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Morrell EL, Navarro MA, Garcia JP, Beingesser J, Uzal FA. Intestinal pathology in goats challenged with Clostridium perfringens type D strain CN1020 wild-type and its genetically modified derivatives. Vet Pathol 2024:3009858241273122. [PMID: 39291644 DOI: 10.1177/03009858241273122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2024]
Abstract
Clostridium perfringens type D is the causative agent of enterotoxemia in sheep, goats, and cattle. Although in sheep and cattle, the disease is mainly characterized by neurological clinical signs and lesions, goats with type D enterotoxemia frequently have alterations of the alimentary system. Epsilon toxin (ETX) is the main virulence factor of C. perfringens type D, although the role of ETX in intestinal lesions in goats with type D enterotoxemia has not been fully characterized. We evaluated the contribution of ETX to C. perfringens type D enteric pathogenicity using an intraduodenal challenge model in young goats, with the virulent C. perfringens type D wild-type strain CN1020; its isogenic etx null mutant; an etx-complemented strain; and sterile, non-toxic culture medium. The intestinal tract of each animal was evaluated grossly, microscopically, and immunohistochemically for activated caspase-3. Both ETX-producing strains induced extensive enterocolitis characterized by severe mucosal necrosis, apoptosis, and diffuse suppurative infiltrates. No significant gross or microscopic lesions were observed in goats inoculated with the non-ETX-containing inocula. These results confirm that ETX is essential for the production of intestinal lesions in goats with type D disease. Also, our results suggest that the intestinal pathology of type D enterotoxemia in goats is, at least in part, associated with apoptosis.
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Giannitti F, García JP, Adams V, Armendano JI, Beingesser J, Rood JI, Uzal FA. Experimental acute Clostridium perfringens type D enterotoxemia in sheep is not characterized by specific renal lesions. Vet Pathol 2023:3009858231171669. [PMID: 37177792 DOI: 10.1177/03009858231171669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Type D enterotoxemia, caused by Clostridium perfringens epsilon toxin (ETX), is one of the most economically important clostridial diseases of sheep. Acute type D enterotoxemia is characterized by well-documented lesions in the nervous, cardiocirculatory, and pulmonary systems. However, discrepancies and confusion exist as to whether renal lesions are part of the spectrum of lesions of this condition, which is controversial considering that for many decades it has been colloquially referred to as "pulpy kidney disease." Here, the authors assess renal changes in an experimental model of acute type D enterotoxemia in sheep and evaluate the possible role of ETX in their genesis. Four groups of 6 sheep each were intraduodenally inoculated with either a wild-type virulent C. perfringens type D strain, an etx knockout mutant unable to produce ETX, the etx mutant strain complemented with the wild-type etx gene that regains the ETX toxin production, or sterile culture medium (control group). All sheep were autopsied less than 24 hours after inoculation; none of them developed gross lesions in the kidneys. Ten predefined histologic renal changes were scored in each sheep. The proportion of sheep with microscopic changes and their severity scores did not differ significantly between groups. Mild intratubular medullary hemorrhage was observed in only 2 of the 12 sheep inoculated with the wild-type or etx-complemented bacterial strains, but not in the 12 sheep of the other 2 groups. The authors conclude that no specific gross or histologic renal lesions are observed in sheep with experimental acute type D enterotoxemia.
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Affiliation(s)
| | - Jorge P García
- Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Buenos Aires, Argentina
| | - Vicki Adams
- Monash University, Parkville, Victoria, Australia
| | - Joaquín I Armendano
- Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Buenos Aires, Argentina
| | - Juliann Beingesser
- California Animal Health and Food Safety Laboratoy, University of California at Davis, San Bernardino, CA
| | | | - Francisco A Uzal
- California Animal Health and Food Safety Laboratoy, University of California at Davis, San Bernardino, CA
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Ma Y, Sannino D, Linden JR, Haigh S, Zhao B, Grigg JB, Zumbo P, Dündar F, Butler D, Profaci CP, Telesford K, Winokur PN, Rumah KR, Gauthier SA, Fischetti VA, McClane BA, Uzal FA, Zexter L, Mazzucco M, Rudick R, Danko D, Balmuth E, Nealon N, Perumal J, Kaunzner U, Brito IL, Chen Z, Xiang JZ, Betel D, Daneman R, Sonnenberg GF, Mason CE, Vartanian T. Epsilon toxin-producing Clostridium perfringens colonize the multiple sclerosis gut microbiome overcoming CNS immune privilege. J Clin Invest 2023; 133:e163239. [PMID: 36853799 PMCID: PMC10145940 DOI: 10.1172/jci163239] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 02/23/2023] [Indexed: 03/01/2023] Open
Abstract
Multiple sclerosis (MS) is a complex disease of the CNS thought to require an environmental trigger. Gut dysbiosis is common in MS, but specific causative species are unknown. To address this knowledge gap, we used sensitive and quantitative PCR detection to show that people with MS were more likely to harbor and show a greater abundance of epsilon toxin-producing (ETX-producing) strains of C. perfringens within their gut microbiomes compared with individuals who are healthy controls (HCs). Isolates derived from patients with MS produced functional ETX and had a genetic architecture typical of highly conjugative plasmids. In the active immunization model of experimental autoimmune encephalomyelitis (EAE), where pertussis toxin (PTX) is used to overcome CNS immune privilege, ETX can substitute for PTX. In contrast to PTX-induced EAE, where inflammatory demyelination is largely restricted to the spinal cord, ETX-induced EAE caused demyelination in the corpus callosum, thalamus, cerebellum, brainstem, and spinal cord, more akin to the neuroanatomical lesion distribution seen in MS. CNS endothelial cell transcriptional profiles revealed ETX-induced genes that are known to play a role in overcoming CNS immune privilege. Together, these findings suggest that ETX-producing C. perfringens strains are biologically plausible pathogens in MS that trigger inflammatory demyelination in the context of circulating myelin autoreactive lymphocytes.
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Affiliation(s)
- Yinghua Ma
- Feil Family Brain and Mind Research Institute
| | | | | | | | - Baohua Zhao
- Feil Family Brain and Mind Research Institute
| | - John B. Grigg
- Jill Roberts Institute for Research in Inflammatory Bowel Disease
- Joan and Sanford I. Weill Department of Medicine, and
- Department of Microbiology and Immunology, Weill Cornell Medical College, Cornell University, New York, New York, USA
- Immunology and Microbial Pathogenesis Program and
| | - Paul Zumbo
- Applied Bioinformatics Core, Division of Hematology/Oncology, Department of Medicine, Institute for Computational Biomedicine, Weill Cornell Medicine, New York, New York, USA
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Friederike Dündar
- Applied Bioinformatics Core, Division of Hematology/Oncology, Department of Medicine, Institute for Computational Biomedicine, Weill Cornell Medicine, New York, New York, USA
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Daniel Butler
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Caterina P. Profaci
- Departments of Pharmacology and Neurosciences, UCSD, San Diego, California, USA
| | | | - Paige N. Winokur
- Harold and Margaret Milliken Hatch Laboratory of Neuro-endocrinology and
| | - Kareem R. Rumah
- Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, New York, USA
| | - Susan A. Gauthier
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Vincent A. Fischetti
- Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, New York, USA
| | - Bruce A. McClane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Francisco A. Uzal
- California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, UCD, Davis, California, USA
| | - Lily Zexter
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | | | | | - David Danko
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | | | - Nancy Nealon
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Jai Perumal
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Ulrike Kaunzner
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Ilana L. Brito
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, USA
| | - Zhengming Chen
- Division of Biostatistics, Department of Population Health Sciences, and
| | - Jenny Z. Xiang
- Genomics Resources Core Facility, Core Laboratories Center, Weill Cornell Medicine, New York, New York, USA
| | - Doron Betel
- Applied Bioinformatics Core, Division of Hematology/Oncology, Department of Medicine, Institute for Computational Biomedicine, Weill Cornell Medicine, New York, New York, USA
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Richard Daneman
- Departments of Pharmacology and Neurosciences, UCSD, San Diego, California, USA
| | - Gregory F. Sonnenberg
- Jill Roberts Institute for Research in Inflammatory Bowel Disease
- Joan and Sanford I. Weill Department of Medicine, and
- Department of Microbiology and Immunology, Weill Cornell Medical College, Cornell University, New York, New York, USA
- Immunology and Microbial Pathogenesis Program and
| | - Christopher E. Mason
- Feil Family Brain and Mind Research Institute
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Timothy Vartanian
- Feil Family Brain and Mind Research Institute
- Immunology and Microbial Pathogenesis Program and
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
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The Specificity of ParR Binding Determines the Incompatibility of Conjugative Plasmids in Clostridium perfringens. mBio 2022; 13:e0135622. [PMID: 35726914 PMCID: PMC9426499 DOI: 10.1128/mbio.01356-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Plasmids that encode the same replication machinery are generally unable to coexist in the same bacterial cell. However, Clostridium perfringens strains often carry multiple conjugative toxin or antibiotic resistance plasmids that are closely related and encode similar Rep proteins. In many bacteria, plasmid partitioning upon cell division involves a ParMRC system; in C. perfringens plasmids, there are approximately 10 different ParMRC families, with significant differences in amino acid sequences between each ParM family (15% to 54% identity). Since plasmids carrying genes belonging to the same ParMRC family are not observed in the same strain, these families appear to represent the basis for plasmid compatibility in C. perfringens. To understand this process, we examined the key recognition steps between ParR DNA-binding proteins and their parC binding sites. The ParR proteins bound to sequences within a parC site from the same ParMRC family but could not interact with a parC site from a different ParMRC family. These data provide evidence that compatibility of the conjugative toxin plasmids of C. perfringens is mediated by their parMRC-like partitioning systems. This process provides a selective advantage by enabling the host bacterium to maintain separate plasmids that encode toxins that are specific for different host targets.
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Mehdizadeh Gohari I, A. Navarro M, Li J, Shrestha A, Uzal F, A. McClane B. Pathogenicity and virulence of Clostridium perfringens. Virulence 2021; 12:723-753. [PMID: 33843463 PMCID: PMC8043184 DOI: 10.1080/21505594.2021.1886777] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/25/2021] [Accepted: 01/29/2021] [Indexed: 12/11/2022] Open
Abstract
Clostridium perfringens is an extremely versatile pathogen of humans and livestock, causing wound infections like gas gangrene (clostridial myonecrosis), enteritis/enterocolitis (including one of the most common human food-borne illnesses), and enterotoxemia (where toxins produced in the intestine are absorbed and damage distant organs such as the brain). The virulence of this Gram-positive, spore-forming, anaerobe is largely attributable to its copious toxin production; the diverse actions and roles in infection of these toxins are now becoming established. Most C. perfringens toxin genes are encoded on conjugative plasmids, including the pCW3-like and the recently discovered pCP13-like plasmid families. Production of C. perfringens toxins is highly regulated via processes involving two-component regulatory systems, quorum sensing and/or sporulation-related alternative sigma factors. Non-toxin factors, such as degradative enzymes like sialidases, are also now being implicated in the pathogenicity of this bacterium. These factors can promote toxin action in vitro and, perhaps in vivo, and also enhance C. perfringens intestinal colonization, e.g. NanI sialidase increases C. perfringens adherence to intestinal tissue and generates nutrients for its growth, at least in vitro. The possible virulence contributions of many other factors, such as adhesins, the capsule and biofilms, largely await future study.
