT 078. Among these types, RT 018 has been reported in Italy and, more recently, in Korea and Japan. In Italy, strains RT 018 have become predominant in the early 2000s, whereas the majority of strains isolated before were RT 126, a type belonging to the same lineage as the RT 078. In this study, we have found that Italian strains RT 018 are resistant to erythromycin, clindamycin, moxifloxacin and rifampicin. Rifampicin resistance is rarely observed in strains RT 018 from other countries and in Italian strains RT 078 and RT 126, therefore the decennial use of rifamycin antibiotics in Italy may be one of the driving factors for the spread of RT 018 in our country. The strains RT 018 examined showed a significant higher adhesion to Caco-2 cells compared to strains RT 078 and RT 126. Furthermore, strains RT 018 became predominant in in vitro competition assays with strains RT 078 or RT 126. If maintained in vivo, these characteristics could lead to a rapid colonization of the intestine by strains RT 018. Under the conditions used, isolates RT 018 produced significantly higher toxins levels compared to strains RT 078 and RT 126, while heat-resistant CFUs production seems to be strain-dependent. Robust toxin production and enhanced sporulation could in part explain the high diffusion and interpatient transmissibility observed for strains RT 018 in the hospital environment. In conclusion, the characteristics observed in the Italian isolates RT 018 seem to contribute in conferring an adaptive advantage to these strains, allowing their successful spread in our country.
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Affiliation(s)
- Fabrizio Barbanti
- Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Patrizia Spigaglia
- Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
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17
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Su YH, Rohani A, Warren CA, Swami NS. Tracking Inhibitory Alterations during Interstrain Clostridium difficile Interactions by Monitoring Cell Envelope Capacitance. ACS Infect Dis 2016; 2:544-551. [PMID: 27547818 PMCID: PMC4985749 DOI: 10.1021/acsinfecdis.6b00050] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Indexed: 01/05/2023]
Abstract
![]()
Global threats arising
from the increasing use of antibiotics coupled
with the high recurrence rates of Clostridium difficile (C. difficile) infections (CDI) after standard
antibiotic treatments highlight the role of commensal probiotic microorganisms,
including nontoxigenic C. difficile (NTCD) strains
in preventing CDI due to highly toxigenic C. difficile (HTCD) strains. However, optimization of the inhibitory permutations
due to commensal interactions in the microbiota requires probes capable
of monitoring phenotypic alterations to C. difficile cells. Herein, by monitoring the field screening behavior of the C. difficile cell envelope with respect to cytoplasmic polarization,
we demonstrate that inhibition of the host-cell colonization ability
of HTCD due to the S-layer alterations occurring after its co-culture
with NTCD can be quantitatively tracked on the basis of the capacitance
of the cell envelope of co-cultured HTCD. Furthermore, it is shown
that effective inhibition requires the dynamic contact of HTCD cells
with freshly secreted extracellular factors from NTCD because contact
with the cell-free supernatant causes only mild inhibition. We envision
a rapid method for screening the inhibitory permutations to arrest C. difficile colonization by routinely probing alterations
in the HTCD dielectrophoretic frequency response due to variations
in the capacitance of its cell envelope.
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Affiliation(s)
- Yi-Hsuan Su
- Department of Electrical & Computer Engineering and ‡Infectious Diseases, School of Medicine, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Ali Rohani
- Department of Electrical & Computer Engineering and ‡Infectious Diseases, School of Medicine, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Cirle A. Warren
- Department of Electrical & Computer Engineering and ‡Infectious Diseases, School of Medicine, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Nathan S. Swami
- Department of Electrical & Computer Engineering and ‡Infectious Diseases, School of Medicine, University of Virginia, Charlottesville, Virginia 22904, United States
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18
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Draft Genome Sequence of Clostridium difficile Strain IT1118, an Epidemic Isolate Belonging to the Emerging PCR Ribotype 018. GENOME ANNOUNCEMENTS 2016; 4:4/4/e00717-16. [PMID: 27445391 PMCID: PMC4956464 DOI: 10.1128/genomea.00717-16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Clostridium difficile PCR ribotype 018 has emerged in Italy, South Korea, and Japan, causing severe infections and outbreaks. In this study, we sequenced the genome of IT1118, an Italian clinical isolate, to clarify the molecular features contributing to the success of this epidemic type.
