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Rodrigues RR, Conrad N, Ferreira MRA, Júnior CM, Alves MLF, Sedrez PA, Müller V, Neis A, Bilhalva MA, Galvão CC, Leite FPL, Conceição FR. Immunogenicity of a recombinant chimera composed of CROP domain segments from the hemorrhagic and lethal toxins of Paeniclostridium sordellii. Anaerobe 2025; 91:102938. [PMID: 39793918 DOI: 10.1016/j.anaerobe.2025.102938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2024] [Revised: 12/15/2024] [Accepted: 12/17/2024] [Indexed: 01/13/2025]
Abstract
Paeniclostridium sordellii is responsible for severe infections in horses, cattle, and sheep, however, conventional vaccines exhibit limitations in production and immunogenicity. This study assessed the immunogenicity of a recombinant bacterin composed of a chimera (rQTcsHL) that combines segments from the lethal (TcsL) and hemorrhagic (TcsH) toxins in mice and sheep. Both immunized animal groups exhibited elevated levels of IgG, with the mice demonstrating moderate protection (<50 %) against lethal challenges, comparable to that of the conventional vaccine. Further molecular optimization is essential to enhance its efficacy.
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Affiliation(s)
- Rafael Rodrigues Rodrigues
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil.
| | - Neida Conrad
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil
| | | | - Clóvis Moreira Júnior
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil
| | - Mariliana Luiza Ferreira Alves
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil; Instituto Federal Sul-rio-grandense, IFSul, Campus Pelotas, Rio Grande do Sul, Brazil
| | - Pamela Aristimunho Sedrez
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil; Instituto de Biologia, Departamento de Microbiologia e Parasitologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil
| | - Vitória Müller
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil
| | - Alessandra Neis
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil
| | - Miguel Andrade Bilhalva
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil
| | - Cleideanny Cancela Galvão
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil
| | - Fábio Pereira Leivas Leite
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil
| | - Fabricio Rochedo Conceição
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brazil
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Rodrigues Rodrigues R, Alves MLF, Bilhalva MA, Kremer FS, Junior CM, Ferreira MRA, Galvão CC, Quatrin PHDN, Conceição FR. Large Clostridial Toxins: A Brief Review and Insights into Antigen Design for Veterinary Vaccine Development. Mol Biotechnol 2024:10.1007/s12033-024-01303-6. [PMID: 39472390 DOI: 10.1007/s12033-024-01303-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2024] [Accepted: 10/08/2024] [Indexed: 12/18/2024]
Abstract
The group of large clostridial toxins (LCTs) includes toxins A (TcdA) and B (TcdB) from Clostridioides difficile, hemorrhagic and lethal toxins from Paeniclostridium sordellii, alpha toxin from Clostridium novyi (TcnA), and cytotoxin from Clostridium perfringens. These toxins are associated with severe pathologies in livestock, including gas gangrene (P. sordellii and C. novyi), infectious necrotic hepatitis (C. novyi), avian necrotic enteritis (C. perfringens), and enterocolitis (C. difficile). Immunoprophylaxis is crucial for controlling these diseases, but traditional vaccines face production challenges, such as labor-intensive processes, and often exhibit low immunogenicity. This has led to increased interest in recombinant vaccines. While TcdA and TcdB are well-studied for human immunization, other LCTs remain poorly characterized and require further investigation. Therefore, this study emphasizes the importance of understanding lesser-explored toxins and proposes using immunoinformatics to identify their immunodominant regions. By mapping these regions using silico tools and considering their homology with TcdA and TcdB, the study aims to guide future research in veterinary vaccinology. It also explores alternatives to overcome the limitations of conventional and recombinant vaccines, offering guidelines for developing more effective vaccination strategies against severe infections in animals.
