''Cladosporium cladosporioides'' is a darkly pigmented mold that occurs world-wide on a wide range of materials both outdoors and indoors. It is one of the most common fungi in outdoor air where its spores are important in seasonal allergic disease. While this species rarely causes invasive disease in animals, it is an important agent of plant disease, attacking both the leaves and fruits of many plants. This species produces asexual spores in delicate, branched chains that break apart readily and drift in the air. It is able to grow under low water conditions and at very low temperatures.

History and classification

Georg Fresenius Johann Baptist Georg Wolfgang Fresenius (25 September 1808 – 1 December 1866) was a German physician and botanist, known for his work in the field of phycology. He was a native of Frankfurt am Main. He studied medicine at the Universities of ...

first described ''Cladosporium cladosporioides'' in 1850, classifying it in the genus ''

Penicillium ''Penicillium'' () is a genus of ascomycetous fungi that is part of the mycobiome of many species and is of major importance in the natural environment, in food spoilage, and in food and drug production. Some members of the genus produce pe ...

'' as ''Penicillium cladosporioides''. In 1880

Pier Andrea Saccardo Pier Andrea Saccardo (23 April 1845 in Treviso, Treviso – 12 February 1920 in Padua) was an Italian botanist and mycologist. Life Saccardo studied at the Lyceum in Venice, and then at the Technical Institute of the University of Padua wher ...

renamed the species, ''Hormodendrum cladosporioides''. Other early names for this taxon included ''Cladosporium hypophyllum'', ''Monilia humicola'' and ''Cladosporium pisicola''. In 1952 that Gerardus Albertus de Vries transferred the species to the genus ''

Cladosporium ''Cladosporium'' is a genus of fungi including some of the most common indoor and outdoor molds. Species produce olive-green to brown or black colonies, and have dark-pigmented conidia that are formed in simple or branching chains. Many species ...

'' where it remains today.

Growth and morphology

''Cladosporium cladosporioides''

reproduces asexually Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the fu ...

and because no

teleomorph In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota: *Teleomorph: the sexual reproductive stage (morph), typically a fruiting body. *Anamorph: an ase ...

has been identified, it is considered an exclusively anamorphic species. Colonies are olive-green to olive-brown and appear velvety or powdery. On a

potato dextrose agar Potato dextrose agar (BAM Media M127
from the U.S.

(PDA) medium, colonies are olive-grey to dull green, velvety and tufted. The edges of the colony can be olive-grey to white, and feathery. The colonies are diffuse and the

mycelia Mycelium (plural mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Fungal colonies composed of mycelium are found in and on soil and many other substrates. A typical single spore germinates ...

form mats and rarely grow upwards from the surface of the colony. On a malt extract agar (MEA) medium, colonies are olive-grey to olive or whitish due to the mycelia growing upwards, and seem velvety to tufted with olive-black or olive-brown edges. The mycelia can be diffuse to tufted and sometimes covers the whole colony. The mycelia appear felt-like, grows flat, and can be effused and furrowed. On oatmeal agar (OA) medium, colonies are olive-grey and there can be a gradient toward the edges of the colony from olive green to dull green, then olive-grey. The upward growth of mycelia can be sparse to abundant and tufted. The mycelia and can be loose to dense and tends to grow flat. ''Cladosporium cladosporioides'' has sparse, unbranched or rarely branched, darkly-pigmented

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 or ...

e that are typically not constricted at the septa. Mature conidiophores are treelike and comprise many long, branched chains of

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 ...

. ''Cladosporium cladosporioides'' produces brown to olive-brown coloured, solitary conidiophores that branch irregularly, forming many ramifications. Each branch tends to be between 40–300 µm in length (exceptionally up to 350 µm) and 2–6 µm in width. The

conidiophores 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 ...

are thin-walled and cylindrical and are formed at the end of ascending hyphae. The conidia are small, single-celled, lemon-shaped and smooth-walled. They form long, fragile chains up to 10 conidia in length with distinctive darkened connective tissue between each spore.

Physiology

''Cladosporium cladosporioides'' produces

antifungal An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as crypto ...

metabolites targeted toward plant pathogens. Three different compounds isolated from ''C. cladosporioides'' ( cladosporin, isocladosporin and 5′-hydroxyasperentin), as well as a compound ( 5′,6-diacetyl cladosporin) synthesized from 5′-hydroxyasperentin have antifungal properties. As these compounds are effective against different types of fungi, ''C. cladosporioides'' is an important species for potential treatment and control of various plant-infecting fungi. The inoculation of ''

Venturia inaequalis ''Venturia inaequalis'' is an ascomycota, ascomycete fungus that causes the apple scab disease. Systematics ''Venturia inaequalis'' anamorphs have been described under the names ''Fusicladium dendriticum'' and ''Spilocaea pomi''. Whether ''V. in ...

