Clostridium difficile/Clostridium sordellii and Clostridium perfringens Toxins

A topical collection in Toxins (ISSN 2072-6651). This collection belongs to the section "Bacterial Toxins".

Viewed by 275362

Editors

Institute of Toxicology, Hannover Medical School, D-30625 Hannover, Germany
Interests: clostridium difficile toxins; large clostridial glycosylating toxins; actin cytoskeleton; cell motility; cytoskeletal proteins; infection; signaling; Rho; Ras
Unité “Bactéries anaérobies et Toxines”, Institut Pasteur, 25-28 Rue du Dr Roux, F-75015 Paris, France
Interests: bacterial protein toxins; clostridial toxins; pore-forming toxins; cellular uptake of bacterial toxins; Rho-GTPases; interactions of clostridial toxins with the actin cytoskeleton; botulinum neurotoxins; passage of the neurotoxins through the epithelial barrier; regulation of clostridial toxin synthesis
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

Clostridium difficile/Clostridium sordellii and Clostridium perfringens are the most common toxigenic clostridia involved in human and animal diseases. The main C. difficile and C. sordellii toxins belong to the large clostridial glucosylating toxin family, which are intracellularly active toxins through inactivation of Rho/Ras-GTPases, whereas C. perfringens toxins are mainly active on cell membrane via a pore-forming activity. In the few last decades, a great effort has been done to better understand the molecular mode of action of these toxins notably by unraveling the toxin structures and their interaction with receptor and/or substrates, as well as by identifying the cell signaling cascade(s) triggered by the toxins and leading to cell perturbation or death. Indeed, a better comprehension of toxin activity is the basis of the development of efficient inhibitors. Moreover, genetic analysis of the toxigenic clostridia shed light on diversity and evolution of toxin variants, and on possible mechanisms of genetic transfers between clostridia and also from other bacteria. Although C. difficile/C. sordellii and C. perfringens are potent toxins responsible for severe pathologies, they represent potential therapeutic tools, for example to kill specific cell populations or to transport therapeutic compounds in specific cells.

Prof. Dr. Michel R. Popoff
Prof. Dr. Harald Genth
Collection Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a double-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Toxins is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.


Keywords

  • Clostridium difficile toxins
  • Clostridium sordellii toxins
  • Clostridium perfringens toxins
  • large clostridial glucosylating toxins
  • pore-forming toxins
  • actin cytoskeleton
  • Rho-GTPases
  • Ras-GTPases
  • apoptosis
  • cell necrosis
  • toxin gene evolution

Published Papers (37 papers)

2024

Jump to: 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015

17 pages, 11828 KiB  
Article
A Streamlined Method to Obtain Biologically Active TcdA and TcdB Toxins from Clostridioides difficile
by Diane Sapa, Anaïs Brosse, Héloïse Coullon, Gauthier Péan de Ponfilly, Thomas Candela and Alban Le Monnier
Toxins 2024, 16(1), 38; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins16010038 - 11 Jan 2024
Viewed by 856
Abstract
The major virulence factors of Clostridioides difficile (C. difficile) are enterotoxins A (TcdA) and B (TcdB). The study of toxins is a crucial step in exploring the virulence of this pathogen. Currently, the toxin purification process is either laborious and time-consuming [...] Read more.
The major virulence factors of Clostridioides difficile (C. difficile) are enterotoxins A (TcdA) and B (TcdB). The study of toxins is a crucial step in exploring the virulence of this pathogen. Currently, the toxin purification process is either laborious and time-consuming in C. difficile or performed in heterologous hosts. Therefore, we propose a streamlined method to obtain functional toxins in C. difficile. Two C. difficile strains were generated, each harboring a sequence encoding a His-tag at the 3′ end of C. difficile 630∆erm tcdA or tcdB genes. Each toxin gene is expressed using the Ptet promoter, which is inducible by anhydro-tetracycline. The obtained purification yields were 0.28 mg and 0.1 mg per liter for rTcdA and rTcdB, respectively. In this study, we successfully developed a simple routine method that allows the production and purification of biologically active rTcdA and rTcdB toxins with similar activities compared to native toxins. Full article
Show Figures

Figure 1

2023

Jump to: 2024, 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015

17 pages, 5391 KiB  
Article
Pyroptosis of Macrophages Induced by Clostridium perfringens Beta-1 Toxin
by Siyu Zhang, Lingling Ma, Fuyang Song, Dong Wang, Kesong Shi, Yong Li, Jin Zeng and Yujiong Wang
Toxins 2023, 15(6), 366; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins15060366 - 29 May 2023
Viewed by 1325
Abstract
Clostridium perfringens beta-1 toxin (CPB1) is responsible for necrotizing enteritis and enterotoxemia. However, whether the release of host inflammatory factors caused by CPB1 is related to pyroptosis, an inflammatory form of programmed cell death, has not been reported. A construct expressing recombinant Clostridium [...] Read more.
Clostridium perfringens beta-1 toxin (CPB1) is responsible for necrotizing enteritis and enterotoxemia. However, whether the release of host inflammatory factors caused by CPB1 is related to pyroptosis, an inflammatory form of programmed cell death, has not been reported. A construct expressing recombinant Clostridium perfringens beta-1 toxin (rCPB1) was created, and the cytotoxic activity of the purified rCPB1 toxin was assessed via CCK-8 assay. The rCPB1-induced macrophage pyroptosis by assessing changes to the expression of pyroptosis-related signal molecules and the pyroptosis pathway of macrophages using quantitative real-time PCR, immunoblotting, ELISA, immunofluorescence, and electron microscopic assays. The results showed that the intact rCPB1 protein was purified from an E. coli expression system, which exhibited moderate cytotoxicity on mouse mononuclear macrophage leukemia cells (RAW264.7), normal colon mucosal epithelial cells (NCM460), and human umbilical vein endothelial cells (HUVEC). rCPB1 could induce pyroptosis in macrophages and HUVEC cells, in part through the Caspase-1-dependent pathway. The rCPB1-induced pyroptosis of RAW264.7 cells could be blocked by inflammasome inhibitor MCC950. These results demonstrated that rCPB1 treatment of macrophages promoted the assembly of NLRP3 inflammasomes and activated Caspase 1; the activated Caspase 1 caused gasdermin D to form plasma membrane pores, leading to the release of inflammatory factors IL-18 and IL-1β, resulting in macrophage pyroptosis. NLRP3 may be a potential therapeutic target for Clostridium perfringes disease. This study provided a novel insight into the pathogenesis of CPB1. Full article
Show Figures

Figure 1

2022

Jump to: 2024, 2023, 2021, 2020, 2019, 2018, 2017, 2016, 2015

15 pages, 1722 KiB  
Article
Characterization of NanR Regulation of Sialidase Production, Sporulation and Enterotoxin Production by Clostridium perfringens Type F Strains Carrying a Chromosomal Enterotoxin Gene
by Jihong Li, Eric Mi, Arhat Pradhan and Bruce A. McClane
Toxins 2022, 14(12), 872; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins14120872 - 13 Dec 2022
Cited by 1 | Viewed by 1360
Abstract
Clostridium perfringens type F food poisoning (FP) strains produce C. perfringens enterotoxin (CPE) to cause a common bacterial food-borne illness in the United States. During FP, CPE is synthesized in the intestines when C. perfringens sporulates. Besides CPE, FP strains also produce sialidases. [...] Read more.
Clostridium perfringens type F food poisoning (FP) strains produce C. perfringens enterotoxin (CPE) to cause a common bacterial food-borne illness in the United States. During FP, CPE is synthesized in the intestines when C. perfringens sporulates. Besides CPE, FP strains also produce sialidases. Most FP strains carry their cpe gene on the chromosome and all surveyed chromosomal cpe (c-cpe) FP strains produce NanH sialidase or both NanJ and NanH sialidases. NanR has been shown previously to regulate sialidase activity in non-FP strains. The current study investigated whether NanR also regulates sialidase activity or influences sporulation and CPE production for c-cpe FP strains SM101 and 01E809. In sporulation medium, the SM101 nanR null mutant showed lower sialidase activity, sporulation, and CPE production than its wild-type parent, while the 01E809 nanR null mutant showed roughly similar sialidase activity, sporulation, and CPE production as its parent. In vegetative medium, the nanR null mutants of both strains produced more spores than their parents while NanR repressed sialidase activity in SM101 but positively regulated sialidase activity in 01E809. These results demonstrate that NanR regulates important virulence functions of c-cpe strains, with this control varying depending on strain and culture conditions. Full article
Show Figures

