''Clostridium perfringens'' (formerly known as ''C.
welchii'', or ''Bacillus welchii'') is a
Gram-positive
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall.
The Gram stain is ...
, bacillus (rod-shaped),
anaerobic,
spore-forming pathogenic bacterium of the genus ''
Clostridium''. ''C. perfringens'' is ever-present in nature and can be found as a normal component of decaying vegetation,
marine sediment
Marine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor. These particles either have their origins in soil and Rock (geology), rocks and have been Sediment transport, ...
, the
intestinal tract of humans and other
vertebrate
Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain.
The vertebrates make up the subphylum Vertebra ...
s,
insect
Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...
s, and
soil
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...
. It has the shortest reported
generation time
In population biology and demography
Demography () is the statistical study of human populations: their size, composition (e.g., ethnic group, age), and how they change through the interplay of fertility (births), mortality (deaths), and mi ...
of any organism at 6.3 minutes in
thioglycolate medium.
''Clostridium perfringens'' is one of the most common causes of
food poisoning
Foodborne illness (also known as foodborne disease and food poisoning) is any illness resulting from the contamination of food by pathogenic bacteria, viruses, or parasites,
as well as prions (the agents of mad cow disease), and toxins such ...
in the United States, alongside
norovirus, ''
Salmonella
''Salmonella'' is a genus of bacillus (shape), rod-shaped, (bacillus) Gram-negative bacteria of the family Enterobacteriaceae. The two known species of ''Salmonella'' are ''Salmonella enterica'' and ''Salmonella bongori''. ''S. enterica'' ...
'', ''
Campylobacter'', and ''
Staphylococcus aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often posi ...
''. However, it can sometimes be ingested and cause no harm.
Infections induced by ''C. perfringens'' are associated with tissue
necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who i ...
,
bacteremia
Bloodstream infections (BSIs) are infections of blood caused by blood-borne pathogens. The detection of microbes in the blood (most commonly accomplished by blood cultures) is always abnormal. A bloodstream infection is different from sepsis, wh ...
, emphysematous
cholecystitis
Cholecystitis is inflammation of the gallbladder. Symptoms include Right upper quadrant (abdomen), right upper abdominal pain, pain in the right shoulder, nausea, vomiting, and occasionally fever. Often gallbladder attacks (biliary colic) precede ...
, and
gas gangrene, which is also known as clostridial
myonecrosis. The specific name, ''perfringens,'' is derived from the
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
(meaning "through") and ("burst"), referring to the disruption of tissue that occurs during gas gangrene. Gas gangrene is caused by alpha toxin, or
α-toxin, that embeds itself into the plasma membrane of cells and disrupts normal cellular function by altering membrane structure.
Research suggests that ''C. perfringens'' is capable of engaging in polymicrobial
anaerobic infections.
It is commonly encountered in
infection
An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...
s as a component of the normal
flora
Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...
. In this case, its role in disease is minor.
''C. perfringens'' toxins are a result of horizontal gene transfer of a neighboring cell's plasmids.
Shifts in genomic make-up are common for this species of bacterium and contribute to novel pathogenesis.
Major toxins are expressed differently in certain populations of ''C. perfringens;'' these populations are organized into strains based on their expressed toxins.
This especially impacts the food industry, as controlling this microbe is important for preventing foodborne illness.
Novel findings in ''C. perfringens'' hyper-motility, which was provisionally thought as non-motile, have been discovered as well.
Findings in metabolic processes reveal more information concerning ''C. perfringens'' pathogenic nature.
Genome
''Clostridium perfringens'' has a stable
G+C content around 27 to 28 percent and average
genome
A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...
size of 3.5 Mb.
Genomes of 56 ''C. perfringens'' strains have since been made available on the
NCBI genomes database for the scientific research community.
Genomic research has revealed surprisingly high diversity in ''C. perfringens''
pangenome, with only 12.6 percent core genes, identified as the most divergent Gram-positive
bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...
reported.
Nevertheless,
16S rRNA
16S ribosomal RNA (or 16Svedberg, S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome (SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure.
The genes coding for it are referred to as ...
regions in between ''C. perfringens'' strains are found to be highly conserved (
sequence identity >99.1%).
The ''Clostridium perfringens'' enterotoxin (CPE)–producing strain has been identified to be a small portion of the overall ''C. perfringens'' population (~1-5%) through genomic testing.
Advances in genetic information surrounding strain A CPE ''C. perfringens'' has allowed techniques such as microbial source tracking (MST) to identify food contamination sources.
The CPE gene has been found within chromosomal DNA as well as plasmid DNA. Plasmid DNA has been shown to play and integral role in cell pathogenesis and encodes for major toxins, including CPE.
''C. perfringens'' has been shown to carry plasmid-containing genes for
antibiotic resistance
Antimicrobial resistance (AMR or AR) occurs when microbes evolve mechanisms that protect them from antimicrobials, which are drugs used to treat infections. This resistance affects all classes of microbes, including bacteria (antibiotic resis ...
