Propionibacterium acnes
Encyclopedia
Propionibacterium acnes is a relatively slow growing, typically aerotolerant anaerobic
gram positive bacterium (rod) that is linked to the skin
condition acne
; it can also cause chronic blepharitis
and endophthalmitis
, the latter particularly following intraocular surgery. The genome
of the bacterium has been sequenced and a study has shown several gene
s that can generate enzyme
s for degrading skin
and protein
s that may be immunogenic (activate the immune system
).
This bacteria is largely commensal
and part of the skin flora
present on most healthy adult human skin. It is usually just barely detectable on the skin of healthy pre-adolescents. It lives primarily on, amongst other things, fatty acid
s in the sebaceous gland
s on sebum secreted by follicle
s. It may also be found throughout the gastrointestinal tract
in humans and many other animals. It is named after its ability to generate propionic acid
.
), possibly spilling bacteria such as Staphylococcus aureus
into the broken skin. Preliminary research shows healthy pores are only colonized by P. acnes while unhealthy ones universally include the non-pore-resident Staphylococcus epidermidis
, amongst other bacterial contaminants. Whether this is a root causality, just opportunistic & a side-effect, or a more complex pathological duality between P. acnes and this particular Staph is not known. P. acnes has also been found in corneal ulcer
s and is a common cause of chronic endophthalmitis
following cataract surgery. Rarely, it infects heart valves leading to endocarditis
, and infections of joints (septic arthritis
) have been reported. Furthermore, Propionibacterium have been found in ventriculostomy
insertion sites, and areas subcutaneous to suture sites in patients that have undergone craniotomy
.
Propionibacterium acnes can be found in bronchoalveolar lavage of approximately 70% patients with sarcoidosis
and is associated with disease activity, however it can be also found in 23% of controls. The sub-species of P. acnes that cause these infections of otherwise sterile tissues (prior to medical procedures), however, are the same sub-species that are found on the skin of individuals that do not have acne-prone skin and thus are likely local contaminants. Moderate to severe Acne vulgaris
appears to be more often associated with virulent sub-strains.
, tetracycline group and other antibiotic
s, and many antibacterial preparations, including clove oil, PCMX, and chlorhexidine gluconate
. Tetracycline-resistant P. acnes is now quite common. Clindamycin
is also frequently used. New facts show that P. acnes is sensitive to some macrolide
s such as azithromycin
, which has a wide spectrum of action. It is normally prescribed 500 mg by mouth, three times weekly for 4 to 6 weeks, but may have post-antibiotic effects by remaining concentrated in lung
tissue for approximately 5 days after treatment stops. Fluoroquinolones may also be effective against P. acnes such as nadifloxacin
, ciprofloxacin
, ofloxacin
and levofloxacin
. They are active against P. acnes and some other microorganism
s that are also part of the poly-infection.
.
s. The bacterium is killed by ultraviolet light
. P. acnes is also especially sensitive to light in the 405–420 nm (near the ultraviolet) range due to an endogenic porphyrin–coporphyrin III. A total irradiance
of 320 J/cm² is found to inactivate this bacteria in vitro. This fact is used in phototherapy. Its photosensitivity can be enhanced by pretreatment with aminolevulinic acid which boosts production of this chemical, although this causes significant side-effects in humans, and in practice was not significantly better than the light treatment alone.
Anaerobic organism
An anaerobic organism or anaerobe is any organism that does not require oxygen for growth. It could possibly react negatively and may even die if oxygen is present...
gram positive bacterium (rod) that is linked to the skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
condition acne
Acne vulgaris
Acne vulgaris is a common human skin disease, characterized by areas of skin with seborrhea , comedones , papules , pustules , Nodules and possibly scarring...
; it can also cause chronic blepharitis
Blepharitis
Blepharitis is an ocular condition characterized by chronic inflammation of the eyelid, the severity and time course of which can vary. Onset can be acute, resolving without treatment within 2–4 weeks , but more generally is a long standing inflammation varying in severity...
and endophthalmitis
Endophthalmitis
Endophthalmitis is an inflammation of the internal coats of the eye. It is a dreaded complication of all intraocular surgeries, particularly cataract surgery, with possible loss of vision and the eye itself. Infectious etiology is the most common and various bacteria and fungi have been isolated as...
, the latter particularly following intraocular surgery. The genome
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....
of the bacterium has been sequenced and a study has shown several 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...
s that can generate 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 for degrading skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
and protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s that may be immunogenic (activate the immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
).