'', a fungus that causes

apple scab Apple scab is a common disease of plants in the rose family ( Rosaceae) that is caused by the ascomycete fungus ''Venturia inaequalis''. While this disease affects several plant genera, including ''Sorbus, Cotoneaster,'' and '' Pyrus'', it is m ...

on apple tree leaves, with ''C. cladosporioides'' led to decreased conidial production in ''V. inaequalis''. As this effect is seen both on younger and older leaves ''C. cladosporioides'' is effective in preventing and controlling infections of ''V. inaequalis'' in apple trees. This species also produces calphostins A, B, C, D and I, which are

protein kinase C In cell biology, Protein kinase C, commonly abbreviated to PKC (EC 2.7.11.13), is a family of protein kinase enzymes that are involved in controlling the function of other proteins through the phosphorylation of hydroxyl groups of serine and t ...

inhibitors. These calphostins have

cytotoxic Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa''). Cell physiology Treating cells ...

activity due to their ability to inhibit

activity.

Ecology

''Cladosporium cladosporioides'' is a common

saprotroph 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 ...

occurring as a secondary infection on decaying, or

necrotic Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...

, parts of plants. This fungus is xerophilic – growing well in low

water activity Water activity (''aw'') is the partial vapor pressure of water in a solution divided by the standard state partial vapor pressure of water. In the field of food science, the standard state is most often defined as pure water at the same tempera ...

environments (e.g., a_W = 0.86–0.88). This species is also

psychrophilic Psychrophiles or cryophiles (adj. ''psychrophilic'' or ''cryophilic'') are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from to . They have an optimal growth temperature at . They are found in ...

, it can grow at temperatures between . ''Cladosporium cladosporioides'' occurs outdoor environments year-round with peak spore concentration in the air occurring in summer where levels can range from 2,000 spores up to 50,000 spores per cubic meter of air. It is among the most common of all outdoor airborne fungi, colonizing plant materials and soil. It has been found in a number of crops, such as wheat, grapes, strawberries, peas and spinach. This species also grows in indoor environments, where it is often associated with the growth of fungi including species of ''

'', ''

Aspergillus versicolor ''Aspergillus versicolor'' is a slow-growing filamentous fungus commonly found in damp indoor environments and on food products. It has a characteristic musty odor associated with moldy homes and is a major producer of the hepatotoxic and carcin ...

'' and ''

Wallemia sebi ''Wallemia sebi'' is a xerophilic fungus of the phylum Basidiomycota. It is commonly found on highly sugared or salted materials, such as jams, bread, cakes, sugar, bacon, salted meats, and salted fish. It is also found in indoor air, house du ...

''. ''Cladosporium cladosporioides'' grows well on wet building materials, paint, wallpaper and textiles, as well as on paper, pulp,

fresco Fresco (plural ''frescos'' or ''frescoes'') is a technique of mural painting executed upon freshly laid ("wet") lime plaster. Water is used as the vehicle for the dry-powder pigment to merge with the plaster, and with the setting of the plaste ...

s, tiles, wet

window sill A windowsill (also written window sill or window-sill, and less frequently in British English, cill) is the horizontal structure or surface at the bottom of a window. Window sills serve to structurally support and hold the window in place. The ...

s and other indoor substrates including salty and sugary foods. Due to its tolerance of lower temperatures, ''C. cladosporioides'' can grow on refrigerated foods and colonize moist surfaces in refrigerators.