Figure 1

13 pages, 1179 KiB  
Article
Identification and Characterization of Clostridium perfringens Atypical CPB2 Toxin in Cell Cultures and Field Samples Using Monoclonal Antibodies
by Anna Serroni, Claudia Colabella, Deborah Cruciani, Marcella Ciullo, Silvia Crotti, Paola Papa, Antonella Di Paolo, Marco Gobbi, Katia Forti, Martina Pellegrini, Romolo Salini, Nicoletta D’Avino, Monica Cagiola, Giovanni Pezzotti and Antonio De Giuseppe
Toxins 2022, 14(11), 796; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins14110796 - 17 Nov 2022
Viewed by 1561
Abstract
A direct sandwich enzyme-linked immunosorbent assay (sELISA) was developed for the detection of the atypical β2-toxin (CPB2) of Clostridium perfringens. Polyclonal (PAbs) and monoclonal (MAbs) antibodies were previously obtained employing recombinant CPB2 produced in the baculovirus system as antigen. In the current [...] Read more.
A direct sandwich enzyme-linked immunosorbent assay (sELISA) was developed for the detection of the atypical β2-toxin (CPB2) of Clostridium perfringens. Polyclonal (PAbs) and monoclonal (MAbs) antibodies were previously obtained employing recombinant CPB2 produced in the baculovirus system as antigen. In the current study, PAbs were used as capture molecules, while purified MAbs conjugated to horseradish peroxidase (MAbs-HRP) were used for the detection of atypical CPB2 toxin. MAbs 5C11E6 and 2G3G6 showed high reactivity, sensitivity and specificity when tested on 232 C. perfringens cell culture isolates. In addition, a reactivity variation among different strains producing atypical CPB2 toxin was observed using the conformation-dependent MAb 23E6E6, suggesting the hypothesis of high instability and/or the existence of different three-dimensional structures of this toxin. Results obtained by sELISA and Western blotting performed on experimentally CPB2-contaminated feces revealed a time-dependent proteolytic degradation as previously observed with the consensus allelic form of CPB2. Finally, the sELISA and an end-point PCR, specific for the atypical cpb2 gene, were used to test field samples (feces, rectal swabs and intestinal contents) from different dead animal species with suspected or confirmed clostridiosis. The comparison of sELISA data with those obtained with end-point PCR suggests this method as a promising tool for the detection of atypical CPB2 toxin. Full article
Show Figures

Figure 1

2021

Jump to: 2024, 2023, 2022, 2020, 2019, 2018, 2017, 2016, 2015

6 pages, 524 KiB  
Article
Humoral Immune Response Evaluation in Horses Vaccinated with Recombinant Clostridium perfringens Toxoids Alpha and Beta for 12 Months
by Nayra F. Q. R. Freitas, Denis Y. Otaka, Cleideanny C. Galvão, Dayane M. de Almeida, Marcos R. A. Ferreira, Clóvis Moreira Júnior, Marina M. M. H. Hidalgo, Fabricio R. Conceição and Felipe M. Salvarani
Toxins 2021, 13(8), 566; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins13080566 - 13 Aug 2021
Cited by 1 | Viewed by 2160
Abstract
In horses, Clostridium perfringens is associated with acute and fatal enterocolitis, which is caused by a beta toxin (CPB), and myonecrosis, which is caused by an alpha toxin (CPA). Although the most effective way to prevent these diseases is through vaccination, specific clostridial [...] Read more.
In horses, Clostridium perfringens is associated with acute and fatal enterocolitis, which is caused by a beta toxin (CPB), and myonecrosis, which is caused by an alpha toxin (CPA). Although the most effective way to prevent these diseases is through vaccination, specific clostridial vaccines for horses against C. perfringens are not widely available. The aim of this study was to pioneer the immunization of horses with three different concentrations (100, 200 and 400 µg) of C. perfringens recombinant alpha (rCPA) and beta (rCPB) proteins, as well as to evaluate the humoral immune response over 360 days. Recombinant toxoids were developed and applied to 50 horses on days 0 and 30. Those vaccines attempted to stimulate the production of alpha antitoxin (anti-CPA) and beta antitoxin (anti-CPB), in addition to becoming innocuous, stable and sterile. There was a reduction in the level of neutralizing anti-CPA and anti-CPB antibodies following the 60th day; therefore, the concentrations of 200 and 400 µg capable of inducing a detectable humoral immune response were not determined until day 180. In practical terms, 200 µg is possibly the ideal concentration for use in the veterinary industry’s production of vaccines against the action of C. perfringens in equine species. Full article
Show Figures

Figure 1

2020

Jump to: 2024, 2023, 2022, 2021, 2019, 2018, 2017, 2016, 2015

16 pages, 2885 KiB  
Article
Receptor Binding Domains of TcdB from Clostridioides difficile for Chondroitin Sulfate Proteoglycan-4 and Frizzled Proteins Are Functionally Independent and Additive
by Daniel Henkel, Helma Tatge, Dennis Schöttelndreier, Liang Tao, Min Dong and Ralf Gerhard
Toxins 2020, 12(12), 736; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins12120736 - 24 Nov 2020
Cited by 19 | Viewed by 3755
Abstract
Toxin B (TcdB) produced by Clostridioides difficile is a main pathogenicity factor that affects a variety of different cell types within the colonic mucosa. TcdB is known to utilize frizzled-1,2,7 and chondroitin sulfate proteoglycan-4 (CSPG4) as protein receptors. By using human cervical cancer [...] Read more.
Toxin B (TcdB) produced by Clostridioides difficile is a main pathogenicity factor that affects a variety of different cell types within the colonic mucosa. TcdB is known to utilize frizzled-1,2,7 and chondroitin sulfate proteoglycan-4 (CSPG4) as protein receptors. By using human cervical cancer cell line HeLa CSPG4 knockout (CSPG4−/−) cells as well as TcdB mutants which do not bind to either CSPG4 or frizzled-1,2,7, or both, we evaluated the impact of the individual receptors for cytopathic and cytotoxic effects of TcdB. We compared TcdB from the reference strain VPI10463 (TcdBVPI) and the endemic strain R20291 (TcdBR20) which does not interact with frizzled-1,2,7. TcdBVPI devoid of CSPG4 binding (TcdBVPI ΔCROP) shows identical cytopathic potency as full-length TcdB in HeLa CSPG4−/− cells, indicating that interaction with frizzled proteins is not affected in the presence of the C-terminal CROP domain. We validated CSPG4 as cellular receptor for both TcdB toxinotypes in HeLa and HEp-2 cells. By exchange of a single phenylalanine residue, 1597 with serine, we generated a mutated TcdBVPI variant (TcdBVPI F1597S) that in accordance with TcdBR20 lacks binding to frizzled-1,2,7 and showed identical potency as TcdBR20 on HeLa cells. This enabled us to estimate the respective share of CSPG4 and frizzled-1,2,7 in the cytotoxic and cytopathic effect induced by TcdB. Our data reveal that binding to frizzled-1,2,7 and to CSPG4 occurs independently and in an additive manner. Full article
Show Figures

Figure 1

14 pages, 982 KiB  
Article
Prevalence, Genotypic and Phenotypic Characterization and Antibiotic Resistance Profile of Clostridium perfringens Type A and D Isolated from Feces of Sheep (Ovis aries) and Goats (Capra hircus) in Punjab, Pakistan
by Mudassar Mohiuddin, Zahid Iqbal, Abubakar Siddique, Shenquan Liao, Muhammad Khalid Farooq Salamat, Nanshan Qi, Ayesha Mohiud Din and Mingfei Sun
Toxins 2020, 12(10), 657; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins12100657 - 14 Oct 2020
Cited by 19 | Viewed by 5242
Abstract
Clostridium perfringens poses a serious threat to small ruminants by causing moderate to severe enterotoxaemia. Due to its ability to produce a wide arsenal of toxins, it is ranked among the most prevalent and important pathogens in livestock. This study focused on the [...] Read more.
Clostridium perfringens poses a serious threat to small ruminants by causing moderate to severe enterotoxaemia. Due to its ability to produce a wide arsenal of toxins, it is ranked among the most prevalent and important pathogens in livestock. This study focused on the molecular characterization of different Clostridium perfringens types along with their antimicrobial resistance profile. An overall higher prevalence of C. perfringens (46.1%) was detected based on mPCR among sheep and goats (healthy and diseased) in the Punjab province, Pakistan. The majority of the isolates were characterized as type A (82%), followed by type D (18%). Among the isolates from diseased sheep and goats, 27% were positive for cpa, 49% for cpa and cpb2, 9% for cpa and etx, 15% for cpa, cpb2 and etx. In the case of isolates from healthy sheep and goats, 59% were positive for cpa, 34% for cpb2 and cpa, 4% for cpa and etx, and 3% for cpa, cpb2 and etx. The prevalence of the beta2 toxin gene in the diseased sheep and goat population was 64% as compared to 37% in healthy animals. All 184 isolates (100%) were sensitive to rifampin and ceftiofur; the majority (57%) was sensitive to teicoplanin, chloramphenicol, amoxicillin, linezolid and enrofloxacin. A lower proportion of isolates (43%) were sensitive to ciprofloxacin and only 14% were susceptible to erythromycin. The findings of this study highlight the higher prevalence of C. perfringens in small ruminants and indicate that detailed pathogenesis studies are necessary to understand the explicit role of various toxins in causing enteric infections in sheep and goats including how they might be exploited to develop vaccines against these diseases. Full article
Show Figures

