''Aspergillus sydowii'' is a

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...

that causes several diseases in humans. It has been implicated in the death of

sea fan Alcyonacea, or soft corals, are an order of corals. In addition to the fleshy soft corals, the order Alcyonacea now contains all species previously known as "gorgonian corals", that produce a more or less hard skeleton, though quite different f ...

corals (''

Gorgonia ''Gorgonia'' is a genus of soft corals, sea fans in the family Gorgoniidae. Species The World Register of Marine Species lists these species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, ...

'' spp.) in the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

Taxonomy

The species was first described in 1913 as ''Sterigmatocystis sydowii'' by

Georges Bainier Georges may refer to: Places * Georges River, New South Wales, Australia * Georges Quay (Dublin) *Georges Township, Fayette County, Pennsylvania Other uses *Georges (name) * ''Georges'' (novel), a novel by Alexandre Dumas * "Georges" (song), a 19 ...

and Auguste Theodore Sartory.

Charles Thom Charles Thom (November 11, 1872 – May 24, 1956) was an American microbiologist and mycologist. Born and raised in Illinois, he received his PhD from the University of Missouri, the first such degree awarded by that institution. He was best k ...

and Margaret Brooks Church transferred it to ''

Aspergillus ' () is a genus consisting of several hundred mold species found in various climates worldwide. ''Aspergillus'' was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Miche ...

'' in 1926.

Description

When grown in

pure culture A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled laboratory conditions. Microbial cultures are foundational and basic diagn ...

on agar plates, ''A. sydowii'' produces blue-green

colonies In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state'' ...

with reddish-brown shades. The

conidia A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the ...

l heads are effuse (spread out), while the stalks of the

conidiophore A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an Asexual reproduction, asexual, non-motility, motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are al ...

s are

hyaline A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none. Histopathology Hyaline cartilage is ...

(translucent), smooth, and measure up to 500 μm. Swollen cells (vesicles) are spherical or nearly so, and the conidiogenous cells (cells that produce conidia) are biseriate—having

phialide The phialide ( ; el, phialis, diminutive of phiale, a broad, flat vessel) is a flask-shaped projection from the vesicle (dilated part of the top of conidiophore) of certain fungi. It projects from the mycelium without increasing in length unless ...

s that arise from metulae (sterile cells below the phialides). The conidia are echinulate (spiky), roughly spherical, and measure 2.5–4.0 μm in diameter.

Habitat and distribution

''Aspergillus sydowii'' is a

saprophytic Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi (f ...

fungus found in soil that can contaminate food and is occasionally pathogenic to humans. It is the predominant fungus found on wheat ''Qu'', the most widely used source of raw microorganisms and crude enzymes for Chinese

rice wine Rice wine is an alcoholic beverage fermented and distilled from rice, traditionally consumed in East Asia, Southeast Asia and South Asia. Rice wine is made by the fermentation of rice starch that has been converted to sugars. Microbes are the so ...

brewing. Since the 1990s it has been found to be present in sea water in the Caribbean region and has been shown to be the cause of

aspergillosis Aspergillosis is a fungal infection of usually the lungs, caused by the genus ''Aspergillus'', a common mould that is breathed in frequently from the air around, but does not usually affect most people. It generally occurs in people with lung dise ...

in sea fans. It is not known to reproduce in the marine environment and several hypotheses exist as to its source. The infective agent may have always existed in the ocean but not previously caused the disease or it may have accumulated after run-off of soil from land. The hypothesis that it entered the ocean via dust blown across the Atlantic from Africa seems unlikely to be correct as none of the samples of dust collected from African locations contained ''A. sydowii'' though they did contain other species of ''

''. A more likely

vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

seems to be the

flamingo tongue snail The flamingo tongue snail (''Cyphoma gibbosum'') is a species of small but brightly colored sea snail, a marine gastropod mollusk in the family Ovulidae, the cowry allies. Distribution This is the most common of several species in the genus ...

(''Cyphoma gibbosum''), a specialist

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

on sea fans, and the fungus has been found in its faeces.

Pathogenicity

''Aspergillus sydowii'' has been implicated in the

pathogenesis Pathogenesis is the process by which a disease or disorder develops. It can include factors which contribute not only to the onset of the disease or disorder, but also to its progression and maintenance. The word comes from Greek πάθος ''pat ...

of several human diseases, including

onychomycosis Onychomycosis, also known as tinea unguium, is a fungal infection of the nail. Symptoms may include white or yellow nail discoloration, thickening of the nail, and separation of the nail from the nail bed. Toenails or fingernails may be affected ...