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Affiliation(s)
- Rafael Rodrigues Rodrigues
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas - Campus Universitário, Capão do Leão, Rio Grande Do Sul, CEP 96160-000, Brazil.
| | - Mariliana Luiza Ferreira Alves
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas - Campus Universitário, Capão do Leão, Rio Grande Do Sul, CEP 96160-000, Brazil
- Instituto Federal Sul-Rio-Grandense, IFSul, Campus Pelotas, Pelotas, Rio Grande Do Sul, Brasil
| | - Miguel Andrade Bilhalva
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas - Campus Universitário, Capão do Leão, Rio Grande Do Sul, CEP 96160-000, Brazil
| | - Frederico Schmitt Kremer
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas - Campus Universitário, Capão do Leão, Rio Grande Do Sul, CEP 96160-000, Brazil
| | - Clóvis Moreira Junior
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas - Campus Universitário, Capão do Leão, Rio Grande Do Sul, CEP 96160-000, Brazil
| | - Marcos Roberto Alves Ferreira
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas - Campus Universitário, Capão do Leão, Rio Grande Do Sul, CEP 96160-000, Brazil
| | - Cleideanny Cancela Galvão
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas - Campus Universitário, Capão do Leão, Rio Grande Do Sul, CEP 96160-000, Brazil
| | - Pedro Henrique Dala Nora Quatrin
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas - Campus Universitário, Capão do Leão, Rio Grande Do Sul, CEP 96160-000, Brazil
| | - Fabricio Rochedo Conceição
- Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas - Campus Universitário, Capão do Leão, Rio Grande Do Sul, CEP 96160-000, Brazil
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Abstract
Large clostridial toxins (LCTs) are a family of bacterial exotoxins that infiltrate and destroy target cells. Members of the LCT family include Clostridioides difficile toxins TcdA and TcdB, Paeniclostridium sordellii toxins TcsL and TcsH, Clostridium novyi toxin TcnA, and Clostridium perfringens toxin TpeL. Since the 19th century, LCT-secreting bacteria have been isolated from the blood, organs, and wounds of diseased individuals, and LCTs have been implicated as the primary virulence factors in a variety of infections, including C. difficile infection and some cases of wound-associated gas gangrene. Clostridia express and secrete LCTs in response to various physiological signals. LCTs invade host cells by binding specific cell surface receptors, ultimately leading to internalization into acidified vesicles. Acidic pH promotes conformational changes within LCTs, which culminates in translocation of the N-terminal glycosyltransferase and cysteine protease domain across the endosomal membrane and into the cytosol, leading first to cytopathic effects and later to cytotoxic effects. The focus of this review is on the role of LCTs in infection and disease, the mechanism of LCT intoxication, with emphasis on recent structural work and toxin subtyping analysis, and the genomic discovery and characterization of LCT homologues. We provide a comprehensive review of these topics and offer our perspective on emerging questions and future research directions for this enigmatic family of toxins.
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Buys A, Crafford J, van Heerden H. Development and evaluation of indirect enzyme-linked immunosorbent assays for the determination of immune response to multiple clostridial antigens in vaccinated captive bred southern white rhinoceros (Ceratotherium simum simum). Acta Vet Scand 2020; 62:57. [PMID: 33028379 PMCID: PMC7541252 DOI: 10.1186/s13028-020-00555-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 09/18/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND An overall increase in poaching of white rhinoceros results in captive breeding becoming a significant component of white rhinoceros conservation. However, this type of conservation comes with its own difficulties. When wildlife is captured, transported and/or confined to a boma environment, they are more predisposed to diseases caused by bacterial organisms such as spore forming Clostridium spp. A southern white rhinoceros (Ceratotherium simum simum) population on a captive bred farm was suspected to be affected by Clostridium infections. These endangered animals were apparently exposed to Clostridium spp., in the conservation area previously used for cattle farming. The rhinoceros population on the breeding operation property was vaccinated with a multi-component clostridial vaccine registered for use in cattle. Multiple indirect enzyme-linked immunosorbent assays (iELISAs) were developed in order to evaluate the serum antibody titres of these vaccinated animals. In evaluating vaccine efficacy, the gold standard mouse neutralization test (MNT) was not available and therefore iELISAs were developed for the detection of serum antibodies to C. perfringens type A (alpha toxin), C. chauvoei (whole cell), C. novyi (alpha toxin), C. septicum (alpha toxin) and C. sordellii (lethal toxin) in the white rhinoceros population using international reference sera of equine origin. Antibody titres against each clostridial antigen was evaluated in the vaccinated white rhinoceros population (n = 75). Analytical specificity showed slight cross-reactions for C. chauvoei and C. perfringens type A with the other antigens. Individual assay cut-off values were calculated with 95% confidence. Coefficient of variance (CV) values for both the international reference sera and in-house control sera across all the antigens were well below 16%, indicating good assay repeatability. This convenient and fast assay is suitable for monitoring humoral immune responses to clostridial antigens in vaccinated white rhinoceroses. RESULTS Checkerboard titrations indicated optimal antigen and antibody concentrations to be used for each respective iELISA developed. Each titration set of the respective international reference and in-house control sera showed good repeatability with low standard deviations and coefficient of variance values calculated between repeats for each antigen. Individual assays proved repeatable and showed good analytical sensitivity and specificity. CONCLUSIONS The developed iELISAs are able to evaluate antibody profiles of phospholipase C, C. chauvoei whole cells, TcnA, ATX, TcsL in white rhinoceros serum using international reference sera.