Figure 1

20 pages, 2398 KiB  
Article
Molecular Characterization of Clostridium perfringens Strains Isolated in Italy
by Katia Forti, Laura Ferroni, Martina Pellegrini, Deborah Cruciani, Antonio De Giuseppe, Silvia Crotti, Paola Papa, Carmen Maresca, Giulio Severi, Maria Luisa Marenzoni and Monica Cagiola
Toxins 2020, 12(10), 650; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins12100650 - 08 Oct 2020
Cited by 24 | Viewed by 4222
Abstract
Clostridium (C.) perfringens is the causative agent of several diseases and enteric infections in animals and humans. The pathogenicity of the bacterium is largely mediated by the production of a wide range of toxins. Individual C. perfringens strains produce only subsets of this [...] Read more.
Clostridium (C.) perfringens is the causative agent of several diseases and enteric infections in animals and humans. The pathogenicity of the bacterium is largely mediated by the production of a wide range of toxins. Individual C. perfringens strains produce only subsets of this toxin repertoire, which permits the classification in seven toxinotypes (A–G). In addition, a variety of minor toxins further characterizes the single strains. The aim of this work was to evaluate, using Polymerase Chain Reaction (PCR) assays, the diversity of 632 C. perfringens strains isolated in Italy over 15 years. The genotyped strains were analyzed to determine the presence of major and minor toxins (cpe, consensus, and atypical cpb2), their geographical origins, and the source of isolation (animal species or food). Our study shows that toxinotype A had the greatest representation (93%) and correlated mainly with consensus cpb2 in a variety of animal species, as well as with atypical cpb2 in the five food samples. Type D, associated with cpe and atypical cpb2 minor toxins, was identified in 3% of the cases, and type F was identified in 2.5%. Seven type C isolates (1.1%) were detected in cattle, whereas the only type B atypical cpb2 isolated in Italy was detected in a goat, and one type E cpe+atypical cpb2 was detected in a sheep. Type G was not detected. Full article
Show Figures

Figure 1

16 pages, 627 KiB  
Review
Human Botulism in France, 1875–2016
by Christine Rasetti-Escargueil, Emmanuel Lemichez and Michel R. Popoff
Toxins 2020, 12(5), 338; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins12050338 - 21 May 2020
Cited by 23 | Viewed by 5239
Abstract
Botulism is a rare but severe disease which is characterized by paralysis and inhibition of secretions. Only a few cases had been reported at the end of the 19th century in France. The disease was frequent during the second world war, and then [...] Read more.
Botulism is a rare but severe disease which is characterized by paralysis and inhibition of secretions. Only a few cases had been reported at the end of the 19th century in France. The disease was frequent during the second world war, and then the incidence decreased progressively. However, human botulism is still present in France with 10–25 cases every year. Food-borne botulism was the main form of botulism in France, whereas infant botulism (17 cases between 2004 and 2016) was rare, and wound and inhalational botulism were exceptional. Type B was the prevalent botulism type and was mainly due to consumption of home-made or small-scale preparations of cured ham and to a lesser extent other pork meat products. In the recent period (2000–2016), a wider diversity of botulism types from various food origin including industrial foods was reported. Severe cases of type A and F botulism as well as type E botulism were more frequent. Albeit rare, the severity of botulism justifies its continued surveillance and recommendations to food industry and consumers regarding food hygiene and preservation practices. Full article
Show Figures

Figure 1

2019

Jump to: 2024, 2023, 2022, 2021, 2020, 2018, 2017, 2016, 2015

16 pages, 2228 KiB  
Article
Effects of Claudin-1 on the Action of Clostridium perfringens Enterotoxin in Caco-2 Cells
by Iman Mehdizadeh Gohari, Jihong Li, Mauricio Navarro, Francisco Uzal and Bruce McClane
Toxins 2019, 11(10), 582; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11100582 - 09 Oct 2019
Cited by 9 | Viewed by 4726
Abstract
Clostridium perfringens enterotoxin (CPE) contributes to diarrhea and an often-lethal enterotoxemia. CPE action starts when it binds to claudin receptors, forming a small complex (90 kDa). Six small complexes then oligomerize to create prepores, followed by insertion of beta-hairpins from CPE to form [...] Read more.
Clostridium perfringens enterotoxin (CPE) contributes to diarrhea and an often-lethal enterotoxemia. CPE action starts when it binds to claudin receptors, forming a small complex (90 kDa). Six small complexes then oligomerize to create prepores, followed by insertion of beta-hairpins from CPE to form beta-barrel pores named CH-1 or CH-2. Of the ~27 members of the human claudin protein family, only some bind CPE. However, both receptor claudins and the nonreceptor claudin-1 (CLDN-1) are associated with the small and CH-1/CH-2 CPE complexes. Therefore, this study evaluated whether claudin-1 affects CPE action by generating a CLDN-1 null mutant in Caco-2 cells using CRISPR-Cas9. Compared to wild-type Caco-2 cells, paracellular permeability of the CLDN-1 mutant was significantly enhanced, suggesting that claudin-1 may reduce CPE absorption during enterotoxemia. The CLDN-1 mutant was also markedly more sensitive than wild-type Caco-2 cells to apically-applied CPE. The mechanism behind this increased sensitivity involved higher CPE binding by the CLDN-1 mutant vs. wild-type Caco-2 cells, which led to more CH-1/CH-2 complex formation. However, the CH-1/CH-2 complexes formed by the CLDN-1 mutant were less stable or trypsin resistant than those of wild-type cells. These results indicate that, although a nonreceptor, CLDN-1 positively and negatively influences CPE action. Full article
Show Figures

Figure 1

15 pages, 1237 KiB  
Article
Prevalence and Genetic Diversity of Toxin Genes in Clinical Isolates of Clostridium perfringens: Coexistence of Alpha-Toxin Variant and Binary Enterotoxin Genes (bec/cpile)
by Asami Matsuda, Meiji Soe Aung, Noriko Urushibara, Mitsuyo Kawaguchiya, Ayako Sumi, Mayumi Nakamura, Yuka Horino, Masahiko Ito, Satoshi Habadera and Nobumichi Kobayashi
Toxins 2019, 11(6), 326; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11060326 - 06 Jun 2019
Cited by 19 | Viewed by 4256
Abstract
Clostridium perfringens (C. perfringens) is responsible for food-borne gastroenteritis and other infectious diseases, and toxins produced by this bacterium play a key role in pathogenesis. Although various toxins have been described for C. perfringens isolates from humans and animals, prevalence of [...] Read more.
Clostridium perfringens (C. perfringens) is responsible for food-borne gastroenteritis and other infectious diseases, and toxins produced by this bacterium play a key role in pathogenesis. Although various toxins have been described for C. perfringens isolates from humans and animals, prevalence of individual toxins among clinical isolates has not yet been well explored. In the present study, a total of 798 C. perfringens clinical isolates were investigated for prevalence of eight toxin genes and their genetic diversity by PCR, nucleotide sequencing, and phylogenetic analysis. Besides the alpha-toxin gene (plc) present in all the isolates, the most common toxin gene was cpe (enterotoxin) (34.2%), followed by cpb2 (beta2 toxin) (1.4%), netB (NetB) (0.3%), and bec/cpile (binary enterotoxin BEC/CPILE) (0.1%), while beta-, epsilon-, and iota-toxin genes were not detected. Genetic analysis of toxin genes indicated a high level of conservation of plc, cpe, and netB. In contrast, cpb2 was revealed to be considerably divergent, containing at least two lineages. Alpha-toxin among 46 isolates was classified into ten sequence types, among which common types were distinct from those reported for avian isolates. A single isolate with bec/cpile harbored a plc variant containing an insertion of 834-bp sequence, suggesting its putative origin from chickens. Full article
Show Figures