This bacteria is largely commensal
Commensalism
In ecology, commensalism is a class of relationship between two organisms where one organism benefits but the other is neutral...
and part of the skin flora
Skin 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...
present on most healthy adult human skin. It is usually just barely detectable on the skin of healthy pre-adolescents. It lives primarily on, amongst other things, fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s in the sebaceous gland
Sebaceous gland
The sebaceous glands are microscopic glands in the skin that secrete an oily/waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals...
s on sebum secreted by follicle
Follicle
Follicle may refer to:*Follicle , a small spherical group of cells containing a cavity:** Dental follicle** Hair follicle** Lymph follicle** Ovarian follicle** Thyroid follicle*Follicle...
s. It may also be found throughout the gastrointestinal tract
Gastrointestinal tract
The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
in humans and many other animals. It is named after its ability to generate propionic acid
Propionic acid
Propanoic acid is a naturally occurring carboxylic acid with chemical formula CH3CH2COOH. It is a clear liquid with a pungent odor...
.
Role in disease
When a pore is blocked, this anaerobic bacterium overgrows and secretes chemicals that break down the wall of the pore and forming an acne lesion (folliculitisFolliculitis
Folliculitis is the inflammation of one or more hair follicles. The condition may occur anywhere on the skin with the exception of the palms of the hands and soles of the feet.- Causes :...
), possibly spilling bacteria such as Staphylococcus aureus
Staphylococcus aureus
Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. It is frequently found as part of the normal skin flora on the skin and nasal passages. It is estimated that 20% of the human population are long-term carriers of S. aureus. S. aureus is the most common species of...
into the broken skin. Preliminary research shows healthy pores are only colonized by P. acnes while unhealthy ones universally include the non-pore-resident Staphylococcus epidermidis
Staphylococcus epidermidis
Staphylococcus epidermidis is one of thirty-three known species belonging to the genus Staphylococcus. It is part of human skin flora, and consequently part of human flora. It can also be found in the mucous membranes and in animals. Due to contamination, it is probably the most common species...
, amongst other bacterial contaminants. Whether this is a root causality, just opportunistic & a side-effect, or a more complex pathological duality between P. acnes and this particular Staph is not known. P. acnes has also been found in corneal ulcer
Corneal ulcer
A corneal ulcer, or ulcerative keratitis, is an inflammatory condition of the cornea involving loss of its outer layer. It is very common in dogs and is sometimes seen in cats...
s and is a common cause of chronic endophthalmitis
Endophthalmitis
Endophthalmitis is an inflammation of the internal coats of the eye. It is a dreaded complication of all intraocular surgeries, particularly cataract surgery, with possible loss of vision and the eye itself. Infectious etiology is the most common and various bacteria and fungi have been isolated as...
following cataract surgery. Rarely, it infects heart valves leading to 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...
, and infections of joints (septic arthritis
Septic arthritis
Septic arthritis is the purulent invasion of a joint by an infectious agent which produces arthritis. People with artificial joints are more at risk than the general population but have slightly different symptoms, are infected with different organisms and require different treatment. Septic...
) have been reported. Furthermore, Propionibacterium have been found in ventriculostomy
Ventriculostomy
Ventriculostomy is a neurosurgical procedure that involves creating a hole within a cerebral ventricle for drainage. It is done by surgically penetrating the skull, dura mater, and brain such that the ventricle of the brain is accessed. When catheter drainage is temporary, it is commonly referred...
insertion sites, and areas subcutaneous to suture sites in patients that have undergone craniotomy
Craniotomy
A craniotomy is a surgical operation in which a bone flap is temporarily removed from the skull to access the brain. Craniotomies are often a critical operation performed on patients recording, brain imaging, and for neurological manipulations such as electrical stimulation and chemical...
.
Propionibacterium acnes can be found in bronchoalveolar lavage of approximately 70% patients with sarcoidosis
Sarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...
and is associated with disease activity, however it can be also found in 23% of controls. The sub-species of P. acnes that cause these infections of otherwise sterile tissues (prior to medical procedures), however, are the same sub-species that are found on the skin of individuals that do not have acne-prone skin and thus are likely local contaminants. Moderate to severe Acne vulgaris
Acne vulgaris
Acne vulgaris is a common human skin disease, characterized by areas of skin with seborrhea , comedones , papules , pustules , Nodules and possibly scarring...
appears to be more often associated with virulent sub-strains.