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Revitt-Mills SA, Vidor CJ, Watts TD, Lyras D, Rood JI, Adams V. Virulence Plasmids of the Pathogenic Clostridia. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0034-2018. [PMID: 31111816 PMCID: PMC11257192 DOI: 10.1128/microbiolspec.gpp3-0034-2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Indexed: 12/12/2022] Open
Abstract
The clostridia cause a spectrum of diseases in humans and animals ranging from life-threatening tetanus and botulism, uterine infections, histotoxic infections and enteric diseases, including antibiotic-associated diarrhea, and food poisoning. The symptoms of all these diseases are the result of potent protein toxins produced by these organisms. These toxins are diverse, ranging from a multitude of pore-forming toxins to phospholipases, metalloproteases, ADP-ribosyltransferases and large glycosyltransferases. The location of the toxin genes is the unifying theme of this review because with one or two exceptions they are all located on plasmids or on bacteriophage that replicate using a plasmid-like intermediate. Some of these plasmids are distantly related whilst others share little or no similarity. Many of these toxin plasmids have been shown to be conjugative. The mobile nature of these toxin genes gives a ready explanation of how clostridial toxin genes have been so widely disseminated both within the clostridial genera as well as in the wider bacterial community.
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Affiliation(s)
- Sarah A Revitt-Mills
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Callum J Vidor
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Thomas D Watts
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Dena Lyras
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Julian I Rood
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Vicki Adams
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
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Clostridium sordellii Pathogenicity Locus Plasmid pCS1-1 Encodes a Novel Clostridial Conjugation Locus. mBio 2018; 9:mBio.01761-17. [PMID: 29339424 PMCID: PMC5770547 DOI: 10.1128/mbio.01761-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
A major virulence factor in Clostridium sordellii-mediated infection is the toxin TcsL, which is encoded within a region of the genome called the pathogenicity locus (PaLoc). C. sordellii isolates carry the PaLoc on the pCS1 family of plasmids, of which there are four characterized members. Here, we determined the potential mobility of pCS1 plasmids and characterized a fifth unique pCS1 member. Using a derivative of the pCS1-1 plasmid from strain ATCC 9714 which had been marked with the ermB erythromycin resistance gene, conjugative transfer into a recipient C. sordellii isolate, R28058, was demonstrated. Bioinformatic analysis of pCS1-1 identified a novel conjugation gene cluster defined as the C. sordellii transfer (cst) locus. Interruption of genes within the cst locus resulted in loss of pCS1-1 transfer, which was restored upon complementation in trans. These studies provided clear evidence that genes within the cst locus are essential for the conjugative transfer of pCS1-1. The cst locus is present on all pCS1 subtypes, and homologous loci were identified on toxin-encoding plasmids from Clostridium perfringens and Clostridium botulinum and also carried within genomes of Clostridium difficile isolates, indicating that it is a widespread clostridial conjugation locus. The results of this study have broad implications for the dissemination of toxin genes and, potentially, antibiotic resistance genes among members of a diverse range of clostridial pathogens, providing these microorganisms with a survival advantage within the infected host. C. sordellii is a bacterial pathogen that causes severe infections in humans and animals, with high mortality rates. While the pathogenesis of C. sordellii infections is not well understood, it is known that the toxin TcsL is an important virulence factor. Here, we have shown the ability of a plasmid carrying the tcsL gene to undergo conjugative transfer between distantly related strains of C. sordellii, which has far-reaching implications for the ability of C. sordellii to acquire the capacity to cause disease. Plasmids that carry tcsL encode a previously uncharacterized conjugation locus, and individual genes within this locus were shown to be required for conjugative transfer. Furthermore, homologues on toxin plasmids from other clostridial species were identified, indicating that this region represents a novel clostridial conjugation locus. The results of this study have broad implications for the dissemination of virulence genes among members of a diverse range of clostridial pathogens.