Figure 1

11 pages, 9740 KiB  
Article
Clostridium perfringens Delta-Toxin Damages the Mouse Small Intestine
by Soshi Seike, Masaya Takehara, Keiko Kobayashi and Masahiro Nagahama
Toxins 2019, 11(4), 232; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11040232 - 22 Apr 2019
Cited by 9 | Viewed by 3590
Abstract
Clostridium perfringens strains B and C cause fatal intestinal diseases in animals. The secreted pore-forming toxin delta-toxin is one of the virulence factors of the strains, but the mechanism of intestinal pathogenesis is unclear. Here, we investigated the effects of delta-toxin on the [...] Read more.
Clostridium perfringens strains B and C cause fatal intestinal diseases in animals. The secreted pore-forming toxin delta-toxin is one of the virulence factors of the strains, but the mechanism of intestinal pathogenesis is unclear. Here, we investigated the effects of delta-toxin on the mouse ileal loop. Delta-toxin caused fluid accumulation and intestinal permeability to fluorescein isothiocyanate (FITC)-dextran in the mouse ileal loop in a dose- and time-dependent manner. Treatment with delta-toxin induced significant histological damage and shortening of villi. Delta-toxin activates a disintegrin and metalloprotease (ADAM) 10, leading to the cleavage of E-cadherin, the epithelial adherens junction protein, in human intestinal epithelial Caco-2 cells. In this study, E-cadherin immunostaining in mouse intestinal epithelial cells was almost undetectable 1 h after toxin treatment. ADAM10 inhibitor (GI254023X) blocked the toxin-induced fluid accumulation and E-cadherin loss in the mouse ileal loop. Delta-toxin stimulated the shedding of intestinal epithelial cells. The shedding cells showed the accumulation of E-cadherin in intracellular vesicles and the increased expression of active caspase-3. Our findings demonstrate that delta-toxin causes intestinal epithelial cell damage through the loss of E-cadherin cleaved by ADAM10. Full article
Show Figures

Figure 1

15 pages, 2622 KiB  
Article
Application of an Endothelial Cell Culture Assay for the Detection of Neutralizing Anti-Clostridium Perfringens Beta-Toxin Antibodies in a Porcine Vaccination Trial
by Olivia K. Richard, Sven Springer, Jacqueline Finzel, Tobias Theuß, Marianne Wyder, Beatriz Vidondo and Horst Posthaus
Toxins 2019, 11(4), 225; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11040225 - 15 Apr 2019
Cited by 5 | Viewed by 3719
Abstract
Background: Beta-toxin (CPB) is the major virulence factor of Clostridium perfringens type C, causing hemorrhagic enteritis in newborn pigs but also other animals and humans. Vaccines containing inactivated CPB are known to induce protective antibody titers in sow colostrum and neutralization of the [...] Read more.
Background: Beta-toxin (CPB) is the major virulence factor of Clostridium perfringens type C, causing hemorrhagic enteritis in newborn pigs but also other animals and humans. Vaccines containing inactivated CPB are known to induce protective antibody titers in sow colostrum and neutralization of the CPB activity is thought to be essential for protective immunity in newborn piglets. However, no method is available to quantify the neutralizing effect of vaccine-induced antibody titers in pigs. (2) Methods: We developed a novel assay for the quantification of neutralizing anti-CPB antibodies. Sera and colostrum of sows immunized with a commercial C. perfringens type A and C vaccine was used to determine neutralizing effects on CPB induced cytotoxicity in endothelial cells. Antibody titers of sows and their piglets were determined and compared to results obtained by an ELISA. (3) Results: Vaccinated sows developed neutralizing antibodies against CPB in serum and colostrum. Multiparous sows developed higher serum and colostrum antibody titers after booster vaccinations than uniparous sows. The antibody titers of sows and those of their piglets correlated highly. Piglets from vaccinated sows were protected against intraperitoneal challenge with C. perfringens type C supernatant. (4) Conclusions: The test based on primary porcine endothelial cells quantifies neutralizing antibody activity in serum and colostrum of vaccinated sows and could be used to reduce and refine animal experimentation during vaccine development. Full article
Show Figures

Figure 1

18 pages, 1956 KiB  
Article
Targeted Mass Spectrometry Analysis of Clostridium perfringens Toxins
by Miloslava Duracova, Jana Klimentova, Alena Myslivcova Fucikova, Lenka Zidkova, Valeria Sheshko, Helena Rehulkova, Jiri Dresler and Zuzana Krocova
Toxins 2019, 11(3), 177; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11030177 - 23 Mar 2019
Cited by 8 | Viewed by 4226
Abstract
Targeted proteomics recently proved to be a technique for the detection and absolute quantification of proteins not easily accessible to classical bottom-up approaches. Due to this, it has been considered as a high fidelity tool to detect potential warfare agents in wide spread [...] Read more.
Targeted proteomics recently proved to be a technique for the detection and absolute quantification of proteins not easily accessible to classical bottom-up approaches. Due to this, it has been considered as a high fidelity tool to detect potential warfare agents in wide spread kinds of biological and environmental matrices. Clostridium perfringens toxins are considered to be potential biological weapons, especially the epsilon toxin which belongs to a group of the most powerful bacterial toxins. Here, the development of a target mass spectrometry method for the detection of C. perfringens protein toxins (alpha, beta, beta2, epsilon, iota) is described. A high-resolution mass spectrometer with a quadrupole-Orbitrap system operating in target acquisition mode (parallel reaction monitoring) was utilized. Because of the lack of commercial protein toxin standards recombinant toxins were prepared within Escherichia coli. The analysis was performed using proteotypic peptides as the target compounds together with their isotopically labeled synthetic analogues as internal standards. Calibration curves were calculated for each peptide in concentrations ranging from 0.635 to 1101 fmol/μL. Limits of detection and quantification were determined for each peptide in blank matrices. Full article
Show Figures

Figure 1

10 pages, 1934 KiB  
Article
Two Clostridium perfringens Type E Isolates in France
by Laure Diancourt, Jean Sautereau, Alexis Criscuolo and Michel R. Popoff
Toxins 2019, 11(3), 138; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11030138 - 01 Mar 2019
Cited by 7 | Viewed by 3988
Abstract
Clostridium perfringens type E is a less frequently isolated C. perfringens type and has not previously been reported in France. We have characterized two recent type E isolates, C. perfringens 508.17 from the intestinal content of a calf that died of enterotoxemia, and [...] Read more.
Clostridium perfringens type E is a less frequently isolated C. perfringens type and has not previously been reported in France. We have characterized two recent type E isolates, C. perfringens 508.17 from the intestinal content of a calf that died of enterotoxemia, and 515.17 from the stool of a 60-year-old woman, subsequent to food poisoning, which contained the plasmid pCPPB-1 with variant iota toxin and C. perfringens enterotoxin genes. Full article
Show Figures

Figure 1

19 pages, 4798 KiB  
Article
Treatment and Prevention of Recurrent Clostridium difficile Infection with Functionalized Bovine Antibody-Enriched Whey in a Hamster Primary Infection Model
by Hans-Jürgen Heidebrecht, William J Weiss, Mark Pulse, Anton Lange, Karina Gisch, Heike Kliem, Sacha Mann, Michael W. Pfaffl, Ulrich Kulozik and Christoph von Eichel-Streiber
Toxins 2019, 11(2), 98; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11020098 - 06 Feb 2019
Cited by 12 | Viewed by 4504
Abstract
Toxin-induced Clostridium difficile infection (CDI) is a major disease characterized by severe diarrhea and high morbidity rates. The aim with this study was to develop an alternative drug for the treatment of CDI. Cows were repeatedly immunized to establish specific immunoglobulin G and [...] Read more.
Toxin-induced Clostridium difficile infection (CDI) is a major disease characterized by severe diarrhea and high morbidity rates. The aim with this study was to develop an alternative drug for the treatment of CDI. Cows were repeatedly immunized to establish specific immunoglobulin G and A titers against toxins A (TcdA) and B (TcdB) and against C. difficile cells in mature milk or colostrum. The effect of three different concentrations of anti-C. difficile whey protein isolates (anti-CD-WPI) and the standard of care antibiotic vancomycin were investigated in an animal model of CD infected hamsters (6 groups, with 10 hamsters each). WPI obtained from the milk of exactly the same cows pre-immunization and a vehicle group served as negative controls. The survival of hamsters receiving anti-CD-WPI was 50, 80 and 100% compared to 10 and 0% for the control groups, respectively. Vancomycin suppressed the growth of C. difficile and thus protected the hamsters at the time of administration, but 90% of these hamsters nevertheless died shortly after discontinuation of treatment. In contrast, the surviving hamsters of the anti-CD-WPI groups survived the entire study period, although they were treated for only 75 h. The specific antibodies not only inactivated the toxins for initial suppression of CDI, but also provoked the inhibition of C. difficile growth after discontinuation, thus preventing recurrence. Oral administration of anti-CD-WPI is a functional therapy of CDI in infected hamsters for both primary treatment and prevention of recurrence. Thus, anti-CD-WPI could address the urgent unmet medical need for treating and preventing recurrent CDI in humans. Full article
Show Figures

