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Hussain H, Nubgan A, Rodríguez C, Imwattana K, Knight DR, Parthala V, Mullany P, Goh S. Removal of mobile genetic elements from the genome of Clostridioides difficile and the implications for the organism's biology. Front Microbiol 2024; 15:1416665. [PMID: 38966395 PMCID: PMC11222575 DOI: 10.3389/fmicb.2024.1416665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 06/04/2024] [Indexed: 07/06/2024] Open
Abstract
Clostridioides difficile is an emerging pathogen of One Health significance. Its highly variable genome contains mobile genetic elements (MGEs) such as transposons and prophages that influence its biology. Systematic deletion of each genetic element is required to determine their precise role in C. difficile biology and contribution to the wider mobilome. Here, Tn5397 (21 kb) and ϕ027 (56 kb) were deleted from C. difficile 630 and R20291, respectively, using allele replacement facilitated by CRISPR-Cas9. The 630 Tn5397 deletant transferred PaLoc at the same frequency (1 × 10-7) as 630 harboring Tn5397, indicating that Tn5397 alone did not mediate conjugative transfer of PaLoc. The R20291 ϕ027 deletant was sensitive to ϕ027 infection, and contained two unexpected features, a 2.7 kb remnant of the mutagenesis plasmid, and a putative catalase gene adjacent to the deleted prophage was also deleted. Growth kinetics of R20291 ϕ027 deletant was similar to wild type (WT) in rich medium but marginally reduced compared with WT in minimal medium. This work indicates the commonly used pMTL8000 plasmid series works well for CRISPR-Cas9-mediated gene deletion, resulting in the largest deleted locus (56.8 kb) described in C. difficile. Removal of MGEs was achieved by targeting conjugative/integrative regions to promote excision and permanent loss. The deletants created will be useful strains for investigating Tn5397 or ϕ027 prophage contribution to host virulence, fitness, and physiology, and a platform for other mutagenesis studies aimed at functional gene analysis without native transposon or phage interference in C. difficile 630 and R20291.
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Affiliation(s)
- Haitham Hussain
- Department of Microbial Diseases, Eastman Dental Institute, University College London, London, United Kingdom
| | - Amer Nubgan
- Department of Clinical, Pharmaceutical and Biological Sciences, University of Hertfordshire, Hatfield, United Kingdom
| | - César Rodríguez
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
| | - Korakrit Imwattana
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Salaya, Thailand
| | - Daniel R. Knight
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
- Department of Microbiology, PathWest Laboratory Medicine WA, Queen Elizabeth II Medical Centre, Nedlands, WA, Australia
| | - Valerija Parthala
- Department of Clinical, Pharmaceutical and Biological Sciences, University of Hertfordshire, Hatfield, United Kingdom
| | - Peter Mullany
- Department of Microbial Diseases, Eastman Dental Institute, University College London, London, United Kingdom
| | - Shan Goh
- Department of Clinical, Pharmaceutical and Biological Sciences, University of Hertfordshire, Hatfield, United Kingdom
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2
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Jandl B, Dighe S, Baumgartner M, Makristathis A, Gasche C, Muttenthaler M. Gastrointestinal Biofilms: Endoscopic Detection, Disease Relevance, and Therapeutic Strategies. Gastroenterology 2024:S0016-5085(24)05054-6. [PMID: 38876174 DOI: 10.1053/j.gastro.2024.04.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 04/10/2024] [Accepted: 04/15/2024] [Indexed: 06/16/2024]
Abstract
Gastrointestinal biofilms are highly heterogenic and spatially organized polymicrobial communities that can expand and cover large areas in the gastrointestinal tract. Gut microbiota dysbiosis, mucus disruption, and epithelial invasion are associated with pathogenic biofilms that have been linked to gastrointestinal disorders such as irritable bowel syndrome, inflammatory bowel diseases, gastric cancer, and colon cancer. Intestinal biofilms are highly prevalent in ulcerative colitis and irritable bowel syndrome patients, and most endoscopists will have observed such biofilms during colonoscopy, maybe without appreciating their biological and clinical importance. Gut biofilms have a protective extracellular matrix that renders them challenging to treat, and effective therapies are yet to be developed. This review covers gastrointestinal biofilm formation, growth, appearance and detection, biofilm architecture and signalling, human host defence mechanisms, disease and clinical relevance of biofilms, therapeutic approaches, and future perspectives. Critical knowledge gaps and open research questions regarding the biofilm's exact pathophysiological relevance and key hurdles in translating therapeutic advances into the clinic are discussed. Taken together, this review summarizes the status quo in gut biofilm research and provides perspectives and guidance for future research and therapeutic strategies.
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Affiliation(s)
- Bernhard Jandl
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria; University of Vienna, Vienna Doctoral School in Chemistry, Vienna, Austria; Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia; Division of Gastroenterology and Hepatology, Department of Internal Medicine 3, Medical University of Vienna, Vienna, Austria
| | - Satish Dighe
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Maximillian Baumgartner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine 3, Medical University of Vienna, Vienna, Austria; CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Athanasios Makristathis
- Division of Clinical Microbiology, Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Christoph Gasche
- Division of Gastroenterology and Hepatology, Department of Internal Medicine 3, Medical University of Vienna, Vienna, Austria; Loha for Life, Center for Gastroenterology and Iron Deficiency, Vienna, Austria
| | - Markus Muttenthaler
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria; Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.
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3
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Warren Norris MAH, Plaskon DM, Tamayo R. Phase Variation of Flagella and Toxins in Clostridioides difficile is Mediated by Selective Rho-dependent Termination. J Mol Biol 2024; 436:168456. [PMID: 38278436 PMCID: PMC10942720 DOI: 10.1016/j.jmb.2024.168456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/16/2024] [Accepted: 01/20/2024] [Indexed: 01/28/2024]
Abstract
Clostridioides difficile is an intestinal pathogen that exhibits phase variation of flagella and toxins through inversion of the flagellar (flg) switch controlling flagellar and toxin gene expression. The transcription termination factor Rho preferentially inhibits swimming motility of bacteria with the 'flg-OFF' switch sequence. How C. difficile Rho mediates this selectivity was unknown. C. difficile Rho contains an N-terminal insertion domain (NID) which is found in a subset of Rho orthologues and confers diverse functions. Here we determined how Rho distinguishes between flg-ON and -OFF mRNAs and the roles of the NID and other domains of C. difficile Rho. Using in vitro ATPase assays, we determined that Rho specifically binds a region containing the left inverted repeat of the flg switch, but only of flg-OFF mRNA, indicating that differential termination is mediated by selective Rho binding. Using a suite of in vivo and in vitro assays in C. difficile, we determined that the NID is essential for Rho termination of flg-OFF mRNA, likely by influencing the ability to form stable hexamers, and the RNA binding domain is critical for flg-OFF specific termination. This work gives insight into the novel mechanism by which Rho interacts with flg mRNA to mediate phase variation of flagella and toxins in C. difficile and broadens our understanding of Rho-mediated termination in an organism with an AT-rich genome.
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Affiliation(s)
- Mercedes A H Warren Norris
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Dylan M Plaskon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, 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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Schneemann M, Heils L, Moos V, Weiß F, Krug SM, Weiner J, Beule D, Gerhard R, Schulzke JD, Bücker R. A Colonic Organoid Model Challenged with the Large Toxins of Clostridioides difficile TcdA and TcdB Exhibit Deregulated Tight Junction Proteins. Toxins (Basel) 2023; 15:643. [PMID: 37999506 PMCID: PMC10674794 DOI: 10.3390/toxins15110643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 11/25/2023] Open
Abstract
BACKGROUND Clostridioides difficile toxins TcdA and TcdB are responsible for diarrhea and colitis. Lack of functional studies in organoid models of the gut prompted us to elucidate the toxin's effects on epithelial barrier function and the molecular mechanisms for diarrhea and inflammation. METHODS Human adult colon organoids were cultured on membrane inserts. Tight junction (TJ) proteins and actin cytoskeleton were analyzed for expression via Western blotting and via confocal laser-scanning microscopy for subcellular localization. RESULTS Polarized intestinal organoid monolayers were established from stem cell-containing colon organoids to apply toxins from the apical side and to perform functional measurements in the organoid model. The toxins caused a reduction in transepithelial electrical resistance in human colonic organoid monolayers with sublethal concentrations. Concomitantly, we detected increased paracellular permeability fluorescein and FITC-dextran-4000. Human colonic organoid monolayers exposed to the toxins exhibited redistribution of barrier-forming TJ proteins claudin-1, -4 and tricellulin, whereas channel-forming claudin-2 expression was increased. Perijunctional F-actin cytoskeleton organization was affected. CONCLUSIONS Adult stem cell-derived human colonic organoid monolayers were applicable as a colon infection model for electrophysiological measurements. The TJ changes noted can explain the epithelial barrier dysfunction and diarrhea in patients, as well as increased entry of luminal antigens triggering inflammation.
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Affiliation(s)
- Martina Schneemann
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Lucas Heils
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Verena Moos
- Department of Gastroenterology, Infectious Diseases and Rheumatology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Franziska Weiß
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Susanne M. Krug
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - January Weiner
- Core Unit Bioinformatics (CUBI), Berlin Institute of Health at Charité—Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Dieter Beule
- Core Unit Bioinformatics (CUBI), Berlin Institute of Health at Charité—Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany
| | - Jörg-Dieter Schulzke
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Roland Bücker
- Clinical Physiology, Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
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Heils L, Schneemann M, Gerhard R, Schulzke JD, Bücker R. CDT of Clostridioides difficile Induces MLC-Dependent Intestinal Barrier Dysfunction in HT-29/B6 Epithelial Cell Monolayers. Toxins (Basel) 2023; 15:54. [PMID: 36668874 PMCID: PMC9866553 DOI: 10.3390/toxins15010054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
Background: Clostridioides difficile binary toxin (CDT) defines the hypervirulence of strains in nosocomial antibiotic-induced colitis with the highest mortality. The objective of our study was to investigate the impact of CDT on the intestinal epithelial barrier and to enlighten the underlying molecular mechanisms. Methods: Functional measurements of epithelial barrier function by macromolecular permeability and electrophysiology were performed in human intestinal HT-29/B6 cell monolayers. Molecular analysis of the spatial distribution of tight junction protein and cytoskeleton was performed by super-resolution STED microscopy. Results: Sublethal concentrations of CDT-induced barrier dysfunction with decreased TER and increased permeability for 332 Da fluorescein and 4 kDa FITC-dextran. The molecular correlate to the functional barrier defect by CDT was found to be a tight junction protein subcellular redistribution with tricellulin, occludin, and claudin-4 off the tight junction domain. This redistribution was shown to be MLCK-dependent. Conclusions: CDT compromised epithelial barrier function in a human intestinal colonic cell model, even in sublethal concentrations, pointing to barrier dysfunction in the intestine and leak flux induction as a diarrheal mechanism. However, this cannot be attributed to the appearance of apoptosis and necrosis, but rather to an opening of the paracellular leak pathway as the result of epithelial tight junction alterations.
