Molecular characterization of Alternaria alternata and Cladosporium herbarum allergens.

Abstract

Investigations of fungal air spora have demonstrated that conidium-forming fungi usually predominate over other fungal groups. Cladosporium herbarum, Alternaria alternata, Penicillium sp. and Aspergillus sp., listed in decreasing frequency of occurrence, are most consistently associated with the highest mean percentages of total fungal spore catches. In addition to daily variations in meteorologie conditions and seasonal changes, both of which have enormous impact on the concentration of air spora, the amount and type of vegetation of a region or microenvironment may be important factors in determining the composition of the airborne fungal population. Over the past two decades most allergologists have recognized a need for more information on fungal allergy because of increased awareness of the problem and the greater number of patients suffering from asthma and rhinitis due to fungi. Seasonal variation in regard to fungi in the air or to those in homes, and their detection and monitoring but also the biological relevance of the allergenic protein in the fungal organism are new fields of studies (1, 2). In the environment, Cladosporium herbarum is the most frequently encountered mould in the air. The dry conidia are carried easily through the air and can be detected in extremely large numbers e.g. a concentration of 35000 conidia/cubic meter can often be measured. The indoor counts to a large extent reflect the outdoor concentration. Depending on climate conditions the conidia may begin to appear in the atmosphere in spring and rise to a peak in either late summer or early autumn. Cladosporium herbarum is one of the most common colonizer of dying and dead plants and also occurs in various soil types and on food. It can frequently be found in uncleaned refrigerators, foodstuff, on wet window frames, in houses with poor ventilation and houses with straw roofs (3, 4, 5).