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Affiliation(s)
- Iman Mehdizadeh Gohari
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Mauricio A. Navarro
- California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California Davis, San Bernardino, CA, USA
| | - Jihong Li
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Archana Shrestha
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Francisco Uzal
- California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California Davis, San Bernardino, CA, USA
| | - Bruce A. McClane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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Hayati M, Tahamtan Y. Toxin typing of Clostridium perfringens Associated with Enterotoxaemia in Sheep in Fars Province. ARCHIVES OF RAZI INSTITUTE 2021; 76:691-697. [PMID: 34824761 PMCID: PMC8605852 DOI: 10.22092/ari.2020.343573.1509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 08/22/2020] [Indexed: 06/13/2023]
Abstract
Clostridium perfringens is implicated in the etiology of some diseases including fatal enterotoxaemia. Determining dominant toxin types of this microorganism can be helpful in epidemiologic surveys and the formulation of more proper vaccines. To understand the pathogenicity of this bacterium, it seems necessary to describe the toxin and virulence genes content of strains involved in enterotoxaemia and other associated diseases. The current study aimed to isolate and type the toxins of C. perfringens in sheep with suspected enterotoxaemia in Fars province by culture-PCR and ELISA methods and to compare them to isolates of a healthy group. Samples of intestinal contents were collected from enterotoxaemia cases and a healthy group of sheep. The presence of alpha, beta, and epsilon toxins were evaluated by ELISA method. After culture and isolation of C. perfringens, toxin typing and screening of isolates for the presence of beta-2 and enterotoxin were performed by PCR method. C. perfringens was isolated from 102 of 167 suspected enterotoxaemia cases of sheep and from 22 of 50 healthy sheep. The PCR results showed that type A was the most prevalent toxin type in both groups, but according to ELISA type D was the dominant toxin type in the clinical group. The enterotoxin gene was detected in 10% of all isolates from healthy and suspected group isolates of types A and D. The beta-2 gene was identified in 35% and 63.6% of enterotoxaemia-associated isolates and isolates not associated with disease, respectively. In conclusion, Type D of C. perfringens was the dominant causative organism of fatal enterotoxaemia in sheep in Fars province.
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Affiliation(s)
- M Hayati
- Microbiology Department, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Shiraz, Iran
| | - Y Tahamtan
- Molecular Biology Department, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Shiraz, Iran
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7
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Giannitti F, García JP, Rood JI, Adams V, Armendano JI, Beingesser J, Uzal FA. Cardiopulmonary Lesions in Sheep Produced by Experimental Acute Clostridium Perfringens Type D Enterotoxemia. Vet Pathol 2020; 58:103-113. [PMID: 33054683 DOI: 10.1177/0300985820965554] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Enterotoxemia caused by Clostridium perfringens type D is one of the most prevalent clostridial diseases of sheep. The lesions of the acute form of this disease, particularly the cerebral lesions, are well characterized; however, detailed descriptions of the cardiac and pulmonary lesions are lacking. Here we describe cardiopulmonary lesions in experimental acute type D enterotoxemia in sheep and determine the role of epsilon toxin (ETX) in the development of these lesions. Four groups of 6 sheep were intraduodenally inoculated with either a wild-type C. perfringens type D strain; its etx knockout mutant, which is unable to produce ETX; the etx mutant complemented with the wild-type etx gene, which regains the ETX toxigenic ability; or sterile culture medium as a control. All sheep were subjected to postmortem examination within 24 hours of inoculation. Lesion scores were compared between groups for pulmonary edema; hydrothorax; ascites; hydropericardium; endocardial, myocardial and epicardial hemorrhages; microscopic lesions of acute myocardial degeneration and necrosis; and myocardial, endocardial, and epicardial edema, hemorrhage, and inflammation. Only sheep inoculated with the wild-type and complemented ETX-toxigenic bacterial strains developed cardiopulmonary lesions, which were present in varying degrees of severity and proportions. These lesions were not present in sheep inoculated with the etx mutant or in the negative control. We conclude that severe acute cardiopulmonary lesions in sheep with experimental enterotoxemia are associated with the capacity of the strains to produce ETX. These changes are likely contributors to the clinical signs and even death of affected animals.
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Affiliation(s)
- Federico Giannitti
- 153579Instituto Nacional de Investigación Agropecuaria (INIA), Plataforma de Investigación en Salud Animal, Estación Experimental INIA La Estanzuela, Colonia, Uruguay
| | - Jorge P García
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Buenos Aires, Argentina
| | | | - Vicki Adams
- 2541Monash University, Clayton, Victoria, Australia
| | - Joaquín I Armendano
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Buenos Aires, Argentina
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Hayati M, Shamseddini M, Tahamtan Y, Sadeghzadeh S, Manavian M, Nikoo D. Isolation and Toxin Typing of Clostridium Perfringens From Sheep, Goats, and Cattle in Fars Province, Iran. INTERNATIONAL JOURNAL OF ENTERIC PATHOGENS 2020. [DOI: 10.34172/ijep.2020.20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Background: Clostridium perfringens is an important anaerobic bacterium found in the intestine of some livestock. It is concerned with the etiology of some diseases including enterotoxaemia. Various diseases are caused by different types of C. perfringens. Nonetheless, there is no published research on molecular typing and distribution of this pathogenic microorganism in Fars province. Objectives: Accordingly, our study focused on the isolation and toxin typing of C. perfringens from sheep, cattle, and goats in different parts of Fars province by the culture and the polymerase chain reaction (PCR) method. Materials and Methods: Approximately 459 fecal samples were collected and cultured on defined media for the isolation of C. perfringens. The confirmed isolates were genotyped by the PCR method using specific primers. Results: C. perfringens was isolated from 30.93% of the total samples. The results of toxin typing showed a total of 76 (54%), 13 (9%), 30 (21%), and 23 (16%) isolates as types A, B, C, and D, respectively. Conclusion: Our results indicated that C. perfringens type A was the most common type in sheep, cattle, and goats while the lowest number of isolates belonged to type B. Finally, the isolation of C. perfringens and toxin typing increase our knowledge of the epidemiology of these diseases and can help in the vaccine industry and better controlling related diseases.
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Affiliation(s)
- Masoumeh Hayati
- Razi Vaccine and Serum Research Institute, Shiraz Branch, Agricultural Research, Education and Extension Organization, Shiraz, Iran
| | - Mehrdad Shamseddini
- Razi Vaccine and Serum Research Institute, Kerman Branch, Agricultural Research, Education and Extension Organization, Kerman, Iran
| | - Yahya Tahamtan
- Razi Vaccine and Serum Research Institute, Shiraz Branch, Agricultural Research, Education and Extension Organization, Shiraz, Iran
| | - Safar Sadeghzadeh
- Razi Vaccine and Serum Research Institute, Shiraz Branch, Agricultural Research, Education and Extension Organization, Shiraz, Iran
| | - Mohsen Manavian
- Razi Vaccine and Serum Research Institute, Shiraz Branch, Agricultural Research, Education and Extension Organization, Shiraz, Iran
| | - Davood Nikoo
- Veterinary Private Sector Clinician, Shiraz, Iran
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Revitt-Mills SA, Watts TD, Lyras D, Adams V, Rood JI. The ever-expanding tcp conjugation locus of pCW3 from Clostridium perfringens. Plasmid 2020; 113:102516. [PMID: 32526229 DOI: 10.1016/j.plasmid.2020.102516] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/20/2020] [Accepted: 04/26/2020] [Indexed: 12/13/2022]
Abstract
The spore-forming, anaerobic Gram positive pathogen Clostridium perfringens encodes many of its disease-causing toxins on closely related conjugative plasmids. Studies of the tetracycline resistance plasmid pCW3 have identified many of the genes involved in conjugative transfer, which are located in the tcp conjugation locus. Upstream of this locus is an uncharacterised region (the cnaC region) that is highly conserved. This study examined the importance in pCW3 conjugation of several highly conserved proteins encoded in the cnaC region. Conjugative mating studies suggested that the SrtD, TcpN and Dam proteins were required for efficient pCW3 transfer between C. perfringens cells from the same strain background. The requirement of these proteins for conjugation was amplified in matings between C. perfringens cells of different strain backgrounds. Additionally, the putative collagen adhesin protein, CnaC, was only required for the optimal transfer of pCW3 between cells of different strain backgrounds. Based on these studies we postulate that CnaC, SrtD, TcpN and Dam are involved in enhancing the transfer frequency of pCW3. These studies have led to a significant expansion of the tcp conjugation locus, which now encompasses a 19 kb region.
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Affiliation(s)
- Sarah A Revitt-Mills
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia.
| | - Thomas D Watts
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Vicki Adams
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Julian I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
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The Tcp plasmids of Clostridium perfringens require the resP gene to ensure stable inheritance. Plasmid 2020; 107:102461. [DOI: 10.1016/j.plasmid.2019.102461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 10/31/2019] [Accepted: 11/05/2019] [Indexed: 11/23/2022]
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11
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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: 1.8] [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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12
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pCP13, a representative of a new family of conjugative toxin plasmids in Clostridium perfringens. Plasmid 2019; 102:37-45. [DOI: 10.1016/j.plasmid.2019.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 12/11/2022]
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13
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In silico Identification of Novel Toxin Homologs and Associated Mobile Genetic Elements in Clostridium perfringens. Pathogens 2019; 8:pathogens8010016. [PMID: 30699957 PMCID: PMC6471305 DOI: 10.3390/pathogens8010016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/16/2019] [Accepted: 01/24/2019] [Indexed: 01/05/2023] Open
Abstract
Clostridium perfringens causes a wide range of diseases in a variety of hosts, due to the production of a diverse set of toxins and extracellular enzymes. The C. perfringens toxins play an important role in pathogenesis, such that the presence and absence of the toxins is used as a typing scheme for the species. In recent years, several new toxins have been discovered that have been shown to be essential or highly correlated to diseases; these include binary enterotoxin (BecAB), NetB and NetF. In the current study, genome sequence analysis of C. perfringens isolates from diverse sources revealed several putative novel toxin homologs, some of which appeared to be associated with potential mobile genetic elements, including transposons and plasmids. Four novel toxin homologs encoding proteins related to the pore-forming Leukocidin/Hemolysin family were found in type A and G isolates. Two novel toxin homologs encoding proteins related to the epsilon aerolysin-like toxin family were identified in Type A and F isolates from humans, contaminated food and turkeys. A novel set of proteins related to clostridial binary toxins was also identified. While phenotypic characterisation is required before any of these homologs can be established as functional toxins, the in silico identification of these novel homologs on mobile genetic elements suggests the potential toxin reservoir of C. perfringens may be much larger than previously thought.