, and

keratomycosis Fungal keratitis is a fungal infection of the cornea, which can lead to blindness. It generally presents with a red, painful eye and blurred vision. There is also increased sensitivity to light, and excessive tears or discharge. It is cause ...

Infection of sea fans

The sea fan ''

Gorgonia ventalina ''Gorgonia ventalina'', the common sea fan and purple sea fan, is a species of sea fan, an octocoral in the family Gorgoniidae. It is found in the western Atlantic Ocean and the Caribbean Sea. Description ''G. ventalina'' is a fan-shaped col ...

'' can be infected by ''Aspergillus sydowii''. An

epizootic In epizoology, an epizootic (from Greek: ''epi-'' upon + ''zoon'' animal) is a disease event in a nonhuman animal population analogous to an epidemic in humans. An epizootic may be restricted to a specific locale (an "outbreak"), general (an "epi ...

epidemic occurred in the 1990s in the Caribbean resulting in the death or injury of many gorgonians. Large individuals were more affected than small ones and reproduction was reduced in infected specimens. The immune response of the sea fan included increased production of

melanin Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...

and other

secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the norm ...

s including

chitinase Chitinases (EC 3.2.1.14, chitodextrinase, 1,4-β-poly-N-acetylglucosaminidase, poly-β-glucosaminidase, β-1,4-poly-N-acetyl glucosamidinase, poly ,4-(N-acetyl-β-D-glucosaminide)glycanohydrolase, (1→4)-2-acetamido-2-deoxy-β-D-glucan glycano ...

and

peroxidase Peroxidases or peroxide reductases ( EC numberbr>1.11.1.x are a large group of enzymes which play a role in various biological processes. They are named after the fact that they commonly break up peroxides. Functionality Peroxidases typically ca ...

, and the aggregation of

amoebocyte An amebocyte or amoebocyte () is a mobile cell (moving like an amoeba) in the body of invertebrates including cnidaria, echinoderms, molluscs, tunicates, sponges and some chelicerates. They move by pseudopodia. Similarly to some of the white blood c ...

s at the infection site.

Bioactive compounds

Several

indole alkaloids Indole alkaloids are a class of alkaloids containing a structural moiety of indole; many indole alkaloids also include isoprene groups and are thus called terpene indole or secologanin tryptamine alkaloids. Containing more than 4100 known differe ...

have recently (2012) been isolated from laboratory-grown

cultures Culture () is an umbrella term which encompasses the social behavior, institutions, and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups.Tyl ...

of the fungus. The compounds -(2-methoxyphenyl)-1-piperazinyl(1-methyl-1H-indol-3-yl)]-methanone, cyclotryprostatin B, fumiquinazoline D, fumitremorgin B, fumiquinazoline C, fumiquinazoline B, fumiquinazoline A, fumiquinazoline F, fumiquinazoline G are all previously known to science, having been found in other ''Aspergillus'' species. Cyclotryprostatin E is a novel compound, known only from this species. Other biological activity, bioactive compounds known to be unique to this fungus include aspergillusenes A and B, (+)-(7''S'')-7-O-methylsydonic acid, and hydrogenated

xanthone Xanthone is an organic compound with the molecular formula O 6H4CO. It is a white solid. In 1939, xanthone was introduced as an insecticide and it currently finds uses as Insecticide, ovicide for codling moth eggs and as a larvicide. Xanthone ...

derivatives aspergillusones A and B. The strain ''A. sydowii'' F5, originally isolated from Chinese wheat, contains an

alpha-galactosidase α-Galactosidase ( EC 3.2.1.22, α-GAL, α-GAL A; systematic name α-D-galactoside galactohydrolase) is a glycoside hydrolase enzyme that catalyses the following reaction: : Hydrolysis of terminal, non-reducing α-D-galactose residues in α-D- ...

enzyme; this enzyme, which

hydrolyses Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis ...

the terminal alpha-galactosyl moieties from

glycolipid Glycolipids are lipids with a carbohydrate attached by a glycosidic (covalent) bond. Their role is to maintain the stability of the cell membrane and to facilitate cellular recognition, which is crucial to the immune response and in the connec ...

s and

glycoprotein Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycos ...

s, is used in

enzyme replacement therapy Enzyme replacement therapy (ERT) is a medical treatment which replaces an enzyme that is deficient or absent in the body. Usually, this is done by giving the patient an intravenous (IV) infusion of a solution containing the enzyme. ERT is availab ...

to functionally compensate for genetic alpha-galactosidase A deficiency.

References

{{Taxonbar, from=Q4807901 sydowii Fungi described in 1913