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19
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Abstract
Infection of the colon with the Gram-positive bacterium Clostridium difficile is potentially life threatening, especially in elderly people and in patients who have dysbiosis of the gut microbiota following antimicrobial drug exposure. C. difficile is the leading cause of health-care-associated infective diarrhoea. The life cycle of C. difficile is influenced by antimicrobial agents, the host immune system, and the host microbiota and its associated metabolites. The primary mediators of inflammation in C. difficile infection (CDI) are large clostridial toxins, toxin A (TcdA) and toxin B (TcdB), and, in some bacterial strains, the binary toxin CDT. The toxins trigger a complex cascade of host cellular responses to cause diarrhoea, inflammation and tissue necrosis - the major symptoms of CDI. The factors responsible for the epidemic of some C. difficile strains are poorly understood. Recurrent infections are common and can be debilitating. Toxin detection for diagnosis is important for accurate epidemiological study, and for optimal management and prevention strategies. Infections are commonly treated with specific antimicrobial agents, but faecal microbiota transplants have shown promise for recurrent infections. Future biotherapies for C. difficile infections are likely to involve defined combinations of key gut microbiota.
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Affiliation(s)
- Wiep Klaas Smits
- Section Experimental Bacteriology, Department of Medical Microbiology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, and Department of Microbiology, Monash University, Victoria, Australia
| | - D. Borden Lacy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, and The Veterans Affairs Tennessee Valley Healthcare System, Nashville Tennessee, USA
| | - Mark H. Wilcox
- Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK
| | - Ed J. Kuijper
- Section Experimental Bacteriology, Department of Medical Microbiology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
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20
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Janoir C. Virulence factors of Clostridium difficile and their role during infection. Anaerobe 2016; 37:13-24. [DOI: 10.1016/j.anaerobe.2015.10.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/16/2015] [Accepted: 10/21/2015] [Indexed: 02/08/2023]
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21
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Abstract
Clostridium difficile infection (CDI) is the leading cause of antimicrobial and health care-associated diarrhea in humans, presenting a significant burden to global health care systems. In the last 2 decades, PCR- and sequence-based techniques, particularly whole-genome sequencing (WGS), have significantly furthered our knowledge of the genetic diversity, evolution, epidemiology, and pathogenicity of this once enigmatic pathogen. C. difficile is taxonomically distinct from many other well-known clostridia, with a diverse population structure comprising hundreds of strain types spread across at least 6 phylogenetic clades. The C. difficile species is defined by a large diverse pangenome with extreme levels of evolutionary plasticity that has been shaped over long time periods by gene flux and recombination, often between divergent lineages. These evolutionary events are in response to environmental and anthropogenic activities and have led to the rapid emergence and worldwide dissemination of virulent clonal lineages. Moreover, genome analysis of large clinically relevant data sets has improved our understanding of CDI outbreaks, transmission, and recurrence. The epidemiology of CDI has changed dramatically over the last 15 years, and CDI may have a foodborne or zoonotic etiology. The WGS era promises to continue to redefine our view of this significant pathogen.
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22
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Furuya-Kanamori L, Marquess J, Yakob L, Riley TV, Paterson DL, Foster NF, Huber CA, Clements ACA. Asymptomatic Clostridium difficile colonization: epidemiology and clinical implications. BMC Infect Dis 2015; 15:516. [PMID: 26573915 PMCID: PMC4647607 DOI: 10.1186/s12879-015-1258-4] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/31/2015] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The epidemiology of Clostridium difficile infection (CDI) has changed over the past decades with the emergence of highly virulent strains. The role of asymptomatic C. difficile colonization as part of the clinical spectrum of CDI is complex because many risk factors are common to both disease and asymptomatic states. In this article, we review the role of asymptomatic C. difficile colonization in the progression to symptomatic CDI, describe the epidemiology of asymptomatic C. difficile colonization, assess the effectiveness of screening and intensive infection control practices for patients at risk of asymptomatic C. difficile colonization, and discuss the implications for clinical practice. METHODS A narrative review was performed in PubMed for articles published from January 1980 to February 2015 using search terms 'Clostridium difficile' and 'colonization' or 'colonisation' or 'carriage'. RESULTS There is no clear definition for asymptomatic CDI and the terms carriage and colonization are often used interchangeably. The prevalence of asymptomatic C. difficile colonization varies depending on a number of host, pathogen, and environmental factors; current estimates of asymptomatic colonization may be underestimated as stool culture is not practical in a clinical setting. CONCLUSIONS Asymptomatic C. difficile colonization presents challenging concepts in the overall picture of this disease and its management. Individuals who are colonized by the organism may acquire protection from progression to disease, however they also have the potential to contribute to transmission in healthcare settings.