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Varela Chavez C, Haustant GM, Baron B, England P, Chenal A, Pauillac S, Blondel A, Popoff MR. The Tip of the Four N-Terminal α-Helices of Clostridium sordellii Lethal Toxin Contains the Interaction Site with Membrane Phosphatidylserine Facilitating Small GTPases Glucosylation. Toxins (Basel) 2016; 8:90. [PMID: 27023605 PMCID: PMC4848617 DOI: 10.3390/toxins8040090] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/01/2016] [Accepted: 03/10/2016] [Indexed: 12/22/2022] Open
Abstract
Clostridium sordellii lethal toxin (TcsL) is a powerful virulence factor responsible for severe toxic shock in man and animals. TcsL belongs to the large clostridial glucosylating toxin (LCGT) family which inactivates small GTPases by glucosylation with uridine-diphosphate (UDP)-glucose as a cofactor. Notably, TcsL modifies Rac and Ras GTPases, leading to drastic alteration of the actin cytoskeleton and cell viability. TcsL enters cells via receptor-mediated endocytosis and delivers the N-terminal glucosylating domain (TcsL-cat) into the cytosol. TcsL-cat was found to preferentially bind to phosphatidylserine (PS)-containing membranes and to increase the glucosylation of Rac anchored to the lipid membrane. We have previously reported that the N-terminal four helical bundle structure (1–93 domain) recognizes a broad range of lipids, but that TcsL-cat specifically binds to PS and phosphatidic acid. Here, we show using mutagenesis that the PS binding site is localized on the tip of the four-helix bundle which is rich in positively-charged amino acids. Residues Y14, V15, F17, and R18 on loop 1, between helices 1 and 2, in coordination with R68 from loop 3, between helices 3 and 4, form a pocket which accommodates L-serine. The functional PS-binding site is required for TcsL-cat binding to the plasma membrane and subsequent cytotoxicity. TcsL-cat binding to PS facilitates a high enzymatic activity towards membrane-anchored Ras by about three orders of magnitude as compared to Ras in solution. The PS-binding site is conserved in LCGTs, which likely retain a common mechanism of binding to the membrane for their full activity towards membrane-bound GTPases.
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Affiliation(s)
- Carolina Varela Chavez
- Unité des Bactéries anaérobies et Toxines, Institut Pasteur, 75724 Paris cedex15, France.
| | | | - Bruno Baron
- Plate-Forme de Biophysique Moléculaires, Institut Pasteur, 75724 Paris cedex15, France.
| | - Patrick England
- Plate-Forme de Biophysique Moléculaires, Institut Pasteur, 75724 Paris cedex15, France.
| | - Alexandre Chenal
- Unité de Biochimie des Interactions Macromoléculaires, Institut Pasteur, 75724 Paris cedex15, France.
| | - Serge Pauillac
- Unité des Bactéries anaérobies et Toxines, Institut Pasteur, 75724 Paris cedex15, France.
| | - Arnaud Blondel
- Unité de Bioinformatique Structurale, Institut Pasteur, 75724 Paris cedex15, France.
| | - Michel-Robert Popoff
- Unité des Bactéries anaérobies et Toxines, Institut Pasteur, 75724 Paris cedex15, France.
