Mucormycosis
Encyclopedia
Zygomycosis is the broadest term to refer to infections caused by bread mold fungi of the zygomycota
phylum. However, because zygomycota has been identified as polyphyletic
, and is not included in modern fungal classification systems, the diseases that Zygomycosis can refer to are better called by their specific names: mucormycosis (after Mucorales
), phycomycosis (after Phycomycetes
) and basidiobolomycosis (after Basidiobolus). These rare yet serious and potentially life-threatening fungal infections, usually affect the face
or oropharyngeal (nose/mouth) cavity. Zygomycosis type infections are most often caused by common fungi found in soil and decaying vegetation. While most individuals are exposed to the fungi on a regular basis those with immune disorders, the immunocompromised, are more prone to fungal infection. These types of infections are also common after natural disasters, such as tornadoes or earthquakes, where people have open wounds that have become filled with soil or vegetative matter.
The condition may affect the gastrointestinal tract
or the skin
. In non-trauma cases, it usually begins in the nose and paranasal sinuses and is one of the most rapidly spreading fungal infections in humans. Common symptoms include thrombosis
and tissue necrosis
. Treatment consists of prompt and intensive antifungal drug
therapy and surgery
to remove the infected tissue. The prognosis varies vastly depending upon an individual patient's circumstances.
and Entomophthorales
, with the former causing far more disease than the latter. These diseases are known as "mucormycosis" and "entomophthoramycosis", respectively.
s and horse
s. These are heterokont
s, not true fungi. Types include pythiosis
(caused by Pythium insidiosum
) and lagenidiosis
.
Zygomycosis has been described in a cat
, where fungal infection of the tracheobronchus
led to respiratory disease requiring euthanasia.
.
Zygomycota
Zygomycota, or zygote fungi, is a phylum of fungi. The name comes from zygosporangia, where resistant spherical spores are formed during sexual reproduction. Approximately 1060 species are known. They are mostly terrestrial in habitat, living in soil or on decaying plant or animal material...
phylum. However, because zygomycota has been identified as polyphyletic
Polyphyly
A polyphyletic group is one whose members' last common ancestor is not a member of the group.For example, the group consisting of warm-blooded animals is polyphyletic, because it contains both mammals and birds, but the most recent common ancestor of mammals and birds was cold-blooded...
, and is not included in modern fungal classification systems, the diseases that Zygomycosis can refer to are better called by their specific names: mucormycosis (after Mucorales
Mucorales
The Mucorales is the largest and best studied order of Zygomycete fungi. Members of this order are sometimes called pin molds.-Systematics:...
), phycomycosis (after Phycomycetes
Phycomycetes
Phycomycetes is an obsolete taxon for certain fungi with nonseptate hyphae.These fungi are currently classified under Zygomycota....
) and basidiobolomycosis (after Basidiobolus). These rare yet serious and potentially life-threatening fungal infections, usually affect the face
Face
The face is a central sense organ complex, for those animals that have one, normally on the ventral surface of the head, and can, depending on the definition in the human case, include the hair, forehead, eyebrow, eyelashes, eyes, nose, ears, cheeks, mouth, lips, philtrum, temple, teeth, skin, and...
or oropharyngeal (nose/mouth) cavity. Zygomycosis type infections are most often caused by common fungi found in soil and decaying vegetation. While most individuals are exposed to the fungi on a regular basis those with immune disorders, the immunocompromised, are more prone to fungal infection. These types of infections are also common after natural disasters, such as tornadoes or earthquakes, where people have open wounds that have become filled with soil or vegetative matter.
The condition may affect 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. ....
or 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...
. In non-trauma cases, it usually begins in the nose and paranasal sinuses and is one of the most rapidly spreading fungal infections in humans. Common symptoms include thrombosis
Thrombosis
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
and tissue necrosis
Necrosis
Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
. Treatment consists of prompt and intensive antifungal drug
Antifungal drug
An antifungal medication is a medication used to treat fungal infections such as athlete's foot, ringworm, candidiasis , serious systemic infections such as cryptococcal meningitis, and others...
therapy and surgery
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
to remove the infected tissue. The prognosis varies vastly depending upon an individual patient's circumstances.
