Corynebacterium
Encyclopedia
Corynebacterium is a genus
of Gram-positive
rod-shaped bacteria
. They are widely distributed in nature and are mostly innocuous. Some are useful in industrial settings such as C. glutamicum. Others can cause human disease. C. diphtheriae
, for example, is the pathogen
responsible for diphtheria
.
group to contain the bacterial rods responsible for causing diphtheria. The genus was defined based on morphological
characteristics. Thanks to studies of 16S-rRNA
, they have been grouped into the subdivision of Gram-positive
eubacteria with high G
:C
content, with close philogenetic relationship to Arthrobacter
, Mycobacterium
, Nocardia
, and Streptomyces
. The term comes from the Greek
corönë ("knotted rod") and bacterion ("rod"). The term "diphtheroids" is used to represent Corynebacteria that are non-pathogenic; for example, C. diphtheriae
would be excluded.
, catalase
positive, non-spore
-forming, non-motile
, rod-shaped bacteria that are straight or slightly curved. Metachromatic granules are usually present representing stored phosphate regions. Their size falls between 2-6 micrometer
s in length and 0.5 micrometers in diameter
. The bacteria group together in a characteristic way, which has been described as the form of a "V", "palisades", or "Chinese letters". They may also appear elliptical
. They are aerobic
or facultatively anaerobic
, chemoorganotroph
s, with a 51–65% genomic
G:C content. They are pleomorphic through their life cycle
: they come in various lengths and frequently have thickenings at either end, depending on the surrounding conditions.
is distinctive, with a predominance of meso-diaminopimelic acid
in the murein wall and many repetitions of arabinogalactan
as well as corynemycolic acid (a mycolic acid
with 22 to 26 carbon
atoms), tied together by disaccharide
bonds called L-Rhap-(1 → 4)--D-GlcNAc-phosphate. These form a complex commonly seen in Corynebacterium species: the mycolyl-AG–peptidoglican (mAGP).
to grow. Some strains also need thiamine
and PABA
. Some of the Corynebacterium with sequenced genomes have between 2.5 and 3 million base pairs. The bacteria grow in Loeffler's medium, blood agar, and trypticase soy agar
(TSA). They form small grayish colonies with a granular appearance, mostly translucent, but with opaque centers, convex, with continuous borders. The color tends to be yellowish white in Loeffler's medium. In TSA, it can form grey colonies with black centers and dentated borders that look similar to flowers (C. gravis), or continuous borders (C. mitis), or a mix between the two forms (C. intermedium).
of humans and animals. Some species are known for their pathogenic effects in humans and other animals. Perhaps the most notable one is C. diphtheriae
, which acquires the capacity to produce diphtheria toxin
only after interacting with a bacteriophage
. Other pathogenic species in humans include: C. amicolatum, C. striatum, C. jeikeium
, C. urealyticum, and C. xerosis (Oteo et al., 2001; Lagrou et al., 1998; Boc & Martone, 1995); all of these are important as pathogens in immunosuppressed
patients. Pathogenic species in other animals include C. bovis
and C. renale
.
, caused by Corynebacterium diphtheriae
. It is an acute and contagious infection characterized by pseudomembranes of dead epithelial cell
s, white blood cell
s, red blood cell
s, and fibrin
that form around the tonsil
s and back of the throat
. It is an uncommon illness that tends to occur in unvaccinated
individuals, especially school-aged children, those in developing countries, elderly, neutropenic
or immunocompromised patients, and those with prosthetic devices such as prosthetic heart valves, shunts
, or catheter
s. It can occasionally infect wounds, the vulva
, the conjunctiva
, and the middle ear
. It can be spread within a hospital
. The virulent and toxigenic strains are lysogenic, and produce an exotoxin
formed by two polypeptide chains, which is itself produced when a bacterium is transformed
by a gene
from the β prophage
.