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Rood JI, Adams V, Lacey J, Lyras D, McClane BA, Melville SB, Moore RJ, Popoff MR, Sarker MR, Songer JG, Uzal FA, Van Immerseel F. Expansion of the Clostridium perfringens toxin-based typing scheme. Anaerobe 2018; 53:5-10. [PMID: 29866424 PMCID: PMC6195859 DOI: 10.1016/j.anaerobe.2018.04.011] [Citation(s) in RCA: 323] [Impact Index Per Article: 53.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 02/07/2023]
Abstract
Clostridium perfringens causes many different histotoxic and enterotoxic diseases in humans and animals as a result of its ability to produce potent protein toxins, many of which are extracellular. The current scheme for the classification of isolates was finalized in the 1960s and is based on their ability to produce a combination of four typing toxins - α-toxin, β-toxin, ε-toxin and ι-toxin - to divide C. perfringens strains into toxinotypes A to E. However, this scheme is now outdated since it does not take into account the discovery of other toxins that have been shown to be required for specific C. perfringens-mediated diseases. We present a long overdue revision of this toxinotyping scheme. The principles for the expansion of the typing system are described, as is a mechanism by which new toxinotypes can be proposed and subsequently approved. Based on these criteria two new toxinotypes have been established. C. perfringens type F consists of isolates that produce C. perfringens enterotoxin (CPE), but not β-toxin, ε-toxin or ι-toxin. Type F strains will include strains responsible for C. perfringens-mediated human food poisoning and antibiotic associated diarrhea. C. perfringens type G comprises isolates that produce NetB toxin and thereby cause necrotic enteritis in chickens. There are at least two candidates for future C. perfringens toxinotypes, but further experimental work is required before these toxinotypes can formally be proposed and accepted.
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Affiliation(s)
- Julian I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia.
| | - Vicki Adams
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Jake Lacey
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia; CSIRO Biosecurity Flagship, Australian Animal Health Laboratory, Geelong, Victoria 3220, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Bruce A McClane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | | - Robert J Moore
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia; School of Science, RMIT University, Bundoora, Victoria 3083, Australia
| | - Michel R Popoff
- Unité Des Bactéries Anaérobies et Toxines, Institut Pasteur, 25 Rue Du Dr Roux, 75724, Paris Cedex 15, France
| | - Mahfuzur R Sarker
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
| | | | - Francisco A Uzal
- California Animal Health and Food Safety Laboratory, San Bernardino Branch, School of Veterinary Medicine, University of California-Davis, San Bernardino, CA 92408, USA
| | - Filip Van Immerseel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Adams V, Han X, Lyras D, Rood JI. Antibiotic resistance plasmids and mobile genetic elements of Clostridium perfringens. Plasmid 2018; 99:32-39. [DOI: 10.1016/j.plasmid.2018.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/25/2018] [Accepted: 07/25/2018] [Indexed: 10/28/2022]
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Whole genome analysis reveals the diversity and evolutionary relationships between necrotic enteritis-causing strains of Clostridium perfringens. BMC Genomics 2018; 19:379. [PMID: 29788909 PMCID: PMC5964661 DOI: 10.1186/s12864-018-4771-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/09/2018] [Indexed: 11/19/2022] Open
Abstract
Background Clostridium perfringens causes a range of diseases in animals and humans including necrotic enteritis in chickens and food poisoning and gas gangrene in humans. Necrotic enteritis is of concern in commercial chicken production due to the cost of the implementation of infection control measures and to productivity losses. This study has focused on the genomic analysis of a range of chicken-derived C. perfringens isolates, from around the world and from different years. The genomes were sequenced and compared with 20 genomes available from public databases, which were from a diverse collection of isolates from chickens, other animals, and humans. We used a distance based phylogeny that was constructed based on gene content rather than sequence identity. Similarity between strains was defined as the number of genes that they have in common divided by their total number of genes. In this type of phylogenetic analysis, evolutionary distance can be interpreted in terms of evolutionary events such as acquisition and loss of genes, whereas the underlying properties (the gene content) can be interpreted in terms of function. We also compared these methods to the sequence-based phylogeny of the core genome. Results Distinct pathogenic clades of necrotic enteritis-causing C. perfringens were identified. They were characterised by variable regions encoded on the chromosome, with predicted roles in capsule production, adhesion, inhibition of related strains, phage integration, and metabolism. Some strains have almost identical genomes, even though they were isolated from different geographic regions at various times, while other highly distant genomes appear to result in similar outcomes with regard to virulence and pathogenesis. Conclusions The high level of diversity in chicken isolates suggests there is no reliable factor that defines a chicken strain of C. perfringens, however, disease-causing strains can be defined by the presence of netB-encoding plasmids. This study reveals that horizontal gene transfer appears to play a significant role in genetic variation of the C. perfringens chromosome as well as the plasmid content within strains.
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Conjugation-Mediated Horizontal Gene Transfer of Clostridium perfringens Plasmids in the Chicken Gastrointestinal Tract Results in the Formation of New Virulent Strains. Appl Environ Microbiol 2017; 83:AEM.01814-17. [PMID: 29030439 DOI: 10.1128/aem.01814-17] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 10/02/2017] [Indexed: 12/12/2022] Open
Abstract
Clostridium perfringens is a gastrointestinal pathogen capable of causing disease in a variety of hosts. Necrotic enteritis in chickens is caused by C. perfringens strains that produce the pore-forming toxin NetB, the major virulence factor for this disease. Like many other C. perfringens toxins and antibiotic resistance genes, NetB is encoded on a conjugative plasmid. Conjugative transfer of the netB-containing plasmid pJIR3535 has been demonstrated in vitro with a netB-null mutant. This study has investigated the effect of plasmid transfer on disease pathogenesis, with two genetically distinct transconjugants constructed under in vitro conditions, within the intestinal tract of chickens. This study also demonstrates that plasmid transfer can occur naturally in the host gut environment without the need for antibiotic selective pressure to be applied. The demonstration of plasmid transfer within the chicken host may have implications for the progression and pathogenesis of C. perfringens-mediated disease. Such horizontal gene transfer events are likely to be common in the clostridia and may be a key factor in strain evolution, both within animals and in the wider environment.IMPORTANCE Clostridium perfringens is a major gastrointestinal pathogen of poultry. C. perfringens strains that express the NetB pore-forming toxin, which is encoded on a conjugative plasmid, cause necrotic enteritis. This study demonstrated that the conjugative transfer of the netB-containing plasmid to two different nonpathogenic strains converted them into disease-causing strains with disease-causing capability similar to that of the donor strain. Plasmid transfer of netB and antibiotic resistance was also demonstrated to occur within the gastrointestinal tract of chickens, with approximately 14% of the isolates recovered comprising three distinct, in vivo-derived, transconjugant types. The demonstration of in vivo plasmid transfer indicates the potential importance of strain plasticity and the contribution of plasmids to strain virulence.
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Watts TD, Johanesen PA, Lyras D, Rood JI, Adams V. Evidence that compatibility of closely related replicons in Clostridium perfringens depends on linkage to parMRC-like partitioning systems of different subfamilies. Plasmid 2017; 91:68-75. [PMID: 28390955 DOI: 10.1016/j.plasmid.2017.03.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 11/17/2022]
Abstract
Clostridium perfringens produces an extensive repertoire of toxins and extracellular enzymes, many of which are intimately involved in the progression of disease and are encoded by genes on conjugative plasmids. In addition, many C. perfringens strains can carry up to five of these conjugative toxin or antimicrobial resistance plasmids, each of which has a similar 35kb backbone. This conserved backbone includes the tcp conjugation locus and the central control region (CCR), which encodes genes involved in plasmid regulation, replication and partitioning, including a parMRC partitioning locus. Most conjugative plasmids in C. perfringens have a conserved replication protein, raising questions as to how multiple, closely related plasmids are maintained within a single strain. Bioinformatics analysis has highlighted the presence of at least 10 different parMRC partitioning system families (parMRCA-J) in these plasmids, with differences in amino acid sequence identity between each ParM family ranging from 15% to 54%. No two plasmids that encode genes belonging to the same partitioning family have been observed in a single strain, suggesting that these families represent the basis for plasmid incompatibility. In an attempt to validate the proposed parMRC incompatibility groups, genetically marked C. perfringens plasmids encoding identical parMRCC or parMRCD homologues or different combinations of parMRCA, parMRCC and parMRCD family homologues were introduced into a single strain via conjugation. The stability of each plasmid was determined using an incompatibility assay in which the plasmid profile of each strain was monitored over the course of two days in the absence of direct selection. The results showed that plasmids with identical parMRCC or parMRCD homologues were incompatible and could not coexist in the absence of external selection. By contrast, plasmids that encoded different parMRC homologues were compatible and could coexist in the same cell in the absence of selection, with the exception of strains housing parMRCC and parMRCD combinations, which showed a minor incompatibility phenotype. In conclusion, we have provided the first direct evidence of plasmid incompatibility in Clostridium spp. and have shown experimentally that the compatibility of conjugative C. perfringens plasmids correlates with the presence of parMRC-like partitioning systems of different phylogenetic subfamilies.
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Affiliation(s)
- Thomas D Watts
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Priscilla A Johanesen
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Julian I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Vicki Adams
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia.
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Wisniewski JA, Rood JI. The Tcp conjugation system of Clostridium perfringens. Plasmid 2017; 91:28-36. [PMID: 28286218 DOI: 10.1016/j.plasmid.2017.03.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 02/24/2017] [Accepted: 03/06/2017] [Indexed: 11/18/2022]
Abstract
The Gram-positive pathogen Clostridium perfringens possesses a family of large conjugative plasmids that is typified by the tetracycline resistance plasmid pCW3. Since these plasmids may carry antibiotic resistance genes or genes encoding extracellular or sporulation-associated toxins, the conjugative transfer of these plasmids appears to be important for the epidemiology of C. perfringens-mediated diseases. Sequence analysis of members of this plasmid family identified a highly conserved 35kb region that encodes proteins with various functions, including plasmid replication and partitioning. The tcp conjugation locus also was identified in this region, initially based on low-level amino acid sequence identity to conjugation proteins from the integrative conjugative element Tn916. Genetic studies confirmed that the tcp locus is required for conjugative transfer and combined with biochemical and structural analyses have led to the development of a functional model of the Tcp conjugation apparatus. This review summarises our current understanding of the Tcp conjugation system, which is now one of the best-characterized conjugation systems in Gram-positive bacteria.
