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Toxins Jul 2016The Gram-positive anaerobic bacterium Clostridium perfringens is widely distributed in nature, especially in soil and the gastrointestinal tracts of humans and animals.... (Review)
Review
The Gram-positive anaerobic bacterium Clostridium perfringens is widely distributed in nature, especially in soil and the gastrointestinal tracts of humans and animals. C. perfringens causes gas gangrene and food poisoning, and it produces extracellular enzymes and toxins that are thought to act synergistically and contribute to its pathogenesis. A complicated regulatory network of toxin genes has been reported that includes a two-component system for regulatory RNA and cell-cell communication. It is necessary to clarify the global regulatory system of these genes in order to understand and treat the virulence of C. perfringens. We summarize the existing knowledge about the regulatory mechanisms here.
Topics: Bacterial Proteins; Bacterial Toxins; Clostridium perfringens; Gene Expression Regulation, Bacterial; Host-Pathogen Interactions; Virulence
PubMed: 27399773
DOI: 10.3390/toxins8070207 -
Anaerobe Oct 2018Clostridium perfringens causes many different histotoxic and enterotoxic diseases in humans and animals as a result of its ability to produce potent protein toxins, many... (Review)
Review
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β-toxin, ε-toxin and ι-toxin - to divide C. perfringens strains into toxinotypes A to E. However, this scheme is now outdated since it does not take into account the discovery of other toxins that have been shown to be required for specific C. perfringens-mediated diseases.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.
Topics: Animals; Bacterial Toxins; Bacterial Typing Techniques; Clostridium Infections; Clostridium perfringens; Humans
PubMed: 29866424
DOI: 10.1016/j.anaerobe.2018.04.011 -
Emerging Microbes & Infections Aug 2018Clostridium perfringens, a rapid-growing pathogen known to secrete an arsenal of >20 virulent toxins, has been associated with intestinal diseases in both animals and... (Review)
Review
Clostridium perfringens, a rapid-growing pathogen known to secrete an arsenal of >20 virulent toxins, has been associated with intestinal diseases in both animals and humans throughout the past century. Recent advances in genomic analysis and experimental systems make it timely to re-visit this clinically and veterinary important pathogen. This Review will summarise our understanding of the genomics and virulence-linked factors, including antimicrobial potentials and secreted toxins of this gut pathogen, and then its up-to-date clinical epidemiology and biological role in the pathogenesis of several important human and animal-associated intestinal diseases, including pre-term necrotising enterocolitis. Finally, we highlight some of the important unresolved questions in relation to C. perfringens-mediated infections, and implications for future research directions.
Topics: Animals; Bacterial Proteins; Bacterial Toxins; Clostridium Infections; Clostridium perfringens; Humans; Virulence
PubMed: 30082713
DOI: 10.1038/s41426-018-0144-8 -
Frontiers in Cellular and Infection... 2019is an important human and animal pathogen that is the primary causative agent of necrotizing enteritis and enterotoxemia in many types of animals; it causes traumatic... (Review)
Review
is an important human and animal pathogen that is the primary causative agent of necrotizing enteritis and enterotoxemia in many types of animals; it causes traumatic gas gangrene in humans and animals and is associated with cases of food poisoning in humans. produces a variety of toxins as well as many enzymes, including three sialidases, NanH, NanI, and NanJ. Sialidases could be important virulence factors that promote the pathogenesis of . Among them, NanI promotes the colonization of in the intestinal tract and enhances the cytotoxic activity and association of several major toxins with host cells. In recent years, studies on the structure and functions of sialidases have yielded interesting results, and the functions of sialic acid and sialidases in bacterial pathogenesis have become a hot research topic. An in-depth understanding and additional studies of sialidases will further elucidate mechanisms of pathogenesis and could promote the development and clinical applications of sialidase inhibitors. This article reviews the structural characteristics, expression regulation, roles of sialidases in pathogenesis, and effects of their inhibitors.