. The pCW3 plasmid is the primary conjugation plasmid responsible for creating antibiotic resistance in ''C. perfringens''. Furthermore, the pCW3 plasmid also encodes for multiple toxins found in pathogenic strains of ''C. perfringens''. Antibiotic resistance genes observed thus far include
tetracycline resistance, efflux protein, and
aminoglycoside resistance.
Within industrial contexts, such as
food production, sequencing genomes for pathogenic strains of ''C. perfringens'' has become an expanding field of research. Poultry production is impacted directly from this trend as antibiotic-resistant strains of ''C. perfringens'' are becoming more common.
By performing a meta-genome analysis, researches are capable to identify novel strains of pathogenic bacterium, such as ''C. perfringens'' B20.
Motility
''Clostridium perfringens'' is provisionally identified as non-motile. They lack flagella; however, recent research suggests gliding as a form of motility.
Hyper-motile variations

In agar plate cultures bacteria with hypermotile variations like SM101 frequently appear around the borders of the colonies. They create long thin filaments that enable them to move quickly, much like bacteria with flagella, according to video imaging of their gliding motion. The causes of the hypermotile phenotype and its immediate descendants were found using genome sequencing. The hypermotile offspring of strains SM101 and SM102, SM124 and SM127, respectively, had 10 and 6 nucleotide polymorphisms (SNPs) in comparison to their parent strains. The hypermotile strains have the common trait of gene mutations related to cell division.
Regulation of gliding motility: The CpAL/VirSR system
Some strains of ''C. perfringens'' cause various diseases like gas gangrene and myonecrosis. Toxins produced that are required for myonecrosis is regulated by the ''C. perfringens'' Agr-like (CpAl) system through the VirSR two-component system. The CpAL/VirSR system is a quorum sensing system encoded by other pathogenic clostridia. Myonecrosis starts at the infection site and involves bacteria migrating deeper via gliding motility. Researchers investigated if the CpAL/VirSR system regulates gliding motility. The study demonstrated that the CpAL/VirSR regulates ''C. perfringens'' gliding motility. Additionally, the study suggests that gliding bacteria in myonecrosis have increased transcription of toxin genes.
Transformation
There are two methods of
genetic manipulation
Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of technologies used to change the genetic makeup of cells, including th ...
via experimentation that have been shown to cause genetic transformation in ''C. perfringens''.
Protoplast transformation
The first report of transformation in ''C. perfringens'' involved
polyethylene
Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging (plastic bags, plastic films, geomembranes and containers including bott ...
glycol-mediated transformation of
protoplast
Protoplast (), is a biology, biological term coined by Johannes von Hanstein, Hanstein in 1880 to refer to the entire cell, excluding the cell wall. Protoplasts can be generated by stripping the cell wall from plant, bacterium, bacterial, or f ...
s. The transformation procedure involved the addition of the plasmid DNA to the protoplasts in the presence of high concentrations of
polyethylene glycol
Polyethylene glycol (PEG; ) is a polyether compound derived from petroleum with many applications, from industrial manufacturing to medicine. PEG is also known as polyethylene oxide (PEO) or polyoxyethylene (POE), depending on its molecular wei ...
. During the first protoplast transformation experiment, L-phase variants of ''C. perfringens'' were generated by
penicillin
Penicillins (P, PCN or PEN) are a group of beta-lactam antibiotic, β-lactam antibiotics originally obtained from ''Penicillium'' Mold (fungus), moulds, principally ''Penicillium chrysogenum, P. chrysogenum'' and ''Penicillium rubens, P. ru ...
treatment in the presence 0.4m sucrose. After the transformation procedure was completed, all of the transformed cells were still in the form of L-phase variants. Reversion to vegetative cells was not obtained, but it was observed that autoplasts (protoplasts derived from
autolysis) were able to be regenerated to produce rods with cell walls and could be transformed with ''C. perfringens'' plasmid DNA.
Electroporation
Electroporation involves the application of a high-voltage electric field to vegetative bacteria cells for a very short period. This technique resulted in major advances in genetic transformation of ''C. perfringens'', due to the bacteria often displaying itself as a vegetative cell or as dormant spores in food. The electric pulse creates pores in the bacterial cell membrane and allows the passive influx of DNA molecules.
Metabolic processes
''C. perfringens'' is an aerotolerant anaerobe bacterium that lives in a variety of environments including soil and human intestinal tract.
''C. perfringens'' is incapable of synthesizing multiple amino acids due to the lack of genes required for biosynthesis.
Instead, the bacterium produces enzymes and toxins to break down host cells and import nutrients from the degrading cell.