Figure 1

2018

Jump to: 2024, 2023, 2022, 2021, 2020, 2019, 2017, 2016, 2015

14 pages, 1482 KiB  
Article
Clostridium perfringens Enterotoxin: The Toxin Forms Highly Cation-Selective Channels in Lipid Bilayers
by Roland Benz and Michel R. Popoff
Toxins 2018, 10(9), 341; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins10090341 - 22 Aug 2018
Cited by 9 | Viewed by 4759
Abstract
One of the numerous toxins produced by Clostridium perfringens is Clostridium perfringens enterotoxin (CPE), a polypeptide with a molecular mass of 35.5 kDa exhibiting three different domains. Domain one is responsible for receptor binding, domain two is involved in hexamer formation and domain [...] Read more.
One of the numerous toxins produced by Clostridium perfringens is Clostridium perfringens enterotoxin (CPE), a polypeptide with a molecular mass of 35.5 kDa exhibiting three different domains. Domain one is responsible for receptor binding, domain two is involved in hexamer formation and domain three has to do with channel formation in membranes. CPE is the major virulence factor of this bacterium and acts on the claudin-receptor containing tight junctions between epithelial cells resulting in various gastrointestinal diseases. The activity of CPE on Vero cells was demonstrated by the entry of propidium iodide (PI) in the cells. The entry of propidium iodide caused by CPE was well correlated with the loss of cell viability monitored by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. CPE formed ion-permeable channels in artificial lipid bilayer membranes with a single-channel conductance of 620 pS in 1 M KCl. The single-channel conductance was not a linear function of the bulk aqueous salt concentration indicating that point-negative charges at the CPE channel controlled ion transport. This resulted in the high cation selectivity of the CPE channels, which suggested that anions are presumably not permeable through the CPE channels. The possible role of cation transport by CPE channels in disease caused by C. perfringens is discussed. Full article
Show Figures

Figure 1

15 pages, 2278 KiB  
Article
The Binary Toxin CDT of Clostridium difficile as a Tool for Intracellular Delivery of Bacterial Glucosyltransferase Domains
by Lara-Antonia Beer, Helma Tatge, Carmen Schneider, Maximilian Ruschig, Michael Hust, Jessica Barton, Stefan Thiemann, Viola Fühner, Giulio Russo and Ralf Gerhard
Toxins 2018, 10(6), 225; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins10060225 - 01 Jun 2018
Cited by 16 | Viewed by 6288
Abstract
Binary toxins are produced by several pathogenic bacteria. Examples are the C2 toxin from Clostridium botulinum, the iota toxin from Clostridium perfringens, and the CDT from Clostridium difficile. All these binary toxins have ADP-ribosyltransferases (ADPRT) as their enzymatically active component that [...] Read more.
Binary toxins are produced by several pathogenic bacteria. Examples are the C2 toxin from Clostridium botulinum, the iota toxin from Clostridium perfringens, and the CDT from Clostridium difficile. All these binary toxins have ADP-ribosyltransferases (ADPRT) as their enzymatically active component that modify monomeric actin in their target cells. The binary C2 toxin was intensively described as a tool for intracellular delivery of allogenic ADPRTs. Here, we firstly describe the binary toxin CDT from C. difficile as an effective tool for heterologous intracellular delivery. Even 60 kDa glucosyltransferase domains of large clostridial glucosyltransferases can be delivered into cells. The glucosyltransferase domains of five tested large clostridial glucosyltransferases were successfully introduced into cells as chimeric fusions to the CDTa adapter domain (CDTaN). Cell uptake was demonstrated by the analysis of cell morphology, cytoskeleton staining, and intracellular substrate glucosylation. The fusion toxins were functional only when the adapter domain of CDTa was N-terminally located, according to its native orientation. Thus, like other binary toxins, the CDTaN/b system can be used for standardized delivery systems not only for bacterial ADPRTs but also for a variety of bacterial glucosyltransferase domains. Full article
Show Figures

Graphical abstract

21 pages, 2262 KiB  
Review
Mechanisms of Action and Cell Death Associated with Clostridium perfringens Toxins
by Mauricio A. Navarro, Bruce A. McClane and Francisco A. Uzal
Toxins 2018, 10(5), 212; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins10050212 - 22 May 2018
Cited by 129 | Viewed by 18039
Abstract
Clostridium perfringens uses its large arsenal of protein toxins to produce histotoxic, neurologic and intestinal infections in humans and animals. The major toxins involved in diseases are alpha (CPA), beta (CPB), epsilon (ETX), iota (ITX), enterotoxin (CPE), and necrotic B-like (NetB) toxins. CPA [...] Read more.
Clostridium perfringens uses its large arsenal of protein toxins to produce histotoxic, neurologic and intestinal infections in humans and animals. The major toxins involved in diseases are alpha (CPA), beta (CPB), epsilon (ETX), iota (ITX), enterotoxin (CPE), and necrotic B-like (NetB) toxins. CPA is the main virulence factor involved in gas gangrene in humans, whereas its role in animal diseases is limited and controversial. CPB is responsible for necrotizing enteritis and enterotoxemia, mostly in neonatal individuals of many animal species, including humans. ETX is the main toxin involved in enterotoxemia of sheep and goats. ITX has been implicated in cases of enteritis in rabbits and other animal species; however, its specific role in causing disease has not been proved. CPE is responsible for human food-poisoning and non-foodborne C. perfringens-mediated diarrhea. NetB is the cause of necrotic enteritis in chickens. In most cases, host–toxin interaction starts on the plasma membrane of target cells via specific receptors, resulting in the activation of intracellular pathways with a variety of effects, commonly including cell death. In general, the molecular mechanisms of cell death associated with C. perfringens toxins involve features of apoptosis, necrosis and/or necroptosis. Full article
Show Figures

Figure 1

2017

Jump to: 2024, 2023, 2022, 2021, 2020, 2019, 2018, 2016, 2015

10486 KiB  
Article
Effect of Clostridium perfringens β-Toxin on Platelets
by Anne Thiel, Helga Mogel, Julia Bruggisser, Arnaud Baumann, Marianne Wyder, Michael H. Stoffel, Artur Summerfield and Horst Posthaus
Toxins 2017, 9(10), 336; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins9100336 - 24 Oct 2017
Cited by 7 | Viewed by 5567
Abstract
Clostridium perfringens β-toxin (CPB) is the major virulence factor of C. perfringens type C causing a hemorrhagic enteritis in animals and humans. In experimentally infected pigs, endothelial binding of CPB was shown to be associated with early vascular lesions and hemorrhage but [...] Read more.
Clostridium perfringens β-toxin (CPB) is the major virulence factor of C. perfringens type C causing a hemorrhagic enteritis in animals and humans. In experimentally infected pigs, endothelial binding of CPB was shown to be associated with early vascular lesions and hemorrhage but without obvious thrombosis of affected vessels, suggesting altered hemostasis in the early phase of the disease. The objective of the present study was to investigate the effect of CPB on platelets, with respect to primary hemostasis. Our results demonstrate that CPB binds to porcine and human platelets and forms oligomers resulting in a time- and dose-dependent cell death. Platelets showed rapid ultrastructural changes, significantly decreased aggregation and could no longer be activated by thrombin. This indicates that CPB affects the physiological function of platelets and counteracts primary hemostasis. Our results add platelets to the list of target cells of CPB and extend the current hypothesis of its role in the pathogenesis of C. perfringens type C enteritis. Full article
Show Figures

Figure 1

2016

Jump to: 2024, 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2015

178 KiB  
Correction
Correction: Chen, S., et al. Identification of an Essential Region for Translocation of Clostridium difficile Toxin B. Toxins 2016, 8, 241
by Shuyi Chen, Haiying Wang, Huawei Gu, Chunli Sun, Shan Li, Hanping Feng and Jufang Wang
Toxins 2016, 8(12), 352; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8120352 - 02 Dec 2016
Cited by 6 | Viewed by 3987
2635 KiB  
Review
Recombinant Alpha, Beta, and Epsilon Toxins of Clostridium perfringens: Production Strategies and Applications as Veterinary Vaccines
by Marcos Roberto A. Ferreira, Gustavo Marçal S. G. Moreira, Carlos Eduardo P. da Cunha, Marcelo Mendonça, Felipe M. Salvarani, Ângela N. Moreira and Fabricio R. Conceição
Toxins 2016, 8(11), 340; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8110340 - 21 Nov 2016
Cited by 34 | Viewed by 10416
Abstract
Clostridium perfringens is a spore-forming, commensal, ubiquitous bacterium that is present in the gastrointestinal tract of healthy humans and animals. This bacterium produces up to 18 toxins. The species is classified into five toxinotypes (A–E) according to the toxins that the bacterium produces: [...] Read more.
Clostridium perfringens is a spore-forming, commensal, ubiquitous bacterium that is present in the gastrointestinal tract of healthy humans and animals. This bacterium produces up to 18 toxins. The species is classified into five toxinotypes (A–E) according to the toxins that the bacterium produces: alpha, beta, epsilon, or iota. Each of these toxinotypes is associated with myriad different, frequently fatal, illnesses that affect a range of farm animals and humans. Alpha, beta, and epsilon toxins are the main causes of disease. Vaccinations that generate neutralizing antibodies are the most common prophylactic measures that are currently in use. These vaccines consist of toxoids that are obtained from C. perfringens cultures. Recombinant vaccines offer several advantages over conventional toxoids, especially in terms of the production process. As such, they are steadily gaining ground as a promising vaccination solution. This review discusses the main strategies that are currently used to produce recombinant vaccines containing alpha, beta, and epsilon toxins of C. perfringens, as well as the potential application of these molecules as vaccines for mammalian livestock animals. Full article
Show Figures