Topics: Animals; Bacterial Adhesion; Bacterial Toxins; Clostridium Infections; Clostridium perfringens; Enzyme Inhibitors; Flavanones; Humans; Intestines; Models, Molecular; N-Acetylneuraminic Acid; Neuraminidase; Protein Conformation; Virulence Factors
PubMed: 31998664
DOI: 10.3389/fcimb.2019.00462 -
Microbiology Spectrum Jun 2016The ability of Clostridium perfringens to form spores plays a key role during the transmission of this Gram-positive bacterium to cause disease. Of particular note, the... (Review)
Review
The ability of Clostridium perfringens to form spores plays a key role during the transmission of this Gram-positive bacterium to cause disease. Of particular note, the spores produced by food poisoning strains are often exceptionally resistant to food environment stresses such as heat, cold, and preservatives, which likely facilitates their survival in temperature-abused foods. The exceptional resistance properties of spores made by most type A food poisoning strains and some type C foodborne disease strains involve their production of a variant small acid-soluble protein-4 that binds more tightly to spore DNA than to the small acid-soluble protein-4 made by most other C. perfringens strains. Sporulation and germination by C. perfringens and Bacillus spp. share both similarities and differences. Finally, sporulation is essential for production of C. perfringens enterotoxin, which is responsible for the symptoms of C. perfringens type A food poisoning, the second most common bacterial foodborne disease in the United States. During this foodborne disease, C. perfringens is ingested with food and then, by using sporulation-specific alternate sigma factors, this bacterium sporulates and produces the enterotoxin in the intestines.
Topics: Bacterial Toxins; Clostridium perfringens; Enterotoxins; Foodborne Diseases; Humans; Spores, Bacterial; United States
PubMed: 27337447
DOI: 10.1128/microbiolspec.TBS-0022-2015 -
Applied and Environmental Microbiology Jan 2017Clostridium perfringens is an important pathogen to human and animals and causes a wide array of diseases, including histotoxic and gastrointestinal illnesses. C.... (Review)
Review
Clostridium perfringens is an important pathogen to human and animals and causes a wide array of diseases, including histotoxic and gastrointestinal illnesses. C. perfringens spores are crucial in terms of the pathogenicity of this bacterium because they can survive in a dormant state in the environment and return to being live bacteria when they come in contact with nutrients in food or the human body. Although the strategies to inactivate C. perfringens vegetative cells are effective, the inactivation of C. perfringens spores is still a great challenge. A number of studies have been conducted in the past decade or so toward developing efficient inactivation strategies for C. perfringens spores and vegetative cells, which include physical approaches and the use of chemical preservatives and naturally derived antimicrobial agents. In this review, different inactivation strategies applied to control C. perfringens cells and spores are summarized, and the potential limitations and challenges of these strategies are discussed.
Topics: Animals; Anti-Infective Agents; Clostridium perfringens; Colony Count, Microbial; Disinfection; Food Preservation; Food Preservatives; Foodborne Diseases; Humans; Microbial Viability; Spores, Bacterial
PubMed: 27795314
DOI: 10.1128/AEM.02731-16 -
Toxins Aug 2019The aim of this study was to assess occurrence of and in honey samples from Kazakhstan. Analyses were carried out using a set of PCR methods for identification of...
The aim of this study was to assess occurrence of and in honey samples from Kazakhstan. Analyses were carried out using a set of PCR methods for identification of anaerobic bacteria, and detection of toxin genes of and . Among 197 samples, was noticed in only one (0.5%). The isolated strain of this pathogen showed the presence of the and genes. strains were isolated from 18 (9%) samples, and mPCR (multiplex PCR) analysis led to them all being classified as toxin type A with the ability to produce α toxin. Sequence analysis of 16S rDNA genes showed occurrence in 4 samples of other anaerobes related to , which were and strains. prevalence in honey samples from Kazakhstan in comparison to the prevalence in samples collected from the other regions seems to be less. The highest prevalence of sp. was noticed in the East Kazakhstan province. Our study is the first survey on BoNT-producing clostridia and prevalence in Kazakh honey.