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Affiliation(s)
- Jessica A Wisniewski
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Julian I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia.
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Mehdizadeh Gohari I, Kropinski AM, Weese SJ, Whitehead AE, Parreira VR, Boerlin P, Prescott JF. NetF-producing Clostridium perfringens: Clonality and plasmid pathogenicity loci analysis. INFECTION GENETICS AND EVOLUTION 2017; 49:32-38. [PMID: 28062388 DOI: 10.1016/j.meegid.2016.12.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 12/21/2016] [Accepted: 12/23/2016] [Indexed: 10/20/2022]
Abstract
Clostridium perfringens is an important cause of foal necrotizing enteritis and canine acute hemorrhagic diarrhea. A major virulence determinant of the strains associated with these diseases appears to be a beta-sheet pore-forming toxin, NetF, encoded within a pathogenicity locus (NetF locus) on a large tcp-conjugative plasmid. Strains producing NetF also produce the putative toxin NetE, encoded within the same pathogenicity locus, as well as CPE enterotoxin and CPB2 on a second plasmid, and sometimes the putative toxin NetG within a pathogenicity locus (NetG locus) on another separate large conjugative plasmid. Previous genome sequences of two netF-positive C. perfringens showed that they both shared three similar plasmids, including the NetF/NetE and CPE/CPB2 toxins-encoding plasmids mentioned above and a putative bacteriocin-encoding plasmid. The main purpose of this study was to determine whether all NetF-producing strains share this common plasmid profile and whether their distinct NetF and CPE pathogenicity loci are conserved. To answer this question, 15 equine and 15 canine netF-positive isolates of C. perfringens were sequenced using Illumina Hiseq2000 technology. In addition, the clonal relationships among the NetF-producing strains were evaluated by core genome multilocus sequence typing (cgMLST). The data obtained showed that all NetF-producing strains have a common plasmid profile and that the defined pathogenicity loci on the plasmids are conserved in all these strains. cgMLST analysis showed that the NetF-producing C. perfringens strains belong to two distinct clonal complexes. The pNetG plasmid was absent from isolates of one of the clonal complexes, and there were minor but consistent differences in the NetF/NetE and CPE/CPB2 plasmids between the two clonal complexes.
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Affiliation(s)
| | - Andrew M Kropinski
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
| | - Scott J Weese
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
| | - Ashley E Whitehead
- Department of Veterinary Clinical and Diagnostic Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Valeria R Parreira
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
| | - Patrick Boerlin
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
| | - John F Prescott
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
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21
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Choo JM, Cheung JK, Wisniewski JA, Steer DL, Bulach DM, Hiscox TJ, Chakravorty A, Smith AI, Gell DA, Rood JI, Awad MM. The NEAT Domain-Containing Proteins of Clostridium perfringens Bind Heme. PLoS One 2016; 11:e0162981. [PMID: 27637108 PMCID: PMC5026354 DOI: 10.1371/journal.pone.0162981] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 08/31/2016] [Indexed: 12/27/2022] Open
Abstract
The ability of a pathogenic bacterium to scavenge iron from its host is important for its growth and survival during an infection. Our studies on C. perfringens gas gangrene strain JIR325, a derivative of strain 13, showed that it is capable of utilizing both human hemoglobin and ferric chloride, but not human holo-transferrin, as an iron source for in vitro growth. Analysis of the C. perfringens strain 13 genome sequence identified a putative heme acquisition system encoded by an iron-regulated surface gene region that we have named the Cht (Clostridium perfringensheme transport) locus. This locus comprises eight genes that are co-transcribed and includes genes that encode NEAT domain-containing proteins (ChtD and ChtE) and a putative sortase (Srt). The ChtD, ChtE and Srt proteins were shown to be expressed in JIR325 cells grown under iron-limited conditions and were localized to the cell envelope. Moreover, the NEAT proteins, ChtD and ChtE, were found to bind heme. Both chtDE and srt mutants were constructed, but these mutants were not defective in hemoglobin or ferric chloride utilization. They were, however, attenuated for virulence when tested in a mouse myonecrosis model, although the virulence phenotype could not be restored via complementation and, as is common with such systems, secondary mutations were identified in these strains. In summary, this study provides evidence for the functional redundancies that occur in the heme transport pathways of this life threatening pathogen.
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Affiliation(s)
- Jocelyn M. Choo
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Jackie K. Cheung
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Jessica A. Wisniewski
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - David L. Steer
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Dieter M. Bulach
- Victorian Bioinformatics Consortium, Monash University, Clayton, Victoria, Australia
| | - Thomas J. Hiscox
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Anjana Chakravorty
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - A. Ian Smith
- Victorian Bioinformatics Consortium, Monash University, Clayton, Victoria, Australia
| | - David A. Gell
- School of Medicine, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Julian I. Rood
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Milena M. Awad
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
- * E-mail:
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Mehdizadeh Gohari I, Kropinski AM, Weese SJ, Parreira VR, Whitehead AE, Boerlin P, Prescott JF. Plasmid Characterization and Chromosome Analysis of Two netF+ Clostridium perfringens Isolates Associated with Foal and Canine Necrotizing Enteritis. PLoS One 2016; 11:e0148344. [PMID: 26859667 PMCID: PMC4747519 DOI: 10.1371/journal.pone.0148344] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 01/15/2016] [Indexed: 01/01/2023] Open
Abstract
The recent discovery of a novel beta-pore-forming toxin, NetF, which is strongly associated with canine and foal necrotizing enteritis should improve our understanding of the role of type A Clostridium perfringens associated disease in these animals. The current study presents the complete genome sequence of two netF-positive strains, JFP55 and JFP838, which were recovered from cases of foal necrotizing enteritis and canine hemorrhagic gastroenteritis, respectively. Genome sequencing was done using Single Molecule, Real-Time (SMRT) technology-PacBio and Illumina Hiseq2000. The JFP55 and JFP838 genomes include a single 3.34 Mb and 3.53 Mb chromosome, respectively, and both genomes include five circular plasmids. Plasmid annotation revealed that three plasmids were shared by the two newly sequenced genomes, including a NetF/NetE toxins-encoding tcp-conjugative plasmid, a CPE/CPB2 toxins-encoding tcp-conjugative plasmid and a putative bacteriocin-encoding plasmid. The putative beta-pore-forming toxin genes, netF, netE and netG, were located in unique pathogenicity loci on tcp-conjugative plasmids. The C. perfringens JFP55 chromosome carries 2,825 protein-coding genes whereas the chromosome of JFP838 contains 3,014 protein-encoding genes. Comparison of these two chromosomes with three available reference C. perfringens chromosome sequences identified 48 (~247 kb) and 81 (~430 kb) regions unique to JFP55 and JFP838, respectively. Some of these divergent genomic regions in both chromosomes are phage- and plasmid-related segments. Sixteen of these unique chromosomal regions (~69 kb) were shared between the two isolates. Five of these shared regions formed a mosaic of plasmid-integrated segments, suggesting that these elements were acquired early in a clonal lineage of netF-positive C. perfringens strains. These results provide significant insight into the basis of canine and foal necrotizing enteritis and are the first to demonstrate that netF resides on a large and unique plasmid-encoded locus.
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Affiliation(s)
| | - Andrew M. Kropinski
- Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Scott J. Weese
- Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Valeria R. Parreira
- Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Ashley E. Whitehead
- Department of Veterinary Clinical and Diagnostic Sciences, University of Calgary, Calgary, Alberta, CSB 101E, Canada
| | - Patrick Boerlin
- Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - John F. Prescott
- Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
- * E-mail:
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Wisniewski JA, Traore DA, Bannam TL, Lyras D, Whisstock JC, Rood JI. TcpM: a novel relaxase that mediates transfer of large conjugative plasmids from Clostridium perfringens. Mol Microbiol 2015; 99:884-96. [PMID: 26560080 DOI: 10.1111/mmi.13270] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2015] [Indexed: 11/30/2022]
Abstract
Conjugative transfer of toxin and antibiotic resistance plasmids in Clostridium perfringens is mediated by the tcp conjugation locus. Surprisingly, neither a relaxase gene nor an origin of transfer (oriT) has been identified on these plasmids, which are typified by the 47 kb tetracycline resistance plasmid pCW3. The tcpM gene (previously called intP) encodes a potential tyrosine recombinase that was postulated to be an atypical relaxase. Mutagenesis and complementation studies showed that TcpM was required for wild-type transfer of pCW3 and that a tyrosine residue, Y259, was essential for TcpM activity, which was consistent with the need for a relaxase-mediated hydrophilic attack at the oriT site. Other catalytic residues conserved in tyrosine recombinases were not required for TcpM activity, suggesting that TcpM was not a site-specific recombinase. Mobilization studies led to the identification of the oriT site, which was located in the 391 bp intergenic region upstream of tcpM. The oriT site was localized to a 150 bp region, and gel mobility shift studies showed that TcpM could bind to this region. Based on these studies we postulate that conjugative transfer of pCW3 involves the atypical relaxase TcpM binding to and processing the oriT site to initiate plasmid transfer.
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Affiliation(s)
- Jessica A Wisniewski
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.,Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Daouda A Traore
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, 3800, Australia
| | - Trudi L Bannam
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.,Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Dena Lyras
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.,Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - James C Whisstock
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, 3800, Australia
| | - Julian I Rood
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.,Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
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Park M, Deck J, Foley SL, Nayak R, Songer JG, Seibel JR, Khan SA, Rooney AP, Hecht DW, Rafii F. Diversity of Clostridium perfringens isolates from various sources and prevalence of conjugative plasmids. Anaerobe 2015; 38:25-35. [PMID: 26608548 DOI: 10.1016/j.anaerobe.2015.11.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 10/27/2015] [Accepted: 11/03/2015] [Indexed: 11/27/2022]
Abstract
Clostridium perfringens is an important pathogen, causing food poisoning and other mild to severe infections in humans and animals. Some strains of C. perfringens contain conjugative plasmids, which may carry antimicrobial resistance and toxin genes. We studied genomic and plasmid diversity of 145 C. perfringens type A strains isolated from soils, foods, chickens, clinical samples, and domestic animals (porcine, bovine and canine), from different geographic areas in the United States between 1994 and 2006, using multiple-locus variable-number tandem repeat analysis (MLVA) and/or pulsed-field gel electrophoresis (PFGE). MLVA detected the genetic diversity in a majority of the isolates. PFGE, using SmaI and KspI, confirmed the MLVA results but also detected differences among the strains that could not be differentiated by MLVA. All of the PFGE profiles of the strains were different, except for a few of the epidemiologically related strains, which were identical. The PFGE profiles of strains isolated from the same domestic animal species were clustered more closely with each other than with other strains. However, a variety of C. perfringens strains with distinct genetic backgrounds were found among the clinical isolates. Variation was also observed in the size and number of plasmids in the strains. Primers for the internal fragment of a conjugative tcpH gene of C. perfringens plasmid pCPF4969 amplified identical size fragments from a majority of strains tested; and this gene hybridized to the various-sized plasmids of these strains. The sequences of the PCR-amplified tcpH genes from 12 strains showed diversity among the tcpH genes. Regardless of the sources of the isolates, the genetic diversity of C. perfringens extended to the plasmids carrying conjugative genes.