Several species cause disease in animals, most notably C. pseudotuberculosis which causes the disease caseous lymphadenitis
and some are also pathogenic in humans. Some attack healthy host
s, while others tend to attack the immunocompromised. Effects of infection include granuloma
tous lymphadenopathy
, pneumonitis
, pharyngitis
, skin infections, and endocarditis
. Corynebacterial endocarditis is seen most frequently in patients with intravascular devices. C. tenuis is believed to cause trichomycosis palmellina and trichomycosis axillaris
. C. striatum may cause axillary odor. C. minutissimum
causes erythrasma
.
s, nucleotide
s, and other nutritional factors (Martín, 1989); bioconversion of steroid
s; degradation of hydrocarbon
s; cheese
aging; and production of enzyme
s (Khurana et al., 2000). Some species produce metabolites similar to antibiotic
s: bacteriocin
s of the corynecin-linocin type, anti-tumor agents, etc. One of the most studied species is C. glutamicum, whose name refers to its capacity to produce glutamic acid
in aerobic conditions. It is used in the foods industry as monosodium glutamate
(MSG) in the production of soy sauce
and yogurt.
Species of Corynebacterium have been used in the mass production of various amino acids including glutamic acid, a popular food additive that is made at a rate of 1.5 million tons/ year by Corynebacterium. The metabolic pathways of Corynebacterium have been further manipulated to produce lysine and threonine.
Expression of functionally active human epidermal growth factor
has been done in C. glutamicum, thus demonstrating a potential for industrial-scale production of human proteins. Expressed proteins can be targeted for secretion through either the general secretory pathway
(Sec) or the twin-arginine translocation pathway (Tat).
Unlike gram-negative bacteria, the gram-positive Corynebacterium lack lipopolysaccharide
s that function as antigenic endotoxins in humans.
, but some are lipophilic.
and nonfermentative:
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of Gram-positive
Gram-positive
Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
rod-shaped bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
. They are widely distributed in nature and are mostly innocuous. Some are useful in industrial settings such as C. glutamicum. Others can cause human disease. C. diphtheriae
Corynebacterium diphtheriae
Corynebacterium diphtheriae is a pathogenic bacterium that causes diphtheria. It is also known as the Klebs-Löffler bacillus, because it was discovered in 1884 by German bacteriologists Edwin Klebs and Friedrich Löffler .-Classification:Four subspecies are recognized: C. diphtheriae mitis, C....
, for example, is the pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
responsible for diphtheria
Diphtheria
Diphtheria is an upper respiratory tract illness caused by Corynebacterium diphtheriae, a facultative anaerobic, Gram-positive bacterium. It is characterized by sore throat, low fever, and an adherent membrane on the tonsils, pharynx, and/or nasal cavity...
.
Taxonomy
The genus Corynebacterium was created by Lehmann and Neumann in 1896 as a taxonomicTaxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
group to contain the bacterial rods responsible for causing diphtheria. The genus was defined based on morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
characteristics. Thanks to studies of 16S-rRNA
Ribosomal RNA
Ribosomal ribonucleic acid is the RNA component of the ribosome, the enzyme that is the site of protein synthesis in all living cells. Ribosomal RNA provides a mechanism for decoding mRNA into amino acids and interacts with tRNAs during translation by providing peptidyl transferase activity...
, they have been grouped into the subdivision of Gram-positive
Gram-positive
Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
eubacteria with high G
Guanine
Guanine is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine . In DNA, guanine is paired with cytosine. With the formula C5H5N5O, guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with...
:C
Cytosine
Cytosine is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine . It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached . The nucleoside of cytosine is cytidine...
content, with close philogenetic relationship to Arthrobacter
Arthrobacter
Arthrobacter is a genus of bacteria that is commonly found in soil. All species in this genus are Gram-positive obligate aerobes that are rods during exponential growth and cocci in their stationary phase....
, Mycobacterium
Mycobacterium
Mycobacterium is a genus of Actinobacteria, given its own family, the Mycobacteriaceae. The genus includes pathogens known to cause serious diseases in mammals, including tuberculosis and leprosy...
, Nocardia
Nocardia
Nocardia is a genus of weakly staining Gram-positive, catalase-positive, rod-shaped bacteria. It forms partially acid-fast beaded branching filaments . It has a total of 85 species. Some species are non-pathogenic while others are responsible for nocardiosis. Nocardia are found worldwide in soil...
, and Streptomyces
Streptomyces
Streptomyces is the largest genus of Actinobacteria and the type genus of the family Streptomycetaceae. Over 500 species of Streptomyces bacteria have been described. As with the other Actinobacteria, streptomycetes are gram-positive, and have genomes with high guanine and cytosine content...