Figure 1

3202 KiB  
Article
Identification of an Essential Region for Translocation of Clostridium difficile Toxin B
by Shuyi Chen, Haiying Wang, Huawei Gu, Chunli Sun, Shan Li, Hanping Feng and Jufang Wang
Toxins 2016, 8(8), 241; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8080241 - 15 Aug 2016
Cited by 10 | Viewed by 6901 | Correction
Abstract
Clostridium difficile toxin A (TcdA) and toxin B (TcdB) are the major virulence factors involved in C. difficile-associated diarrhea and pseudomembranous colitis. TcdA and TcdB both contain at least four distinct domains: the glucosyltransferase domain, cysteine protease domain, receptor binding domain, and [...] Read more.
Clostridium difficile toxin A (TcdA) and toxin B (TcdB) are the major virulence factors involved in C. difficile-associated diarrhea and pseudomembranous colitis. TcdA and TcdB both contain at least four distinct domains: the glucosyltransferase domain, cysteine protease domain, receptor binding domain, and translocation domain. Few studies have investigated the translocation domain and its mechanism of action. Recently, it was demonstrated that a segment of 97 amino acids (AA 1756–1852, designated D97) within the translocation domain of TcdB is essential for the in vitro and in vivo toxicity of TcdB. However, the mechanism by which D97 regulates the action of TcdB in host cells and the important amino acids within this region are unknown. In this study, we discovered that a smaller fragment, amino acids 1756–1780, located in the N-terminus of the D97 fragment, is essential for translocation of the effector glucosyltransferase domain into the host cytosol. A sequence of 25AA within D97 is predicted to form an alpha helical structure and is the critical part of D97. The deletion mutant TcdB∆1756–1780 showed similar glucosyltransferase and cysteine protease activity, cellular binding, and pore formation to wild type TcdB, but it failed to induce the glucosylation of Rho GTPase Rac1 of host cells. Moreover, we found that TcdB∆1756–1780 was rapidly degraded in the endosome of target cells, and therefore its intact glucosyltransferase domain was unable to translocate efficiently into host cytosol. Our finding provides an insight into the molecular mechanisms of action of TcdB in the intoxication of host cells. Full article
Show Figures

Graphical abstract

541 KiB  
Review
Regulation of Toxin Production in Clostridium perfringens
by Kaori Ohtani and Tohru Shimizu
Toxins 2016, 8(7), 207; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8070207 - 05 Jul 2016
Cited by 60 | Viewed by 9867
Abstract
The Gram-positive anaerobic bacterium Clostridium perfringens is widely distributed in nature, especially in soil and the gastrointestinal tracts of humans and animals. C. perfringens causes gas gangrene and food poisoning, and it produces extracellular enzymes and toxins that are thought to act synergistically [...] Read more.
The Gram-positive anaerobic bacterium Clostridium perfringens is widely distributed in nature, especially in soil and the gastrointestinal tracts of humans and animals. C. perfringens causes gas gangrene and food poisoning, and it produces extracellular enzymes and toxins that are thought to act synergistically and contribute to its pathogenesis. A complicated regulatory network of toxin genes has been reported that includes a two-component system for regulatory RNA and cell-cell communication. It is necessary to clarify the global regulatory system of these genes in order to understand and treat the virulence of C. perfringens. We summarize the existing knowledge about the regulatory mechanisms here. Full article
Show Figures

Figure 1

1272 KiB  
Article
The Sialidase NanS Enhances Non-TcsL Mediated Cytotoxicity of Clostridium sordellii
by Milena M. Awad, Julie Singleton and Dena Lyras
Toxins 2016, 8(6), 189; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8060189 - 17 Jun 2016
Cited by 10 | Viewed by 4743
Abstract
The clostridia produce an arsenal of toxins to facilitate their survival within the host environment. TcsL is one of two major toxins produced by Clostridium sordellii, a human and animal pathogen, and is essential for disease pathogenesis of this bacterium. C. sordellii [...] Read more.
The clostridia produce an arsenal of toxins to facilitate their survival within the host environment. TcsL is one of two major toxins produced by Clostridium sordellii, a human and animal pathogen, and is essential for disease pathogenesis of this bacterium. C. sordellii produces many other toxins, but the role that they play in disease is not known, although previous work has suggested that the sialidase enzyme NanS may be involved in the characteristic leukemoid reaction that occurs during severe disease. In this study we investigated the role of NanS in C. sordellii disease pathogenesis. We constructed a nanS mutant and showed that NanS is the only sialidase produced from C. sordellii strain ATCC9714 since sialidase activity could not be detected from the nanS mutant. Complementation with the wild-type gene restored sialidase production to the nanS mutant strain. Cytotoxicity assays using sialidase-enriched culture supernatants applied to gut (Caco2), vaginal (VK2), and cervical cell lines (End1/E6E7 and Ect1/E6E7) showed that NanS was not cytotoxic to these cells. However, the cytotoxic capacity of a toxin-enriched supernatant to the vaginal and cervical cell lines was substantially enhanced in the presence of NanS. TcsL was not the mediator of the observed cytotoxicity since supernatants harvested from a TcsL-deficient strain displayed similar cytotoxicity levels to TcsL-containing supernatants. This study suggests that NanS works synergistically with an unknown toxin or toxins to exacerbate C. sordellii-mediated tissue damage in the host. Full article
Show Figures

Graphical abstract

1094 KiB  
Review
The Regulatory Networks That Control Clostridium difficile Toxin Synthesis
by Isabelle Martin-Verstraete, Johann Peltier and Bruno Dupuy
Toxins 2016, 8(5), 153; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8050153 - 14 May 2016
Cited by 104 | Viewed by 13557
Abstract
The pathogenic clostridia cause many human and animal diseases, which typically arise as a consequence of the production of potent exotoxins. Among the enterotoxic clostridia, Clostridium difficile is the main causative agent of nosocomial intestinal infections in adults with a compromised gut microbiota [...] Read more.
The pathogenic clostridia cause many human and animal diseases, which typically arise as a consequence of the production of potent exotoxins. Among the enterotoxic clostridia, Clostridium difficile is the main causative agent of nosocomial intestinal infections in adults with a compromised gut microbiota caused by antibiotic treatment. The symptoms of C. difficile infection are essentially caused by the production of two exotoxins: TcdA and TcdB. Moreover, for severe forms of disease, the spectrum of diseases caused by C. difficile has also been correlated to the levels of toxins that are produced during host infection. This observation strengthened the idea that the regulation of toxin synthesis is an important part of C. difficile pathogenesis. This review summarizes our current knowledge about the regulators and sigma factors that have been reported to control toxin gene expression in response to several environmental signals and stresses, including the availability of certain carbon sources and amino acids, or to signaling molecules, such as the autoinducing peptides of quorum sensing systems. The overlapping regulation of key metabolic pathways and toxin synthesis strongly suggests that toxin production is a complex response that is triggered by bacteria in response to particular states of nutrient availability during infection. Full article
Show Figures

Figure 1

3816 KiB  
Review
Clostridium difficile Toxins A and B: Insights into Pathogenic Properties and Extraintestinal Effects
by Stefano Di Bella, Paolo Ascenzi, Steven Siarakas, Nicola Petrosillo and Alessandra Di Masi
Toxins 2016, 8(5), 134; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8050134 - 03 May 2016
Cited by 162 | Viewed by 29938
Abstract
Clostridium difficile infection (CDI) has significant clinical impact especially on the elderly and/or immunocompromised patients. The pathogenicity of Clostridium difficile is mainly mediated by two exotoxins: toxin A (TcdA) and toxin B (TcdB). These toxins primarily disrupt the cytoskeletal structure and the tight [...] Read more.
Clostridium difficile infection (CDI) has significant clinical impact especially on the elderly and/or immunocompromised patients. The pathogenicity of Clostridium difficile is mainly mediated by two exotoxins: toxin A (TcdA) and toxin B (TcdB). These toxins primarily disrupt the cytoskeletal structure and the tight junctions of target cells causing cell rounding and ultimately cell death. Detectable C. difficile toxemia is strongly associated with fulminant disease. However, besides the well-known intestinal damage, recent animal and in vitro studies have suggested a more far-reaching role for these toxins activity including cardiac, renal, and neurologic impairment. The creation of C. difficile strains with mutations in the genes encoding toxin A and B indicate that toxin B plays a major role in overall CDI pathogenesis. Novel insights, such as the role of a regulator protein (TcdE) on toxin production and binding interactions between albumin and C. difficile toxins, have recently been discovered and will be described. Our review focuses on the toxin-mediated pathogenic processes of CDI with an emphasis on recent studies. Full article
Show Figures