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Affiliation(s)
- Lucas Heils
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Martina Schneemann
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany
| | - Jörg-Dieter Schulzke
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Roland Bücker
- Clinical Physiology, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
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6
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Auranofin and Baicalin Inhibit Clostridioides difficile Growth and Sporulation: An In vitro Study. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2022. [DOI: 10.22207/jpam.16.3.01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clostridioides difficile is a principal cause of hospital-acquired gastrointestinal infections, with sporulation and toxin production being key determinants in the disease pathogenesis. Although infections have been escalating and the complications can be life-threatening, the narrow pipeline of approved therapeutics has not witnessed an equivalent surge. With the unfolding of worrisome mutations and antimicrobial resistance, attention has been drawn to either discovering new therapeutics, or even better, repurposing already available ones. Consequently, this study was undertaken to assess the anti-clostridial activity of auranofin, an anti-rheumatic FDA-approved therapeutic; and baicalin, a natural flavone glycoside with reported anti-microbial potential. In comparison with vancomycin, the in vitro efficacy of auranofin and baicalin was tested against hypervirulent C. difficile (BAA-1870TM). Broth suspensions were prepared with and without the three agents and anaerobically incubated. At 24- and 48-hours post-incubation, serial dilutions were prepared and inoculated onto agar plates. Viable cell counts and viable spore counts were then quantified. Meanwhile, toxin production was assessed via ELISA. At a concentration as low as 3 μg/mL, auranofin demonstrated a potent anti-clostridial activity. Both auranofin and baicalin exhibited a remarkable reduction in C. difficile viable cell counts (P-value 0.03 for each) and spore counts (P-values 0.023 and 0.045 respectively). While auranofin and baicalin proved to be non-inferior to vancomycin as inhibitors of C. difficile growth, both drugs proved to be superior to vancomycin in decreasing the spore counts 48-hours post inoculation. Additionally, auranofin markedly reduced C. difficile toxin production (P-value 0.021); a feature that was deficient in both baicalin and vancomycin. To enrich the currently limited repertoire of anti-clostridial drugs, further research is encouraging to compare between the in vivo efficacy of auranofin and that of baicalin. Both agents represent promising approaches that could address the unfulfilled needs in controlling C. difficile infection.
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7
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Clostridial Diseases of Horses: A Review. Vaccines (Basel) 2022; 10:vaccines10020318. [PMID: 35214776 PMCID: PMC8876495 DOI: 10.3390/vaccines10020318] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/10/2022] [Accepted: 02/13/2022] [Indexed: 11/17/2022] Open
Abstract
The clostridial diseases of horses can be divided into three major groups: enteric/enterotoxic, histotoxic, and neurotoxic. The main enteric/enterotoxic diseases include those produced by Clostridium perfringens type C and Clostridioides difficile, both of which are characterized by enterocolitis. The main histotoxic diseases are gas gangrene, Tyzzer disease, and infectious necrotic hepatitis. Gas gangrene is produced by one or more of the following microorganisms: C. perfringens type A, Clostridium septicum, Paeniclostridium sordellii, and Clostridium novyi type A, and it is characterized by necrotizing cellulitis and/or myositis. Tyzzer disease is produced by Clostridium piliforme and is mainly characterized by multifocal necrotizing hepatitis. Infectious necrotic hepatitis is produced by Clostridium novyi type B and is characterized by focal necrotizing hepatitis. The main neurotoxic clostridial diseases are tetanus and botulism, which are produced by Clostridium tetani and Clostridium botulinum, respectively. Tetanus is characterized by spastic paralysis and botulism by flaccid paralysis. Neither disease present with specific gross or microscopic lesions. The pathogenesis of clostridial diseases involves the production of toxins. Confirming a diagnosis of some of the clostridial diseases of horses is sometimes difficult, mainly because some agents can be present in tissues of normal animals. This paper reviews the main clostridial diseases of horses.
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8
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Panpetch W, Phuengmaung P, Cheibchalard T, Somboonna N, Leelahavanichkul A, Tumwasorn S. Lacticaseibacillus casei Strain T21 Attenuates Clostridioides difficile Infection in a Murine Model Through Reduction of Inflammation and Gut Dysbiosis With Decreased Toxin Lethality and Enhanced Mucin Production. Front Microbiol 2021; 12:745299. [PMID: 34925261 PMCID: PMC8672038 DOI: 10.3389/fmicb.2021.745299] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/02/2021] [Indexed: 12/18/2022] Open
Abstract
Clostridioides difficile is a major cause of diarrhea in patients with antibiotic administration. Lacticaseibacillus casei T21, isolated from a human gastric biopsy, was tested in a murine C. difficile infection (CDI) model and colonic epithelial cells (Caco-2 and HT-29). Daily administration of L. casei T21 [1 × 108 colony forming units (CFU)/dose] for 4 days starting at 1 day before C. difficile challenge attenuated CDI as demonstrated by a reduction in mortality rate, weight loss, diarrhea, gut leakage, gut dysbiosis, intestinal pathology changes, and levels of pro-inflammatory cytokines [interleukin (IL)-1β, tumor necrosis factor (TNF)-α, macrophage inflammatory protein 2 (MIP-2), and keratinocyte chemoattractant (KC)] in the intestinal tissue and serum. Conditioned media from L. casei T21 exerted biological activities that fight against C. difficile as demonstrated in colonic epithelial cells by the following: (i) suppression of gene expression and production of IL-8, an important chemokine involved in C. difficile pathogenesis, (ii) reduction in the expression of SLC11A1 (solute carrier family 11 member 1) and HuR (human antigen R), important genes for the lethality of C. difficile toxin B, (iii) augmentation of intestinal integrity, and (iv) up-regulation of MUC2, a mucosal protective gene. These results supported the therapeutic potential of L. casei T21 for CDI and the need for further study on the intervention capabilities of CDI.
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Affiliation(s)
- Wimonrat Panpetch
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Pornpimol Phuengmaung
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Thanya Cheibchalard
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Naraporn Somboonna
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
- Microbiome Research Unit for Probiotics in Food and Cosmetics, Chulalongkorn University, Bangkok, Thailand
| | - Asada Leelahavanichkul
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Department of Microbiology, Faculty of Medicine, Center of Excellence in Immunology and Immune-Mediated Diseases, Bangkok, Thailand
- *Correspondence: Asada Leelahavanichkul,
| | - Somying Tumwasorn
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Microbiome Research Unit for Probiotics in Food and Cosmetics, Chulalongkorn University, Bangkok, Thailand
- Somying Tumwasorn,
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Uzal FA, Arroyo LG, Navarro MA, Gomez DE, Asín J, Henderson E. Bacterial and viral enterocolitis in horses: a review. J Vet Diagn Invest 2021; 34:354-375. [PMID: 34763560 DOI: 10.1177/10406387211057469] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Enteritis, colitis, and enterocolitis are considered some of the most common causes of disease and death in horses. Determining the etiology of these conditions is challenging, among other reasons because different causes produce similar clinical signs and lesions, and also because some agents of colitis can be present in the intestine of normal animals. We review here the main bacterial and viral causes of enterocolitis of horses, including Salmonella spp., Clostridium perfringens type A NetF-positive, C. perfringens type C, Clostridioides difficile, Clostridium piliforme, Paeniclostridium sordellii, other clostridia, Rhodococcus equi, Neorickettsia risticii, Lawsonia intracellularis, equine rotavirus, and equine coronavirus. Diarrhea and colic are the hallmark clinical signs of colitis and enterocolitis, and the majority of these conditions are characterized by necrotizing changes in the mucosa of the small intestine, colon, cecum, or in a combination of these organs. The presumptive diagnosis is based on clinical, gross, and microscopic findings, and confirmed by detection of some of the agents and/or their toxins in the intestinal content or feces.
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Affiliation(s)
- Francisco A Uzal
- California Animal Health and Food Safety Laboratory, University of California-Davis, San Bernardino Laboratory, USA
| | - Luis G Arroyo
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Mauricio A Navarro
- California Animal Health and Food Safety Laboratory, University of California-Davis, San Bernardino Laboratory, USA.,Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Diego E Gomez
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Javier Asín
- California Animal Health and Food Safety Laboratory, University of California-Davis, San Bernardino Laboratory, USA
| | - Eileen Henderson
- California Animal Health and Food Safety Laboratory, University of California-Davis, San Bernardino Laboratory, USA
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10
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Krishna A, Chopra T. Prevention of Infection due to Clostridium (Clostridioides) difficile. Infect Dis Clin North Am 2021; 35:995-1011. [PMID: 34752229 DOI: 10.1016/j.idc.2021.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Clostridium (Clostridioides) difficile infection (CDI) causes significant morbidity and mortality in the United States every year. Prevention of CDI is difficult because of spore durability and requires implementation of multipronged strategies. Two categories of prevention strategies are infection control and prevention and risk factor reduction. Hand hygiene, contact precautions, patient isolation, and environmental decontamination are cornerstones of infection control and prevention. Risk factor reduction should focus on antibiotic stewardship to reduce unnecessary antibiotic use. If CDI incidence remains higher than the institution's goal despite these measures, then special measures should be considered.
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Affiliation(s)
- Amar Krishna
- Internal Medicine, Norther Light AR Gould Hospital, 140 Academy Street, Presque Isle, ME 04769, USA.
| | - Teena Chopra
- Infectious Diseases, Wayne State University/Detroit Medical Center, UHC-2B, 4201 St Antoine, Detroit, MI 48201, USA
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11
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Taha AE. Raw Animal Meats as Potential Sources of Clostridium difficile in Al-Jouf, Saudi Arabia. Food Sci Anim Resour 2021; 41:883-893. [PMID: 34632406 PMCID: PMC8460330 DOI: 10.5851/kosfa.2021.e44] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/07/2021] [Accepted: 08/10/2021] [Indexed: 12/17/2022] Open
Abstract
Clostridium difficile present in feces of food animals may
contaminate their meats and act as a potential source of C.
difficile infection (CDI) to humans. C. difficile
resistance to antibiotics, its production of toxins and spores play major roles
in the pathogenesis of CDI. This is the first study to evaluate C.
difficile prevalence in retail raw animal meats, its antibiotics
susceptibilities and toxigenic activities in Al-Jouf, Saudi Arabia. Totally, 240
meat samples were tested. C. difficile was identified by
standard microbiological and biochemical methods. Vitek-2 compact system
confirmed C. difficile isolates were 15/240 (6.3%).
Toxins A/B were not detected by Xpect C. difficile toxin A/B
tests. Although all isolates were susceptible to vancomycin and metronidazole,
variable degrees of reduced susceptibilities to moxifloxacin, clindamycin or
tetracycline antibiotics were detected by Epsilon tests. C.
difficile strains with reduced susceptibility to antibiotics should
be investigated. Variability between the worldwide reported C.
difficile contamination levels could be due to absence of a gold
standard procedure for its isolation. Establishment of a unified testing
algorithm for C. difficile detection in food products is
definitely essential to evaluate the inter-regional variation in its prevalence
on national and international levels. Proper use of antimicrobials during animal
husbandry is crucial to control the selective drug pressure on C.
difficile strains associated with food animals. Investigating the
protective or pathogenic potential of non-toxigenic C.
difficile strains and the possibility of gene transfer from certain
toxigenic/ antibiotics-resistant to non-toxigenic/antibiotics-sensitive strains,
respectively, should be worthy of attention.