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Affiliation(s)
- Miseon Park
- Division of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR 72079, USA
| | - Joanna Deck
- Division of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR 72079, USA
| | - Steven L Foley
- Division of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR 72079, USA
| | - Rajesh Nayak
- Division of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR 72079, USA
| | | | | | - Saeed A Khan
- Division of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR 72079, USA
| | - Alejandro P Rooney
- Crop Protection Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, Peoria, IL 61604, USA
| | - David W Hecht
- Division of Infectious Diseases, Loyola University Medical Center, Maywood, IL 60126, USA
| | - Fatemeh Rafii
- Division of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR 72079, USA.
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Hassan KA, Elbourne LD, Tetu SG, Melville SB, Rood JI, Paulsen IT. Genomic analyses of Clostridium perfringens isolates from five toxinotypes. Res Microbiol 2015; 166:255-63. [DOI: 10.1016/j.resmic.2014.10.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/29/2014] [Accepted: 10/07/2014] [Indexed: 10/24/2022]
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Adams V, Watts TD, Bulach DM, Lyras D, Rood JI. Plasmid partitioning systems of conjugative plasmids from Clostridium perfringens. Plasmid 2015; 80:90-6. [PMID: 25929175 DOI: 10.1016/j.plasmid.2015.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 04/05/2015] [Accepted: 04/13/2015] [Indexed: 11/15/2022]
Abstract
Many pathogenic strains of Clostridium perfringens carry several highly similar toxin or antibiotic resistance plasmids that have 35 to 40 kb of very closely related syntenous sequences, including regions that carry the genes encoding conjugative transfer, plasmid replication and plasmid maintenance functions. Key questions are how are these closely related plasmids stably maintained in the same cell and what is the basis for plasmid incompatibility in C. perfringens. Comparative analysis of the Rep proteins encoded by these plasmids suggested that this protein was not the basis for plasmid incompatibility since plasmids carried in a single strain often encoded an almost identical Rep protein. These plasmids all carried a similar, but not identical, parMRC plasmid partitioning locus. Phylogenetic analysis of the deduced ParM proteins revealed that these proteins could be divided into ten separate groups. Importantly, in every strain that carried more than one of these plasmids, the respective ParM proteins were from different phylogenetic groups. Similar observations were made from the analysis of phylogenetic trees of the ParR proteins and the parC loci. These findings provide evidence that the basis for plasmid incompatibility in the conjugative toxin and resistance plasmid family from C. perfringens resides in subtle differences in the parMRC plasmid partitioning loci carried by these plasmids.
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Affiliation(s)
- Vicki Adams
- Department of Microbiology, Monash University, Clayton, Melbourne, Victoria, 3800, Australia
| | - Thomas D Watts
- Department of Microbiology, Monash University, Clayton, Melbourne, Victoria, 3800, Australia
| | - Dieter M Bulach
- Department of Microbiology, Monash University, Clayton, Melbourne, Victoria, 3800, Australia; Victorian Bioinformatics Consortium, Monash University, Clayton, Melbourne, Victoria, 3800, Australia; Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative, Carlton, Melbourne, Victoria, 3053, Australia
| | - Dena Lyras
- Department of Microbiology, Monash University, Clayton, Melbourne, Victoria, 3800, Australia
| | - Julian I Rood
- Department of Microbiology, Monash University, Clayton, Melbourne, Victoria, 3800, Australia.
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Uzal FA, Freedman JC, Shrestha A, Theoret JR, Garcia J, Awad MM, Adams V, Moore RJ, Rood JI, McClane BA. Towards an understanding of the role of Clostridium perfringens toxins in human and animal disease. Future Microbiol 2015; 9:361-77. [PMID: 24762309 DOI: 10.2217/fmb.13.168] [Citation(s) in RCA: 276] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Clostridium perfringens uses its arsenal of >16 toxins to cause histotoxic and intestinal infections in humans and animals. It has been unclear why this bacterium produces so many different toxins, especially since many target the plasma membrane of host cells. However, it is now established that C. perfringens uses chromosomally encoded alpha toxin (a phospholipase C) and perfringolysin O (a pore-forming toxin) during histotoxic infections. In contrast, this bacterium causes intestinal disease by employing toxins encoded by mobile genetic elements, including C. perfringens enterotoxin, necrotic enteritis toxin B-like, epsilon toxin and beta toxin. Like perfringolysin O, the toxins with established roles in intestinal disease form membrane pores. However, the intestinal disease-associated toxins vary in their target specificity, when they are produced (sporulation vs vegetative growth), and in their sensitivity to intestinal proteases. Producing many toxins with diverse characteristics likely imparts virulence flexibility to C. perfringens so it can cause an array of diseases.
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Affiliation(s)
- Francisco A Uzal
- California Animal Health & Food Safety Laboratory System, University of California-Davis, CA, USA
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28
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Revitt-Mills SA, Rood JI, Adams V. Clostridium perfringens extracellular toxins and enzymes: 20 and counting. MICROBIOLOGY AUSTRALIA 2015. [DOI: 10.1071/ma15039] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Clostridium perfringens is a Gram-positive, anaerobic bacterium that is widely distributed in the environment; it is found in soil and commonly inhabits the gastrointestinal tract of humans and animals1,2. The ubiquitous nature of this bacterium has resulted in it becoming a major cause of histotoxic and enteric diseases3. The success of C. perfringens as both a pathogen and a commensal bacterium lies in its ability to produce a large number of potent toxins and extracellular enzymes4. This diverse toxin repertoire results in a broad range of diseases including gas gangrene, various enterotoxaemias, food poisoning and necrotic enteritis4–6. Since 2007, six new toxins have been identified, adding to the ever-increasing range of potential C. perfringens virulence determinants. This paper briefly reviews the plethora of toxins and extracellular enzymes produced by C. perfringens, highlighting their importance in disease and strain classification as well as introducing the latest additions to the ever increasing C. perfringens toxin family.
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Two novel membrane proteins, TcpD and TcpE, are essential for conjugative transfer of pCW3 in Clostridium perfringens. J Bacteriol 2014; 197:774-81. [PMID: 25488300 DOI: 10.1128/jb.02466-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The anaerobic pathogen Clostridium perfringens encodes either toxin genes or antibiotic resistance determinants on a unique family of conjugative plasmids that have a novel conjugation region, the tcp locus. Studies of the paradigm conjugative plasmid from C. perfringens, the 47-kb tetracycline resistance plasmid pCW3, have identified several tcp-encoded proteins that are involved in conjugative transfer and form part of the transfer apparatus. In this study, the role of the conserved hypothetical proteins TcpD, TcpE, and TcpJ was examined. Mutation and complementation analyses showed that TcpD and TcpE were essential for the conjugative transfer of pCW3, whereas TcpJ was not required. To analyze the TcpD and TcpE proteins in C. perfringens, functional hemagglutinin (HA)-tagged derivatives were constructed. Western blots showed that TcpD and TcpE localized to the cell envelope fraction independently of the presence of other pCW3-encoded proteins. Finally, examination of the subcellular localization of TcpD and TcpE by immunofluorescence showed that these proteins were concentrated at both poles of C. perfringens donor cells, where they are postulated to form essential components of the multiprotein complex that comprises the transfer apparatus.
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30
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Abstract
Plasmid-encoded virulence factors are important in the pathogenesis of diseases caused by spore-forming bacteria. Unlike many other bacteria, the most common virulence factors encoded by plasmids in Clostridium and Bacillus species are protein toxins. Clostridium perfringens causes several histotoxic and enterotoxin diseases in both humans and animals and produces a broad range of toxins, including many pore-forming toxins such as C. perfringens enterotoxin, epsilon-toxin, beta-toxin, and NetB. Genetic studies have led to the determination of the role of these toxins in disease pathogenesis. The genes for these toxins are generally carried on large conjugative plasmids that have common core replication, maintenance, and conjugation regions. There is considerable functional information available about the unique tcp conjugation locus carried by these plasmids, but less is known about plasmid maintenance. The latter is intriguing because many C. perfringens isolates stably maintain up to four different, but closely related, toxin plasmids. Toxin genes may also be plasmid-encoded in the neurotoxic clostridia. The tetanus toxin gene is located on a plasmid in Clostridium tetani, but the botulinum toxin genes may be chromosomal, plasmid-determined, or located on bacteriophages in Clostridium botulinum. In Bacillus anthracis it is well established that virulence is plasmid determined, with anthrax toxin genes located on pXO1 and capsule genes on a separate plasmid, pXO2. Orthologs of these plasmids are also found in other members of the Bacillus cereus group such as B. cereus and Bacillus thuringiensis. In B. thuringiensis these plasmids may carry genes encoding one or more insecticidal toxins.
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Freedman JC, Theoret JR, Wisniewski JA, Uzal FA, Rood JI, McClane BA. Clostridium perfringens type A-E toxin plasmids. Res Microbiol 2014; 166:264-79. [PMID: 25283728 DOI: 10.1016/j.resmic.2014.09.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 09/04/2014] [Accepted: 09/09/2014] [Indexed: 12/26/2022]
Abstract
Clostridium perfringens relies upon plasmid-encoded toxin genes to cause intestinal infections. These toxin genes are associated with insertion sequences that may facilitate their mobilization and transfer, giving rise to new toxin plasmids with common backbones. Most toxin plasmids carry a transfer of clostridial plasmids locus mediating conjugation, which likely explains the presence of similar toxin plasmids in otherwise unrelated C. perfringens strains. The association of many toxin genes with insertion sequences and conjugative plasmids provides virulence flexibility when causing intestinal infections. However, incompatibility issues apparently limit the number of toxin plasmids maintained by a single cell.