Graphical abstract

1544 KiB  
Article
Metal Ion Activation of Clostridium sordellii Lethal Toxin and Clostridium difficile Toxin B
by Harald Genth, Ilona Schelle and Ingo Just
Toxins 2016, 8(4), 109; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8040109 - 13 Apr 2016
Cited by 6 | Viewed by 5214
Abstract
Lethal Toxin from Clostridium sordellii (TcsL) and Toxin B from Clostridium difficile (TcdB) belong to the family of the “Large clostridial glycosylating toxins.” These toxins mono-O-glucosylate low molecular weight GTPases of the Rho and Ras families by exploiting UDP-glucose as a hexose donor. [...] Read more.
Lethal Toxin from Clostridium sordellii (TcsL) and Toxin B from Clostridium difficile (TcdB) belong to the family of the “Large clostridial glycosylating toxins.” These toxins mono-O-glucosylate low molecular weight GTPases of the Rho and Ras families by exploiting UDP-glucose as a hexose donor. TcsL is casually involved in the toxic shock syndrome and the gas gangrene. TcdB—together with Toxin A (TcdA)—is causative for the pseudomembranous colitis (PMC). Here, we present evidence for the in vitro metal ion activation of the glucosyltransferase and the UDP-glucose hydrolysis activity of TcsL and TcdB. The following rating is found for activation by divalent metal ions: Mn2+ > Co2+ > Mg2+ >> Ca2+, Cu2+, Zn2+. TcsL and TcdB thus require divalent metal ions providing an octahedral coordination sphere. The EC50 values for TcsL were estimated at about 28 µM for Mn2+ and 180 µM for Mg2+. TcsL and TcdB further require co-stimulation by monovalent K+ (not by Na+). Finally, prebound divalent metal ions were dispensible for the cytopathic effects of TcsL and TcdB, leading to the conclusion that TcsL and TcdB recruit intracellular metal ions for activation of the glucosyltransferase activity. With regard to the intracellular metal ion concentrations, TcsL and TcdB are most likely activated by K+ and Mg2+ (rather than Mn2+) in mammalian target cells. Full article
Show Figures

Graphical abstract

3728 KiB  
Article
EGA Protects Mammalian Cells from Clostridium difficile CDT, Clostridium perfringens Iota Toxin and Clostridium botulinum C2 Toxin
by Leonie Schnell, Ann-Katrin Mittler, Mirko Sadi, Michel R. Popoff, Carsten Schwan, Klaus Aktories, Andrea Mattarei, Domenico Azarnia Tehran, Cesare Montecucco and Holger Barth
Toxins 2016, 8(4), 101; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8040101 - 01 Apr 2016
Cited by 7 | Viewed by 6953
Abstract
The pathogenic bacteria Clostridium difficile, Clostridium perfringens and Clostridium botulinum produce the binary actin ADP-ribosylating toxins CDT, iota and C2, respectively. These toxins are composed of a transport component (B) and a separate enzyme component (A). When both components assemble on the [...] Read more.
The pathogenic bacteria Clostridium difficile, Clostridium perfringens and Clostridium botulinum produce the binary actin ADP-ribosylating toxins CDT, iota and C2, respectively. These toxins are composed of a transport component (B) and a separate enzyme component (A). When both components assemble on the surface of mammalian target cells, the B components mediate the entry of the A components via endosomes into the cytosol. Here, the A components ADP-ribosylate G-actin, resulting in depolymerization of F-actin, cell-rounding and eventually death. In the present study, we demonstrate that 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA), a compound that protects cells from multiple toxins and viruses, also protects different mammalian epithelial cells from all three binary actin ADP-ribosylating toxins. In contrast, EGA did not inhibit the intoxication of cells with Clostridium difficile toxins A and B, indicating a possible different entry route for this toxin. EGA does not affect either the binding of the C2 toxin to the cells surface or the enzyme activity of the A components of CDT, iota and C2, suggesting that this compound interferes with cellular uptake of the toxins. Moreover, for C2 toxin, we demonstrated that EGA inhibits the pH-dependent transport of the A component across cell membranes. EGA is not cytotoxic, and therefore, we propose it as a lead compound for the development of novel pharmacological inhibitors against clostridial binary actin ADP-ribosylating toxins. Full article
Show Figures

Graphical abstract

4390 KiB  
Article
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
by Carolina Varela Chavez, Georges Michel Haustant, Bruno Baron, Patrick England, Alexandre Chenal, Serge Pauillac, Arnaud Blondel and Michel-Robert Popoff
Toxins 2016, 8(4), 90; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8040090 - 25 Mar 2016
Cited by 10 | Viewed by 5383
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 [...] Read more.
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. Full article
Show Figures

Graphical abstract

2264 KiB  
Review
Clostridium perfringens Enterotoxin: Action, Genetics, and Translational Applications
by John C. Freedman, Archana Shrestha and Bruce A. McClane
Toxins 2016, 8(3), 73; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8030073 - 16 Mar 2016
Cited by 133 | Viewed by 23441
Abstract
Clostridium perfringens enterotoxin (CPE) is responsible for causing the gastrointestinal symptoms of several C. perfringens food- and nonfood-borne human gastrointestinal diseases. The enterotoxin gene (cpe) is located on either the chromosome (for most C. perfringens type A food poisoning strains) or [...] Read more.
Clostridium perfringens enterotoxin (CPE) is responsible for causing the gastrointestinal symptoms of several C. perfringens food- and nonfood-borne human gastrointestinal diseases. The enterotoxin gene (cpe) is located on either the chromosome (for most C. perfringens type A food poisoning strains) or large conjugative plasmids (for the remaining type A food poisoning and most, if not all, other CPE-producing strains). In all CPE-positive strains, the cpe gene is strongly associated with insertion sequences that may help to assist its mobilization and spread. During disease, CPE is produced when C. perfringens sporulates in the intestines, a process involving several sporulation-specific alternative sigma factors. The action of CPE starts with its binding to claudin receptors to form a small complex; those small complexes then oligomerize to create a hexameric prepore on the membrane surface. Beta hairpin loops from the CPE molecules in the prepore assemble into a beta barrel that inserts into the membrane to form an active pore that enhances calcium influx, causing cell death. This cell death results in intestinal damage that causes fluid and electrolyte loss. CPE is now being explored for translational applications including cancer therapy/diagnosis, drug delivery, and vaccination. Full article
Show Figures

Figure 1

1288 KiB  
Review
Perfringolysin O Theta Toxin as a Tool to Monitor the Distribution and Inhomogeneity of Cholesterol in Cellular Membranes
by Masashi Maekawa, Yanbo Yang and Gregory D. Fairn
Toxins 2016, 8(3), 67; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8030067 - 08 Mar 2016
Cited by 38 | Viewed by 11158
Abstract
Cholesterol is an essential structural component of cellular membranes in eukaryotes. Cholesterol in the exofacial leaflet of the plasma membrane is thought to form membrane nanodomains with sphingolipids and specific proteins. Additionally, cholesterol is found in the intracellular membranes of endosomes and has [...] Read more.
Cholesterol is an essential structural component of cellular membranes in eukaryotes. Cholesterol in the exofacial leaflet of the plasma membrane is thought to form membrane nanodomains with sphingolipids and specific proteins. Additionally, cholesterol is found in the intracellular membranes of endosomes and has crucial functions in membrane trafficking. Furthermore, cellular cholesterol homeostasis and regulation of de novo synthesis rely on transport via both vesicular and non-vesicular pathways. Thus, the ability to visualize and detect intracellular cholesterol, especially in the plasma membrane, is critical to understanding the complex biology associated with cholesterol and the nanodomains. Perfringolysin O (PFO) theta toxin is one of the toxins secreted by the anaerobic bacteria Clostridium perfringens and this toxin forms pores in the plasma membrane that causes cell lysis. It is well understood that PFO recognizes and binds to cholesterol in the exofacial leaflets of the plasma membrane, and domain 4 of PFO (D4) is sufficient for the binding of cholesterol. Recent studies have taken advantage of this high-affinity cholesterol-binding domain to create a variety of cholesterol biosensors by using a non-toxic PFO or the D4 in isolation. This review highlights the characteristics and usefulness of, and the principal findings related to, these PFO-derived cholesterol biosensors. Full article
Show Figures