''C. perfringens'' has a complete set of
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
s for
glycolysis
Glycolysis is the metabolic pathway that converts glucose () into pyruvic acid, pyruvate and, in most organisms, occurs in the liquid part of cells (the cytosol). The Thermodynamic free energy, free energy released in this process is used to form ...
and
glycogen
Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. It is the main storage form of glucose in the human body.
Glycogen functions as one of three regularly used forms ...
metabolism. In the fermentation pathway,
pyruvate
Pyruvic acid (CH3COCOOH) is the simplest of the alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate base, CH3COCOO−, is an intermediate in several metabolic pathways throughout the cell.
Pyruvic ...
is converted into
acetyl-CoA
Acetyl-CoA (acetyl coenzyme A) is a molecule that participates in many biochemical reactions in protein, carbohydrate and lipid metabolism. Its main function is to deliver the acetyl group to the citric acid cycle (Krebs cycle) to be oxidation, o ...
by
pyruvate-ferredoxin oxidoreductase, producing
CO2 gas and reduced
ferredoxin
Ferredoxins (from Latin ''ferrum'': iron + redox, often abbreviated "fd") are iron–sulfur proteins that mediate electron transfer in a range of metabolic reactions. The term "ferredoxin" was coined by D.C. Wharton of the DuPont Co. and applied t ...
.
Electrons from the reduced ferredoxin are transferred to protons by hydrogenase, resulting in the formation of hydrogen molecules (H2) that are released from the cell along with
CO2. Pyruvate is also converted to
lactate by
lactate dehydrogenase
Lactate dehydrogenase (LDH or LD) is an enzyme found in nearly all living cells. LDH catalyzes the conversion of pyruvic acid, pyruvate to lactic acid, lactate and back, as it converts NAD+ to NADH and back. A dehydrogenase is an enzyme that t ...
, whereas acetyl-CoA is converted into
ethanol
Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...
,
acetate
An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic, or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called ...
, and
butyrate through various enzymatic reactions, completing the
anaerobic glycolysis that serves as a potential main energy source for ''C. perfringens''. ''C. perfringens'' utilizes a variety of sugars such as
fructose
Fructose (), or fruit sugar, is a Ketose, ketonic monosaccharide, simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and gal ...
,
galactose
Galactose (, ''wikt:galacto-, galacto-'' + ''wikt:-ose#Suffix 2, -ose'', ), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweetness, sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epime ...
,
glycogen
Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. It is the main storage form of glucose in the human body.
Glycogen functions as one of three regularly used forms ...
,
lactose
Lactose is a disaccharide composed of galactose and glucose and has the molecular formula C12H22O11. Lactose makes up around 2–8% of milk (by mass). The name comes from (Genitive case, gen. ), the Latin word for milk, plus the suffix ''-o ...
,
maltose
}
Maltose ( or ), also known as maltobiose or malt sugar, is a disaccharide formed from two units of glucose joined with an α(1→4) bond. In the isomer isomaltose, the two glucose molecules are joined with an α(1→6) bond. Maltose is the tw ...
,
mannose,
raffinose,
starch
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diet ...
, and
sucrose
Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula .
For human consumption, sucrose is extracted and refined ...
, and various genes for
glycolytic
Glycolysis is the metabolic pathway that converts glucose () into pyruvic acid, pyruvate and, in most organisms, occurs in the liquid part of cells (the cytosol). The Thermodynamic free energy, free energy released in this process is used to form ...
enzymes. The amino acids of these various enzymes and sugar molecules are converted to
propionate through
propionyl-CoA, which results in energy production.
Virulence
Membrane-damaging enzymes, pore-forming toxins, intracellular toxins, and hydrolytic enzymes are the functional categories into which ''C. perfringens''
' virulence factors may be divided. These virulence factor-encoding genes can be found on chromosomes and large plasmids.
Carbohydrate-active enzymes
The human gastrointestinal tract is lined with
intestinal mucosa that secrete
mucus
Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and muc ...
and act as a defense mechanism against pathogens, toxins, and harmful substances. Mucus is made up of
mucin
Mucins () are a family of high molecular weight, heavily glycosylated proteins ( glycoconjugates) produced by epithelial tissues in most animals. Mucins' key characteristic is their ability to form gels; therefore they are a key component in ...
s containing several
O-linked glycan glycoprotein
Glycoproteins are proteins which contain oligosaccharide (sugar) chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known a ...
s that recognizes and forms a barrier around microbes, preventing them from attaching to endothelial cells and infecting them.
''C. perfringens'' can secrete different
carbohydrate-active enzymes (CAZymes) that aid in degrading mucins and other O-glycans within the intestinal mucosa. These enzymes include: Sialidases, Hexosaminidases, Galactosidases, and Fucosidases belonging to various
glycoside hydrolase families.
Sialidase
Sialidases, also called neuraminidases, function to breakdown mucin by
hydrolyzing the terminal sialic acid residues located within the protein through the process of
desialylation. ''C. perfringens'' has three sialidases belonging to
glycoside hydrolase family 33 (GH33): NanH, NanI, and NanJ. All strains of ''C. perfringens'' encode for at least one of these enzymes.