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Affiliation(s)
- Ahmed E Taha
- Microbiology and Immunology Unit, Department of Pathology, College of Medicine, Jouf University, Al-Jouf, Saudi Arabia.,Medical Microbiology and Immunology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
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12
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Lin Q, Pollock NR, Banz A, Lantz A, Xu H, Gu L, Gerding DN, Garey KW, Gonzales-Luna AJ, Zhao M, Song L, Duffy DC, Kelly CP, Chen X. Toxin A-Predominant Pathogenic Clostridioides difficile: A Novel Clinical Phenotype. Clin Infect Dis 2021; 70:2628-2633. [PMID: 31400280 DOI: 10.1093/cid/ciz727] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/30/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Most Clostridioides difficile toxinogenic strains produce both toxins A and B (A+B+), but toxin A-negative, toxin B-positive (A-B+) variants also cause disease. We report the identification of a series of pathogenic clinical C. difficile isolates that produce high amounts of toxin A with low or nondetectable toxin B. METHODS An ultrasensitive, quantitative immunoassay was used to measure toxins A and B in stool samples from 187 C. difficile infection (CDI) patients and 44 carriers. Isolates were cultured and assessed for in vitro toxin production and in vivo phenotypes (mouse CDI model). RESULTS There were 7 CDI patients and 6 carriers who had stools with detectable toxin A (TcdA, range 23-17 422 pg/mL; 5.6% of samples overall) but toxin B (TcdB) below the clinical detection limit (<20 pg/mL; median TcdA:B ratio 17.93). Concentrations of toxin A far exceeded B in in vitro cultures of all 12 recovered isolates (median TcdA:B ratio 26). Of 8 toxin A>>B isolates tested in mice, 4 caused diarrhea, and 3 of those 4 caused lethal disease. Ribotyping demonstrated strain diversity. TcdA-predominant samples were also identified at 2 other centers, with similar frequencies (7.5% and 6.8%). CONCLUSIONS We report the discovery of clinical pathogenic C. difficile strains that produce high levels of toxin A but minimal or no toxin B. This pattern of toxin production is not rare (>5% of isolates) and is consistently observed in vitro and in vivo in humans and mice. Our study highlights the significance of toxin A in human CDI pathogenesis and has important implications for CDI diagnosis, treatment, and vaccine development.
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Affiliation(s)
- Qianyun Lin
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Divisions of Gastroenterology, Massachusetts
| | - Nira R Pollock
- Infectious Diseases, Beth Israel Deaconess Medical Center, Massachusetts.,Department of Laboratory Medicine, Boston Children's Hospital, Massachusetts
| | | | | | - Hua Xu
- Divisions of Gastroenterology, Massachusetts
| | - Limei Gu
- Divisions of Gastroenterology, Massachusetts
| | - Dale N Gerding
- Department of Veterans Affairs, Edward Hines Jr Veterans Affairs Hospital, Hines, Illinois
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | - Anne J Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | | | | | | | | | - Xinhua Chen
- Divisions of Gastroenterology, Massachusetts
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Foschetti DA, Braga-Neto MB, Bolick D, Moore J, Alves LA, Martins CS, Bomfin LE, Santos A, Leitão R, Brito G, Warren CA. Clostridium difficile toxins or infection induce upregulation of adenosine receptors and IL-6 with early pro-inflammatory and late anti-inflammatory pattern. ACTA ACUST UNITED AC 2020; 53:e9877. [PMID: 32725081 PMCID: PMC7405017 DOI: 10.1590/1414-431x20209877] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 05/29/2020] [Indexed: 02/06/2023]
Abstract
Clostridium difficile causes intestinal inflammation, which increases adenosine. We compared the expression of adenosine receptors (AR) subtypes A1, A2A, A2B, and A3 in HCT-8, IEC-6 cells, and isolated intestinal epithelial cells, challenged or not with Clostridium difficile toxin A and B (TcdA and TcdB) or infection (CDI). In HCT-8, TcdB induced an early A2BR expression at 6 h and a late A2AR expression at 6 and 24 h. In addition, both TcdA and TcdB increased IL-6 expression at all time-points (peak at 6 h) and PSB603, an A2BR antagonist, decreased IL-6 expression and production. In isolated cecum epithelial cells, TcdA induced an early expression of A2BR at 2s and 6 h, followed by a late expression of A2AR at 6 and 24 h and of A1R at 24 h. In CDI, A2AR and A2BR expressions were increased at day 3, but not at day 7. ARs play a role in regulating inflammation during CDI by inducing an early pro-inflammatory and a late anti-inflammatory response. The timing of interventions with AR antagonist or agonists may be of relevance in treatment of CDI.
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Affiliation(s)
- D A Foschetti
- Departamento de Morfologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - M B Braga-Neto
- Departamento de Morfologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - D Bolick
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | - J Moore
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | - L A Alves
- Departamento de Ciências Médicas, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - C S Martins
- Departamento de Morfologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - L E Bomfin
- Departamento de Ciências Médicas, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - Aaqa Santos
- Departamento de Morfologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - Rfc Leitão
- Departamento de Morfologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - Gac Brito
- Departamento de Morfologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil
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Identification of the role of toxin B in the virulence of Clostridioides difficile based on integrated bioinformatics analyses. Int Microbiol 2020; 23:575-587. [PMID: 32388701 DOI: 10.1007/s10123-020-00128-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 03/03/2020] [Accepted: 04/13/2020] [Indexed: 02/08/2023]
Abstract
PURPOSE Clostridioides difficile toxin B (TcdB) plays a critical role in C. difficile infection (CDI), a common and costly healthcare-associated disease. The aim of the current study was to explore the intracellular and potent systemic effects of TcdB on human colon epithelial cells utilizing Gene Expression Omnibus and bioinformatic methods. METHODS Two datasets (GSE63880 and GSE29008) were collected to extract data components of mRNA of TcdB-treated human colon epithelial cells; "limma" package of "R" software was used to screen the differential genes, and "pheatmap" package was applied to construct heat maps for the differential genes; Metascape website was utilized for protein-protein interaction network and Molecular Complex Detection analysis, and Genome Ontology (GO) was used to analyze the selected differential genes. Quantitative real-time PCR (qRT-PCR) and Western blot were performed to validate the expression of hub genes. RESULTS GO terms involved in DNA replication and cell cycle were identified significantly enriched in TcdB-treated human colon epithelial cells. Moreover, the decreased expression of DNA replication-related genes, MCM complex, and CDC45 in C. difficile (TcdA-/TcdB+)-infected Caco-2 cells were validated via qRT-PCR and Western blot assays. CONCLUSIONS In conclusion, the integrated analysis of different gene expression datasets allowed us to identify a set of genes and GO terms underlying the mechanisms of CDI induced by TcdB. It would aid in understanding of the molecular mechanisms underlying TcdB-exposed colon epithelial cells and provide the basis for developing diagnosis biomarkers, treatment, and prevention strategies.
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Simecka JW, Fulda KG, Pulse M, Lee JH, Vitucci J, Nguyen P, Taylor P, Filipetto F, Espinoza AM, Sharma S. Primary care clinics can be a source of exposure to virulent Clostridium (now Clostridioides) difficile: An environmental screening study of hospitals and clinics in Dallas-Fort Worth region. PLoS One 2019; 14:e0220646. [PMID: 31415582 PMCID: PMC6695158 DOI: 10.1371/journal.pone.0220646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 07/19/2019] [Indexed: 01/05/2023] Open
Abstract
C. difficile is an endospore-forming pathogen, which is becoming a common cause of microbial health-care associated gastrointestinal disease in the United States. Both healthy and symptomatic patients can shed C. difficile spores into the environment, which can survive for long periods, being resistant to desiccation, heat, and disinfectants. In healthcare facilities, environmental contamination with C. difficile is a major concern as a potential source of exposure to this pathogen and risk of disease in susceptible patients. Although hospital-acquired infection is recognized, community-acquired infection is an increasingly recognized health problem. Primary care clinics may be a significant source of exposure to this pathogen; however, there are limited data about presence of environmental C. difficile within clinics. To address the potential for primary care clinics as a source of environmental exposure to virulent C. difficile, we measured the frequency of environmental contamination with spores in clinic examination rooms and hospital rooms in Dallas-Fort Worth (DFW) area of Texas. The ribotypes and presence of toxin genes from some environmental isolates were compared. Our results indicate primary care clinics have higher frequencies of contamination than hospitals. After notification of the presence of C. difficile spores in the clinics and an educational discussion to emphasize the importance of this infection and methods of infection prevention, environmental contamination in clinics was reduced on subsequent sampling to that found in hospitals. Thus, primary care clinics can be a source of exposure to virulent C. difficile, and recognition of this possibility can result in improved infection prevention, potentially reducing community-acquired C. difficile infections and subsequent disease.
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Affiliation(s)
- Jerry W. Simecka
- Department of Pharmaceutical Sciences and UNT Preclinical Services, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, United States of America
- * E-mail:
| | - Kimberly G. Fulda
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, United States of America
- The North Texas Primary Care Practice-Based Research Network (NorTex), University of North Texas Health Science Center, Fort Worth, TX, United States of America
| | - Mark Pulse
- Department of Pharmaceutical Sciences and UNT Preclinical Services, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, United States of America
| | - Joon-hak Lee
- Department of Biostatistics and Epidemiology, School of Public Health, University of North Texas Health Science Center, Fort Worth, TX, United States of America
| | - John Vitucci
- Department of Pharmaceutical Sciences and UNT Preclinical Services, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, United States of America
| | - Phung Nguyen
- Department of Pharmaceutical Sciences and UNT Preclinical Services, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, United States of America
| | - Patricia Taylor
- The Dallas-Fort Worth Hospital Council Education and Research Foundation, Irving, TX, United States of America
| | - Frank Filipetto
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, United States of America
- The North Texas Primary Care Practice-Based Research Network (NorTex), University of North Texas Health Science Center, Fort Worth, TX, United States of America
| | - Anna M. Espinoza
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, United States of America
- The North Texas Primary Care Practice-Based Research Network (NorTex), University of North Texas Health Science Center, Fort Worth, TX, United States of America
| | - Sushma Sharma
- The Dallas-Fort Worth Hospital Council Education and Research Foundation, Irving, TX, United States of America
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Kullin BR, Reid S, Abratt V. Clostridium difficile in patients attending tuberculosis hospitals in Cape Town, South Africa, 2014-2015. Afr J Lab Med 2018; 7:846. [PMID: 30568907 PMCID: PMC6295828 DOI: 10.4102/ajlm.v7i2.846] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 09/28/2018] [Indexed: 01/05/2023] Open
Abstract
Background Diarrhoea due to Clostridium difficile infection (CDI) poses a significant burden on healthcare systems around the world. However, there are few reports on the current status of the disease in sub-Saharan Africa. Objectives This study examined the occurrence of CDI in a South African population of tuberculosis patients, as well as the molecular epidemiology and antibiotic susceptibility profiles of C. difficile strains responsible for disease. Methods Toxigenic C. difficile in patients with suspected CDI attending two specialist tuberculosis hospitals in the Cape Town area were detected using a PCR-based diagnostic assay (Xpert® C. difficile). C. difficile strains isolated from PCR-positive specimens were characterised by ribotyping, multilocus variable-number tandem-repeat analysis and antibiotic susceptibility testing. Results The period prevalence of CDI was approximately 70.07 cases per 1000 patient admissions. Strains belonging to ribotype 017 (RT017) made up over 95% of the patient isolates and all of them were multi-drug resistant. Multilocus variable-number tandem-repeat analysis revealed several clusters of highly related C. difficile RT017 strains present in tuberculosis patients in several wards at each hospital. Conclusion Tuberculosis patients represent a population that may be at an increased risk of developing CDI and, in addition, may constitute a multi-drug resistant reservoir of this bacterium. This warrants further investigation and surveillance of the disease in this patient group and other high-risk patient groups in sub-Saharan Africa.