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Chong E, Winikoff B, Charles D, Agnew K, Prentice JL, Limbago BM, Platais I, Louie K, Jones HE, Shannon C. Vaginal and Rectal Clostridium sordellii and Clostridium perfringens Presence Among Women in the United States. Obstet Gynecol 2016; 127:360-8. [PMID: 26942366 PMCID: PMC5793214 DOI: 10.1097/aog.0000000000001239] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE To characterize the presence of Clostridium sordellii and Clostridium perfringens in the vagina and rectum, identify correlates of presence, and describe strain diversity and presence of key toxins. METHODS We conducted an observational cohort study in which we screened a diverse cohort of reproductive-aged women in the United States up to three times using vaginal and rectal swabs analyzed by molecular and culture methods. We used multivariate regression models to explore predictors of presence. Strains were characterized by pulsed-field gel electrophoresis and tested for known virulence factors by polymerase chain reaction assays. RESULTS Of 4,152 participants enrolled between 2010 and 2013, 3.4% (95% confidence interval [CI] 2.9-4.0) were positive for C sordellii and 10.4% (95% CI 9.5-11.3) were positive for C perfringens at baseline. Among the 66% with follow-up data, 94.7% (95% CI 88.0-98.3) of those positive for C sordellii and 74.4% (95% CI 69.0-79.3) of those positive for C perfringens at baseline were negative at follow-up. At baseline, recent gynecologic surgery was associated with C sordellii presence, whereas a high body mass index was associated with C perfringens presence in adjusted models. Two of 238 C sordellii isolates contained the lethal toxin gene, and none contained the hemorrhagic toxin gene. Substantial strain diversity was observed in both species with few clusters and no dominant clones identified. CONCLUSION The relatively rare and transient nature of C sordellii and C perfringens presence in the vagina and rectum makes it inadvisable to use any screening or prophylactic approach to try to prevent clostridial infection. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, www.clinicaltrials.gov, NCT01283828.
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Clostridium sordellii Lethal-Toxin Autoprocessing and Membrane Localization Activities Drive GTPase Glucosylation Profiles in Endothelial Cells. mSphere 2015; 1:mSphere00012-15. [PMID: 27303685 PMCID: PMC4863631 DOI: 10.1128/msphere.00012-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/05/2015] [Indexed: 11/20/2022] Open
Abstract
Clostridium sordellii is a bacterium that can infect humans and cause serious disease and death. The principle virulence factor associated with clinical symptoms is a large protein toxin known as lethal toxin. The mechanism of lethal-toxin intoxication is assumed to be similar to that of the homologous toxins from C. difficile, but very few studies have been done in the context of endothelial cells, a relevant target in C. sordellii infections. This study was designed to test the role of the lethal-toxin enzymatic activities and membrane localization in endothelial cell toxicity and host substrate modification. Clostridium sordellii infections cause gangrene and edema in humans and gastrointestinal infections in livestock. One of the principle virulence factors is TcsL, a large protein toxin which glucosylates host GTPases to cause cytopathic and cytotoxic effects. TcsL has two enzymatic domains, an N-terminal glucosyltransferase domain (GTD) and an autoprocessing domain responsible for release of the GTD within the cell. The GTD can then use its N-terminal membrane localization domain (MLD) for orientation on membranes and modification of GTPases. This study describes the use of conditionally immortalized murine pulmonary microvascular endothelial cells as a model for the study of TcsL functional activities. Point mutations that disrupt the glucosyltransferase, autoprocessing, or membrane localization activities were introduced into a recombinant version of TcsL, and the activities of these mutants were compared to those of wild-type toxin. We observed that all mutants are defective or impaired in cytotoxicity but differ in their modification of Rac1 and Ras. The data suggest a model where differences in GTPase localization dictate cellular responses to intoxication and highlight the importance of autoprocessing in the function of TcsL. IMPORTANCEClostridium sordellii is a bacterium that can infect humans and cause serious disease and death. The principle virulence factor associated with clinical symptoms is a large protein toxin known as lethal toxin. The mechanism of lethal-toxin intoxication is assumed to be similar to that of the homologous toxins from C. difficile, but very few studies have been done in the context of endothelial cells, a relevant target in C. sordellii infections. This study was designed to test the role of the lethal-toxin enzymatic activities and membrane localization in endothelial cell toxicity and host substrate modification.