Role in disease

Plants

''Cladosporium cladosporioides'' and '' C. herbarum'' cause ''Cladosporium'' rot of red wine grapevines. The incidence of infection is much higher when the harvest of the grapes is delayed. Over 50% of grape clusters can be affected at harvest, which greatly reduced the yield and affects the wine quality. This delay is required in order for the phenolic compounds in the grapes to ripen and contribute to the aroma and flavour development in wine of optimum quality. Symptoms of ''Cladosporium'' rot are typically observed on mature grapes and are characterized by dehydration, a small area of decay that is firm, and a layer of olive-green mould. Although leaf removal reduces the incidence of infection by many species of fungi, it leads to an increase in ''C. cladosporioides'' populations on grape clusters and an increase in rotten grapes at harvest. Removal of diseased leaves is therefore counter-indicated in the control of this fungus. The only recommendation made to avoid severe ''Cladosporium'' infections of grape clusters is to limit periods of continuous exposure to sunlight. This species has also been involved in the rotting of strawberry blossoms. Infection of strawberry blossoms by ''C. cladosporioides'' has been associated with simultaneous infections by '' Xanthomonas fragariae'' (in California), and more recently '' C. tenuissimum'' (in Korea). ''C. cladosporioides'' infects the

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

sepals A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

petals Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corolla''. Petals are usually ...

and

pistils Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

of the strawberry blossom and is typically observed on older flowers with dehisced

and signs of

senescence Senescence () or biological aging is the gradual deterioration of functional characteristics in living organisms. The word ''senescence'' can refer to either cellular senescence or to senescence of the whole organism. Organismal senescence inv ...

. From 1997-2000, there was a higher proportion of misshapen fruits due to ''C. cladosporioides'' infection, and their

culling In biology, culling is the process of segregating organisms from a group according to desired or undesired characteristics. In animal breeding, it is the process of removing or segregating animals from a breeding stock based on a specific tr ...

affected the strawberry industry in California. Infection leads to

necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...

of the entire flower, or parts of it, as well as to the production of small and misshapen fruits and green-grey

sporulation In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

on the stigma. A higher occurrence of infection is observed in strawberry plants cultivated outdoors than cultivated in a greenhouse.

Animals

''Cladosporium cladosporioides'' rarely causes infections in humans, although superficial infections have been reported. It can occasionally cause pulmonary and cutaneous

phaeohyphomycosis Phaeohyphomycosis is a diverse group of fungal infections, caused by dematiaceous fungi whose morphologic characteristics in tissue include hyphae, yeast-like cells, or a combination of these. It can be associated an array of melanistic filamento ...

and it has been isolated from

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...

in an

immunocompromised Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that a ...

patient. This species can trigger asthmatic reactions due to the presence of allergens and

beta-glucans Beta-glucans, β-glucans comprise a group of β-D-glucose polysaccharides (glucans) naturally occurring in the cell walls of cereals, bacteria, and Fungus, fungi, with significantly differing Physical chemistry, physicochemical properties depend ...

on its

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

surface. In mice, living ''C. cladosporioides'' spores have induced hyperresponsiveness of the lungs, as well as an increase in

eosinophils Eosinophils, sometimes called eosinophiles or, less commonly, acidophils, are a variety of white blood cells (WBCs) and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates. A ...

, which are

white blood cells White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from mult ...

typically associated with

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

tic and

allergic Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...

reactions. ''Cladosporium cladosporioides'' can also induce respiratory inflammation due to the up-regulation of

macrophage inflammatory protein Macrophage Inflammatory Proteins (MIP) belong to the family of chemotactic cytokines known as chemokines. In humans, there are two major forms, MIP-1α and MIP-1β that are now (according to the new nomenclature) officially named CCL3 and CCL4, r ...

(MIP)-2 and

keratinocyte Keratinocytes are the primary type of Cell (biology), cell found in the epidermis (skin), epidermis, the outermost layer of the skin. In humans, they constitute 90% of epidermal skin cells. Basal cells in the stratum basale, basal layer (''str ...

chemoattractant (KC), which are

cytokine Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...

s involved in the mediation of inflammation. A case of

mycotic 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 ...

encephalitis Encephalitis is inflammation of the brain. The severity can be variable with symptoms including reduction or alteration in consciousness, headache, fever, confusion, a stiff neck, and vomiting. Complications may include seizures, hallucinations, ...

and

nephritis Nephritis is inflammation of the kidneys and may involve the glomeruli, tubules, or interstitial tissue surrounding the glomeruli and tubules. It is one of several different types of nephropathy. Types * Glomerulonephritis is inflammation of th ...

due to ''C. cladosporioides'' has been described in a dog, resulting in altered behaviour, depression, abnormal reflexes in all 4 limbs and loss of vision. Post-mortem examination indicated posterior brainstem and

cerebellar The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...

lesions, confirming the causative involvement of the agent.

References

External links

* * {{DEFAULTSORT:Cladosporium cladosporioides Fungal plant pathogens and diseases Wheat diseases Cladosporium Fungi described in 1880