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Affiliation(s)
- Brian R Kullin
- Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Cape Town, South Africa
| | - Sharon Reid
- Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Cape Town, South Africa
| | - Valerie Abratt
- Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Cape Town, South Africa
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17
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Ersöz ŞŞ, Coşansu S. Prevalence of Clostridium difficile Isolated from Beef and Chicken Meat Products in Turkey. Korean J Food Sci Anim Resour 2018; 38:759-767. [PMID: 30206435 PMCID: PMC6131381 DOI: 10.5851/kosfa.2018.e14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 11/25/2022] Open
Abstract
The concern about the possibility of food can be a vehicle for the transmission
of Clostridium difficile to humans has been raised recently due
to the similarities among the strains isolated from patients, foods and food
animals. In this study, therefore, the prevalence of C.
difficile was investigated in beef and chicken meat products
collected from 57 different butcher shops, markets and fast food restaurants in
Sakarya province of Turkey. Two out of 101 samples (1.98%) was positive for
C. difficile indicating a very low prevalence. The pathogen
was isolated from an uncooked meatball sample and a cooked meat döner
sample, whereas not detected in chicken meat samples. The meatball isolate was
resistant to vancomycin and tetracycline, while the cooked meat döner
isolate was resistant to vancomycin and metronidazole. Both isolates were
sensitive to moxifloxacin and clindamycin. Toxins A and B were not detected.
This study reveals the presence of C. difficile in further
processed beef products in Turkey.
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Affiliation(s)
- Şeyma Şeniz Ersöz
- Food Engineering Department, Engineering Faculty, Sakarya University, Esentepe Campus, 54187, Sakarya, Turkey
| | - Serap Coşansu
- Food Engineering Department, Engineering Faculty, Sakarya University, Esentepe Campus, 54187, Sakarya, Turkey
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AbdelKhalek A, Abutaleb NS, Mohammad H, Seleem MN. Antibacterial and antivirulence activities of auranofin against Clostridium difficile. Int J Antimicrob Agents 2018; 53:54-62. [PMID: 30273668 DOI: 10.1016/j.ijantimicag.2018.09.018] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 09/14/2018] [Accepted: 09/22/2018] [Indexed: 12/14/2022]
Abstract
Clostridium difficile is a deadly, opportunistic bacterial pathogen. In the last two decades, C. difficile infections (CDIs) have become a national concern because of the emergence of hypervirulent mutants with increased capability to produce toxins and spores. This has resulted in an increased number of infections and deaths associated with CDI. The scarcity of anticlostridial drugs has led to unsatisfactory cure rates, elevated recurrence rates and permitted enhanced colonization with other drug-resistant pathogens (such as vancomycin-resistant enterococci) in afflicted patients. Therefore, both patients and physicians are facing an urgent need for more effective therapies to treat CDI. In an effort to find new anticlostridial drugs, we investigated auranofin, an FDA-approved oral antirheumatic drug that has recently been found to possess antibacterial activity. Auranofin exhibited potent activity against C. difficile isolates, inhibiting growth at a concentration of 1 µg/mL against 50% of all tested isolates. Auranofin inhibited both toxin production and spore formation, a property lacking in both vancomycin and metronidazole (the primary agents used to treat CDI). Auranofin had a direct protective activity against C. difficile toxin-mediated inflammation and inhibited the growth of vancomycin-resistant enterococci. Auranofin is a promising candidate that warrants further investigation as a treatment option for C. difficile infections.
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Affiliation(s)
- Ahmed AbdelKhalek
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
| | - Nader S Abutaleb
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
| | - Haroon Mohammad
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
| | - Mohamed N Seleem
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute of Inflammation, Immunology, and Infectious Disease, West Lafayette, IN 47907, USA.
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Zhang Y, Li S, Yang Z, Shi L, Yu H, Salerno-Goncalves R, Saint Fleur A, Feng H. Cysteine Protease-Mediated Autocleavage of Clostridium difficile Toxins Regulates Their Proinflammatory Activity. Cell Mol Gastroenterol Hepatol 2018; 5:611-625. [PMID: 29930981 PMCID: PMC6009800 DOI: 10.1016/j.jcmgh.2018.01.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/30/2018] [Indexed: 02/04/2023]
Abstract
BACKGROUND & AIMS Clostridium difficile toxin A (TcdA) and C difficile toxin toxin B (TcdB), the major virulence factors of the bacterium, cause intestinal tissue damage and inflammation. Although the 2 toxins are homologous and share a similar domain structure, TcdA is generally more inflammatory whereas TcdB is more cytotoxic. The functional domain of the toxins that govern the proinflammatory activities of the 2 toxins is unknown. METHODS Here, we investigated toxin domain functions that regulate the proinflammatory activity of C difficile toxins. By using a mouse ilea loop model, human tissues, and immune cells, we examined the inflammatory responses to a series of chimeric toxins or toxin mutants deficient in specific domain functions. RESULTS Blocking autoprocessing of TcdB by mutagenesis or chemical inhibition, while reducing cytotoxicity of the toxin, significantly enhanced its proinflammatory activities in the animal model. Furthermore, a noncleavable mutant TcdB was significantly more potent than the wild-type toxin in the induction of proinflammatory cytokines in human colonic tissues and immune cells. CONCLUSIONS In this study, we identified a novel mechanism of regulating the biological activities of C difficile toxins in that cysteine protease-mediated autoprocessing regulates toxins' proinflammatory activities. Our findings provide new insight into the pathogenesis of C difficile infection and the design of therapeutics against the disease.
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Key Words
- 3D, 3-dimensional
- ACPD, CPD domain of TcdA
- Autoprocessing
- Bgt, GTD of TcdB
- Br, RBD of TcdB
- C difficile
- CDI, Clostridium difficile infection
- CPD, cysteine protease domain
- Cysteine Protease
- GT, glucosyltransferase
- GTD, glucosyltransferase domain
- IL, interleukin
- Inflammation
- InsP6, inositol hexakisphosphate
- MPO, myeloperoxidase
- PBMC, peripheral blood mononuclear cell
- PBS, phosphate-buffered saline
- PCR, polymerase chain reaction
- RBD, receptor binding domain
- TER, transepithelial electrical resistance
- TcdA, Clostridium difficile toxin A
- TcdB, Clostridium difficile toxin B
- Toxins
- aTcdA, GTD deficient TcdA
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Affiliation(s)
- Yongrong Zhang
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Shan Li
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Zhiyong Yang
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Lianfa Shi
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Hua Yu
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Rosangela Salerno-Goncalves
- Department of Pediatrics and Center for Vaccine Development, School of Medicine, University of Maryland, Baltimore, Maryland
| | - Ashley Saint Fleur
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland
| | - Hanping Feng
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland,Correspondence Address correspondence to: Hanping Feng, PhD, 650 W Baltimore Street, Room 7211, Baltimore, Maryland 21201. fax: (410) 706-6511.
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Salazar CL, Reyes C, Atehortua S, Sierra P, Correa MM, Paredes-Sabja D, Best E, Fawley WN, Wilcox M, González Á. Molecular, microbiological and clinical characterization of Clostridium difficile isolates from tertiary care hospitals in Colombia. PLoS One 2017; 12:e0184689. [PMID: 28902923 PMCID: PMC5597206 DOI: 10.1371/journal.pone.0184689] [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: 05/11/2017] [Accepted: 08/29/2017] [Indexed: 12/21/2022] Open
Abstract
In Colombia, the epidemiology and circulating genotypes of Clostridium difficile have not yet been described. Therefore, we molecularly characterized clinical isolates of C.difficile from patients with suspicion of C.difficile infection (CDI) in three tertiary care hospitals. C.difficile was isolated from stool samples by culture, the presence of A/B toxins were detected by enzyme immunoassay, cytotoxicity was tested by cell culture and the antimicrobial susceptibility determined. After DNA extraction, tcdA, tcdB and binary toxin (CDTa/CDTb) genes were detected by PCR, and PCR-ribotyping performed. From a total of 913 stool samples collected during 2013-2014, 775 were included in the study. The frequency of A/B toxins-positive samples was 9.7% (75/775). A total of 143 isolates of C.difficile were recovered from culture, 110 (76.9%) produced cytotoxic effect in cell culture, 100 (69.9%) were tcdA+/tcdB+, 11 (7.7%) tcdA-/tcdB+, 32 (22.4%) tcdA-/tcdB- and 25 (17.5%) CDTa+/CDTb+. From 37 ribotypes identified, ribotypes 591 (20%), 106 (9%) and 002 (7.9%) were the most prevalent; only one isolate corresponded to ribotype 027, four to ribotype 078 and four were new ribotypes (794,795, 804,805). All isolates were susceptible to vancomycin and metronidazole, while 85% and 7.7% were resistant to clindamycin and moxifloxacin, respectively. By multivariate analysis, significant risk factors associated to CDI were, staying in orthopedic service, exposure to third-generation cephalosporins and staying in an ICU before CDI symptoms; moreover, steroids showed to be a protector factor. These results revealed new C. difficile ribotypes and a high diversity profile circulating in Colombia different from those reported in America and European countries.
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Affiliation(s)
- Clara Lina Salazar
- Research Group in Anaerobic Bacteria (GIBA), School of Microbiology, Universidad de Antioquia, Medellín, Colombia
| | - Catalina Reyes
- Basic and Applied Microbiology Research Group (MICROBA), School of Microbiology, Universidad de Antioquia, Medellín, Colombia
| | | | - Patricia Sierra
- Clínica León XIII, IPS Universitaria, Universidad de Antioquia, Medellín, Colombia
| | - Margarita María Correa
- Molecular Microbiology Group, School of Microbiology, Universidad de Antioquia, Medellín, Colombia
| | - Daniel Paredes-Sabja
- Microbiota-Host Interactions and Clostridia Research Group, Departamento de Ciencias Biológicas, at Universidad Andres Bello, Santiago, Chile
| | - Emma Best
- Departament of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom
| | - Warren N. Fawley
- Departament of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom
| | - Mark Wilcox
- Departament of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom
| | - Ángel González
- Basic and Applied Microbiology Research Group (MICROBA), School of Microbiology, Universidad de Antioquia, Medellín, Colombia
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Hutton ML, Cunningham BA, Mackin KE, Lyon SA, James ML, Rood JI, Lyras D. Bovine antibodies targeting primary and recurrent Clostridium difficile disease are a potent antibiotic alternative. Sci Rep 2017. [PMID: 28623367 PMCID: PMC5473923 DOI: 10.1038/s41598-017-03982-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The increased incidence of antibiotic resistant 'superbugs' has amplified the use of broad spectrum antibiotics worldwide. An unintended consequence of antimicrobial treatment is disruption of the gastrointestinal microbiota, resulting in susceptibility to opportunistic pathogens, such as Clostridium difficile. Paradoxically, treatment of C. difficile infections (CDI) also involves antibiotic use, leaving patients susceptible to re-infection. This serious health threat has led to an urgent call for the development of new therapeutics to reduce or replace the use of antibiotics to treat bacterial infections. To address this need, we have developed colostrum-derived antibodies for the prevention and treatment of CDI. Pregnant cows were immunised to generate hyperimmune bovine colostrum (HBC) containing antibodies that target essential C. difficile virulence components, specifically, spores, vegetative cells and toxin B (TcdB). Mouse infection and relapse models were used to compare the capacity of HBC to prevent or treat primary CDI as well as prevent recurrence. Administration of TcdB-specific colostrum alone, or in combination with spore or vegetative cell-targeted colostrum, prevents and treats C. difficile disease in mice and reduces disease recurrence by 67%. C. difficile-specific colostrum should be re-considered as an immunotherapeutic for the prevention or treatment of primary or recurrent CDI.