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Affiliation(s)
- John C Freedman
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - James R Theoret
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | | - Francisco A Uzal
- California Animal Health and Food Safety Laboratory, San Bernadino Branch, School of Veterinary Medicine, University of California-Davis, San Bernadino, CA, USA
| | - Julian I Rood
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Bruce A McClane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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32
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Alves GG, Machado de Ávila RA, Chávez-Olórtegui CD, Lobato FCF. Clostridium perfringens epsilon toxin: the third most potent bacterial toxin known. Anaerobe 2014; 30:102-7. [PMID: 25234332 DOI: 10.1016/j.anaerobe.2014.08.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/18/2014] [Accepted: 08/19/2014] [Indexed: 01/24/2023]
Abstract
Epsilon toxin (ETX) is produced by Clostridium perfringens type B and D strains and causes enterotoxemia, a highly lethal disease with major impacts on the farming of domestic ruminants, particularly sheep. ETX belongs to the aerolysin-like pore-forming toxin family. Although ETX has striking similarities to other toxins in this family, ETX is often more potent, with an LD50 of 100 ng/kg in mice. Due to this high potency, ETX is considered as a potential bioterrorism agent and has been classified as a category B biological agent by the Centers for Disease Control and Prevention (CDC) of the United States. The protoxin is converted to an active toxin through proteolytic cleavage performed by specific proteases. ETX is absorbed and acts locally in the intestines then subsequently binds to and causes lesions in other organs, including the kidneys, lungs and brain. The importance of this toxin for veterinary medicine and its possible use as a biological weapon have drawn the attention of researchers and have led to a large number of studies investigating ETX. The aim of the present work is to review the existing knowledge on ETX from C. perfringens type B and D.
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Affiliation(s)
- Guilherme Guerra Alves
- Veterinary School, Universidade Federal de Minas Gerais (UFMG), Antônio Carlos Avenue, 6627, Belo Horizonte, MG CEP 31.270-901, Brazil.
| | | | - Carlos Delfin Chávez-Olórtegui
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Antônio Carlos Avenue, 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - Francisco Carlos Faria Lobato
- Veterinary School, Universidade Federal de Minas Gerais (UFMG), Antônio Carlos Avenue, 6627, Belo Horizonte, MG CEP 31.270-901, Brazil.
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33
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Garcia JP, Giannitti F, Finnie JW, Manavis J, Beingesser J, Adams V, Rood JI, Uzal FA. Comparative neuropathology of ovine enterotoxemia produced by Clostridium perfringens type D wild-type strain CN1020 and its genetically modified derivatives. Vet Pathol 2014; 52:465-75. [PMID: 24964921 DOI: 10.1177/0300985814540543] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Clostridium perfringens type D causes enterotoxemia in sheep and goats. The disease is mediated by epsilon toxin (ETX), which affects the cerebrovascular endothelium, increasing vascular permeability and leading to cerebral edema. In the present study, we compared the distribution and severity of the cerebrovascular changes induced in lambs by C. perfringens type D strain CN1020, its isogenic etx null mutant, and the ETX-producing complemented mutant. We also applied histochemical and immunohistochemical markers to further characterize the brain lesions induced by ETX. Both ETX-producing strains induced extensive cerebrovascular damage that did not differ significantly between each other in nature, neuroanatomic distribution, or severity. By contrast, lambs inoculated with the etx mutant or sterile, nontoxic culture medium did not develop detectable brain lesions, confirming that the neuropathologic effects observed in these infections are dependent on ETX production. Lambs treated with the wild-type and complemented strains showed perivascular and mural vascular edema, as well as serum albumin extravasation, particularly severe in the cerebral white matter, midbrain, medulla oblongata, and cerebellum. Brains of animals inoculated with the ETX-producing strains showed decreased expression of glial fibrillary acidic protein and increased expression of aquaporin-4 in the end-feet processes of the astrocytes around blood vessels. Early axonal injury was demonstrated with anti-amyloid precursor protein immunohistochemistry. Perivascular accumulation of macrophages/microglia with intracytoplasmic albumin globules was also observed in these animals. This study demonstrates that ETX is responsible for the major cerebrovascular changes in C. perfringens type D-induced disease.
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Affiliation(s)
- J P Garcia
- California Animal Health and Food Safety Laboratory System-San Bernardino Branch, School of Veterinary Medicine, University of California, Davis, San Bernardino, CA, USA These authors contributed equally to the research and are joint first authors
| | - F Giannitti
- California Animal Health and Food Safety Laboratory System-Davis Branch, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA These authors contributed equally to the research and are joint first authors
| | - J W Finnie
- SA Pathology, Hanson Institute Centre for Neurological Diseases and School of Veterinary Science, University of Adelaide, Adelaide, SA, Australia
| | - J Manavis
- SA Pathology, Hanson Institute Centre for Neurological Diseases and School of Veterinary Science, University of Adelaide, Adelaide, SA, Australia
| | - J Beingesser
- California Animal Health and Food Safety Laboratory System-San Bernardino Branch, School of Veterinary Medicine, University of California, Davis, San Bernardino, CA, USA
| | - V Adams
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - J I Rood
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - F A Uzal
- California Animal Health and Food Safety Laboratory System-San Bernardino Branch, School of Veterinary Medicine, University of California, Davis, San Bernardino, CA, USA
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Abstract
In both humans and animals, Clostridium perfringens is an important cause of histotoxic infections and diseases originating in the intestines, such as enteritis and enterotoxemia. The virulence of this Gram-positive, anaerobic bacterium is heavily dependent upon its prolific toxin-producing ability. Many of the ∼16 toxins produced by C. perfringens are encoded by large plasmids that range in size from ∼45 kb to ∼140 kb. These plasmid-encoded toxins are often closely associated with mobile elements. A C. perfringens strain can carry up to three different toxin plasmids, with a single plasmid carrying up to three distinct toxin genes. Molecular Koch's postulate analyses have established the importance of several plasmid-encoded toxins when C. perfringens disease strains cause enteritis or enterotoxemias. Many toxin plasmids are closely related, suggesting a common evolutionary origin. In particular, most toxin plasmids and some antibiotic resistance plasmids of C. perfringens share an ∼35-kb region containing a Tn916-related conjugation locus named tcp (transfer of clostridial plasmids). This tcp locus can mediate highly efficient conjugative transfer of these toxin or resistance plasmids. For example, conjugative transfer of a toxin plasmid from an infecting strain to C. perfringens normal intestinal flora strains may help to amplify and prolong an infection. Therefore, the presence of toxin genes on conjugative plasmids, particularly in association with insertion sequences that may mobilize these toxin genes, likely provides C. perfringens with considerable virulence plasticity and adaptability when it causes diseases originating in the gastrointestinal tract.
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35
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Popoff MR, Bouvet P. Genetic characteristics of toxigenic Clostridia and toxin gene evolution. Toxicon 2013; 75:63-89. [DOI: 10.1016/j.toxicon.2013.05.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 04/30/2013] [Accepted: 05/08/2013] [Indexed: 12/14/2022]
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Stoughton W, Poole T, Kuskie K, Liu M, Bishop K, Morrissey A, Takai S, Cohen N. Transfer of the Virulence-Associated Protein A-Bearing Plasmid between Field Strains of Virulent and Avirulent Rhodococcus equi. J Vet Intern Med 2013; 27:1555-62. [DOI: 10.1111/jvim.12210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- W. Stoughton
- Department of Large Animal Clinical Sciences; Texas A&M University; College Station TX
| | - T. Poole
- Southern Plains Agricultural Research Center; Agricultural Research Service; U.S. Department of Agriculture; College Station TX
| | - K. Kuskie
- Department of Large Animal Clinical Sciences; Texas A&M University; College Station TX
| | - M. Liu
- Department of Large Animal Clinical Sciences; Texas A&M University; College Station TX
| | - K. Bishop
- Department of Large Animal Clinical Sciences; Texas A&M University; College Station TX
| | - A. Morrissey
- Department of Large Animal Clinical Sciences; Texas A&M University; College Station TX
| | - S. Takai
- School of Veterinary Medicine and Animal Sciences; Kitasoto University; Towada Aomori Japan
| | - N. Cohen
- Department of Large Animal Clinical Sciences; Texas A&M University; College Station TX
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Epsilon toxin is essential for the virulence of Clostridium perfringens type D infection in sheep, goats, and mice. Infect Immun 2013; 81:2405-14. [PMID: 23630957 DOI: 10.1128/iai.00238-13] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clostridium perfringens type D causes disease in sheep, goats, and other ruminants. Type D isolates produce, at minimum, alpha and epsilon (ETX) toxins, but some express up to five different toxins, raising questions about which toxins are necessary for the virulence of these bacteria. We evaluated the contribution of ETX to C. perfringens type D pathogenicity in an intraduodenal challenge model in sheep, goats, and mice using a virulent C. perfringens type D wild-type strain (WT), an isogenic ETX null mutant (etx mutant), and a strain where the etx mutation has been reversed (etx complemented). All sheep and goats, and most mice, challenged with the WT isolate developed acute clinical disease followed by death in most cases. Sheep developed various gross and/or histological changes that included edema of brain, lungs, and heart as well as hydropericardium. Goats developed various effects, including necrotizing colitis, pulmonary edema, and hydropericardium. No significant gross or histological abnormalities were observed in any mice infected with the WT strain. All sheep, goats, and mice challenged with the isogenic etx mutant remained clinically healthy for ≥24 h, and no gross or histological abnormalities were observed in those animals. Complementation of etx knockout restored virulence; most goats, sheep, and mice receiving this complemented mutant developed clinical and pathological changes similar to those observed in WT-infected animals. These results indicate that ETX is necessary for type D isolates to induce disease, supporting a key role for this toxin in type D disease pathogenesis.
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Identification of accessory genome regions in poultry Clostridium perfringens isolates carrying the netB plasmid. J Bacteriol 2013; 195:1152-66. [PMID: 23292780 DOI: 10.1128/jb.01032-12] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Necrotic enteritis (NE) is an economically important disease of poultry caused by certain Clostridium perfringens type A strains. NE pathogenesis involves the NetB toxin, which is encoded on a large conjugative plasmid within a 42-kb pathogenicity locus. Recent multilocus sequence type (MLST) studies have identified two predominant NE-associated clonal groups, suggesting that host genes are also involved in NE pathogenesis. We used microarray comparative genomic hybridization (CGH) to assess the gene content of 54 poultry isolates from birds that were healthy or that suffered from NE. A total of 400 genes were variably present among the poultry isolates and nine nonpoultry strains, many of which had putative functions related to nutrient uptake and metabolism and cell wall and capsule biosynthesis. The variable genes were organized into 142 genomic regions, 49 of which contained genes significantly associated with netB-positive isolates. These regions included three previously identified NE-associated loci as well as several apparent fitness-related loci, such as a carbohydrate ABC transporter, a ferric-iron siderophore uptake system, and an adhesion locus. Additional loci were related to plasmid maintenance. Cluster analysis of the CGH data grouped all of the netB-positive poultry isolates into two major groups, separated according to two prevalent clonal groups based on MLST analysis. This study identifies chromosomal loci associated with netB-positive poultry strains, suggesting that the chromosomal background can confer a selective advantage to NE-causing strains, possibly through mechanisms involving iron acquisition, carbohydrate metabolism, and plasmid maintenance.