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Couchman EC, Browne HP, Dunn M, Lawley TD, Songer JG, Hall V, Petrovska L, Vidor C, Awad M, Lyras D, Fairweather NF. Clostridium sordellii genome analysis reveals plasmid localized toxin genes encoded within pathogenicity loci. BMC Genomics 2015; 16:392. [PMID: 25981746 PMCID: PMC4434542 DOI: 10.1186/s12864-015-1613-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 05/05/2015] [Indexed: 11/17/2022] Open
Abstract
Background Clostridium sordellii can cause severe infections in animals and humans, the latter associated with trauma, toxic shock and often-fatal gynaecological infections. Strains can produce two large clostridial cytotoxins (LCCs), TcsL and TcsH, related to those produced by Clostridium difficile, Clostridium novyi and Clostridium perfringens, but the genetic basis of toxin production remains uncharacterised. Results Phylogenetic analysis of the genome sequences of 44 strains isolated from human and animal infections in the UK, US and Australia placed the species into four clades. Although all strains originated from animal or clinical disease, only 5 strains contained LCC genes: 4 strains contain tcsL alone and one strain contains tcsL and tcsH. Four toxin-positive strains were found within one clade. Where present, tcsL and tcsH were localised in a pathogenicity locus, similar to but distinct from that present in C. difficile. In contrast to C. difficile, where the LCCs are chromosomally localised, the C. sordellii tcsL and tcsH genes are localised on plasmids. Our data suggest gain and loss of entire toxigenic plasmids in addition to horizontal transfer of the pathogenicity locus. A high quality, annotated sequence of ATCC9714 reveals many putative virulence factors including neuraminidase, phospholipase C and the cholesterol-dependent cytolysin sordellilysin that are highly conserved between all strains studied. Conclusions Genome analysis of C. sordellii reveals that the LCCs, the major virulence factors, are localised on plasmids. Many strains do not contain the LCC genes; it is probable that in several of these cases the plasmid has been lost upon laboratory subculture. Our data are consistent with LCCs being the primary virulence factors in the majority of infections, but LCC-negative strains may precipitate certain categories of infection. A high quality genome sequence reveals putative virulence factors whose role in virulence can be investigated. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1613-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Edward C Couchman
- Department of Life Sciences, Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK.
| | | | - Matt Dunn
- Wellcome Trust Sanger Institute, Hinxton, UK.
| | | | - J Glenn Songer
- Department of Veterinary Science and Microbiology, University of Arizona, Tucson, USA.
| | - Val Hall
- Anaerobe Reference Laboratory, University Hospital of Wales, Cardiff, UK.
| | | | - Callum Vidor
- Department of Microbiology, Monash University, Clayton, VIC, 3800, Australia.
| | - Milena Awad
- Department of Microbiology, Monash University, Clayton, VIC, 3800, Australia.
| | - Dena Lyras
- Department of Microbiology, Monash University, Clayton, VIC, 3800, Australia.
| | - Neil F Fairweather
- Department of Life Sciences, Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK.
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Foot infection by Clostridium sordellii: case report and review of 15 cases in France. J Clin Microbiol 2015; 53:1423-7. [PMID: 25609723 DOI: 10.1128/jcm.03414-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We report a case of foot infection by Clostridium sordellii and review 15 human infections registered at a Reference Center in France during the period 1998 to 2011. All strains were found nontoxigenic, lacking the lethal toxin gene coding for TcsL. Like Clostridium septicum, several C. sordellii infections were associated with intestinal neoplasms.