. The term comes from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
corönë ("knotted rod") and bacterion ("rod"). The term "diphtheroids" is used to represent Corynebacteria that are non-pathogenic; for example, C. diphtheriae
Corynebacterium diphtheriae
Corynebacterium diphtheriae is a pathogenic bacterium that causes diphtheria. It is also known as the Klebs-Löffler bacillus, because it was discovered in 1884 by German bacteriologists Edwin Klebs and Friedrich Löffler .-Classification:Four subspecies are recognized: C. diphtheriae mitis, C....
would be excluded.
Characteristics
The principal features of the Corynebacterium genus were described by Collins and Cummins in 1986. They are Gram-positiveGram-positive
Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
, catalase
Catalase
Catalase is a common enzyme found in nearly all living organisms that are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen...
positive, non-spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
-forming, non-motile
Motility
Motility is a biological term which refers to the ability to move spontaneously and actively, consuming energy in the process. Most animals are motile but the term applies to single-celled and simple multicellular organisms, as well as to some mechanisms of fluid flow in multicellular organs, in...
, rod-shaped bacteria that are straight or slightly curved. Metachromatic granules are usually present representing stored phosphate regions. Their size falls between 2-6 micrometer
Micrometer
A micrometer , sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw used widely for precise measurement of small distances in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier,...
s in length and 0.5 micrometers in diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
. The bacteria group together in a characteristic way, which has been described as the form of a "V", "palisades", or "Chinese letters". They may also appear elliptical
Ellipse
In geometry, an ellipse is a plane curve that results from the intersection of a cone by a plane in a way that produces a closed curve. Circles are special cases of ellipses, obtained when the cutting plane is orthogonal to the cone's axis...
. They are aerobic
Aerobic organism
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...
or facultatively anaerobic
Facultative anaerobic organism
A facultative anaerobic organism is an organism, usually a bacterium, that makes ATP by aerobic respiration if oxygen is present but is also capable of switching to fermentation...
, chemoorganotroph
Chemoorganotroph
Chemoorganotrophs are organisms which use organic compounds as their energy source. These organic chemicals include glucose and acetate. All animals are chemoorganotrophs, as are fungi, protozoa, and some bacteria. Indeed, most heterotrophs are chemoorganotrophs. However, chemolithotrophs instead...
s, with a 51–65% genomic
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
G:C content. They are pleomorphic through their life cycle
Biological life cycle
A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...
: they come in various lengths and frequently have thickenings at either end, depending on the surrounding conditions.
Cell wall
The cell wallCell wall
The cell wall is the tough, usually flexible but sometimes fairly rigid layer that surrounds some types of cells. It is located outside the cell membrane and provides these cells with structural support and protection, and also acts as a filtering mechanism. A major function of the cell wall is to...
is distinctive, with a predominance of meso-diaminopimelic acid
Diaminopimelic acid
Diaminopimelic acid is an amino acid, representing an epsilon-carboxy derivative of lysine.DAP is a characteristic of certain cell walls of some bacteria. When provided, they exhibit normal growth. When in deficiency, they still grow but with the inability to make new cell wall proteoglycan.This...
in the murein wall and many repetitions of arabinogalactan
Arabinogalactan
Arabinogalactan is a biopolymer consisting of arabinose and galactose monosaccharides. Two classes of arabinogalactans are found in nature: plant arabinogalactan and microbial arabinogalactan. In plants, it is a major constituent of many gums, including gum arabic, gum gutti and so on...
as well as corynemycolic acid (a mycolic acid
Mycolic acid
Mycolic acids are long fatty acids found in the cell walls of the mycolata taxon, a group of bacteria that includes Mycobacterium tuberculosis, the causative agent of the disease tuberculosis. They form the major component of the cell wall of mycolata species...
with 22 to 26 carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
atoms), tied together by disaccharide
Disaccharide
A disaccharide or biose is the carbohydrate formed when two monosaccharides undergo a condensation reaction which involves the elimination of a small molecule, such as water, from the functional groups only. Like monosaccharides, disaccharides form an aqueous solution when dissolved in water...
bonds called L-Rhap-(1 → 4)--D-GlcNAc-phosphate. These form a complex commonly seen in Corynebacterium species: the mycolyl-AG–peptidoglican (mAGP).