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Leal É, Villanova FE, Lin W, Hu F, Liu Q, Liu Y, Cui S. Interclade recombination in porcine parvovirus strains. J Gen Virol 2012; 93:2692-2704. [DOI: 10.1099/vir.0.045765-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
Abstract
A detailed analysis of the Ns1/Vp1Vp2 genome region of the porcine parvovirus (PPV) strains isolated from vaccinated animals was performed. We found many inconsistencies in the phylogenetic trees of these viral isolates, such as low statistical support and strains with long branches in the phylogenetic trees. Thus, we used distance-based and phylogenetic methods to distinguish de facto recombinants from spurious recombination signals. We found a mosaic virus in which the Ns1 gene was acquired from one PPV clade and the Vp1Vp2 gene was acquired from a distinct phylogenetic clade. We also described the interclade mosaic structure of the Vp1Vp2 gene of a reference strain. If recombination is an adaptive mechanism over the course of PPV evolution, we would likely observe increasing numbers of chimeric strains over time. However, when the PPV sequences isolated from 1964 to 2011 were analysed, only two chimeric strains were detected. Thus, PPV recombination is an independent event, resulting from close contact between animals housed in high-density conditions.
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Affiliation(s)
- Élcio Leal
- Federal University of Pará, Belém, Brazil
| | | | - Wencheng Lin
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of CAAS, Heilongjiang, PR China
| | - Feng Hu
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of CAAS, Heilongjiang, PR China
| | - Qinfang Liu
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of CAAS, Heilongjiang, PR China
| | - Yebing Liu
- China Institute of Veterinary Drug Control, Beijing 100081, PR China
| | - Shangjin Cui
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of CAAS, Heilongjiang, PR China
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40
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Genotypic and phenotypic characterization of Clostridium perfringens isolates from Darmbrand cases in post-World War II Germany. Infect Immun 2012; 80:4354-63. [PMID: 23027533 DOI: 10.1128/iai.00818-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clostridium perfringens type C strains are the only non-type-A isolates that cause human disease. They are responsible for enteritis necroticans, which was termed Darmbrand when occurring in post-World War II Germany. Darmbrand strains were initially classified as type F because of their exceptional heat resistance but later identified as type C strains. Since only limited information exists regarding Darmbrand strains, this study genetically and phenotypically characterized seven 1940s era Darmbrand-associated strains. Results obtained indicated the following. (i) Five of these Darmbrand isolates belong to type C, carry beta-toxin (cpb) and enterotoxin (cpe) genes on large plasmids, and express both beta-toxin and enterotoxin. The other two isolates are cpe-negative type A. (ii) All seven isolates produce highly heat-resistant spores with D(100) values (the time that a culture must be kept at 100°C to reduce its viability by 90%) of 7 to 40 min. (iii) All of the isolates surveyed produce the same variant small acid-soluble protein 4 (Ssp4) made by type A food poisoning isolates with a chromosomal cpe gene that also produce extremely heat-resistant spores. (iv) The Darmbrand isolates share a genetic background with type A chromosomal-cpe-bearing isolates. Finally, it was shown that both the cpe and cpb genes can be mobilized in Darmbrand isolates. These results suggest that C. perfringens type A and C strains that cause human food-borne illness share a spore heat resistance mechanism that likely favors their survival in temperature-abused food. They also suggest possible evolutionary relationships between Darmbrand strains and type A strains carrying a chromosomal cpe gene.
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Harkness JM, Li J, McClane BA. Identification of a lambda toxin-negative Clostridium perfringens strain that processes and activates epsilon prototoxin intracellularly. Anaerobe 2012; 18:546-52. [PMID: 22982043 DOI: 10.1016/j.anaerobe.2012.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 07/23/2012] [Accepted: 09/03/2012] [Indexed: 01/06/2023]
Abstract
Clostridium perfringens type B and D strains produce epsilon toxin (ETX), which is one of the most potent clostridial toxins and is involved in enteritis and enterotoxemias of domestic animals. ETX is produced initially as an inactive prototoxin that is typically then secreted and processed by intestinal proteases or possibly, for some strains, lambda toxin. During the current work a unique C. perfringens strain was identified that intracellularly processes epsilon prototoxin to an active form capable of killing MDCK cells. This activated toxin is not secreted but instead is apparently released upon lysis of bacterial cells entering stationary phase. These findings broaden understanding of the pathogenesis of type B and D infections by identifying a new mechanism of ETX activation.
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Affiliation(s)
- Justine M Harkness
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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Bantwal R, Bannam TL, Porter CJ, Quinsey NS, Lyras D, Adams V, Rood JI. The peptidoglycan hydrolase TcpG is required for efficient conjugative transfer of pCW3 in Clostridium perfringens. Plasmid 2012; 67:139-47. [PMID: 22244927 DOI: 10.1016/j.plasmid.2011.12.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 12/30/2011] [Indexed: 10/14/2022]
Abstract
Peptidoglycan hydrolases that are specifically associated with bacterial conjugation systems are postulated to facilitate the assembly of the transfer apparatus by creating a temporally and spatially controlled local opening in the peptidoglycan layer. To date little is known about the role of such enzymes in conjugation systems from Gram-positive bacteria. Conjugative plasmids from the Gram-positive pathogen Clostridium perfringens all encode two putative peptidoglycan hydrolases, TcpG and TcpI, within the conserved tcp transfer locus. Mutation and complementation analysis was used to demonstrate that a functional tcpG gene, but not the tcpI gene, was required for efficient conjugative transfer of pCW3. Furthermore, it was also shown that each of the two predicted catalytic domains of TcpG was functional in C. perfringens and that the predicted catalytic site residues, E-111, D-136, and C-238, present within these functional domains were required for optimal TcpG function. Escherichia coli cells producing TcpG demonstrated a distinctive autoagglutination phenotype and partially purified recombinant TcpG protein was shown to have peptidoglycan hydrolase-like activity on cognate peptidoglycan from C. perfringens. Based on these results it is suggested that TcpG is a functional peptidoglycan hydrolase that is required for efficient conjugative transfer of pCW3, presumably by facilitating the penetration of the pCW3 translocation complex through the cell wall.
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Affiliation(s)
- Radhika Bantwal
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
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Epsilon-toxin production by Clostridium perfringens type D strain CN3718 is dependent upon the agr operon but not the VirS/VirR two-component regulatory system. mBio 2011; 2:mBio.00275-11. [PMID: 22167225 PMCID: PMC3236063 DOI: 10.1128/mbio.00275-11] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clostridium perfringens type B and D strains cause enterotoxemias and enteritis in livestock after proliferating in the intestines and producing epsilon-toxin (ETX), alpha-toxin (CPA), and, usually, perfringolysin O (PFO). Although ETX is one of the most potent bacterial toxins, the regulation of ETX production by type B or D strains remains poorly understood. The present work determined that the type D strain CN3718 upregulates production of ETX upon close contact with enterocyte-like Caco-2 cells. This host cell-induced upregulation of ETX expression was mediated at the transcriptional level. Using an isogenic agrB null mutant and complemented strain, the agr operon was shown to be required when CN3718 produces ETX in broth culture or, via a secreted signal consistent with a quorum-sensing (QS) effect, upregulates ETX production upon contact with host cells. These findings provide the first insights into the regulation of ETX production, as well as additional evidence that the Agr-like QS system functions as a global regulator of C. perfringens toxin production. Since it was proposed previously that the Agr-like QS system regulates C. perfringens gene expression via the VirS/VirR two-component regulatory system, an isogenic virR null mutant of CN3718 was constructed to evaluate the importance of VirS/VirR for CN3718 toxin production. This mutation affected production of CPA and PFO, but not ETX, by CN3718. These results provide the first indication that C. perfringens toxin expression regulation by the Agr-like quorum-sensing system may not always act via the VirS/VirR two-component system. IMPORTANCE Mechanisms by which Clostridium perfringens type B and D strains regulate production of epsilon-toxin (ETX), a CDC class B select toxin, are poorly understood. Production of several other toxins expressed by C. perfringens is wholly or partially regulated by both the Agr-like quorum-sensing (QS) system and the VirS/VirR two-component regulatory system, so the present study tested whether ETX expression by type D strain CN3718 also requires these regulatory systems. The agr operon was shown to be essential for signaling CN3718 to produce ETX in broth culture or to upregulate ETX production upon close contact with enterocyte-like Caco-2 cells, which may have pathogenic relevance since ETX is produced intestinally. However, ETX production remained at wild-type levels after inactivation of the VirS/VirR system in CN3718. These findings provide the first information regarding regulation of ETX production and suggest Agr-like QS toxin production regulation in C. perfringens does not always require the VirS/VirR system.
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Necrotic enteritis-derived Clostridium perfringens strain with three closely related independently conjugative toxin and antibiotic resistance plasmids. mBio 2011; 2:mBio.00190-11. [PMID: 21954306 PMCID: PMC3181468 DOI: 10.1128/mbio.00190-11] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The pathogenesis of avian necrotic enteritis involves NetB, a pore-forming toxin produced by virulent avian isolates of Clostridium perfringens type A. To determine the location and mobility of the netB structural gene, we examined a derivative of the tetracycline-resistant necrotic enteritis strain EHE-NE18, in which netB was insertionally inactivated by the chloramphenicol and thiamphenicol resistance gene catP. Both tetracycline and thiamphenicol resistance could be transferred either together or separately to a recipient strain in plate matings. The separate transconjugants could act as donors in subsequent matings, which demonstrated that the tetracycline resistance determinant and the netB gene were present on different conjugative elements. Large plasmids were isolated from the transconjugants and analyzed by high-throughput sequencing. Analysis of the resultant data indicated that there were actually three large conjugative plasmids present in the original strain, each with its own toxin or antibiotic resistance locus. Each plasmid contained a highly conserved 40-kb region that included plasmid replication and transfer regions that were closely related to the 47-kb conjugative tetracycline resistance plasmid pCW3 from C. perfringens. The plasmids were as follows: (i) a conjugative 49-kb tetracycline resistance plasmid that was very similar to pCW3, (ii) a conjugative 82-kb plasmid that contained the netB gene and other potential virulence genes, and (iii) a 70-kb plasmid that carried the cpb2 gene, which encodes a different pore-forming toxin, beta2 toxin. The anaerobic bacterium Clostridium perfringens can cause an avian gastrointestinal disease known as necrotic enteritis. Disease pathogenesis is not well understood, although the plasmid-encoded pore-forming toxin NetB, is an important virulence factor. In this work, we have shown that the plasmid that carries the netB gene is conjugative and has a 40-kb region that is very similar to replication and transfer regions found within each of the sequenced conjugative plasmids from C. perfringens. We also showed that this strain contained two additional large plasmids that were also conjugative and carried a similar 40-kb region. One of these plasmids encoded beta2 toxin, and the other encoded tetracycline resistance. To our knowledge, this is the first report of a bacterial strain that carries three closely related but different independently conjugative plasmids. These results have significant implications for our understanding of the transmission of virulence and antibiotic resistance genes in pathogenic bacteria.