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Vidor C, Awad M, Lyras D. Antibiotic resistance, virulence factors and genetics of Clostridium sordellii. Res Microbiol 2014; 166:368-74. [PMID: 25290059 DOI: 10.1016/j.resmic.2014.09.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/25/2014] [Accepted: 09/09/2014] [Indexed: 02/04/2023]
Abstract
Clostridium sordellii is gram positive bacterial pathogen of humans and animals. While the incidence of human-related C. sordellii infection is low, the mortality rate associated with infection is high. Of particular concern are C. sordellii infections after child-birth or medical abortion, which have an almost 100% mortality rate. Recent genetic and epidemiological work has increased our understanding of how this pathogen has evolved and how it causes disease. This review will summarise studies involving the genetics of C. sordellii, including an antibiotic resistance profile, the genetic determinants of virulence and mutagenesis of C. sordellii.
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Affiliation(s)
- Callum Vidor
- Department of Microbiology, Monash University, Victoria 3800, Australia.
| | - Milena Awad
- Department of Microbiology, Monash University, Victoria 3800, Australia.
| | - Dena Lyras
- Department of Microbiology, Monash University, Victoria 3800, Australia.
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Genth H, Pauillac S, Schelle I, Bouvet P, Bouchier C, Varela-Chavez C, Just I, Popoff MR. Haemorrhagic toxin and lethal toxin from Clostridium sordellii strain vpi9048: molecular characterization and comparative analysis of substrate specificity of the large clostridial glucosylating toxins. Cell Microbiol 2014; 16:1706-21. [PMID: 24905543 DOI: 10.1111/cmi.12321] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 05/12/2014] [Accepted: 05/29/2014] [Indexed: 12/16/2022]
Abstract
Large clostridial glucosylating toxins (LCGTs) are produced by toxigenic strains of Clostridium difficile, Clostridium perfringens, Clostridium novyi and Clostridium sordellii. While most C. sordellii strains solely produce lethal toxin (TcsL), C. sordellii strain VPI9048 co-produces both hemorrhagic toxin (TcsH) and TcsL. Here, the sequences of TcsH-9048 and TcsL-9048 are provided, showing that both toxins retain conserved LCGT features and that TcsL and TcsH are highly related to Toxin A (TcdA) and Toxin B (TcdB) from C. difficile strain VPI10463. The substrate profile of the toxins was investigated with recombinant LCGT transferase domains (rN) and a wide panel of small GTPases. rN-TcsH-9048 and rN-TcdA-10463 glucosylated preferably Rho-GTPases but also Ras-GTPases to some extent. In this respect, rN-TcsH-9048 and rN-TcdA-10463 differ from the respective full-length TcsH-9048 and TcdA-10463, which exclusively glucosylate Rho-GTPases. rN-TcsL-9048 and full length TcsL-9048 glucosylate both Rho- and Ras-GTPases, whereas rN-TcdB-10463 and full length TcdB-10463 exclusively glucosylate Rho-GTPases. Vero cells treated with full length TcsH-9048 or TcdA-10463 also showed glucosylation of Ras, albeit to a lower extent than of Rho-GTPases. Thus, in vitro analysis of substrate spectra using recombinant transferase domains corresponding to the auto-proteolytically cleaved domains, predicts more precisely the in vivo substrates than the full length toxins. Except for TcdB-1470, all LCGTs evoked increased expression of the small GTPase RhoB, which exhibited cytoprotective activity in cells treated with TcsL isoforms, but pro-apoptotic activity in cells treated with TcdA, TcdB, and TcsH. All LCGTs induced a rapid dephosphorylation of pY118-paxillin and of pS144/141-PAK1/2 prior to actin filament depolymerization indicating that disassembly of focal adhesions is an early event leading to the disorganization of the actin cytoskeleton.
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Affiliation(s)
- Harald Genth
- Institute of Toxicology, Medical School Hannover, Hannover, Germany
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