Topics: Clostridium botulinum; Clostridium perfringens; DNA, Ribosomal; Honey; Kazakhstan; RNA, Ribosomal, 16S; Real-Time Polymerase Chain Reaction
PubMed: 31412583
DOI: 10.3390/toxins11080472 -
Toxins Nov 2016is a major cause of histotoxic and intestinal infections of humans and other animals. This Gram-positive anaerobic bacterium can produce up to three sialidases named... (Review)
Review
is a major cause of histotoxic and intestinal infections of humans and other animals. This Gram-positive anaerobic bacterium can produce up to three sialidases named NanH, NanI, and NanJ. The role of sialidases in histotoxic infections, such as gas gangrene (clostridial myonecrosis), remains equivocal. However, recent in vitro studies suggest that NanI may contribute to intestinal virulence by upregulating production of some toxins associated with intestinal infection, increasing the binding and activity of some of those toxins, and enhancing adherence of to intestinal cells. Possible contributions of NanI to intestinal colonization are further supported by observations that the strains causing acute food poisoning in humans often lack the gene, while other strains causing chronic intestinal infections in humans usually carry a gene. Certain sialidase inhibitors have been shown to block NanI activity and reduce adherence to cultured enterocyte-like cells, opening the possibility that sialidase inhibitors could be useful therapeutics against intestinal infections. These initial in vitro observations should be tested for their in vivo significance using animal models of intestinal infections.
Topics: Animals; Bacterial Proteins; Bacterial Toxins; Clostridium Infections; Clostridium perfringens; Gene Expression Regulation, Fungal; Humans; Intestinal Diseases; Neuraminidase; Virulence
PubMed: 27869757
DOI: 10.3390/toxins8110341 -
Microbes and Environments 2012Recent advances in understanding the genetics of enterotoxigenic Clostridium perfringens, including whole genome sequencing of a chromosomal cpe strain and sequencing of... (Review)
Review
Recent advances in understanding the genetics of enterotoxigenic Clostridium perfringens, including whole genome sequencing of a chromosomal cpe strain and sequencing of several cpe-carrying large plasmids, have led to the development of molecular approaches to more precisely investigate isolates involved in human gastrointestinal diseases and isolates present in the environment. Sequence-based PCR genotyping of the cpe locus (cpe genotyping PCR assays) has provided new information about cpe-positive type A C. perfringens including: 1) Foodborne C. perfringens outbreaks can be caused not only by chromosomal cpe type A strains with extremely heat-resistant spores, but also less commonly by less heat-resistant spore-forming plasmid cpe type A strains; 2) Both chromosomal cpe and plasmid cpe C. perfringens type A strains can be found in retail foods, healthy human feces and the environment, such as in sewage; 3) Most environmental cpe-positive C. perfringens type A strains carry their cpe gene on plasmids. Moreover, recent studies indicated that the cpe loci of type C, D, and E strains differ from the cpe loci of type A strains and from the cpe loci of each other, indicating that the cpe loci of C. perfringens have remarkable diversity. Multi-locus sequence typing (MLST) indicated that the chromosomal cpe strains responsible for most food poisoning cases have distinct genetic characteristics that provide unique biological properties, such as the formation of highly heat-resistant spores. These and future advances should help elucidate the epidemiology of enterotoxigenic C. perfringens and also contribute to the prevention of C. perfringens food poisoning outbreaks and other CPE-associated human diseases.
Topics: Clostridium Infections; Clostridium perfringens; Enterotoxins; Foodborne Diseases; Gastrointestinal Diseases; Genes, Bacterial; Genetic Variation; Genotype; Humans; Molecular Diagnostic Techniques; Multilocus Sequence Typing; Spores, Bacterial
PubMed: 22504431
DOI: 10.1264/jsme2.me12002 -
Microbiology Spectrum Jul 2019The pathogenesis of clostridial myonecrosis or gas gangrene involves an interruption to the blood supply to the infected tissues, often via a traumatic wound, anaerobic...
The pathogenesis of clostridial myonecrosis or gas gangrene involves an interruption to the blood supply to the infected tissues, often via a traumatic wound, anaerobic growth of the infecting clostridial cells, the production of extracellular toxins, and toxin-mediated cell and tissue damage. This review focuses on host-pathogen interactions in -mediated and -mediated myonecrosis. The major toxins involved are α-toxin, which has phospholipase C and sphingomyelinase activity, and α-toxin, a β-pore-forming toxin that belongs to the aerolysin family. Although these toxins are cytotoxic, their effects on host cells are quite complex, with a range of intracellular cell signaling pathways induced by their action on host cell membranes.
Topics: Anaerobiosis; Bacterial Toxins; Clostridium perfringens; Clostridium septicum; Gas Gangrene; Host-Pathogen Interactions; Humans; Wounds and Injuries
PubMed: 31350831
DOI: 10.1128/microbiolspec.GPP3-0024-2018