The mold Cladosporium was first described in 1816. Members of Cladosporium are widely distributed worldwide and commonly found on all kinds of plant material, soil, food, paint, textiles and other organic matters. They are also found colonizing as secondary invaders leaves infested by other plant pathogenic fungi.
Cladosporium spores represent the most common fungal component isolated from air. Being small, dry and usually formed in branched, easy to break chains, Cladosporium spores are well adapted to be easily released into the air and spread in large numbers over long distances.
Medical Relevance of Cladosporium Spores
Most members of Cladosporium group do not cause disease in humans. Cladosporium spores are of medical relevance given that long-term exposure to these spores can cause adverse health effects, including allergies and asthma symptoms.
The mechanism of sensitization of human beings by molds in general is not well understood. However, there are several possibilities, among them inhalation of dried mycelia in house dust or inhalation of spores from outdoor or indoor sources. It is well known that spores of Cladosporium are common in indoor and outdoor air. Cladosporium herbarum, for example, is an important cause of allergies.
While there no established safe or unsafe levels of airborne mold spores, a concentration of 3000 Cladosporium spores m3 in the air has been suggested as a threshold value for clinical significance.
Prevalence of Cladosporium Spores in Indoor Environment
Cladosporium is one of the most commonly recovered molds from indoor air followed by others such as Penicillium and Aspergillus. In summer the levels of Cladosporium spores in outdoor air are very high. In fact, most of the Cladosporium spores found in indoor environment in summer originate from outdoors.