''C. perfringens'' can secrete NanI and NanJ through secretion signal
peptide
Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty am ...
s located on each protein. Research suggests that NanH operates in the cytoplasm of ''C. perfringens'', as it does not contain a secretion signal peptide. NanH contains only a catalytic domain, whereas NanI and NanJ contain a
catalytic domain and additional
carbohydrate-binding modules (CBMs) to aid in catalytic activity. Located on their N-terminals, NanI contains CBM40, whereas NanJ contains both CBM40 and CBM32. Based on studies analyzing the three-dimensional structure of NanI, its
active site has a pocket-like orientation that aids in the removal of sialic acid residues from sialomucins in the intestinal mucosa.
Hexosaminidase
The mucus layer consists of intestinal mucin glycans, glycolipids, and glycoproteins that contain
hexosamines
Hexosamines are amino sugars created by adding an amine group to a hexose.
Examples include:
* Fructosamine (based upon fructose)
* Galactosamine (based upon galactose)
* Glucosamine (based upon glucose)
* Mannosamine (based upon mannose)
Ext ...
, such as
N-acetylglucosamine (GlcNAc) and
N-acetylgalactosamine (GalNAc). ''C. perfringens'' encodes for eight
hexosaminidases that break down hexosamines in the mucus. These hexosaminidases belong to four glycoside hydrolase families: GH36, GH84, GH89, and GH123.
''C. perfringens'' encodes for AagA (''Cp''GH36A) and ''Cp''GH36B in
glycoside hydrolase family 36 (GH36): AagA removes GalNAc from O-glycans, and ''Cp''GH36B is expected to have a similar structure to AagA, but specificities on its function are unknown. NagH, NagI, NagJ, and NagK, belonging to glycoside hydrolase family 84 (GH84), cleave terminal GlcNAc residues using a substrate-assisted digestion mechanism. AgnC (''Cp''GH89), belonging to
glycoside hydrolase family 89 (GH89), both cleaves GlcNAc from the ends of mucin glycans and acts on gastric mucin. Belonging to glycoside hydrolase family 123 (GH123), ''Cp''Nga123 cleaves GalNAc, but research suggests that it only breaks down glycans taken up by ''C. perfringens'' due to the absence of a secretion signal peptide.
Galactosidase
''C. perfringens'' has four
galactosidases that belong to the
glycoside hydrolase family 2 (GH2): ''Cp''GH2A, ''Cp''GH2B, ''Cp''GH2C, and ''Cp''GH2D. Research suggests that these enzymes are effective at breaking down core mucin glycan structures with the ability to bind
galactose
Galactose (, ''wikt:galacto-, galacto-'' + ''wikt:-ose#Suffix 2, -ose'', ), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweetness, sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epime ...
using CBM51. However, minimal research exists on the specific functioning of galactosidases in ''C. perfringens''.
Fucosidase
Fucose monosaccharides are located on the terminal ends of core O-linked glycans. ''C. perfringens'' encodes for three fucosidases that belong to two glycoside hydrolase families: Afc1 and Afc2 in
glycoside hydrolase family 29 (GH29), and Afc3 in glycoside hydrolase family 95 (GH95). Afc3 contains a C-terminal CBM51 and is the only fucosidase that contains a carbohydrate-binding module in ''C. perfringens''. Fucosyl residues tend to cover the ends of glycans and protect them against enzymatic digestion, so research suggests that the ability of fucosidases to cleave complex and diverse fucosyl linkages is due to long-term adaptations in ''C. perfringens'' that persisted within close range of mucins.
Major toxins
There are five major toxins produced by ''Clostridium perfringens.'' Alpha, beta, epsilon and enterotoxin are toxins that increase a cells permeability which causes an ion imbalance while iota toxins destroy the cell's actin cytoskeleton.
On the basis of which major, "typing" toxins are produced, ''C. perfringens'' can be classified into seven "toxinotypes", A, B, C, D, E, F and G:
Alpha toxin
Alpha toxin (CPA) is a zinc-containing phospholipase C, composed of two structural domains, which destroy a cell's membrane. Alpha toxins are produced by all five types of ''C. perfringens.'' This toxin is linked to
gas gangrene of humans and animals. Most cases of gas gangrene has been related to a deep wound being contaminated by soil that harbors ''C. perfringens''.
Beta toxin
Beta toxins (CPB) are a protein that causes hemorrhagic
necrotizing enteritis and
enterotoxaemia in both animals (type B) and humans (type C) which leads to the infected individual's feces becoming bloody and their intestines necrotizing.
Proteolytic enzymes, such as trypsin, can break down CPB, making them ineffective. Therefore, the presence of trypsin inhibitors in colostrum makes CPB especially deadly for mammal offspring.