Culture
Corynebacteria grow slowly, even on enriched media. In terms of nutritional requirements, all need biotinBiotin
Biotin, also known as Vitamin H or Coenzyme R, is a water-soluble B-complex vitamin discovered by Bateman in 1916. It is composed of a ureido ring fused with a tetrahydrothiophene ring. A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring...
to grow. Some strains also need thiamine
Thiamine
Thiamine or thiamin or vitamin B1 , named as the "thio-vitamine" is a water-soluble vitamin of the B complex. First named aneurin for the detrimental neurological effects if not present in the diet, it was eventually assigned the generic descriptor name vitamin B1. Its phosphate derivatives are...
and PABA
4-Aminobenzoic acid
4-Aminobenzoic acid is an organic compound with the formula H2NC6H4CO2H. PABA is a white grey crystalline substance that is only slightly soluble in water...
. Some of the Corynebacterium with sequenced genomes have between 2.5 and 3 million base pairs. The bacteria grow in Loeffler's medium, blood agar, and trypticase soy agar
Trypticase soy agar
Trypticase soy agar is a bacterial growth medium.The medium contains enzymatic digests of casein and soybean meal which provides amino acids and other nitrogenous substances making it a nutritious medium for a variety of organisms. Glucose is the energy source. Sodium chloride maintains the osmotic...
(TSA). They form small grayish colonies with a granular appearance, mostly translucent, but with opaque centers, convex, with continuous borders. The color tends to be yellowish white in Loeffler's medium. In TSA, it can form grey colonies with black centers and dentated borders that look similar to flowers (C. gravis), or continuous borders (C. mitis), or a mix between the two forms (C. intermedium).
Habitat
Corynebacteria species occur commonly in nature in the soil, water, plants, and food products. The non-diphtheiroid Corynebacterium can even be found in the mucosa and normal skin floraSkin flora
The skin flora are the microorganisms which reside on the skin. Most research has been upon those that reside upon the 2 square metres of human skin. Many of them are bacteria of which there are around 1000 species upon human skin from 19 phyla. The total number of bacteria on an average human has...
of humans and animals. Some species are known for their pathogenic effects in humans and other animals. Perhaps the most notable one is C. diphtheriae
Corynebacterium diphtheriae
Corynebacterium diphtheriae is a pathogenic bacterium that causes diphtheria. It is also known as the Klebs-Löffler bacillus, because it was discovered in 1884 by German bacteriologists Edwin Klebs and Friedrich Löffler .-Classification:Four subspecies are recognized: C. diphtheriae mitis, C....
, which acquires the capacity to produce diphtheria toxin
Diphtheria toxin
Diphtheria toxin is an exotoxin secreted by Corynebacterium diphtheriae, the pathogen bacterium that causes diphtheria. Unusually, the toxin gene is encoded by a bacteriophage...
only after interacting with a bacteriophage
Bacteriophage
A bacteriophage is any one of a number of viruses that infect bacteria. They do this by injecting genetic material, which they carry enclosed in an outer protein capsid...
. Other pathogenic species in humans include: C. amicolatum, C. striatum, C. jeikeium
Corynebacterium jeikeium
Corynebacterium jeikeium is a rod-shaped, catalase-positive, aerobic species of actinobacteria in the genus Corynebacterium. C. jeikeium is pathogenic, typically causing an opportunistic infection seen most frequently in bone marrow transplant patients.C. jeikeium is usually susceptible to...
, C. urealyticum, and C. xerosis (Oteo et al., 2001; Lagrou et al., 1998; Boc & Martone, 1995); all of these are important as pathogens in immunosuppressed
Immunosuppression
Immunosuppression involves an act that reduces the activation or efficacy of the immune system. Some portions of the immune system itself have immuno-suppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse reaction to treatment of other...
patients. Pathogenic species in other animals include C. bovis
Corynebacterium bovis
Corynebacterium bovis is a pathogenic veterinary bacterium that causes mastitis and pyelonephritis in cattle.C. bovis is a facultatively anaerobic Gram positive organism, characterized by non-encapsulated, non-sporulated, immobile, straight or curved rods with a length of 1 to 8 µm and width of...
and C. renale
Corynebacterium renale
Corynebacterium renale is a pathogenic veterinary bacterium that causes cystitis and pyelonephritis in cattle.C. renale is a facultatively anaerobic Gram positive organism, characterized by non-encapsulated, non-sporulated, immobile, straight or curved rods with a length of 1 to 8 µm and width of...