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Affiliation(s)
- Melanie L Hutton
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Bliss A Cunningham
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Kate E Mackin
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Shelley A Lyon
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Meagan L James
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Julian I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia.
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Kheradmand M, Jalilian S, Alvandi A, Abiri R. Prevalence of Clostridium difficile and its toxigenic genotype in beef samples in west of Iran. IRANIAN JOURNAL OF MICROBIOLOGY 2017; 9:169-173. [PMID: 29225756 PMCID: PMC5719511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND AND OBJECTIVES Clostridium difficile is the leading cause of nosocomial diarrhea and pseudomembranous colitis. The prevalence of C. difficile infection differs in various geographical areas. The aim of this study was to determine the prevalence of C. difficile isolates and the prevalence of cdd3, tcdA and tcdB genes in beef samples in Kermanshah Province. MATERIALS AND METHODS One hundred ground beef samples were randomly collected from the butchers of Kermanshah province during March 2014 to March 2015. Following alcohol shock, minced meat samples were incubated in a specific culture medium for 5 to 7 days. The suspicious colonies were analyzed by biochemical tests and frequency of C. difficile and cdd3, tcdA and tcdB genes was assessed by PCR using specific primers. RESULTS In total, 30% samples were positive for C. difficile and all the isolates harbored Cdd3 gene. Combined dual-gene frequency of A+B+, A-B+ and A+B- strains in the positive were 0%, 3.3%, and 26.6% respectively, while 21 samples (70%) were non-toxigenic (A-B-). CONCLUSION In this study, the presence of C. difficile in beef as a source of contamination was confirmed. It was also shown that the incidence of C. difficile in ground meat was relatively higher than many other studies.
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Affiliation(s)
| | | | | | - Ramin Abiri
- Corresponding author: Ramin Abiri, PhD, Microbiology Department, Faculty of Medicine, Kermanshah University of Medical Sciences, Shirudi Blvd., Parastar Blvd, Postal code: 6714869914, Kermanshah, Iran. Tel: +98-912-277-3648, Fax: +98-833-427-4621,
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Collery MM, Kuehne SA, McBride SM, Kelly ML, Monot M, Cockayne A, Dupuy B, Minton NP. What's a SNP between friends: The influence of single nucleotide polymorphisms on virulence and phenotypes of Clostridium difficile strain 630 and derivatives. Virulence 2016; 8:767-781. [PMID: 27652799 PMCID: PMC5626343 DOI: 10.1080/21505594.2016.1237333] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Clostridium difficile is a major cause of antibiotic induced diarrhea worldwide, responsible for significant annual mortalities and represents a considerable economic burden on healthcare systems. The two main C. difficile virulence factors are toxins A and B. Isogenic toxin B mutants of 2 independently isolated erythromycin-sensitive derivatives (630E and 630Δerm) of strain 630 were previously shown to exhibit substantively different phenotypes. Compared to 630, strain 630E and its progeny grow slower, achieve lower final cell densities, exhibit a reduced capacity for spore-formation, produce lower levels of toxin and are less virulent in the hamster infection model. By the same measures, strain 630Δerm and its derivatives more closely mirror the behavior of 630. Genome sequencing revealed that 630Δerm had acquired 7 unique Single Nucleotide Polymorphisms (SNPs) compared to 630 and 630E, while 630E had 9 SNPs and a DNA inversion not found in the other 2 strains. The relatively large number of mutations meant that the identification of those responsible for the altered properties of 630E was not possible, despite the restoration of 3 mutations to wildtype by allelic exchange and comparative RNAseq analysis of all 3 strains. The latter analysis revealed large differences in gene expression between the 3 strains, explaining in part why no single SNP could restore the phenotypic differences. Our findings suggest that strain 630Δerm should be favored over 630E as a surrogate for 630 in genetic-based studies. They also underline the importance of effective strain curation and the need to genome re-sequence master seed banks wherever possible.
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Affiliation(s)
- Mark M Collery
- a Clostridia Research Group , BBSRC/EPSRC Synthetic Biology Research Center (SBRC), School of Life Sciences, University of Nottingham , Nottingham , UK
| | - Sarah A Kuehne
- a Clostridia Research Group , BBSRC/EPSRC Synthetic Biology Research Center (SBRC), School of Life Sciences, University of Nottingham , Nottingham , UK.,b NIHR Biomedical Research Unit in Gastrointestinal and Liver Diseases at Nottingham University Hospitals NHS Trust , University of Nottingham , Nottingham , UK
| | - Shonna M McBride
- c Department of Microbiology and Immunology , Emory Antibiotic Resistance Center, Emory University , Atlanta , GA , USA
| | - Michelle L Kelly
- a Clostridia Research Group , BBSRC/EPSRC Synthetic Biology Research Center (SBRC), School of Life Sciences, University of Nottingham , Nottingham , UK
| | - Marc Monot
- d Laboratoire Pathogenèse des Bactéries Anaérobies , Institut Pasteur , Paris , France
| | - Alan Cockayne
- a Clostridia Research Group , BBSRC/EPSRC Synthetic Biology Research Center (SBRC), School of Life Sciences, University of Nottingham , Nottingham , UK
| | - Bruno Dupuy
- d Laboratoire Pathogenèse des Bactéries Anaérobies , Institut Pasteur , Paris , France
| | - Nigel P Minton
- a Clostridia Research Group , BBSRC/EPSRC Synthetic Biology Research Center (SBRC), School of Life Sciences, University of Nottingham , Nottingham , UK.,b NIHR Biomedical Research Unit in Gastrointestinal and Liver Diseases at Nottingham University Hospitals NHS Trust , University of Nottingham , Nottingham , UK
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25
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Advances in the Microbiome: Applications to Clostridium difficile Infection. J Clin Med 2016; 5:jcm5090083. [PMID: 27657145 PMCID: PMC5039486 DOI: 10.3390/jcm5090083] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 09/02/2016] [Accepted: 09/13/2016] [Indexed: 12/14/2022] Open
Abstract
Clostridium difficile is a major cause of morbidity and mortality worldwide, causing over 400,000 infections and approximately 29,000 deaths in the United States alone each year. C. difficile is the most common cause of nosocomial diarrhoea in the developed world, and, in recent years, the emergence of hyper-virulent (mainly ribotypes 027 and 078, sometimes characterised by increased toxin production), epidemic strains and an increase in the number of community-acquired infections has caused further concern. Antibiotic therapy with metronidazole, vancomycin or fidaxomicin is the primary treatment for C. difficile infection (CDI). However, CDI is unique, in that, antibiotic use is also a major risk factor for acquiring CDI or recurrent CDI due to disruption of the normal gut microbiota. Therefore, there is an urgent need for alternative, non-antibiotic therapeutics to treat or prevent CDI. Here, we review a number of such potential treatments which have emerged from advances in the field of microbiome research.
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26
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Cooper CC, Jump RLP, Chopra T. Prevention of Infection Due to Clostridium difficile. Infect Dis Clin North Am 2016; 30:999-1012. [PMID: 27660089 DOI: 10.1016/j.idc.2016.07.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Clostridium difficile is one of the foremost nosocomial pathogens. Preventing infection is particularly challenging. Effective prevention efforts typically require a multifaceted bundled approach. A variety of infection control procedures may be advantageous, including strict hand decontamination with soap and water, contact precautions, and using chlorine-containing decontamination agents. Additionally, risk factor reduction can help reduce the burden of disease. The risk factor modification is principally accomplished though antibiotic stewardship programs. Unfortunately, most of the current evidence for prevention is in acute care settings. This review focuses on preventative approaches to reduce the incidence of Clostridium difficile infection in healthcare settings.
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Affiliation(s)
- Christopher C Cooper
- Division of Infectious Diseases, Wayne State University, 3990 John R. Street, 5 Hudson, Detroit, MI 48201, USA
| | - Robin L P Jump
- Infectious Disease Section, Medical Division, Geriatric Research Education and Clinical Center (GRECC), Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA; Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Teena Chopra
- Division of Infectious Diseases, Wayne State University, 3990 John R. Street, 5 Hudson, Detroit, MI 48201, USA.
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27
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A Tetraspecific VHH-Based Neutralizing Antibody Modifies Disease Outcome in Three Animal Models of Clostridium difficile Infection. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2016; 23:774-84. [PMID: 27413067 PMCID: PMC5014919 DOI: 10.1128/cvi.00730-15] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 07/01/2016] [Indexed: 12/17/2022]
Abstract
Clostridium difficile infection (CDI), a leading cause of nosocomial infection, is a serious disease in North America, Europe, and Asia. CDI varies greatly from asymptomatic carriage to life-threatening diarrhea, toxic megacolon, and toxemia. The incidence of community-acquired infection has increased due to the emergence of hypervirulent antibiotic-resistant strains. These new strains contribute to the frequent occurrence of disease relapse, complicating treatment, increasing hospital stays, and increasing morbidity and mortality among patients. Therefore, it is critical to develop new therapeutic approaches that bypass the development of antimicrobial resistance and avoid disruption of gut microflora. Here, we describe the construction of a single heteromultimeric VHH-based neutralizing agent (VNA) that targets the two primary virulence factors of Clostridium difficile, toxins A (TcdA) and B (TcdB). Designated VNA2-Tcd, this agent has subnanomolar toxin neutralization potencies for both C. difficile toxins in cell assays. When given systemically by parenteral administration, VNA2-Tcd protected against CDI in gnotobiotic piglets and mice and to a lesser extent in hamsters. Protection from CDI was also observed in gnotobiotic piglets treated by gene therapy with an adenovirus that promoted the expression of VNA2-Tcd.
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28
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CodY-Dependent Regulation of Sporulation in Clostridium difficile. J Bacteriol 2016; 198:2113-30. [PMID: 27246573 DOI: 10.1128/jb.00220-16] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 05/22/2016] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED Clostridium difficile must form a spore to survive outside the gastrointestinal tract. The factors that trigger sporulation in C. difficile remain poorly understood. Previous studies have suggested that a link exists between nutritional status and sporulation initiation in C. difficile In this study, we investigated the impact of the global nutritional regulator CodY on sporulation in C. difficile strains from the historical 012 ribotype and the current epidemic 027 ribotype. Sporulation frequencies were increased in both backgrounds, demonstrating that CodY represses sporulation in C. difficile The 027 codY mutant exhibited a greater increase in spore formation than the 012 codY mutant. To determine the role of CodY in the observed sporulation phenotypes, we examined several factors that are known to influence sporulation in C. difficile Using transcriptional reporter fusions and quantitative reverse transcription-PCR (qRT-PCR) analysis, we found that two loci associated with the initiation of sporulation, opp and sinR, are regulated by CodY. The data demonstrate that CodY is a repressor of sporulation in C. difficile and that the impact of CodY on sporulation and expression of specific genes is significantly influenced by the strain background. These results suggest that the variability of CodY-dependent regulation is an important contributor to virulence and sporulation in current epidemic isolates. This report provides further evidence that nutritional state, virulence, and sporulation are linked in C. difficile IMPORTANCE This study sought to examine the relationship between nutrition and sporulation in C. difficile by examining the global nutritional regulator CodY. CodY is a known virulence and nutritional regulator of C. difficile, but its role in sporulation was unknown. Here, we demonstrate that CodY is a negative regulator of sporulation in two different ribotypes of C. difficile We also demonstrate that CodY regulates known effectors of sporulation, Opp and SinR. These results support the idea that nutrient limitation is a trigger for sporulation in C. difficile and that the response to nutrient limitation is coordinated by CodY. Additionally, we demonstrate that CodY has an altered role in sporulation regulation for some strains.