Antibiotic sensitivity
P. acnes can be killed by benzoyl peroxideBenzoyl peroxide
Benzoyl peroxide is an organic compound in the peroxide family. It consists of two benzoyl groups bridged by a peroxide link. Its structural formula is [C6H5C]2O2. It is one of the most important organic peroxides in terms of applications and the scale of its production...
, tetracycline group and other 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, and many antibacterial preparations, including clove oil, PCMX, and chlorhexidine gluconate
Chlorhexidine gluconate
Chlorhexidine is a chemical antiseptic. It is effective on both Gram-positive and Gram-negative bacteria, although it is less effective with some Gram-negative bacteria. It has both bactericidal and bacteriostatic mechanisms of action, the mechanism of action being membrane disruption, not ATPase...
. Tetracycline-resistant P. acnes is now quite common. Clindamycin
Clindamycin
Clindamycin rINN is a lincosamide antibiotic. It is usually used to treat infections with anaerobic bacteria but can also be used to treat some protozoal diseases, such as malaria...
is also frequently used. New facts show that P. acnes is sensitive to some macrolide
Macrolide
The macrolides are a group of drugs whose activity stems from the presence of a macrolide ring, a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered...
s such as azithromycin
Azithromycin
Azithromycin is an azalide, a subclass of macrolide antibiotics. Azithromycin is one of the world's best-selling antibiotics...
, which has a wide spectrum of action. It is normally prescribed 500 mg by mouth, three times weekly for 4 to 6 weeks, but may have post-antibiotic effects by remaining concentrated in lung
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
tissue for approximately 5 days after treatment stops. Fluoroquinolones may also be effective against P. acnes such as nadifloxacin
Nadifloxacin
Nadifloxacin is a topical fluoroquinolone antibiotic for the treatment of acne vulgaris...
, ciprofloxacin
Ciprofloxacin
Ciprofloxacin is a synthetic chemotherapeutic antibiotic of the fluoroquinolone drug class.It is a second-generation fluoroquinolone antibacterial. It kills bacteria by interfering with the enzymes that cause DNA to rewind after being copied, which stops synthesis of DNA and of...
, ofloxacin
Ofloxacin
Ofloxacin is a synthetic chemotherapeutic antibiotic of the fluoroquinolone drug class considered to be a second-generation fluoroquinolone. The original brand, Floxin, has been discontinued by the manufacturer in the United States on 18 June 2009, though generic equivalents continue to be...
and levofloxacin
Levofloxacin
Levofloxacin is a synthetic chemotherapeutic antibiotic of the fluoroquinolone drug class and is used to treat severe or life-threatening bacterial infections or bacterial infections that have failed to respond to other antibiotic classes. It is sold under various brand names, such as Levaquin and...
. They are active against P. acnes and some other microorganism
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
s that are also part of the poly-infection.
Phage sensitivity
P. acnes has known phages that can attack it, and these can be used to type it. Proposals exist to employ lytic phages for therapeutic purposes for acne vulgarisAcne vulgaris
Acne vulgaris is a common human skin disease, characterized by areas of skin with seborrhea , comedones , papules , pustules , Nodules and possibly scarring...
.
Photosensitivity
P. acnes glows orange when exposed to Wood's light— believed to be due to the presence of endogenous porphyrinPorphyrin
Porphyrins are a group of organic compounds, many naturally occurring. One of the best-known porphyrins is heme, the pigment in red blood cells; heme is a cofactor of the protein hemoglobin. Porphyrins are heterocyclic macrocycles composed of four modified pyrrole subunits interconnected at...
s. The bacterium is killed by ultraviolet light
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
. P. acnes is also especially sensitive to light in the 405–420 nm (near the ultraviolet) range due to an endogenic porphyrin–coporphyrin III. A total irradiance
Irradiance
Irradiance is the power of electromagnetic radiation per unit area incident on a surface. Radiant emittance or radiant exitance is the power per unit area radiated by a surface. The SI units for all of these quantities are watts per square meter , while the cgs units are ergs per square centimeter...
of 320 J/cm² is found to inactivate this bacteria in vitro. This fact is used in phototherapy. Its photosensitivity can be enhanced by pretreatment with aminolevulinic acid which boosts production of this chemical, although this causes significant side-effects in humans, and in practice was not significantly better than the light treatment alone.