Graphical abstract

493 KiB  
Review
Reactive Oxygen Species as Additional Determinants for Cytotoxicity of Clostridium difficile Toxins A and B
by Claudia Frädrich, Lara-Antonia Beer and Ralf Gerhard
Toxins 2016, 8(1), 25; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins8010025 - 18 Jan 2016
Cited by 19 | Viewed by 10603
Abstract
Clostridium difficile infections can induce mild to severe diarrhoea and the often associated characteristic pseudomembranous colitis. Two protein toxins, the large glucosyltransferases TcdA and TcdB, are the main pathogenicity factors that can induce all clinical symptoms in animal models. The classical molecular mode [...] Read more.
Clostridium difficile infections can induce mild to severe diarrhoea and the often associated characteristic pseudomembranous colitis. Two protein toxins, the large glucosyltransferases TcdA and TcdB, are the main pathogenicity factors that can induce all clinical symptoms in animal models. The classical molecular mode of action of these homologous toxins is the inhibition of Rho GTPases by mono-glucosylation. Rho-inhibition leads to breakdown of the actin cytoskeleton, induces stress-activated and pro-inflammatory signaling and eventually results in apoptosis of the affected cells. An increasing number of reports, however, have documented further qualities of TcdA and TcdB, including the production of reactive oxygen species (ROS) by target cells. This review summarizes observations dealing with the production of ROS induced by TcdA and TcdB, dissects pathways that contribute to this phenomenon and speculates about ROS in mediating pathogenesis. In conclusion, ROS have to be considered as a discrete, glucosyltransferase-independent quality of at least TcdB, triggered by different mechanisms. Full article
Show Figures

Figure 1

2015

Jump to: 2024, 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016

1142 KiB  
Review
Membrane-Binding Mechanism of Clostridium perfringens Alpha-Toxin
by Masataka Oda, Yutaka Terao, Jun Sakurai and Masahiro Nagahama
Toxins 2015, 7(12), 5268-5275; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins7124880 - 03 Dec 2015
Cited by 49 | Viewed by 13771
Abstract
Clostridium perfringens alpha-toxin is a key mediator of gas gangrene, which is a life-threatening infection that manifests as fever, pain, edema, myonecrosis, and gas production. Alpha-toxin possesses phospholipase C and sphingomyelinase activities. The toxin is composed of an N-terminal domain (1–250 aa, [...] Read more.
Clostridium perfringens alpha-toxin is a key mediator of gas gangrene, which is a life-threatening infection that manifests as fever, pain, edema, myonecrosis, and gas production. Alpha-toxin possesses phospholipase C and sphingomyelinase activities. The toxin is composed of an N-terminal domain (1–250 aa, N-domain), which is the catalytic site, and a C-terminal domain (251–370 aa, C-domain), which is the membrane-binding site. Immunization of mice with the C-domain of alpha-toxin prevents the gas gangrene caused by C. perfringens, whereas immunization with the N-domain has no effect. The central loop domain (55–93 aa), especially H….SW84Y85….G, plays an important role in the interaction with ganglioside GM1a. The toxin binds to lipid rafts in the presence of a GM1a/TrkA complex, and metabolites from phosphatidylcholine to diacylglycerol through the enzymatic activity of alpha-toxin itself. These membrane dynamics leads to the activation of endogenous PLCγ-1 via TrkA. In addition, treatment with alpha-toxin leads to the formation of diacylglycerol at membrane rafts in ganglioside-deficient DonQ cells; this in turn triggers endocytosis and cell death. This article summarizes the current the membrane-binding mechanism of alpha-toxin in detail. Full article
Show Figures

Figure 1

1061 KiB  
Review
The Role of Rho GTPases in Toxicity of Clostridium difficile Toxins
by Shuyi Chen, Chunli Sun, Haiying Wang and Jufang Wang
Toxins 2015, 7(12), 5254-5267; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins7124874 - 02 Dec 2015
Cited by 54 | Viewed by 10772
Abstract
Clostridium difficile (C. difficile) is the main cause of antibiotic-associated diarrhea prevailing in hospital settings. In the past decade, the morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Toxin A (TcdA) [...] Read more.
Clostridium difficile (C. difficile) is the main cause of antibiotic-associated diarrhea prevailing in hospital settings. In the past decade, the morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Toxin A (TcdA) and toxin B (TcdB), the two exotoxins of C. difficile, are the major virulence factors of CDI. The common mode of action of TcdA and TcdB is elicited by specific glucosylation of Rho-GTPase proteins in the host cytosol using UDP-glucose as a co-substrate, resulting in the inactivation of Rho proteins. Rho proteins are the key members in many biological processes and signaling pathways, inactivation of which leads to cytopathic and cytotoxic effects and immune responses of the host cells. It is supposed that Rho GTPases play an important role in the toxicity of C. difficile toxins. This review focuses on recent progresses in the understanding of functional consequences of Rho GTPases glucosylation induced by C. difficile toxins and the role of Rho GTPases in the toxicity of TcdA and TcdB. Full article
Show Figures

Graphical abstract

344 KiB  
Article
Veal Calves Produce Less Antibodies against C. Perfringens Alpha Toxin Compared to Beef Calves
by Bonnie R. Valgaeren, Bart Pardon, Evy Goossens, Stefanie Verherstraeten, Sophie Roelandt, Leen Timbermont, Nicky Van Der Vekens, Sabrina Stuyvaert, Linde Gille, Laura Van Driessche, Freddy Haesebrouck, Richard Ducatelle, Filip Van Immerseel and Piet Deprez
Toxins 2015, 7(7), 2586-2597; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins7072586 - 10 Jul 2015
Cited by 5 | Viewed by 5144
Abstract
Enterotoxaemia is a disease with a high associated mortality rate, affecting beef and veal calves worldwide, caused by C. perfringens alpha toxin and perfringolysin. A longitudinal study was conducted to determine the dynamics of antibodies against these toxins in 528 calves on 4 [...] Read more.
Enterotoxaemia is a disease with a high associated mortality rate, affecting beef and veal calves worldwide, caused by C. perfringens alpha toxin and perfringolysin. A longitudinal study was conducted to determine the dynamics of antibodies against these toxins in 528 calves on 4 beef and 15 veal farms. The second study aimed to determine the effect of solid feed intake on the production of antibodies against alpha toxin and perfringolysin. The control group only received milk replacer, whereas in the test group solid feed was provided. Maternal antibodies for alpha toxin were present in 45% of the veal calves and 66% of the beef calves. In beef calves a fluent transition from maternal to active immunity was observed for alpha toxin, whereas almost no veal calves developed active immunity. Perfringolysin antibodies significantly declined both in veal and beef calves. In the second study all calves were seropositive for alpha toxin throughout the experiment and solid feed intake did not alter the dynamics of alpha and perfringolysin antibodies. In conclusion, the present study showed that veal calves on a traditional milk replacer diet had significantly lower alpha toxin antibodies compared to beef calves in the risk period for enterotoxaemia, whereas no differences were noticed for perfringolysin. Full article
Show Figures

Figure 1

697 KiB  
Review
Perfringolysin O: The Underrated Clostridium perfringens Toxin?
by Stefanie Verherstraeten, Evy Goossens, Bonnie Valgaeren, Bart Pardon, Leen Timbermont, Freddy Haesebrouck, Richard Ducatelle, Piet Deprez, Kristin R. Wade, Rodney Tweten and Filip Van Immerseel
Toxins 2015, 7(5), 1702-1721; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins7051702 - 14 May 2015
Cited by 50 | Viewed by 11687
Abstract
The anaerobic bacterium Clostridium perfringens expresses multiple toxins that promote disease development in both humans and animals. One such toxin is perfringolysin O (PFO, classically referred to as θ toxin), a pore-forming cholesterol-dependent cytolysin (CDC). PFO is secreted as a water-soluble monomer that [...] Read more.
The anaerobic bacterium Clostridium perfringens expresses multiple toxins that promote disease development in both humans and animals. One such toxin is perfringolysin O (PFO, classically referred to as θ toxin), a pore-forming cholesterol-dependent cytolysin (CDC). PFO is secreted as a water-soluble monomer that recognizes and binds membranes via cholesterol. Membrane-bound monomers undergo structural changes that culminate in the formation of an oligomerized prepore complex on the membrane surface. The prepore then undergoes conversion into the bilayer-spanning pore measuring approximately 250–300 Å in diameter. PFO is expressed in nearly all identified C. perfringens strains and harbors interesting traits that suggest a potential undefined role for PFO in disease development. Research has demonstrated a role for PFO in gas gangrene progression and bovine necrohemorrhagic enteritis, but there is limited data available to determine if PFO also functions in additional disease presentations caused by C. perfringens. This review summarizes the known structural and functional characteristics of PFO, while highlighting recent insights into the potential contributions of PFO to disease pathogenesis. Full article
Show Figures

Figure 1

Back to TopTop