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29
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Rodriguez C, Van Broeck J, Taminiau B, Delmée M, Daube G. Clostridium difficile infection: Early history, diagnosis and molecular strain typing methods. Microb Pathog 2016; 97:59-78. [PMID: 27238460 DOI: 10.1016/j.micpath.2016.05.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/18/2016] [Accepted: 05/02/2016] [Indexed: 01/05/2023]
Abstract
Recognised as the leading cause of nosocomial antibiotic-associated diarrhoea, the incidence of Clostridium difficile infection (CDI) remains high despite efforts to improve prevention and reduce the spread of the bacterium in healthcare settings. In the last decade, many studies have focused on the epidemiology and rapid diagnosis of CDI. In addition, different typing methods have been developed for epidemiological studies. This review explores the history of C. difficile and the current scope of the infection. The variety of available laboratory tests for CDI diagnosis and strain typing methods are also examined.
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Affiliation(s)
- C Rodriguez
- Food Science Department, FARAH, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.
| | - J Van Broeck
- Belgian Reference Centre for Clostridium Difficile (NRC), Pôle de microbiologie médicale, Université Catholique de Louvain, Brussels, Belgium
| | - B Taminiau
- Food Science Department, FARAH, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium
| | - M Delmée
- Belgian Reference Centre for Clostridium Difficile (NRC), Pôle de microbiologie médicale, Université Catholique de Louvain, Brussels, Belgium
| | - G Daube
- Food Science Department, FARAH, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium
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Abstract
The gastrointestinal system of horses is affected by a large variety of inflammatory infectious and noninfectious conditions. The most prevalent form of gastritis is associated with ulceration of the pars esophagea. Although the diagnostic techniques for alimentary diseases of horses have improved significantly over the past few years, difficulties still exist in establishing the causes of a significant number of enteric diseases in this species. This problem is compounded by several agents of enteric disease also being found in the intestine of clinically normal horses, which questions the validity of the mere detection of these agents in the intestine.
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Affiliation(s)
- Francisco A Uzal
- California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California Davis, 105 West Central Avenue, San Bernardino, CA 92409, USA.
| | - Santiago S Diab
- California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
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31
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Upadhyay A, Mooyottu S, Yin H, Nair MS, Bhattaram V, Venkitanarayanan K. Inhibiting Microbial Toxins Using Plant-Derived Compounds and Plant Extracts. MEDICINES (BASEL, SWITZERLAND) 2015; 2:186-211. [PMID: 28930207 PMCID: PMC5456214 DOI: 10.3390/medicines2030186] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 06/07/2023]
Abstract
Many pathogenic bacteria and fungi produce potentially lethal toxins that cause cytotoxicity or impaired cellular function either at the site of colonization or other locations in the body through receptor-mediated interactions. Various factors, including biotic and abiotic environments, competing microbes, and chemical cues affect toxin expression in these pathogens. Recent work suggests that several natural compounds can modulate toxin production in pathogenic microbes. However, studies explaining the mechanistic basis for their effect are scanty. This review discusses the potential of various plant-derived compounds for reducing toxin production in foodborne and other microbes. In addition, studies highlighting their anti-toxigenic mechanism(s) are discussed.
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Affiliation(s)
- Abhinav Upadhyay
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
| | - Shankumar Mooyottu
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
| | - Hsinbai Yin
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
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Sachdeva M, Leeds JA. Subinhibitory concentrations of LFF571 reduce toxin production by Clostridium difficile. Antimicrob Agents Chemother 2015; 59:1252-7. [PMID: 25512411 PMCID: PMC4335859 DOI: 10.1128/aac.04436-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/07/2014] [Indexed: 01/05/2023] Open
Abstract
LFF571 is a novel semisynthetic thiopeptide antibacterial that is undergoing investigation for safety and efficacy in patients with moderate Clostridium difficile infections. LFF571 inhibits bacterial protein synthesis by interacting with elongation factor Tu (EF-Tu) and interrupting complex formation between EF-Tu and aminoacyl-tRNA. Given this mechanism of action, we hypothesized that concentrations of LFF571 below those necessary to inhibit bacterial growth would reduce steady-state toxin levels in C. difficile cultures. We investigated C. difficile growth and toxin A and B levels in the presence of LFF571, fidaxomicin, vancomycin, and metronidazole. LFF571 led to strain-dependent effects on toxin production, including decreased toxin levels after treatment with subinhibitory concentrations, and more rapid declines in toxin production than in inhibition of colony formation. Fidaxomicin, which is an RNA synthesis inhibitor, conferred a similar pattern to LFF571 with respect to toxin levels versus viable cell counts. The incubation of two toxigenic C. difficile strains with subinhibitory concentrations of vancomycin, a cell wall synthesis inhibitor, increased toxin levels in the supernatant over those of untreated cultures. A similar phenomenon was observed with one metronidazole-treated strain of C. difficile. These studies indicate that LFF571 and fidaxomicin generally result in decreased C. difficile toxin levels in culture supernatants, whereas treatment of some strains with vancomycin or metronidazole had the potential to increase toxin levels. Although the relevance of these findings remains to be studied in patients, reducing toxin levels with sub-growth-inhibitory concentrations of an antibiotic is hypothesized to be beneficial in alleviating symptoms.
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Affiliation(s)
- Meena Sachdeva
- Novartis Institutes for BioMedical Research, Infectious Disease Area, Emeryville, California, USA
| | - Jennifer A Leeds
- Novartis Institutes for BioMedical Research, Infectious Disease Area, Emeryville, California, USA
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Abstract
Clostridium difficile is associated with a spectrum of clinical manifestations ranging from asymptomatic carriage to severe life-threatening pseudomembranous colitis. Current perspectives indicate that C difficile pathogenesis is a multifactorial disease process dictated by pathogenic toxin production, gut microbial dysbiosis, and altered host inflammatory responses. This article summarizes recent findings underpinning the cellular and molecular mechanisms regulating bacterial virulence and sheds new light on the critical roles of the host immune response, intestinal microbiota, and metabolome in mediating disease pathogenesis.
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Affiliation(s)
- Tanya M Monaghan
- Biomedical Research Unit, NIHR Nottingham Digestive Diseases Centre, Nottingham University Hospitals NHS Trust, Derby Road, Nottingham NG7 2UH, UK.
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34
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Abstract
Clostridium difficile is an important nosocomial pathogen and the leading cause of antibiotic-associated diarrhea. Multilocus sequence typing indicates that C. difficile strains belong to five distinct genetic clades encompassing several PCR ribotypes (RT). Since their emergence in 2003, hypervirulent RT027 strains have been a major focus of research; in contrast, our current understanding of RT017-mediated disease pathogenesis lags far behind. In this study, we aimed to characterize host immunity to CF5 and M68, two genetically well-defined RT017 strains. Both strains engaged with host Toll-like receptor 2/6 (TLR2/6), TLR2-CD14, and TLR5 to similar extents in a model cell line. Despite this, CF5 mediated significantly greater dendritic cell (DC) interleukin-12 (IL-12), IL-27, and IL-10 immunity than M68. Both strains elicited similar IL-1β mRNA levels, and yet only M68 caused a marked increase in secretory IL-1β. A CF5 cocultured-DC cytokine milieu drove an equipotent Th1 and Th17 response, while M68 promoted greater Th17 immunity. Human gastrointestinal ex vivo cytokine responses to both strains were characterized. Taken together, our data suggest that C. difficile strains mediate overlapping and yet distinct mucosal and DC/T cell immunity. Finally, toxin-driven IL-1β release supports the hypothesis that this cytokine axis is a likely target for therapeutic intervention for C. difficile infection.
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Esfandiari Z, Jalali M, Ezzatpanah H, Weese J, Chamani M. Prevalence and Characterization of Clostridium difficile in Beef and Mutton Meats of Isfahan Region, Iran. Jundishapur J Microbiol 2014; 7:e16771. [PMID: 25485054 PMCID: PMC4255216 DOI: 10.5812/jjm.16771] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Revised: 02/25/2014] [Accepted: 05/25/2014] [Indexed: 11/28/2022] Open
Abstract
Background: Clostridium difficile (C. difficile) is a frequent cause of nosocomial infections. During last few years, the mortality rate of C. difficile infection (CDI) increased in healthcare facilities. This organism has become a major public health concern in developed nations. Because of the increasing incidence of acquired-CDI (CA-CDI) and notable genetic overlap between C. difficile isolates from animals and humans, meat has defined as one of the probable transmission route of C. diffiicle to humans. Objectives: This study was performed to determine the prevalence of toxigenic C. difficile in beef and mutton meats consumed as human food in Isfahan, central part of Iran. Furthermore the polymerase chain reaction (PCR)-ribotyping employed to compare the genetic pattern of positive isolates in meat with clinical ones. Materials and Methods: A total of 200 raw meat samples (81 beef and 119 mutton) were purchased from meat packaging plants. The samples were anaerobically cultured in C. difficile moxalactam norfloxacin (CDMN) broth and plated on selective enrichment medium. The suspicious colonies were recultured on blood agar anaerobically. All C. difficile isolates identified by morphological and biochemical testing were screened by PCR for the presence of genes encoding the triose phosphate isomerase (tpi), toxin A (tcdA), toxin B (tcdB) and binary toxin (cdtB). The genomes of extracted isolates were analyzed by 16S-23S rRNA-based PCR ribotyping. Results: The overall prevalence of C. difficile with two toxigenic genes including tcdA and tcdB was estimated at 4.0%. C. difficile was detected in 2.8%, 2.1%, 3.6% and 6.2% of chopped beef, ground beef, chopped mutton and ground mutton, respectively. The cdtB gene was not found in positive isolates. Eight different ribotypes were found in isolated strains that were not identical with those belonging to patients with CDI. Conclusions: The results of PCR-ribotyping indicate that no relationship exists between clinical and meat isolates. We therefore conclude that other sources than meat may function as a vector for CA-CDI.
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Affiliation(s)
- Zahra Esfandiari
- Department of Food Science and Technology, College of Food Science and Technology, Tehran Science and Research Branch, Islamic Azad University, Tehran, IR Iran
| | - Mohammad Jalali
- Infectious Diseases and Tropical Medicine Research Center, School of Food Sciences and Nutrition, Isfahan University of Medical Sciences, Isfahan, IR Iran
| | - Hamid Ezzatpanah
- Department of Food Science and Technology, College of Food Science and Technology, Tehran Science and Research Branch, Islamic Azad University, Tehran, IR Iran
- Corresponding author: Hamid Ezzatpanah, Department of Food Science and Technology, College of Food Science and Technology, Tehran Science and Research Branch, Islamic Azad University, Tehran, 14515.775, IR Iran. Tel: +98-2144865023, Fax: +98-2144865025, E-mail:
| | - J.Scott Weese
- Department of Pathobiology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Mohammad Chamani
- Department of Animal Science, Faculty of Agriculture and Natural Resources, Tehran Science and Research Branch, Islamic Azad University, Tehran, IR Iran
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Diebel LN, Liberati DM. Reinforcement of the intestinal mucus layer protects against Clostridium difficile intestinal injury in vitro. J Am Coll Surg 2014; 219:460-8. [PMID: 25067805 DOI: 10.1016/j.jamcollsurg.2014.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 04/02/2014] [Accepted: 05/16/2014] [Indexed: 01/28/2023]
Abstract
BACKGROUND Clostridium difficile infection is increasing in incidence and severity. Attributable factors include virulence factors, including C difficile toxins A and B, as well as host immunologic status. The mucus component of the intestinal barrier is impaired by malnutrition, shock insults, and alterations in the gut microbiome. Exogenous phosphatidylcholine (PC) administration results in reinforcement of the mucus layer and is of therapeutic benefit in chronic ulcerative colitis. We therefore studied the role of exogenous PC combined with secretory immunoglobulin A (IgA) in intestinal barrier function against C difficile infection in vitro. STUDY DESIGN Dimeric IgA was placed in the basal chambers of mucus-producing (HT29-methotrexate) and non-mucus-producing (HT29) strains of intestinal epithelial monolayers and allowed to undergo transcytosis and, in additional experiments, exogenous colostral IgA (30 ng/mL) was added to the apical media. After subsequent coculture with PC and C difficile toxin A in the apical chamber, tumor necrosis factor-α, interleukin-6, toxin A uptake, intestinal epithelial cell monolayer permeability, and necrosis were determined. RESULTS A significant decrease of 4- to 5-fold in tumor necrosis factor-α and interleukin-6 levels and equally significant decreases in toxin A uptake and permeability changes in the intestinal cell monolayers with mucus or PC and transcytosed or colostral IgA vs control are shown. All groups analyzed also displayed a 2- to 3-fold reduction in necrosis. CONCLUSIONS Mucus or "exogenous" mucus in the form of PC has a synergistic role with secretory IgA in barrier defense against C difficile toxin A. Exogenous PC administration can be a therapeutic adjunct in patients with severe or recalcitrant C difficile infection.