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Affiliation(s)
- Luis Furuya-Kanamori
- Research School of Population Health, The Australian National University, Building 62 Mills Road, Canberra, ACT 2601, Australia.
| | - John Marquess
- School of Population Health, The University of Queensland, Herston, QLD, Australia.
- Queensland Department of Health, Communicable Diseases Unit, Herston, QLD, Australia.
| | - Laith Yakob
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.
| | - Thomas V Riley
- Microbiology and Immunology, School of Pathology and Laboratory Medicine, The University of Western Australia, Nedlands, WA, Australia.
- PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands, WA, Australia.
| | - David L Paterson
- The University of Queensland, UQ Centre for Clinical Research, Herston, QLD, Australia.
| | - Niki F Foster
- PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands, WA, Australia.
| | - Charlotte A Huber
- The University of Queensland, UQ Centre for Clinical Research, Herston, QLD, Australia.
| | - Archie C A Clements
- Research School of Population Health, The Australian National University, Building 62 Mills Road, Canberra, ACT 2601, Australia.
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23
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The Clostridium difficile Protease Cwp84 Modulates both Biofilm Formation and Cell-Surface Properties. PLoS One 2015; 10:e0124971. [PMID: 25922949 PMCID: PMC4414356 DOI: 10.1371/journal.pone.0124971] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 03/19/2015] [Indexed: 01/05/2023] Open
Abstract
Clostridium difficile is responsible for 15-20% of antibiotic-associated diarrheas, and nearly all cases of pseudomembranous colitis. Among the cell wall proteins involved in the colonization process, Cwp84 is a protease that cleaves the S-layer protein SlpA into two subunits. A cwp84 mutant was previously shown to be affected for in vitro growth but not in its virulence in a hamster model. In this study, the cwp84 mutant elaborated biofilms with increased biomass compared with the parental strain, allowing the mutant to grow more robustly in the biofilm state. Proteomic analyses of the 630Δerm bacteria growing within the biofilm revealed the distribution of abundant proteins either in cell surface, matrix or supernatant fractions. Of note, the toxin TcdA was found in the biofilm matrix. Although the overall proteome differences between the cwp84 mutant and the parental strains were modest, there was still a significant impact on bacterial surface properties such as altered hydrophobicity. In vitro and in vivo competition assays revealed that the mutant was significantly impaired for growth only in the planktonic state, but not in biofilms or in vivo. Taken together, our results suggest that the phenotypes in the cwp84 mutant come from either the accumulation of uncleaved SlpA, or the ability of Cwp84 to cleave as yet undetermined proteins.
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24
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Willing SE, Candela T, Shaw HA, Seager Z, Mesnage S, Fagan RP, Fairweather NF. Clostridium difficile surface proteins are anchored to the cell wall using CWB2 motifs that recognise the anionic polymer PSII. Mol Microbiol 2015; 96:596-608. [PMID: 25649385 PMCID: PMC4973711 DOI: 10.1111/mmi.12958] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2015] [Indexed: 01/05/2023]
Abstract
Gram‐positive surface proteins can be covalently or non‐covalently anchored to the cell wall and can impart important properties on the bacterium in respect of cell envelope organisation and interaction with the environment. We describe here a mechanism of protein anchoring involving tandem CWB2 motifs found in a large number of cell wall proteins in the Firmicutes. In the Clostridium difficile cell wall protein family, we show the three tandem repeats of the CWB2 motif are essential for correct anchoring to the cell wall. CWB2 repeats are non‐identical and cannot substitute for each other, as shown by the secretion into the culture supernatant of proteins containing variations in the patterns of repeats. A conserved Ile Leu Leu sequence within the CWB2 repeats is essential for correct anchoring, although a preceding proline residue is dispensable. We propose a likely genetic locus encoding synthesis of the anionic polymer PSII and, using RNA knock‐down of key genes, reveal subtle effects on cell wall composition. We show that the anionic polymer PSII binds two cell wall proteins, SlpA and Cwp2, and these interactions require the CWB2 repeats, defining a new mechanism of protein anchoring in Gram‐positive bacteria.