Causes
Pathogenic Zygomycosis is caused by species in two orders: MucoralesMucorales
The Mucorales is the largest and best studied order of Zygomycete fungi. Members of this order are sometimes called pin molds.-Systematics:...
and Entomophthorales
Entomophthorales
The Entomophthorales are an order of fungi that were previously classified in the class Zygomycetes. A new subphylum, Entomophthoromycotina, has recently been described for them.Most species of the Entomophthorales are pathogens of insects...
, with the former causing far more disease than the latter. These diseases are known as "mucormycosis" and "entomophthoramycosis", respectively.
- Order MucoralesMucoralesThe Mucorales is the largest and best studied order of Zygomycete fungi. Members of this order are sometimes called pin molds.-Systematics:...
(mucormycosisMucormycosisZygomycosis is the broadest term to refer to infections caused by bread mold fungi of the zygomycota phylum. However, because zygomycota has been identified as polyphyletic, and is not included in modern fungal classification systems, the diseases that Zygomycosis can refer to are better called by...
)- Family MucoraceaeMucoraceaeThe Mucoraceae are a family of fungi of the order Mucorales, characterized by having the thallus not segmented or ramified. Pathogenic genera include Absidia, Apophysomyces, Mucor, Rhizomucor, and Rhizopus. According to a 2008 estimate, the family contains 25 genera and 129...
- AbsidiaAbsidiaAbsidia is a genus of fungi in the family Mucoraceae. The best known species is the pathogenic Absidia corymbifera, which causes zygomycosis, especially in the form of mycotic spontaneous abortion in cows. It can also cause mucormycosis in humans. It is an allergenic that could cause mucorosis in...
(Absidia corymbiferaAbsidia corymbiferaAbsidia corymbifera is a species in the genus Absidia.It can cause human disease.It is sometimes referred to as Mycocladus corymbifer....
) - ApophysomycesApophysomycesApophysomyces is a filamentous fungus that is commonly found in soil and decaying vegetation. It normally grows in tropical to subtropical regions....
(Apophysomyces elegans) - MucorMucorMucor is a microbial genus of about 3000 species of moulds commonly found in soil, digestive systems, plant surfaces, and rotten vegetable matter.-Description:...
(Mucor indicusMucor indicusMucor indicus is a species of Mucor.It can cause human disease....
) - RhizomucorRhizomucorRhizomucor is a genus of fungi in the Mucoraceae family. The widespread genus contains six species. Rhizomucor parasiticus, the species originally selected as the type, is now considered synonymous with Rhizomucor pusillus....
(Rhizomucor pusillusRhizomucor pusillusRhizomucor pusillus is a species of Rhizomucor.It can cause human disease....
) - RhizopusRhizopusRhizopus is a genus of common saprobic fungi on plants and specialized parasites on animals. They are found on a wide variety of organic substrates, including "mature fruits and vegetables", faeces, jellies, syrups, leather, bread, peanuts and tobacco. Some Rhizopus species are opportunistic agents...
(Rhizopus oryzaeRhizopus oryzaeRhizopus oryzae is a fungus that lives worldwide in dead organic matter. An opportunistic human pathogen, it is one causative agent of zygomycosis . The RA 99-880 strain, which was isolated from a fatal infection, had its genome sequenced by the Broad Institute in 2004–2005. R...
)
- Absidia
- Family CunninghamellaceaeCunninghamellaceaeCunninghamellaceae is a family of fungi in the Mucorales order....
- CunninghamellaCunninghamellaCunninghamella is a genus of fungus in the Mucorales order, and the family Cunninghamellaceae. Members of this genus are often used in studies investigating the metabolism of drugs, because these species metabolize a wide range of drugs in manners similar to mammalian enzyme systems...
(Cunninghamella bertholletiaeCunninghamella bertholletiaeCunninghamella bertholletiae is a species of Cunninghamella.It can cause human disease....
)
- Cunninghamella
- Family ThamnidiaceaeThamnidiaceaeThe Thamnidiaceae are a family of fungi in the order Mucorales....
- Cokeromyces (Cokeromyces recurvatusCokeromyces recurvatusCokeromyces recurvatus is a pathogenic fungus. Described as a new species in 1950, it was isolated from rabbit dung collected in Illinois.It appears similar to Coccidioides immitis....
)
- Cokeromyces (Cokeromyces recurvatus
- Family SaksenaeaceaeSaksenaeaceaeThe Saksenaeaceae are a family of fungi in the order Mucorales.-Description:This family is characterized by having sporangia that are lageniform and columellate. Zygospores are unknown....