Epsilon toxin
Epsilon toxin (ETX) is a protein produced by type B and type D strains of ''C. perfringens.'' This toxin is currently ranked the third most potent bacterial toxin known. ETX causes
enterotoxaemia in mainly goats and sheep, but cattle are sometime susceptible to it as well. An experiment using mice found that ETX had an LD50 of 50-110 ng/kg. The excessive production of ETX increases the permeability of the intestines. This causes severe edema in organs such as the brain and kidneys.
The very low LD50 of ETX has led to concern that it may be used as a bioweapon. It appeared on the
select agent lists of the US CDC and USDA, until it was removed in 2012. There are no human vaccines for this toxin, but effective vaccines for animals exist.
Iota toxin
Iota toxin (ITX) is a protein produced by type E strains of ''C. perfringens.'' Iota toxins are made up of two, unlinked proteins that form a multimeric complex on cells. Iota toxins prevent the formation of filamentous actin. This causes the destruction of the cells cytoskeleton which in turn leads to the death of the cell as it can no longer maintain homeostasis.
Enterotoxin
This toxin (CPE) causes food poisoning. It alters intracellular claudin tight junctions in gut epithelial cells. This pore-forming toxin also can bind to human ileal and colonic epithelium in vitro and necrotize it. Through the caspase-3 pathway, this toxin can cause apoptosis of affected cells. This toxin is linked to type F strains, but has also been found to be produced by certain types of C, D, and E strains.
Other toxins
TpeL is a toxin found in type B, C, and G
strains. It is in the same
protein family
A protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be ...
as
''C. difficile'' toxin A. It does not appear important in the pathogenesis of types B and C infections, but may contribute to virulence in type G strains. It glycosylates Rho and
Ras GTPases, disrupting host cell signaling.
Infection
Tissue
necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who i ...
,
bacteremia
Bloodstream infections (BSIs) are infections of blood caused by blood-borne pathogens. The detection of microbes in the blood (most commonly accomplished by blood cultures) is always abnormal. A bloodstream infection is different from sepsis, wh ...
, emphysematous
cholecystitis
Cholecystitis is inflammation of the gallbladder. Symptoms include Right upper quadrant (abdomen), right upper abdominal pain, pain in the right shoulder, nausea, vomiting, and occasionally fever. Often gallbladder attacks (biliary colic) precede ...
, and
gas gangrene, also known as clostridial
myonecrosis, have been linked to infections associated with ''C. perfringens''.
Research suggests that ''C. perfringens'' is capable of engaging in polymicrobial
anaerobic infections.
''Clostridium perfringens'' is a common cause of food poisoning in the United States. ''C. perfringens'' produces spores, and when these
spore
In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...
s are consumed, they produce a toxin that causes diarrhea. Foods cooked in large batches and held at unsafe temperatures (between 40 °F and 140 °F) are the source of ''C. perfringens'' food poisoning outbreaks. Meats such as poultry, beef, and pork are commonly linked to ''C. perfringens'' food poisoning. ''C. perfringens'' can proliferate in foods that are improperly stored due to the spore's ability to survive normal cooking temperatures. The type A toxin of ''C. perfringens'', also known as the CPA is responsible for food poisoning.
''Clostridium perfringens'' is the most common bacterial agent for
gas gangrene.
Gas gangrene is induced by
α-toxin that embeds itself into the plasma membrane of cells and disrupts normal cellular function by altering membrane structure.
Some symptoms include blisters, tachycardia, swelling, and jaundice.
''C. perfringens'' is most commonly known for foodborne illness but can translocate from a gastrointestinal source into the bloodstream which causes
bacteremia
Bloodstream infections (BSIs) are infections of blood caused by blood-borne pathogens. The detection of microbes in the blood (most commonly accomplished by blood cultures) is always abnormal. A bloodstream infection is different from sepsis, wh ...
. ''C. perfringens'' bacteremia can lead to toxin-mediated intravascular hemolysis and septic shock. This is rare as it makes up less than 1% of bloodstream isolates but is highly fatal with a reported mortality rate of 27% to 58%.
''Clostridium perfringens'' food poisoning can also lead to another disease known as enteritis necroticans or
clostridial necrotizing enteritis, (also known as pigbel); this is caused by ''C. perfringens'' type C. This infection is often fatal. Large numbers of ''C. perfringens'' grow in the intestines and secrete exotoxin. This exotoxin causes necrosis of the intestines, varying levels of hemorrhaging, and perforation of the intestine. Inflammation usually occurs in sections of the jejunum, midsection of the small intestine.
Perfringolysin O (''pfoA'')-positive ''C. perfringens'' strains were also associated with the rapid onset of
necrotizing enterocolitis in preterm infants.
A strain of ''C. perfringens'' might be implicated in
multiple sclerosis
Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit ...