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Affiliation(s)
- Lawrence N Diebel
- Department of Surgery, Wayne State University Medical Center, Detroit, MI.
| | - David M Liberati
- Department of Surgery, Wayne State University Medical Center, Detroit, MI
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37
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Variations in virulence and molecular biology among emerging strains of Clostridium difficile. Microbiol Mol Biol Rev 2014; 77:567-81. [PMID: 24296572 DOI: 10.1128/mmbr.00017-13] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Clostridium difficile is a Gram-positive, spore-forming organism which infects and colonizes the large intestine, produces potent toxins, triggers inflammation, and causes significant systemic complications. Treating C. difficile infection (CDI) has always been difficult, because the disease is both caused and resolved by antibiotic treatment. For three and a half decades, C. difficile has presented a treatment challenge to clinicians, and the situation took a turn for the worse about 10 years ago. An increase in epidemic outbreaks related to CDI was first noticed around 2003, and these outbreaks correlated with a sudden increase in the mortality rate of this illness. Further studies discovered that these changes in CDI epidemiology were associated with the rapid emergence of hypervirulent strains of C. difficile, now collectively referred to as NAP1/BI/027 strains. The discovery of new epidemic strains of C. difficile has provided a unique opportunity for retrospective and prospective studies that have sought to understand how these strains have essentially replaced more historical strains as a major cause of CDI. Moreover, detailed studies on the pathogenesis of NAP1/BI/027 strains are leading to new hypotheses on how this emerging strain causes severe disease and is more commonly associated with epidemics. In this review, we provide an overview of CDI, discuss critical mechanisms of C. difficile virulence, and explain how differences in virulence-associated factors between historical and newly emerging strains might explain the hypervirulence exhibited by this pathogen during the past decade.
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Occurrence of Clostridium difficile PCR-ribotype 027 and it's closely related PCR-ribotype 176 in hospitals in Poland in 2008-2010. Anaerobe 2014; 28:13-7. [PMID: 24799338 DOI: 10.1016/j.anaerobe.2014.04.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 04/03/2014] [Accepted: 04/17/2014] [Indexed: 01/05/2023]
Abstract
Since 2003, a rising incidence of Clostridium difficile infection (CDI) in North America and Europe has coincided with outbreaks of C. difficile PCR ribotype 027. This ribotype was not observed in Poland until 2008. In the period 2008-2010, outbreaks of antibiotic-associated diarrhoea occurred in three different hospitals in Poland. Of 30 C. difficile isolates available for microbiological characterisation, 17 (56%) were positive for binary toxin genes and belonged to PCR ribotype 027 (n = 7) and its closely related PCR ribotype 176 (n = 10). All 17 binary toxin-positive C. difficile strains demonstrated high-level resistance to fluoroquinolones (minimum inhibitory concentration (MIC) ≥ 32 mg/L), including ciprofloxacin, gatifloxacin, and moxifloxacin, as well as erythromycin and clindamycin (MIC ≥ 256 mg/L for both). Of 14 patients from whom clinical information was available, 50% had a severe form of CDI, defined by fever (>38.5 °C), decreased kidney function, and high leucocyte count. We conclude that outbreaks of CDI associated with hypervirulent strains belonging to PCR ribotypes 027 and 176 occurred in hospitals in Poland. Further studies evaluating the clinical impact of type 176 are urgently needed.
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Zhu S, Zhang L, Zhang C, Chen X, Chen Q, Li Z. Comparison of polymerase chain reaction ribotyping, toxinotyping and nutritional aspects of toxin production of Clostridium difficile strains. Biomed Rep 2014; 2:477-480. [PMID: 24944791 DOI: 10.3892/br.2014.270] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 04/10/2014] [Indexed: 01/05/2023] Open
Abstract
Clostridium difficile (C. difficile) is the leading cause of infectious diarrhea in hospitals worldwide. Enterotoxin A (TcdA) and cytotoxin B (TcdB), have been identified as the main virulence factors of C. difficile. In China, data on polymerase chain reaction (PCR) ribotypes and abilities of hospital-derived C. difficile isolates to produce TcdA and TcdB are sparse. In this study, we identified 40 C. difficile isolates from the Taizhou hospital and investigated their PCR ribotypes based on the 16S-23S rRNA gene intergenic spacer region. The ability of different ribotypes to produce TcdA and TcdB was determined by immunochromatography and cytotoxicity assays, respectively. The effects of the nutritional status on the production of these toxins were also investigated.
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Affiliation(s)
- Shanshan Zhu
- Department of Clinical Laboratory, Taizhou Central Hospital, Taizhou, Zhejiang 318000, P.R. China
| | - Liming Zhang
- Department of Clinical Laboratory, Taizhou Central Hospital, Taizhou, Zhejiang 318000, P.R. China
| | - Chunling Zhang
- Department of Clinical Laboratory, Taizhou Central Hospital, Taizhou, Zhejiang 318000, P.R. China
| | - Xianjun Chen
- Department of Clinical Laboratory, Taizhou Central Hospital, Taizhou, Zhejiang 318000, P.R. China
| | - Qi Chen
- Department of Clinical Laboratory, Taizhou Central Hospital, Taizhou, Zhejiang 318000, P.R. China
| | - Zhaoyun Li
- School of Laboratory and Life Science, Wenzhou Medical University, Wenzhou 325035, P.R. China
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40
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Clostridium difficile extracytoplasmic function σ factor σV regulates lysozyme resistance and is necessary for pathogenesis in the hamster model of infection. Infect Immun 2014; 82:2345-55. [PMID: 24664503 DOI: 10.1128/iai.01483-13] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Clostridium difficile is a clinically important pathogen and the most common cause of hospital-acquired infectious diarrhea. Expression of the C. difficile gene csfV, which encodes σ(V), an extracytoplasmic function σ factor, is induced by lysozyme, which damages the peptidoglycan of bacteria. Here we show that σ(V) is required for lysozyme resistance in C. difficile. Using microarray analysis, we identified the C. difficile genes whose expression is dependent upon σ(V) and is induced by lysozyme. Although the peptidoglycan of wild-type C. difficile is intrinsically highly deacetylated, we have found that exposure to lysozyme leads to additional peptidoglycan deacetylation. This lysozyme-induced deacetylation is dependent upon σ(V). Expression of pdaV, which encodes a putative peptidoglycan deacetylase, was able to increase lysozyme resistance of a csfV mutant. The csfV mutant strain is severely attenuated compared to wild-type C. difficile in a hamster model of C. difficile-associated disease. We conclude that the σ(V) signal transduction system, which senses the host innate immune defense enzyme lysozyme, is required for lysozyme resistance and is necessary during C. difficile infection.
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41
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Pizarro-Guajardo M, Olguín-Araneda V, Barra-Carrasco J, Brito-Silva C, Sarker MR, Paredes-Sabja D. Characterization of the collagen-like exosporium protein, BclA1, of Clostridium difficile spores. Anaerobe 2014; 25:18-30. [DOI: 10.1016/j.anaerobe.2013.11.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 10/07/2013] [Accepted: 11/14/2013] [Indexed: 01/05/2023]
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42
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Enyeart PJ, Mohr G, Ellington AD, Lambowitz AM. Biotechnological applications of mobile group II introns and their reverse transcriptases: gene targeting, RNA-seq, and non-coding RNA analysis. Mob DNA 2014; 5:2. [PMID: 24410776 PMCID: PMC3898094 DOI: 10.1186/1759-8753-5-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 11/19/2013] [Indexed: 12/21/2022] Open
Abstract
Mobile group II introns are bacterial retrotransposons that combine the activities of an autocatalytic intron RNA (a ribozyme) and an intron-encoded reverse transcriptase to insert site-specifically into DNA. They recognize DNA target sites largely by base pairing of sequences within the intron RNA and achieve high DNA target specificity by using the ribozyme active site to couple correct base pairing to RNA-catalyzed intron integration. Algorithms have been developed to program the DNA target site specificity of several mobile group II introns, allowing them to be made into ‘targetrons.’ Targetrons function for gene targeting in a wide variety of bacteria and typically integrate at efficiencies high enough to be screened easily by colony PCR, without the need for selectable markers. Targetrons have found wide application in microbiological research, enabling gene targeting and genetic engineering of bacteria that had been intractable to other methods. Recently, a thermostable targetron has been developed for use in bacterial thermophiles, and new methods have been developed for using targetrons to position recombinase recognition sites, enabling large-scale genome-editing operations, such as deletions, inversions, insertions, and ‘cut-and-pastes’ (that is, translocation of large DNA segments), in a wide range of bacteria at high efficiency. Using targetrons in eukaryotes presents challenges due to the difficulties of nuclear localization and sub-optimal magnesium concentrations, although supplementation with magnesium can increase integration efficiency, and directed evolution is being employed to overcome these barriers. Finally, spurred by new methods for expressing group II intron reverse transcriptases that yield large amounts of highly active protein, thermostable group II intron reverse transcriptases from bacterial thermophiles are being used as research tools for a variety of applications, including qRT-PCR and next-generation RNA sequencing (RNA-seq). The high processivity and fidelity of group II intron reverse transcriptases along with their novel template-switching activity, which can directly link RNA-seq adaptor sequences to cDNAs during reverse transcription, open new approaches for RNA-seq and the identification and profiling of non-coding RNAs, with potentially wide applications in research and biotechnology.
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Affiliation(s)
| | | | | | - Alan M Lambowitz
- Departments of Molecular Biosciences and Chemistry, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA.