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Affiliation(s)
- Stephanie E Willing
- Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
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25
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Martin J. The contribution of strains and hosts to outcomes in Clostridium difficile infection. Infect Dis Clin North Am 2015; 29:51-61. [PMID: 25582645 DOI: 10.1016/j.idc.2014.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Acquisition of Clostridium difficile spores can be followed by a spectrum of clinical outcomes ranging from asymptomatic transit through the bowel to severe colitis and death. This clinical variability is a product of bacterial virulence and host susceptibility to the pathogen. It is important to identify patients at high risk of poor outcome so that increased monitoring and optimal treatment strategies can be instigated. This article discusses the evidence linking strain type to clinical outcome, including the importance of toxin and nontoxin virulence factors. It reviews host factors and their relationship with C difficile infection susceptibility, recurrence, and mortality.
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Affiliation(s)
- Jessica Martin
- University of Leeds, Old Medical School, Leeds General Infirmary, Leeds LS1 3EX, UK.
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26
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Su YH, Warren CA, Guerrant R, Swami NS. Dielectrophoretic monitoring and interstrain separation of intact Clostridium difficile based on their S(Surface)-layers. Anal Chem 2014; 86:10855-63. [PMID: 25343746 PMCID: PMC4222627 DOI: 10.1021/ac5029837] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 10/09/2014] [Indexed: 12/16/2022]
Abstract
Clostridium difficile (C. difficile) infection (CDI) rates have exhibited a steady rise worldwide over the last two decades and the infection poses a global threat due to the emergence of antibiotic resistant strains. Interstrain antagonistic interactions across the host microbiome form an important strategy for controlling the emergence of CDI. The current diagnosis method for CDI, based on immunoassays for toxins produced by pathogenic C. difficile strains, is limited by false negatives due to rapid toxin degradation. Furthermore, simultaneous monitoring of nontoxigenic C. difficile strains is not possible, due to absence of these toxins, thereby limiting its application toward the control of CDI through optimizing antagonistic interstrain interactions. Herein, we demonstrate that morphological differences within the cell wall of particular C. difficile strains with differing S-layer proteins can induce systematic variations in their electrophysiology, due alterations in cell wall capacitance. As a result, dielectrophoretic frequency analysis can enable the independent fingerprinting and label-free separation of intact microbials of each strain type from mixed C. difficile samples. The sensitivity of this contact-less electrophysiological method is benchmarked against the immunoassay and microbial growth rate methods for detecting alterations within both, toxigenic and nontoxigenic C. difficile strains after vancomycin treatment. This microfluidic diagnostic platform can assist in the development of therapies for arresting clostridial infections by enabling the isolation of individual strains, optimization of antibiotic treatments and the monitoring of microbiomes.