(MS) nascent (
Pattern III) lesions. Tests in
mice
A mouse (: mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
found that two strains of intestinal ''C. perfringens'' that produced epsilon toxins (ETX) caused MS-like damage in the brain, and earlier work had identified this strain of ''C. perfringens'' in a human with MS. MS patients were found to be 10 times more likely to be immune-reactive to the epsilon toxin than healthy people. Greatly increased rates of gut colonization by type B and D ''C. perfringens'' are seen in MS patients.
Tissue gas occurs when ''C. perfringens'' infects corpses. It causes extremely accelerated decomposition and can only be stopped by
embalming the corpse. Tissue gas most commonly occurs to those who have died from gangrene, large
decubitus ulcers, necrotizing fasciitis or to those who had soil, feces, or water contaminated with ''C. perfringens'' forced into an open wound.
Clinical manifestations
''Clostridium perfringens'' infections can lead to various clinical manifestations, ranging from mild gastrointestinal symptoms to life-threatening conditions. The most common presentation is food poisoning, characterized by acute abdominal pain, diarrhea, and, in some cases, vomiting, typically occurring 6 to 24 hours after the ingestion of contaminated food. Unlike many other foodborne illnesses, fever is usually absent. Symptoms are usually self-limiting and resolve within 24 to 48 hours; however, severe dehydration can occur in cases of significant fluid loss. Symptoms of dehydration include dry mouth, decreased urine output, dizziness, and fatigue. Severe symptoms such as diarrhea that persists for more than 48 hours, the inability to keep fluids down, or signs of severe dehydration may necessitate medical attention. Most people are able to recover from ''C. perfringens'' food poisoning without treatment. However, people who experience diarrhea are usually instructed to drink water or rehydration solutions.
Gas gangrene caused by ''Clostridium perfringens'' is characterized by severe symptoms, including intense pain at the injury site, fever, rapid heart rate, sweating, and anxiety. The affected area may show signs of swelling, discoloration (ranging from pale to dark red or purplish), and large, discolored blisters filled with foul-smelling fluid. As the toxins spread, skin and muscle tissue are rapidly destroyed, leading to large areas of dead tissue, gas pockets under the skin (crepitus), and possible
renal failure
Kidney failure, also known as renal failure or end-stage renal disease (ESRD), is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney fa ...
due to red blood cell destruction.
Sepsis
Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs.
This initial stage of sepsis is followed by suppression of the immune system. Common signs and s ...
and
septic shock may also occur, which can be fatal.
Necrotizing enteritis caused by ''Clostridium perfringens'' presents with a wide range of symptoms, which can vary in severity. The clinical signs range from mild diarrhea to more severe manifestations such as intense abdominal pain, vomiting, bloody stools, and even septic shock. In the most serious cases, the infection can lead to death.
Diagnosis
The diagnosis of ''Clostridium perfringens'' food poisoning relies on laboratory detection of the bacterium or its toxin in either a patient’s stool sample or contaminated food linked to the illness. A positive stool culture would have growth of at least 10 cfu/g of C. ''perfringens''. Stool studies include
WBCs,
ova, and parasites in order to rule out other potential
etiologies.
ELISA
The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay is a solid-phase type of enzyme immunoassay (EIA) to detect the presence of ...
testing is used to detect the CPA toxin. Diagnosing ''C. perfringens'' food poisoning is relatively uncommon for several reasons. Most individuals with this foodborne illness do not seek medical care or submit a stool sample for testing, and routine testing for ''C. perfringens'' is not typically performed in clinical laboratories. Additionally, public health laboratories generally conduct testing for this pathogen only in the event of an outbreak.
The diagnosis of gas gangrene typically involves several methods to confirm the infection. Imaging techniques such as
X-ray
An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...
s,
CT scan
A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...
s, or
MRIs can reveal gas bubbles or tissue changes indicative of muscle damage. Additionally, bacterial staining or culture of fluid taken from the wound helps identify ''Clostridium perfringens'' and other bacteria responsible for the infection. In some cases, a
biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, an interventional radiologist, or an interventional cardiology, interventional cardiologist. The process involves the extraction of sampling (medicine), sample ...
is performed, where a sample of the affected tissue is analyzed for signs of damage or necrosis.
The diagnosis of clostridial necrotizing enteritis is primarily based on the patient's clinical symptoms, which can include severe abdominal pain, vomiting, and bloody diarrhea. Additionally, confirmation of the presence of ''Clostridium perfringens''
type C toxin in stool samples is crucial for accurate diagnosis.
