Cladosporium Species Information

40+ species. Ubiquitous, Cosmopolitan. One of the most common molds found worldwide.

Cladosporium species have a world-wide distribution and are among the most common air-borne fungi. Some 500 species have been described. Cladosporium species are frequently isolated as contaminants

Cladosporium Scientific Information

Vegetative hyphae, conidiophores and conidia are equally pigmented. Conidiophores are more or less distinct from the vegetative hyphae, are erect, straight or flexuous, unbranched or branched only in the apical region, with geniculate sympodial elongation in some species. Conidia are 1- to 4-celled, smooth, verrucose or echinulate, with a distinct dark hilum and are produced in branched acropetal chains. The term blastocatenate is often used to describe chains of conidia where the youngest conidium is at the apical or distal end of the chain. Note, the conidia closest to the conidiophore and where the chains branch, are usually "shield-shaped". The presence of shield-shaped conidia, a distinct hilum, and chains of conidia that readily disarticulate, are diagnostic for the genus Cladosporium.

Cladosporium Growth Characteristics

Colonies are rather slow growing, mostly olivaceous-brown to blackish brown but also sometimes grey, buff or brown, suede-like to floccose, often becoming powdery due to the production of abundant conidia. Cladosporium produces a black pigment so that when it grows on a surface it looks black.

Grows well on cellulose surfaces.

Where is Cladosporium found?

Cladosporium is one of the most common mold species found in indoor and outdoor environments. In most cases, outdoor concentrations are higher than those indoors.

Typically when Cladosporium levels (associated with an indoor source) are elevated, other mold types will be elevated as well. As such, Cladosporium may only be an indicator of potential mold exposures.

Often found growing outside in soil, plant litter and decaying plants as well as on leaves.

Often found inside growing on textiles, wood, moist window sills, tile grout and often in bathrooms where the relative humidity is regularly above 50%. Also can be found growing on sheetrock, subfloor, OSB and plywood among other surfaces.

Is Cladosporium Allergenic?

Cladosporium, like all known mold species, can cause allergic sensitization in potentially sensitive individuals. As such, it can cause chronic allergic rhinitis, asthma, and possibly fungal sinusitis.

It is a potential allegen. Some people may experience hay fever, asthma and or Hot tub lung, Moldy wall hypersensitivity.

Many such infestations are localized and unlikely to cause any significant exposure. When infestation is severe, health risks are increased. It may pose a risk to an asthmatic individual if they have been sensitized to Cladosporium.

Toxins Produced by Cladosporium

Yes, this mold does produce the toxins Cladosporin and emodin. Neither is known to be highly toxic.

Cladosporium Health Effects

Generally speaking it does not present human risk but some reports have linked some species with chromoblastomycosis.

Localized infestations in a house can cause high airborne indoor concentrations that can pose a significant exposure risk. Such infestations should be remediated; remediation is possible when the infestation source is found. However, one should realize that after re-mediation you are likely to still find some Cladosporium present since outdoor air by itself is a major source.

Cladosporium Uses

Some enzymes produced by C. Herbarum are used in the production of oral contraceptives. The enzymes allow for the transformation of steroid intermediates such as pregnenolone and progesterone.

How to test for / identify the presence of Cladosporium

For identification, isolates are best grown on potato dextrose agar or 2% malt extract agar at 20-25C. Microscopic mounts are best made using a cellotape flag or slide culture preparation mounted in lactophenol cotton blue. A drop of alcohol is usually needed to detach the cellotape flag from the stick, and to act as a wetting agent.

This mold can be identified via air and direct sampling methods.

Is Cladosporium a "black mold"