.
Role in disease
The most notable human infection is diphtheriaDiphtheria
Diphtheria is an upper respiratory tract illness caused by Corynebacterium diphtheriae, a facultative anaerobic, Gram-positive bacterium. It is characterized by sore throat, low fever, and an adherent membrane on the tonsils, pharynx, and/or nasal cavity...
, caused by Corynebacterium diphtheriae
Corynebacterium diphtheriae
Corynebacterium diphtheriae is a pathogenic bacterium that causes diphtheria. It is also known as the Klebs-Löffler bacillus, because it was discovered in 1884 by German bacteriologists Edwin Klebs and Friedrich Löffler .-Classification:Four subspecies are recognized: C. diphtheriae mitis, C....
. It is an acute and contagious infection characterized by pseudomembranes of dead epithelial cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
s, white blood cell
White blood cell
White blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...
s, red blood cell
Red blood cell
Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...
s, and fibrin
Fibrin
Fibrin is a fibrous, non-globular protein involved in the clotting of blood. It is a fibrillar protein that is polymerised to form a "mesh" that forms a hemostatic plug or clot over a wound site....
that form around the tonsil
Tonsil
Palatine tonsils, occasionally called the faucial tonsils, are the tonsils that can be seen on the left and right sides at the back of the throat....
s and back of the throat
Pharynx
The human pharynx is the part of the throat situated immediately posterior to the mouth and nasal cavity, and anterior to the esophagus and larynx. The human pharynx is conventionally divided into three sections: the nasopharynx , the oropharynx , and the laryngopharynx...
. It is an uncommon illness that tends to occur in unvaccinated
Vaccine
A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins...
individuals, especially school-aged children, those in developing countries, elderly, neutropenic
Neutropenia
Neutropenia, from Latin prefix neutro- and Greek suffix -πενία , is a granulocyte disorder characterized by an abnormally low number of neutrophils, the most important type of white blood cell...
or immunocompromised patients, and those with prosthetic devices such as prosthetic heart valves, shunts
Shunt (medical)
In medicine, a shunt is a hole or a small passage which moves, or allows movement of fluid from one part of the body to another. The term may describe either congenital or acquired shunts; and acquired shunts may be either biological or mechanical.* Cardiac shunts may be described as...
, or catheter
Catheter
In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...
s. It can occasionally infect wounds, the vulva
Vulva
The vulva consists of the external genital organs of the female mammal. This article deals with the vulva of the human being, although the structures are similar for other mammals....
, the conjunctiva
Conjunctiva
The conjunctiva covers the sclera and lines the inside of the eyelids. It is composed of rare stratified columnar epithelium.-Function:...
, and the middle ear
Middle ear
The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. The mammalian middle ear contains three ossicles, which couple vibration of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear has...
. It can be spread within a hospital
Nosocomial infection
A nosocomial infection , also known as a hospital-acquired infection or HAI, is an infection whose development is favoured by a hospital environment, such as one acquired by a patient during a hospital visit or one developing among hospital staff...
. The virulent and toxigenic strains are lysogenic, and produce an exotoxin
Exotoxin
An exotoxin is a toxin excreted by a microorganism, like bacteria, fungi, algae, and protozoa. An exotoxin can cause damage to the host by destroying cells or disrupting normal cellular metabolism. They are highly potent and can cause major damage to the host...
formed by two polypeptide chains, which is itself produced when a bacterium is transformed
Transformation (genetics)
In molecular biology transformation is the genetic alteration of a cell resulting from the direct uptake, incorporation and expression of exogenous genetic material from its surroundings and taken up through the cell membrane. Transformation occurs naturally in some species of bacteria, but it can...
by a gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
from the β prophage
Prophage
A prophage is a phage genome inserted and integrated into the circular bacterial DNA chromosome. A prophage, also known as a temperate phage, is any virus in the lysogenic cycle; it is integrated into the host chromosome or exists as an extrachromosomal plasmid. Technically, a virus may be called...