Epidemiology
''Clostridium perfringens'' is responsible for an estimated 966,000 cases annually, or about 10.3% of all foodborne illnesses in which a pathogen is identified. Transmission typically occurs when food contaminated with ''C. perfringens'' spores is consumed, allowing the bacteria to produce a toxin in the intestines that causes diarrhea. Outbreaks are often associated with foods cooked in large batches, such as poultry, meat, and gravy, and held at unsafe temperatures between 40-140 °F, which allows the bacteria to thrive. These outbreaks tend to occur in settings where large groups are served, such as hospitals, school cafeterias, prisons, nursing homes, and catered events. In most cases, ''C. perfringens'' infection causes mild symptoms, including watery diarrhea and mild abdominal cramps, with symptoms typically appearing 8 to 12 hours after consuming contaminated food and resolving within 24 hours. About 90% of affected individuals recover without seeking medical attention, usually within two days. However, vulnerable groups such as the elderly, young children, and immunocompromised individuals face a higher risk of severe complications like dehydration, which can lead to more serious illness or, in rare cases, death. Each year, ''C. perfringens'' infections result in approximately 438 hospitalizations and 26 deaths, accounting for 0.8% of foodborne illness-related hospitalizations and 1.9% of associated deaths. Outbreaks are most common in November and December, coinciding with holiday foods like turkey and roast beef. The economic burden of ''C. perfringens'' is significant, estimated at $342.7 million annually, including $53.2 million in medical costs, $64.3 million in productivity loss, and $225 million related to fatalities.
Clostridial necrotizing enteritis is rare in the United States; typically, it occurs in populations with a higher risk. Data show that of the 9.4 million cases of foodborne illness in the United States each year, only about 11% are caused by ''Clostridium perfringens''. "Risk factors for
enteritis necroticans include protein-deficient diet, unhygienic food preparation, sporadic feasts of meat (after long periods of a protein-deficient diet), diets containing large amounts of
trypsin
Trypsin is an enzyme in the first section of the small intestine that starts the digestion of protein molecules by cutting long chains of amino acids into smaller pieces. It is a serine protease from the PA clan superfamily, found in the dig ...
inhibitors (sweet potatoes), and areas prone to infection of the parasite ''Ascaris'' (produces a trypsin inhibitor). This disease is contracted in populations living in New Guinea, parts of Africa, Central America, South America, and Asia.
Risk factors for gas gangrene include severe injuries, abdominal surgeries, and underlying health conditions such as colon cancer, diseases of the blood vessels, diabetes, and diverticulitis. However, the most common way to get gas gangrene is through a traumatic injury. In the United States, there is only about 1000 cases of gas gangrene per year. When addressed with adequate care, gas gangrene has a mortality rate of 20-30% but has a mortality rate of 100% if left untreated.
Food poisoning incidents
On May 7, 2010, 42 residents and 12 staff members at a Louisiana (USA) state psychiatric hospital were affected and experienced vomiting, abdominal cramps, and diarrhea. Three patients died within 24 hours. The outbreak was linked to chicken which was cooked a day before it was served and was not cooled down according to hospital guidelines. The outbreak affected 31% of the residents of the hospital and 69% of the staff who ate the chicken. How many of the affected residents ate the chicken is unknown.
In May 2011, a man died after allegedly eating food contaminated with the bacteria on a Transatlantic flight, transatlantic American Airlines flight. The man's wife and daughter were suing American and LSG Sky Chefs, the German company that prepared the inflight food.
In December 2012, a 46-year-old woman died two days after eating a Christmas Day meal at a pub in Hornchurch, Essex, England. She was among about 30 people to fall ill after eating the meal. Samples taken from the victims contained ''C. perfringens''. The hotel manager and the cook were jailed for forging cooking records relating to the cooking of the turkey.
In December 2014, 87-year-old Bessie Scott died three days after eating a church potluck supper in Nackawic, New Brunswick, Canada. Over 30 other people reported signs of gastrointestinal illness, diarrhea, and abdominal pain. The province's acting chief medical officer says, ''Clostridium perfringens'' is the bacteria [sic] that most likely caused the woman's death.
In October 2016, 66-year-old Alex Zdravich died four days after eating an enchilada, burrito, and taco at Agave Azul in West Lafayette, Indiana, United States. Three others who dined the same day reported signs of foodborne illness, which were consistent with the symptoms and rapid onset of ''C. perfringens'' infection. They later tested positive for the presence of the bacteria, but the leftover food brought home by Zdravich tested negative.
In November 2016, food contaminated with ''C. perfringens'' caused three individuals to die, and another 22 to be sickened, after a Thanksgiving (United States), Thanksgiving luncheon hosted by a church in Antioch, California, United States.
In January 2017, a mother and her son sued a restaurant in Rochester, New York, United States, as they and 260 other people were sickened after eating foods contaminated with ''C. perfringens''. "Officials from the Monroe County Department of Public Health closed down the Golden Ponds after more than a fourth of its Thanksgiving Day guests became ill. An inspection revealed a walk-in refrigerator with food spills and mold, a damaged gasket preventing the door from closing, and mildew growing inside."