- SaksenaeaSaksenaeaSaksenaea is a genus of fungi in the Saksenaeaceae family. Circumscribed in 1953, the genus contains two pathogenic species capable of causing severe human infections....
(Saksenaea vasiformisSaksenaea vasiformisSaksenaea vasiformis is an infectious fungus associated with cutaneous or subcutaneous lesions following trauma.-External links:* Description...
)
- Saksenaea
- Family SyncephalastraceaeSyncephalastraceaeThe Syncephalastraceae are a family of fungi in the order Mucorales. Members of this family have a widespread distribution, but are more common in tropical and subtropical regions.-Description:...
- Syncephalastrum (Syncephalastrum racemosum)
- Family Mucoraceae
- Order EntomophthoralesEntomophthoralesThe Entomophthorales are an order of fungi that were previously classified in the class Zygomycetes. A new subphylum, Entomophthoromycotina, has recently been described for them.Most species of the Entomophthorales are pathogens of insects...
(entomophthoramycosisEntomophthoramycosisEntomophthoramycosis is a mycosis caused by Entomophthorales.Examples include basidiobolomycosis and conidiobolomycosis.-Treatment:...
)- Family BasidiobolaceaeBasidiobolaceaeThe Basidiobolaceae are a family of fungi in the order Entomophthorales....
- Basidiobolus (Basidiobolus ranarumBasidiobolus ranarumBasidiobolus ranarum is a microscopic fungus in the order Entomophthorales.-Life cycle:It produces large, spherical, asexual spores that are forcibly discharged. These spores can germinate directly to produce hyphae...
)
- Basidiobolus (Basidiobolus ranarum
- Family AncylistaceaeAncylistaceaeThe Ancylistaceae are a family of fungi in the order Entomophthorales....
- ConidiobolusConidiobolusConidiobolus is a genus of fungi.It is responsible for the condition conidiobolomycosis.Species include Conidiobolus coronatus and Conidiobolus incongruus....
(Conidiobolus coronatusConidiobolus coronatusConidiobolus coronatus is a species of Conidiobolus.It is associated with conidiobolomycosis....
/Conidiobolus incongruusConidiobolus incongruusConidiobolus incongruus is a species of Conidiobolus.It is associated with conidiobolomycosis....
)
- Conidiobolus
- Family Basidiobolaceae
Oomycosis in animals
The term oomycosis is used to describe oomycete infections. These are more common in animals, notably dogDog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s and horse
Horse
The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...
s. These are heterokont
Heterokont
The heterokonts or stramenopiles are a major line of eukaryotes currently containing more than 100,000 known species. Most are algae, ranging from the giant multicellular kelp to the unicellular diatoms, which are a primary component of plankton...
s, not true fungi. Types include pythiosis
Pythiosis
Pythiosis is a form of infectious disease caused by Pythium insidiosum. It occurs most commonly in dogs and horses, but is also found in cats, cattle, and humans. The disease is typically found in young, large breed dogs. Pythium occupies swamps in late summer and infects dogs who drink water...
(caused by Pythium insidiosum
Pythium insidiosum
Pythium insidiosum is a species of Pythium.It can cause pythiosis....
) and lagenidiosis
Lagenidiosis
Lagenidiosis is a type of infectious disease.The best known species of Lagenidium is Lagenidium giganteum, a parasite of mosquito larvae used in biological control of mosquitoes. The disease lagenidiosis in dogs is caused by a new species of Lagenidium that has not yet been properly named. ...
.
Zygomycosis has been described in a cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
, where fungal infection of the tracheobronchus
Tracheobronchial tree
The tracheobronchial tree is the structure from the trachea, bronchi, and bronchioles that forms the airways that supply air to the lungs. It is within the neck and the chest. The structure looks like a tree because the trachea splits into the right and left mainstem bronchi, which "branch" into...
led to respiratory disease requiring euthanasia.
Zygomycosis in natural disasters
Zygomycosis has been found in survivors of the 2004 Indian Ocean earthquake and tsunami and in survivors of 2011 Joplin, Missouri tornado2011 Joplin tornado
The 2011 Joplin tornado was a devastating EF5 multiple-vortex tornado that struck Joplin, Missouri, USA late in the afternoon of Sunday, May 22, 2011. It was part of a larger late-May tornado outbreak sequence and reached a maximum width of in excess of during its path through the southern part of...
.