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In vitro and in vivo antibacterial evaluation of cadazolid, a new antibiotic for treatment of Clostridium difficile infections. Antimicrob Agents Chemother 2013; 58:892-900. [PMID: 24277020 DOI: 10.1128/aac.01830-13] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Clostridium difficile is a leading cause of health care-associated diarrhea with significant morbidity and mortality, and new options for the treatment of C. difficile-associated diarrhea (CDAD) are needed. Cadazolid is a new oxazolidinone-type antibiotic that is currently in clinical development for treatment of CDAD. Here, we report the in vitro and in vivo antibacterial evaluation of cadazolid against C. difficile. Cadazolid showed potent in vitro activity against C. difficile with a MIC range of 0.125 to 0.5 μg/ml, including strains resistant to linezolid and fluoroquinolones. In time-kill kinetics experiments, cadazolid showed a bactericidal effect against C. difficile isolates, with >99.9% killing in 24 h, and was more bactericidal than vancomycin. In contrast to metronidazole and vancomycin, cadazolid strongly inhibited de novo toxin A and B formation in stationary-phase cultures of toxigenic C. difficile. Cadazolid also inhibited C. difficile spore formation substantially at growth-inhibitory concentrations. In the hamster and mouse models for CDAD, cadazolid was active, conferring full protection from diarrhea and death with a potency similar to that of vancomycin. These findings support further investigations of cadazolid for the treatment of CDAD.
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Kasendra M, Barrile R, Leuzzi R, Soriani M. Clostridium difficile toxins facilitate bacterial colonization by modulating the fence and gate function of colonic epithelium. J Infect Dis 2013; 209:1095-104. [PMID: 24273043 DOI: 10.1093/infdis/jit617] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The contribution of Clostridium difficile toxin A and B (TcdA and TcdB) to cellular intoxication has been studied extensively, but their impact on bacterial colonization remains unclear. By setting up 2- and 3-dimensional in vitro models of polarized gut epithelium, we investigated how C. difficile infection is affected by host cell polarity and whether TcdA and TcdB contribute to such events. Indeed, we observed that C. difficile adhesion and penetration of the mucosal barrier are substantially enhanced in poorly polarized or ethylene glycol tetraacetic acid-treated cells, indicating that bacteria bind preferentially to the basolateral (BL) cell surface. In this context, we demonstrated that sub-lethal concentrations of C. difficile TcdA are able to alter cell polarity by causing redistribution of plasma membrane components between distinct surface domains. Taken together, the data suggest that toxin-mediated modulation of host cell organization may account for the capacity of this opportunistic pathogen to gain access to BL receptors, leading to a successful colonization of the colonic mucosa.
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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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The second messenger cyclic Di-GMP regulates Clostridium difficile toxin production by controlling expression of sigD. J Bacteriol 2013; 195:5174-85. [PMID: 24039264 DOI: 10.1128/jb.00501-13] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The Gram-positive obligate anaerobe Clostridium difficile causes potentially fatal intestinal diseases. How this organism regulates virulence gene expression is poorly understood. In many bacterial species, the second messenger cyclic di-GMP (c-di-GMP) negatively regulates flagellar motility and, in some cases, virulence. c-di-GMP was previously shown to repress motility of C. difficile. Recent evidence indicates that flagellar gene expression is tightly linked with expression of the genes encoding the two C. difficile toxins TcdA and TcdB, which are key virulence factors for this pathogen. Here, the effect of c-di-GMP on expression of the toxin genes tcdA and tcdB was determined, and the mechanism connecting flagellar and toxin gene expressions was examined. In C. difficile, increasing c-di-GMP levels reduced the expression levels of tcdA and tcdB, as well as that of tcdR, which encodes an alternative sigma factor that activates tcdA and tcdB expression. We hypothesized that the C. difficile orthologue of the flagellar alternative sigma factor SigD (FliA; σ(28)) mediates regulation of toxin gene expression in response to c-di-GMP. Indeed, ectopic expression of sigD in C. difficile resulted in increased expression levels of tcdR, tcdA, and tcdB. Furthermore, sigD expression enhanced toxin production and increased the cytopathic effect of C. difficile on cultured fibroblasts. Finally, evidence is provided that SigD directly activates tcdR expression and that SigD cannot activate tcdA or tcdB expression independent of TcdR. Taken together, these data suggest that SigD positively regulates toxin genes in C. difficile and that c-di-GMP can inhibit both motility and toxin production via SigD, making this signaling molecule a key virulence gene regulator in C. difficile.
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Abstract
Clostridium difficile infection, the most frequent cause of nosocomial diarrhea, disproportionately affects older adults. The two most important risk factors for developing C. difficile infection are antimicrobial exposure and age >65 years old. Risk factors specific to older adults are frequent interactions with healthcare systems and age-related changes in physiology, including immune senescence and changes to the gut microbiome. Metronidazole and oral vancomcyin are the mainstays of conventional treatment for C. difficile infection. Alternative therapies include fidaxomicin, a narrow-spectrum macrocyclic antibiotic, and fectal bacteriotherapy, which offers an excellent therapeutic outcome. Strategies to prevent C. difficile infections include enhanced infection control measures and reducing inappropriate antimicrobial use through stewardship.
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Affiliation(s)
- Robin LP Jump
- Geriatric Research Education & Clinical Center & Infectious Diseases Section, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
- Division of Infectious Diseases & HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
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Schneeberg A, Neubauer H, Schmoock G, Grossmann E, Seyboldt C. Presence of Clostridium difficile PCR ribotype clusters related to 033, 078 and 045 in diarrhoeic calves in Germany. J Med Microbiol 2013; 62:1190-1198. [DOI: 10.1099/jmm.0.056473-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
This study provides data on the distribution and relationship of C. difficile PCR ribotypes in diarrhoeic calves in Germany. C. difficile was isolated from 176 of 999 (17.6 %) faecal samples or swabs of diarrhoeic calves from 603 farms collected between January 2010 and August 2012 by eight federal laboratories of six states. Strains were assigned to 17 PCR ribotypes. PCR ribotypes 033 (57 %), 078 (17 %) and 045/FLI01 (closest match to 045 in the WEBRIBO database; 9 %) were found the most frequently. Nine per cent of all culture-positive tested animals shed more than one multiple locus variable number tandem repeat analysis (MLVA) or PCR ribotype. Eight PCR ribotypes with related profiles (including 033, 078 and 045/FLI01) representing 92 % of all isolates were grouped into three clusters. Molecular relatedness was supported by the absence of the MLVA locus A6
Cd
only in clustered strains and identical toxin gene profiles for strains within each cluster. Previously reported mulitilocus sequence typing analysis for PCR ribotypes that were also recovered in this study found identical sequence types and a tcdC deletion (Δ39 bp) for 033, 045, 078 and 126 (ST-11), confirming this clustering. A different geographical occurrence of PCR ribotypes was shown for cluster 033 (found more frequently in southern Germany) and 045 (found more frequently in northern Germany). This study showed that clusters of C. difficile PCR ribotypes related to 033, 078 and 045 are predominant in diarrhoeic calves in Germany. The high number of strains belonging to PCR ribotype 078 demonstrated that diarrhoeic calves are also potential reservoirs for human pathogenic C. difficile strains.
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Affiliation(s)
- Alexander Schneeberg
- Institute of Bacterial Infections and Zoonoses at the Federal Research Institute for Animal Health (Friedrich-Loeffler-Institut), Naumburger Strasse 96a, 07743 Jena, Germany
| | - Heinrich Neubauer
- Institute of Bacterial Infections and Zoonoses at the Federal Research Institute for Animal Health (Friedrich-Loeffler-Institut), Naumburger Strasse 96a, 07743 Jena, Germany
| | - Gernot Schmoock
- Institute of Bacterial Infections and Zoonoses at the Federal Research Institute for Animal Health (Friedrich-Loeffler-Institut), Naumburger Strasse 96a, 07743 Jena, Germany
| | - Ernst Grossmann
- Aulendorf State Veterinary Diagnostic Centre, Löwenbreitestrasse 18/20, 88326 Aulendorf, Germany
| | - Christian Seyboldt
- Institute of Bacterial Infections and Zoonoses at the Federal Research Institute for Animal Health (Friedrich-Loeffler-Institut), Naumburger Strasse 96a, 07743 Jena, Germany
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Jafari NV, Kuehne SA, Bryant CE, Elawad M, Wren BW, Minton NP, Allan E, Bajaj-Elliott M. Clostridium difficile modulates host innate immunity via toxin-independent and dependent mechanism(s). PLoS One 2013; 8:e69846. [PMID: 23922820 PMCID: PMC3726775 DOI: 10.1371/journal.pone.0069846] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 06/13/2013] [Indexed: 11/30/2022] Open
Abstract
Clostridium difficile infection (CDI) is the leading cause of hospital and community-acquired antibiotic-associated diarrhoea and currently represents a significant health burden. Although the role and contribution of C. difficile toxins to disease pathogenesis is being increasingly understood, at present other facets of C. difficile-host interactions, in particular, bacterial-driven effects on host immunity remain less studied. Using an ex-vivo model of infection, we report that the human gastrointestinal mucosa elicits a rapid and significant cytokine response to C. difficile. Marked increase in IFN-γ with modest increase in IL-22 and IL-17A was noted. Significant increase in IL-8 suggested potential for neutrophil influx while presence of IL-12, IL-23, IL-1β and IL-6 was indicative of a cytokine milieu that may modulate subsequent T cell immunity. Majority of C. difficile-driven effects on murine bone-marrow-derived dendritic cell (BMDC) activation were toxin-independent; the toxins were however responsible for BMDC inflammasome activation. In contrast, human monocyte-derived DCs (mDCs) released IL-1β even in the absence of toxins suggesting host-specific mediation. Infected DC-T cell crosstalk revealed the ability of R20291 and 630 WT strains to elicit a differential DC IL-12 family cytokine milieu which culminated in significantly greater Th1 immunity in response to R20291. Interestingly, both strains induced a similar Th17 response. Elicitation of mucosal IFN-γ/IL-17A and Th1/Th17 immunity to C. difficile indicates a central role for this dual cytokine axis in establishing antimicrobial immunity to CDI.
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Affiliation(s)
- Nazila V. Jafari
- Infectious Diseases and Microbiology Unit, Institute of Child Health, University College London, London, United Kingdom
| | - Sarah A. Kuehne
- Clostridia Research Group, Nottingham Digestive Diseases Centre NIHR Biomedical Research Unit, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Clare E. Bryant
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Mamoun Elawad
- Gastroenterology Department, Great Ormond Street Hospital, London, United Kingdom
| | - Brendan W. Wren
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Nigel P. Minton
- Clostridia Research Group, Nottingham Digestive Diseases Centre NIHR Biomedical Research Unit, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Elaine Allan
- Research Department of Microbial Diseases, Eastman Dental Institute, University College London, London, United Kingdom
| | - Mona Bajaj-Elliott
- Infectious Diseases and Microbiology Unit, Institute of Child Health, University College London, London, United Kingdom
- * E-mail:
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50
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A clinical and epidemiological review of non-toxigenic Clostridium difficile. Anaerobe 2013; 22:1-5. [PMID: 23727391 DOI: 10.1016/j.anaerobe.2013.05.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 05/07/2013] [Accepted: 05/15/2013] [Indexed: 12/21/2022]
Abstract
Clostridium difficile is a significant nosocomial threat to human health and is the most commonly identified cause of antibiotic-associated diarrhea. The development of C. difficile colitis requires production of toxins A and/or B, but some strains do not express these proteins. These non-toxigenic C. difficile (NTCD) have garnered attention for their capacity to colonize humans and potentially reduce the risk for symptomatic colitis caused by toxigenic strains. Isolates of NTCD have been obtained from the environment as well as from animal and human sources. Studies in a hamster CDI model have demonstrated a protective effect of NTCD against toxigenic infection. The extent to which this protective effect of NTCD occurs in humans remains to be defined. Evidence for a therapeutic or preventive role for NTCD is limited but clinical prophylaxis studies are ongoing. NTCD potentially represents an exciting new tool in preventing CDI and its recurrences.
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