Actinomycosis is a rare
infectious
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
l disease caused by ''
Actinomyces
''Actinomyces'' is a genus of the Actinomycetia class of bacteria. They all are gram-positive. ''Actinomyces'' species are facultatively anaerobic and they grow best under anaerobic conditions. ''Actinomyces'' species may form endospores, an ...
'' species.
The name refers to ray-like appearance of the organisms in the granules. About 70% of infections are due to either ''
Actinomyces israelii
''Actinomyces israelii'' is a species of Gram-positive, rod-shaped bacteria within the genus ''Actinomyces''. Known to live commensally on and within humans, ''A. israelii'' is an opportunistic pathogen and a cause of actinomycosis. Many physi ...
'' or ''
A. gerencseriae''.
[ Infection can also be caused by '' Streptomyces somaliensis'' and '' Propionibacterium propionicus''. The condition is likely to be a polymicrobial ]anaerobic infection Anaerobic infections are caused by anaerobic bacteria. Obligately anaerobic bacteria do not grow on solid media in room air (0.04% carbon dioxide and 21% oxygen); facultatively anaerobic bacteria can grow in the presence or absence of air. Microaer ...
.
Signs and symptoms
The disease is characterised by the formation of painful abscess
An abscess is a collection of pus that has built up within the tissue of the body. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pressed. The area of redness often extends b ...
es in the mouth
In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...
, lungs
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of th ...
, breast
The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues.
In females, it serves as the mammary gland, which produces and secret ...
, or gastrointestinal tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...
.[ Actinomycosis abscesses grow larger as the disease progresses, often over months. In severe cases, they may penetrate the surrounding bone and muscle to the skin, where they break open and leak large amounts of ]pus
Pus is an exudate, typically white-yellow, yellow, or yellow-brown, formed at the site of inflammation during bacterial or fungal infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection ...
, which often contains characteristic granules filled with progeny bacteria. These granules are often called "sulfur granules" due to their yellow appearance, although they may also be white, gray or brown.
Causes
Actinomycosis is primarily caused by any of several members of the bacterial genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''Actinomyces
''Actinomyces'' is a genus of the Actinomycetia class of bacteria. They all are gram-positive. ''Actinomyces'' species are facultatively anaerobic and they grow best under anaerobic conditions. ''Actinomyces'' species may form endospores, an ...
''. These bacteria are generally anaerobes
An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenate ...
. In animals, they normally live in the small spaces between the teeth and gums, causing infection only when they can multiply freely in anoxic
The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts:
* Anoxic waters, sea water, fresh water or groundwater that are depleted of diss ...
environments. An affected human often has recently had dental work, poor oral hygiene
Oral hygiene is the practice of keeping one's mouth clean and free of disease and other problems (e.g. bad breath) by regular brushing of the teeth (dental hygiene) and cleaning between the teeth. It is important that oral hygiene be carried out ...
, periodontal disease
Periodontal disease, also known as gum disease, is a set of inflammatory conditions affecting the tissues surrounding the teeth. In its early stage, called gingivitis, the gums become swollen and red and may bleed. It is considered the main caus ...
, radiation therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...
, or trauma (broken jaw) causing local tissue damage to the oral mucosa
The oral mucosa is the mucous membrane lining the inside of the mouth. It comprises stratified squamous epithelium, termed "oral epithelium", and an underlying connective tissue termed ''lamina propria''. The oral cavity has sometimes been descri ...
, all of which predispose the person to developing actinomycosis. ''A. israelii'' is a normal commensal
Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...
species part of the microbiota species of the lower reproductive tract of women. They are also normal commensals among the gut flora
Gut microbiota, gut microbiome, or gut flora, are the microorganisms, including bacteria, archaea, fungi, and viruses that live in the digestive tracts of animals. The gastrointestinal metagenome is the aggregate of all the genomes of the gut mi ...
of the caecum
The cecum or caecum is a pouch within the peritoneum that is considered to be the beginning of the large intestine. It is typically located on the right side of the body (the same side of the body as the appendix, to which it is joined). The wo ...
; thus, abdominal actinomycosis can occur following removal of the appendix. The three most common sites of infection are decayed teeth, the lungs, and the intestines
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans ...
. Actinomycosis infections are typically polymicrobial, containing additional bacterial species; as ''Actinomyces'' itself has little invasive ability, these other species often aid in the infection process.