.
Several species cause disease in animals, most notably C. pseudotuberculosis which causes the disease caseous lymphadenitis
Caseous lymphadenitis
Caseous lymphadenitis is an infectious disease caused by the bacterium Corynebacterium pseudotuberculosis found mostly in goats and sheep that at present has no cure. It manifests itself predominantly in the form of large, pus-filled cysts on the neck, sides and udders of goats and sheep...
and some are also pathogenic in humans. Some attack healthy host
Host (biology)
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
s, while others tend to attack the immunocompromised. Effects of infection include granuloma
Granuloma
Granuloma is a medical term for a tiny collection of immune cells known as macrophages. Granulomas form when the immune system attempts to wall off substances that it perceives as foreign but is unable to eliminate. Such substances include infectious organisms such as bacteria and fungi as well as...
tous lymphadenopathy
Lymphadenopathy
Lymphadenopathy is a term meaning "disease of the lymph nodes." It is, however, almost synonymously used with "swollen/enlarged lymph nodes". It could be due to infection, auto-immune disease, or malignancy....
, pneumonitis
Pneumonitis
Pneumonitis or pulmonitis is a general term that refers to inflammation of lung tissue.Pneumonia is pneumonitis combined with consolidation and exudation...
, pharyngitis
Pharyngitis
Pharyngitis is an inflammation of the throat or pharynx. In most cases it is quite painful, and is the most common cause of a sore throat.Like many types of inflammation, pharyngitis can be acute – characterized by a rapid onset and typically a relatively short course – or chronic....
, skin infections, and endocarditis
Endocarditis
Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves . Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or even on intracardiac devices...
. Corynebacterial endocarditis is seen most frequently in patients with intravascular devices. C. tenuis is believed to cause trichomycosis palmellina and trichomycosis axillaris
Trichomycosis axillaris
Trichomycosis axillaris is a superficial bacterial colonization of the hair shafts in sweat gland–bearing areas, such as the armpits and the pubic area...
. C. striatum may cause axillary odor. C. minutissimum
Corynebacterium minutissimum
Corynebacterium minutissimum is a species of corynebacterium.It is associated with erythrasma, a type of skin rash. It can be distinguished from similar-appearing rashes by exposing the area to the light of a Wood's lamp; C. minutissimum produces porphyrins that fluoresce coral-red....
causes erythrasma
Erythrasma
Erythrasma is a skin disease that causes brown, scaly skin patches. It is caused by the gram positive bacterium Corynebacterium minutissimum.It is prevalent among diabetics, the obese, and in warm climates and is worsened by wearing occlusive clothing....
.
Industrial Uses
Non-pathogenic species of Corynebacterium are used for very important industrial applications, such as the production of amino acidAmino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s, nucleotide
Nucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
s, and other nutritional factors (Martín, 1989); bioconversion of steroid
Steroid
A steroid is a type of organic compound that contains a characteristic arrangement of four cycloalkane rings that are joined to each other. Examples of steroids include the dietary fat cholesterol, the sex hormones estradiol and testosterone, and the anti-inflammatory drug dexamethasone.The core...
s; degradation of hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
s; cheese
Cheese
Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms....
aging; and production of enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
s (Khurana et al., 2000). Some species produce metabolites similar to antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s: bacteriocin
Bacteriocin
Bacteriocins are proteinaceous toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strain. They are typically considered to be narrow spectrum antibiotics, though this has been debated...
s of the corynecin-linocin type, anti-tumor agents, etc. One of the most studied species is C. glutamicum, whose name refers to its capacity to produce glutamic acid
Glutamic acid
Glutamic acid is one of the 20 proteinogenic amino acids, and its codons are GAA and GAG. It is a non-essential amino acid. The carboxylate anions and salts of glutamic acid are known as glutamates...
in aerobic conditions. It is used in the foods industry as monosodium glutamate
Monosodium glutamate
Monosodium glutamate, also known as sodium glutamate or MSG, is the sodium salt of glutamic acid, one of the most abundant naturally occurring non-essential amino acids....
(MSG) in the production of soy sauce
Soy sauce
Soy sauce is a condiment produced by fermenting soybeans with Aspergillus oryzae or Aspergillus sojae molds, along with water and salt...
and yogurt.