In July 2018, 647 people reported symptoms after eating at a Chipotle Mexican Grill restaurant in Powell, Ohio, United States. Stool samples tested by the Centers for Disease Control and Prevention, CDC tested positive for ''C. perfringens''.
In November 2018, approximately 300 people in Concord, North Carolina, United States, were sickened by food at a church barbecue that tested positive for ''C. perfringens''.
In 2021, a foodborne illness outbreak in Homer, Alaska, affected approximately 80 employees of South Peninsula Hospital and was traced to Cubano sandwiches served during staff meals. The Alaska Department of Health and Social Services identified the likely cause as ''C. perfringens''. No hospitalizations were reported, and the outbreak was contained to hospital staff. Such localized outbreaks are considered uncommon in Alaska when not tied to a national foodborne incident.
Prevention
Preventing ''Clostridium perfringens'' contamination and growth involves careful food handling, proper cooking, and appropriate storage practices. Most foods, especially beef and chicken, can be protected by cooking them to the recommended internal temperatures. Using a kitchen thermometer is the most reliable way to check that meats reach safe cooking temperatures. As a general rule, food should be avoided if it smells, tastes, looks off, or has been left out at unsafe temperatures for a long period of time.
''C. perfringens'' spores can multiply within a temperature range of 59 °F (15 °C) to 122 °F (50 °C). To prevent bacterial growth, leftovers should be refrigerated within two hours of preparation, with their temperature chilled down to below 40 °F (4 °C). Large portions of food that contain meat, should be divided into smaller containers before refrigeration to ensure even cooling. Before serving leftovers, they should be reheated to at least 165 °F (74 °C) to destroy any bacteria that may have grown during storage.
High-risk foods, such as canned vegetables, smoked or cured meats, and salted or smoked fish, require additional attention. Improper processing or storage can allow bacteria to grow and produce dangerous toxins. Signs of contamination, such as unusual odors, changes in texture, or bulging cans (also known as "bombage"), indicate food spoilage and should be disposed.
Preventing
gas gangrene involves taking precautions to avoid bacterial infections. Healthcare providers follow strict protocols to prevent infections, including those caused by ''Clostridium perfringens''. To reduce the risk of gas gangrene, individuals should clean wounds thoroughly with soap and water and seek medical attention for deep or uncleanable wounds. It is also essential to monitor injuries for changes in skin condition or the onset of severe pain. Wearing protective gear when engaging in activities like biking or motorcycling can help prevent injury. Additionally, working with healthcare providers to manage underlying conditions that affect circulation or weaken the immune system can further reduce the risk of infection.
Treatment
The treatment of ''Clostridium perfringens'' infections depends on the type and severity of the condition. For severe infections, such as
gas gangrene (clostridial myonecrosis), the primary approach involves surgical debridement of the affected area. This procedure removes devitalized tissue where bacteria grow, which limits the spread of the infection. Antimicrobial, Antimicrobial therapy is usually started at the same time, with penicillin being the most commonly used drug.
However, ''C. perfringens'' shows different resistance patterns with about 20% of strains being resistant to clindamycin, and 10% being resistant to metronidazole. ''C. perfringens'' is often more susceptible to vancomycin when compared to other pathogenic ''Clostridia'', making it an alternative option for treatment in some cases.
Therapies, such as hyperbaric oxygen therapy (HBOT), may also be used for severe clostridial tissue infections. HBOT increases oxygen delivery to infected tissues, creating an environment that inhibits the growth of anaerobic bacteria like ''C. perfringens''. While not commonly used, HBOT can be beneficial in certain cases.
For foodborne illness caused by ''C. perfringens'', treatment is typically unnecessary. Most people who suffer from food poisoning caused by ''C. perfringens'' usually fight off the illness without the need of any antibiotics. Extra fluids should be drank consistently until diarrhea dissipates.
Research
''C. perfringens'' has shown increasing Multiple drug resistance, multidrug resistance, particularly in strains from humans and animals. High resistance levels were found with antibiotics such as tetracycline, erythromycin, and sulfonamides. Genetic factors, misuse of antibiotics, and bacterial evolution are the cause of this issue. This highlights the importance of finding new treatment strategies.
Multilocus sequence typing, Multilocus Sequence Typing (MLST) and Whole genome sequencing, Whole Genome Sequencing (WGS) have been used to find the genetic diversity of ''C. perfringens''. These methods have identified 195 distinct sequence types grouped into 25 clonal complexes from 322 genomes. Phylogenetic groups were also found in multiple different hosts and environmental sources. This highlights the bacteria's transmission potential and adaptability across species.
References
External links
Clostridium perfringensgenomes and related information a
PATRIC a Bioinformatics Resource Center funded b
NIAIDPathema-''Clostridium'' ResourceType strain of ''Clostridium perfringens'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q309465
Bacteria described in 1937
Clostridium, perfringens
Food microbiology
Gas gangrene
Gram-positive bacteria
Medical aspects of death
Pathogenic bacteria