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Bokori-Brown M, Savva CG, Fernandes da Costa SP, Naylor CE, Basak AK, Titball RW. Molecular basis of toxicity of Clostridium perfringens epsilon toxin. FEBS J 2011; 278:4589-601. [PMID: 21518257 DOI: 10.1111/j.1742-4658.2011.08140.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Clostridium perfringens ε-toxin is produced by toxinotypes B and D strains. The toxin is the aetiological agent of dysentery in newborn lambs but is also associated with enteritis and enterotoxaemia in goats, calves and foals. It is considered to be a potential biowarfare or bioterrorism agent by the US Government Centers for Disease Control and Prevention. The relatively inactive 32.9 kDa prototoxin is converted to active mature toxin by proteolytic cleavage, either by digestive proteases of the host, such as trypsin and chymotrypsin, or by C. perfringens λ-protease. In vivo, the toxin appears to target the brain and kidneys, but relatively few cell lines are susceptible to the toxin, and most work has been carried out using Madin-Darby canine kidney (MDCK) cells. The binding of ε-toxin to MDCK cells and rat synaptosomal membranes is associated with the formation of a stable, high molecular weight complex. The crystal structure of ε-toxin reveals similarity to aerolysin from Aeromonas hydrophila, parasporin-2 from Bacillus thuringiensis and a lectin from Laetiporus sulphureus. Like these toxins, ε-toxin appears to form heptameric pores in target cell membranes. The exquisite specificity of the toxin for specific cell types suggests that it binds to a receptor found only on these cells.
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Affiliation(s)
- Monika Bokori-Brown
- Biosciences, College of Life and Environmental Sciences, University of Exeter, UK
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Characterization of toxin plasmids in Clostridium perfringens type C isolates. Infect Immun 2010; 78:4860-9. [PMID: 20823204 DOI: 10.1128/iai.00715-10] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Clostridium perfringens type C isolates cause enteritis necroticans in humans or necrotizing enteritis and enterotoxemia in domestic animals. Type C isolates always produce alpha toxin and beta toxin but often produce additional toxins, e.g., beta2 toxin or enterotoxin. Since plasmid carriage of toxin-encoding genes has not been systematically investigated for type C isolates, the current study used Southern blot hybridization of pulsed-field gels to test whether several toxin genes are plasmid borne among a collection of type C isolates. Those analyses revealed that the surveyed type C isolates carry their beta toxin-encoding gene (cpb) on plasmids ranging in size from ∼65 to ∼110 kb. When present in these type C isolates, the beta2 toxin gene localized to plasmids distinct from the cpb plasmid. However, some enterotoxin-positive type C isolates appeared to carry their enterotoxin-encoding cpe gene on a cpb plasmid. The tpeL gene encoding the large clostridial cytotoxin was localized to the cpb plasmids of some cpe-negative type C isolates. The cpb plasmids in most surveyed isolates were found to carry both IS1151 sequences and the tcp genes, which can mediate conjugative C. perfringens plasmid transfer. A dcm gene, which is often present near C. perfringens plasmid-borne toxin genes, was identified upstream of the cpb gene in many type C isolates. Overlapping PCR analyses suggested that the toxin-encoding plasmids of the surveyed type C isolates differ from the cpe plasmids of type A isolates. These findings provide new insight into plasmids of proven or potential importance for type C virulence.
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Marshall KM, Bradshaw M, Johnson EA. Conjugative botulinum neurotoxin-encoding plasmids in Clostridium botulinum. PLoS One 2010; 5:e11087. [PMID: 20552020 PMCID: PMC2884020 DOI: 10.1371/journal.pone.0011087] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 05/17/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Clostridium botulinum produces seven distinct serotypes of botulinum neurotoxins (BoNTs). The genes encoding different subtype neurotoxins of serotypes A, B, F and several dual neurotoxin-producing strains have been shown to reside on plasmids, suggesting that intra- and interspecies transfer of BoNT-encoding plasmids may occur. The objective of the present study was to determine whether these C. botulinum BoNT-encoding plasmids are conjugative. METHODOLOGY/PRINCIPAL FINDINGS C. botulinum BoNT-encoding plasmids pBotCDC-A3 (strain CDC-A3), pCLJ (strain 657Ba) and pCLL (strain Eklund 17B) were tagged with the erythromycin resistance marker (Erm) using the ClosTron mutagenesis system by inserting a group II intron into the neurotoxin genes carried on these plasmids. Transfer of the tagged plasmids from the donor strains CDC-A3, 657Ba and Eklund 17B to tetracycline-resistant recipient C. botulinum strains was evaluated in mating experiments. Erythromycin and tetracycline resistant transconjugants were isolated from donor:recipient mating pairs tested. Transfer of the plasmids to the transconjugants was confirmed by pulsed-field gel electrophoresis (PFGE) and Southern hybridizations. Transfer required cell-to-cell contact and was DNase resistant. This indicates that transfer of these plasmids occurs via a conjugation mechanism. CONCLUSIONS/SIGNIFICANCE This is the first evidence supporting conjugal transfer of native botulinum neurotoxin-encoding plasmids in C. botulinum, and provides a probable mechanism for the lateral distribution of BoNT-encoding plasmids to other C. botulinum strains. The potential transfer of C. botulinum BoNT-encoding plasmids to other bacterial hosts in the environment or within the human intestine is of great concern for human pathogenicity and necessitates further characterization of these plasmids.
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Affiliation(s)
| | | | - Eric A. Johnson
- Department of Bacteriology, College of Agriculture and Life Sciences, University of Wisconsin, Madison, Wisconsin, United States of America
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Uzal FA, Vidal JE, McClane BA, Gurjar AA. Clostridium Perfringens Toxins Involved in Mammalian Veterinary Diseases. THE OPEN TOXINOLOGY JOURNAL 2010; 2:24-42. [PMID: 24511335 PMCID: PMC3917546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Clostridium perfringens is a gram-positive anaerobic rod that is classified into 5 toxinotypes (A, B, C, D, and E) according to the production of 4 major toxins, namely alpha (CPA), beta (CPB), epsilon (ETX) and iota (ITX). However, this microorganism can produce up to 16 toxins in various combinations, including lethal toxins such as perfringolysin O (PFO), enterotoxin (CPE), and beta2 toxin (CPB2). Most diseases caused by this microorganism are mediated by one or more of these toxins. The role of CPA in intestinal disease of mammals is controversial and poorly documented, but there is no doubt that this toxin is essential in the production of gas gangrene of humans and several animal species. CPB produced by C. perfringens types B and C is responsible for necrotizing enteritis and enterotoxemia mainly in neonatal individuals of several animal species. ETX produced by C. perfringens type D is responsible for clinical signs and lesions of enterotoxemia, a predominantly neurological disease of sheep and goats. The role of ITX in disease of animals is poorly understood, although it is usually assumed that the pathogenesis of intestinal diseases produced by C. perfringens type E is mediated by this toxin. CPB2, a necrotizing and lethal toxin that can be produced by all types of C. perfringens, has been blamed for disease in many animal species, but little information is currently available to sustain or rule out this claim. CPE is an important virulence factor for C. perfringens type A gastrointestinal disease in humans and dogs; however, the data implicating CPE in other animal diseases remains ambiguous. PFO does not seem to play a direct role as the main virulence factor for animal diseases, but it may have a synergistic role with CPA-mediated gangrene and ETX-mediated enterotoxemia. The recent improvement of animal models for C. perfringens infection and the use of toxin gene knock-out mutants have demonstrated the specific pathogenic role of several toxins of C. perfringens in animal disease. These research tools are helping us to establish the role of each C. perfringens toxin in animal disease, to investigate the in vivo mechanism of action of these toxins, and to develop more effective vaccines against diseases produced by these microorganisms.
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Affiliation(s)
- F. A. Uzal
- California Animal Health and Food Safety Laboratory System, San Bernardino Branch, School of Veterinary Medicine, University of California, Davis, San Bernardino, CA 92408, USA,Address correspondence to this author at the California Animal Health and Food Safety Laboratory System, San Bernardino Branch, School of Veterinary Medicine, University of California, Davis, San Bernardino, CA 92408, USA;
| | - J. E. Vidal
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - B. A. McClane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA,Department of Molecular Virology and Microbiology Graduate Program, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - A. A. Gurjar
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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Characterization of virulence plasmid diversity among Clostridium perfringens type B isolates. Infect Immun 2009; 78:495-504. [PMID: 19858300 DOI: 10.1128/iai.00838-09] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The important veterinary pathogen Clostridium perfringens type B is unique for producing the two most lethal C. perfringens toxins, i.e., epsilon-toxin and beta-toxin. Our recent study (K. Miyamoto, J. Li, S. Sayeed, S. Akimoto, and B. A. McClane, J. Bacteriol. 190:7178-7188, 2008) showed that most, if not all, type B isolates carry a 65-kb epsilon-toxin-encoding plasmid. However, this epsilon-toxin plasmid did not possess the cpb gene encoding beta-toxin, suggesting that type B isolates carry at least one additional virulence plasmid. Therefore, the current study used Southern blotting of pulsed-field gels to localize the cpb gene to approximately 90-kb plasmids in most type B isolates, although a few isolates carried a approximately 65-kb cpb plasmid distinct from their etx plasmid. Overlapping PCR analysis then showed that the gene encoding the recently discovered TpeL toxin is located approximately 3 kb downstream of the plasmid-borne cpb gene. As shown earlier for their epsilon-toxin-encoding plasmids, the beta-toxin-encoding plasmids of type B isolates were found to carry a tcp locus, suggesting that they are conjugative. Additionally, IS1151-like sequences were identified upstream of the cpb gene in type B isolates. These IS1151-like sequences may mobilize the cpb gene based upon detection of possible cpb-containing circular transposition intermediates. Most type B isolates also possessed a third virulence plasmid that carries genes encoding urease and lambda-toxin. Collectively, these findings suggest that type B isolates are among the most plasmid dependent of all C. perfringens isolates for virulence, as they usually carry three potential virulence plasmids.
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