Species of Corynebacterium have been used in the mass production of various amino acids including glutamic acid, a popular food additive that is made at a rate of 1.5 million tons/ year by Corynebacterium. The metabolic pathways of Corynebacterium have been further manipulated to produce lysine and threonine.
Expression of functionally active human epidermal growth factor
Epidermal growth factor
Epidermal growth factor or EGF is a growth factor that plays an important role in the regulation of cell growth, proliferation, and differentiation by binding to its receptor EGFR...
has been done in C. glutamicum, thus demonstrating a potential for industrial-scale production of human proteins. Expressed proteins can be targeted for secretion through either the general secretory pathway
Secretory pathway
The secretory pathway is a series of steps a cell uses to move proteins out of the cell; a process known as secretion. The path of a protein destined for secretion has its origins in the rough endoplasmic reticulum, a membrane-bound compartment in the cell...
(Sec) or the twin-arginine translocation pathway (Tat).
Unlike gram-negative bacteria, the gram-positive Corynebacterium lack lipopolysaccharide
Lipopolysaccharide
Lipopolysaccharides , also known as lipoglycans, are large molecules consisting of a lipid and a polysaccharide joined by a covalent bond; they are found in the outer membrane of Gram-negative bacteria, act as endotoxins and elicit strong immune responses in animals.-Functions:LPS is the major...
s that function as antigenic endotoxins in humans.
Species
Most species of corynebacteria are non-lipophilicLipophilic bacteria
Lipophilic bacteria are bacteria that may proliferate in lipids.-Types:They include lipophilic corynebacteria..Propionibacterium acnes is a type of liphophilic bacteria, releasing fatty acids and worsening comedones....
, but some are lipophilic.
Non-lipophilic
The nonlipophilic bacteria may be classified as fermentativeFermentation (biochemistry)
Fermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. In contrast, respiration is where electrons are donated to an exogenous electron acceptor, such as oxygen,...
and nonfermentative:
- Fermentative Corynebacteria
- Corynebacterium diphtheriaeCorynebacterium diphtheriaeCorynebacterium diphtheriae is a pathogenic bacterium that causes diphtheria. It is also known as the Klebs-Löffler bacillus, because it was discovered in 1884 by German bacteriologists Edwin Klebs and Friedrich Löffler .-Classification:Four subspecies are recognized: C. diphtheriae mitis, C....
group - Corynebacterium xerosis and Corynebacterium striatum
- Corynebacterium minutissimumCorynebacterium minutissimumCorynebacterium minutissimum is a species of corynebacterium.It is associated with erythrasma, a type of skin rash. It can be distinguished from similar-appearing rashes by exposing the area to the light of a Wood's lamp; C. minutissimum produces porphyrins that fluoresce coral-red....
- Corynebacterium amycolatum
- Corynebacterium glucuronolyticum
- Corynebacterium argentoratense
- Corynebacterium matruchotiiCorynebacterium matruchotiiCorynebacterium matruchotii is one of the 12 or more bacterial species in the genus Corynebacterium. Corynebacteria occur within the normal flora of the human body....
- Corynebacterium sp.
- Corynebacterium diphtheriae
- Nonfermentative Corynebacteria
- Corynebacterium afermentans subsp. afermentans
- Corynebacterium auris
- Corynebacterium pseudodiphtheriticum
- Corynebacterium propinquum
Lipophilic
- Corynebacterium jeikeiumCorynebacterium jeikeiumCorynebacterium jeikeium is a rod-shaped, catalase-positive, aerobic species of actinobacteria in the genus Corynebacterium. C. jeikeium is pathogenic, typically causing an opportunistic infection seen most frequently in bone marrow transplant patients.C. jeikeium is usually susceptible to...
- Corynebacterium urealyticum
- Corynebacterium afermentans subsp. lipophilum
- Corynebacterium accolens
- Corynebacterium macginleyi
- CDC coryneform groups F-1 and G
- Corynebacterium bovisCorynebacterium bovisCorynebacterium bovis is a pathogenic veterinary bacterium that causes mastitis and pyelonephritis in cattle.C. bovis is a facultatively anaerobic Gram positive organism, characterized by non-encapsulated, non-sporulated, immobile, straight or curved rods with a length of 1 to 8 µm and width of...