''Apophysomyces'' is a
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of filamentous
fungi
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
that are commonly found in soil and decaying vegetation. Species normally grow in
tropical
The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...
to
subtropical
The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...
regions.
The genus ''Apophysomyces'' historically was
monospecific
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...
, containing only the
type species
In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...
''
Apophysomyces elegans''. In 2010, three new species were described: ''variabilis'', ''trapeziformis'', and ''ossiformis''.
Characteristics
Among the other members of zygomycetes, ''Apophysomyces elegans'' mostly resembles those from genus ''
Absidia
''Absidia'' is a genus of fungi in the family Cunninghamellaceae. ''Absidia'' species are ubiquitous in most environments where they are often associated with warm decaying plant matter, such as compost heaps. Some species in the genus can caus ...
''. However, its bell-shaped (although not conical) apophyses (outgrowth), the existence of its foot-cell like
hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one o ...
l segment,
rhizoid
Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the root hairs of vascular land plants. Similar structures are formed by some fungi. Rhizoids may be un ...
s produced opposite to the sporangiophores upon cultivation on plain
agar
Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from " ogonori" and " tengusa". As found in nature, agar is a mixture of two components, t ...
, the darker and thicker
subapical
A subapical consonant is a consonant made by contact with the underside of the tip of the tongue. The only common subapical articulations are in the postalveolar to palatal region, which are called "retroflex".
Most so-called retroflex consonants ...
segment, and inability to
sporulate on routine culture media help in distinguishing ''Apophysomyces elegans''.
[Davise H. Larone, "Medically Important Fungi - A Guide to Identification", 3rd ed. (1995). (ASM Press, Washington, D.C.). (ISBN is for 4th ed.)]
''Apophysomyces elegans'' is a thermotolerant fungus: it has been found to grow favourably at temperatures of 26 °C and 37 °C, and it grows rapidly at 42 °C. Its colonies are fluffy and cottony in appearance. The surface of the colony is white initially and turns to a brownish-grey or yellowish-cream as the culture ages, while the underside is white to pale yellow in colour.
Pathogenicity
Normally, no special precautions are needed with regard to this
fungus
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
.
However, ''Apophysomyces elegans'' and ''Apophysomyces trapeziformis'' are able to cause
mucormycosis
Mucormycosis, also known as black fungus, is a severe fungal infection that comes under fulminant fungal sinusitis, usually in people who are immunocompromised. It is curable only when diagnosed early. Symptoms depend on where in the body the ...
, in humans, which is often fatal but very rare.
Reports of other mammals being infected are mostly restricted to captive species, but in 2021 a female
lesser long-nosed bat
The lesser long-nosed bat (''Leptonycteris yerbabuenae'') is a medium-sized bat found in Central and North America. It is sometimes known as Sanborn's long-nosed bat or the Mexican long-nosed bat, though the latter name is better avoided since it ...
was found with
mucormycosis
Mucormycosis, also known as black fungus, is a severe fungal infection that comes under fulminant fungal sinusitis, usually in people who are immunocompromised. It is curable only when diagnosed early. Symptoms depend on where in the body the ...
in the wild.
Infection is usually acquired via traumatic implantations associated with soil or decaying vegetable matter (such as from accidental injuries or insect bites). Invasive soft tissue infections can develop on burns or wounds which are contaminated by soil. Unlike other
zygomycosis, the affected host is usually otherwise
immunocompetent
In immunology, immunocompetence is the ability of the body to produce a normal immune response following exposure to an antigen. Immunocompetence is the opposite of immunodeficiency (also known as ''immuno-incompetence'' or being ''immuno-comprom ...
. ''Apophysomyces elegans'' infections present most commonly as
necrotizing fasciitis
Necrotizing fasciitis (NF), also known as flesh-eating disease, is an infection that kills the body's soft tissue. It is a serious disease that begins and spreads quickly. Symptoms include red or purple or black skin, swelling, severe pain, fever ...
and/or
osteomyelitis
Osteomyelitis (OM) is the infectious inflammation of bone marrow. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The feet, spine, and hips are the most commonly involved bones in adults.
The cause is ...
.
Systemic and secondary renal and
bladder infections
have also been reported.
See also
*
Mucormycosis
Mucormycosis, also known as black fungus, is a severe fungal infection that comes under fulminant fungal sinusitis, usually in people who are immunocompromised. It is curable only when diagnosed early. Symptoms depend on where in the body the ...
(specific term for infection caused by fungi of the order Mucorales)
*
Zygomycosis (a more generic term for infection caused by Mucoraceae and various other fungus varieties; the term
Mucormycosis
Mucormycosis, also known as black fungus, is a severe fungal infection that comes under fulminant fungal sinusitis, usually in people who are immunocompromised. It is curable only when diagnosed early. Symptoms depend on where in the body the ...
is preferred).
References
External links
Image of ''Apophysomyces sp.''''Apophysomyces'' species
from Index Fungorum
PubMed search page
(using search term "''apophysomyces''")
{{Taxonbar, from=Q4780512
Zygomycota
Zygomycota genera