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Diagnosis
The diagnosis of actinomycosis can be a difficult one to make. In addition to microbiological examinations, magnetic resonance imaging
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio wave ...
and immunoassay
An immunoassay (IA) is a biochemical test that measures the presence or concentration of a macromolecule or a small molecule in a solution through the use of an antibody (usually) or an antigen (sometimes). The molecule detected by the immunoass ...
s may be helpful.
Treatment
''Actinomyces'' bacteria are generally sensitive to penicillin
Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum using ...
, which is frequently used to treat actinomycosis. In cases of penicillin allergy, doxycycline
Doxycycline is a broad-spectrum tetracycline class antibiotic used in the treatment of infections caused by bacteria and certain parasites. It is used to treat bacterial pneumonia, acne, chlamydia infections, Lyme disease, cholera, typhus, an ...
is used.
Sulfonamides
In organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this group is unreactive. ...
such as sulfamethoxazole may be used as an alternative regimen at a total daily dosage of 2–4 grams. Response to therapy is slow and may take months.
Hyperbaric oxygen therapy may also be used as an adjunct to conventional therapy when the disease process is refractory to antibiotics and surgical treatment.
Epidemiology
Disease incidence is greater in males between the ages of 20 and 60 years than in females. Before antibiotic treatments became available, the incidence in the Netherlands and Germany was one per 100,000 people/year. Incidence in the U.S. in the 1970s was one per 300,000 people/year, while in Germany in 1984, it was estimated to be one per 40,000 people/year. The use of intrauterine device
An intrauterine device (IUD), also known as intrauterine contraceptive device (IUCD or ICD) or coil, is a small, often T-shaped birth control device that is inserted into the uterus to prevent pregnancy. IUDs are one form of long-acting rever ...
s (IUDs) has increased incidence of genitourinary actinomycosis in females. Incidence of oral actinomycosis, which is harder to diagnose, has increased.
History
In 1877, pathologist
Pathology is the study of the causal, causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when us ...
Otto Bollinger
Otto Bollinger (2 April 1843 – 13 August 1909) was a German pathologist born in Altenkirchen, Kusel, Rhineland-Palatinate.
In 1868, he obtained his doctorate in Berlin and two years later received his habilitation. He taught classes at the ...
described the presence of ''A. bovis'' in cattle, and shortly afterwards, James Israel
James Adolf Israel (2 February 1848 – 2 February 1926) was a German surgeon.
Academic background
Israel was a native of Berlin, where he was born to Jewish parents. In 1870, Israel received his medical doctorate from Friedrich-Wilhelm ...
discovered ''A. israelii'' in humans. In 1890, Eugen Bostroem isolated the causative organism from a culture of grain, grasses, and soil. After Bostroem's discovery, a general misconception existed that actinomycosis was a mycosis
Fungal infection, also known as mycosis, is disease caused by fungi. Different types are traditionally divided according to the part of the body affected; superficial, subcutaneous, and systemic. Superficial fungal infections include common ti ...
that affected individuals who chewed grass or straw. The pathogen is still known as the “great masquerader". ''Bergey's Manual of Systematic Bacteriology
''Bergey's Manual of Systematic Bacteriology'' is the main resource for determining the identity of prokaryotic organisms, emphasizing bacterial species, using every characterizing aspect.
The manual was published subsequent to the ''Bergey's Manu ...
'' classified the organism as bacterial in 1939, but the disease remained classified as a fungus in the 1955 edition of the '' Control of Communicable Diseases in Man''.
Violinist Joseph Joachim
Joseph Joachim (28 June 1831 – 15 August 1907) was a Hungarian violinist, conductor, composer and teacher who made an international career, based in Hanover and Berlin. A close collaborator of Johannes Brahms, he is widely regarded as one of ...
died of actinomycosis on 15 August 1907.
The Norwegian painter Halfdan Egedius
Halfdan Egedius (May 5, 1877 – February 2, 1899) was a Norwegian painter and illustrator.
Biography
Halfdan Johnsen Egedius was born in Drammen in Buskerud county and grew up in Christiania (now Oslo). His interest in painting and illustratio ...
died from actinomycosis on 2 February 1899.
Other animals
Actinomycosis occurs rarely in humans, but rather frequently in cattle
Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...
as a disease called "lumpy jaw". This name refers to the large abscess
An abscess is a collection of pus that has built up within the tissue of the body. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pressed. The area of redness often extends b ...
es that grow on the head and neck of the infected animal. It can also rarely affect sheep, swine, horses, dogs, and other mammals.
References
Further reading
*
External links
{{Gram-positive actinobacteria diseases
Bacterial diseases
Atypical pneumonias