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Affiliation(s)
- Yi-Hsuan Su
- Electrical
and Computer Engineering, University of
Virginia at Thornton Hall, 351 McCormick Road, P.O. Box 400743, Charlottesville, Virginia 22904, United States
| | - Cirle A. Warren
- Infectious
Diseases, School of Medicine, University
of Virginia at Infectious Diseases & International Health, P.O. Box 801379, Charlottesville, Virginia 22908, United
States
| | - Richard
L. Guerrant
- Infectious
Diseases, School of Medicine, University
of Virginia at Infectious Diseases & International Health, P.O. Box 801379, Charlottesville, Virginia 22908, United
States
| | - Nathan S. Swami
- Electrical
and Computer Engineering, University of
Virginia at Thornton Hall, 351 McCormick Road, P.O. Box 400743, Charlottesville, Virginia 22904, United States
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27
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Merrigan MM, Venugopal A, Roxas JL, Anwar F, Mallozzi MJ, Roxas BAP, Gerding DN, Viswanathan VK, Vedantam G. Surface-layer protein A (SlpA) is a major contributor to host-cell adherence of Clostridium difficile. PLoS One 2013; 8:e78404. [PMID: 24265687 PMCID: PMC3827033 DOI: 10.1371/journal.pone.0078404] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 09/11/2013] [Indexed: 12/18/2022] Open
Abstract
Clostridium difficile is a leading cause of antibiotic-associated diarrhea, and a significant etiologic agent of healthcare-associated infections. The mechanisms of attachment and host colonization of C. difficile are not well defined. We hypothesize that non-toxin bacterial factors, especially those facilitating the interaction of C. difficile with the host gut, contribute to the initiation of C. difficile infection. In this work, we optimized a completely anaerobic, quantitative, epithelial-cell adherence assay for vegetative C. difficile cells, determined adherence proficiency under multiple conditions, and investigated C. difficile surface protein variation via immunological and DNA sequencing approaches focused on Surface-Layer Protein A (SlpA). In total, thirty-six epidemic-associated and non-epidemic associated C. difficile clinical isolates were tested in this study, and displayed intra- and inter-clade differences in attachment that were unrelated to toxin production. SlpA was a major contributor to bacterial adherence, and individual subunits of the protein (varying in sequence between strains) mediated host-cell attachment to different extents. Pre-treatment of host cells with crude or purified SlpA subunits, or incubation of vegetative bacteria with anti-SlpA antisera significantly reduced C. difficile attachment. SlpA-mediated adherence-interference correlated with the attachment efficiency of the strain from which the protein was derived, with maximal blockage observed when SlpA was derived from highly adherent strains. In addition, SlpA-containing preparations from a non-toxigenic strain effectively blocked adherence of a phylogenetically distant, epidemic-associated strain, and vice-versa. Taken together, these results suggest that SlpA plays a major role in C. difficile infection, and that it may represent an attractive target for interventions aimed at abrogating gut colonization by this pathogen.
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Affiliation(s)
- Michelle M. Merrigan
- Department of Microbiology and Immunology, Loyola University Medical Center, Maywood, Illinois, United States of America
| | - Anilrudh Venugopal
- St. John's Hospital and Medical Center and Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Jennifer L. Roxas
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Farhan Anwar
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Michael J. Mallozzi
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Bryan A. P. Roxas
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Dale N. Gerding
- Hines VA Hospital, Hines, Illinois, United States of America
- Division of Infectious Diseases, Loyola University Chicago Stritch School of Medicine, Maywood, Illinois, United States of America
| | - V. K. Viswanathan
- School of Animal and Comparative Biomedical Sciences
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
- The Bio5 Institute for Collaborative Research, University of Arizona, Tucson, Arizona, United States of America
| | - Gayatri Vedantam
- School of Animal and Comparative Biomedical Sciences
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
- The Bio5 Institute for Collaborative Research, University of Arizona, Tucson, Arizona, United States of America
- Southern Arizona VA Healthcare System, Tucson, Arizona, United States of America
- * E-mail:
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Abstract
Clostridium difficile infections (CDI) have emerged as a major cause of healthcare associated disease, and recent epidemiological evidence also suggests an important role in community-acquired diarrhea. This increase is associated with specific types, especially PCR ribotypes 027 and 078, which are sometimes referred to as “hypervirulent”. Over the past years major advances have been made in our understanding of C. difficile pathogenicity, with the identification and characterization of the major clostridial toxins TcdA and TcdB. However, the relation between the toxins, their regulation, and “hypervirulence” remain unclear. Here I review our current understanding of C. difficile pathogenicity and argue that “hypervirulent” is an inadequate term to describe PCR ribotypes 027 and 078, that the ability of C. difficile to cause problematic infections is a consequence of a multifactorial process that extends beyond toxins, sporulation, and antimicrobial resistance, and that vigilance is in order toward types that are closely related to ribotypes 027 and 078, but are currently not considered problematic.
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Affiliation(s)
- Wiep Klaas Smits
- Department of Medical Microbiology; Leiden University Medical Center; Leiden, the Netherlands
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