Do fungal spore morphological traits correlate with allergenicity?

Abstract

Fungal spores, like pollen, are identified as sources of allergens, yet fungal spore morphology, unlike pollen morphology, has not been correlated with allergenicity. In this study, we listed allergenic fungi reported from published literature and gathered information about their spore morphologies including the species’ lifestyle, the ability to produce mycotoxins, and the types of hypersensitivity reactions they induced. We tested the association of these spore traits with the hypersensitivity reaction through correspondence analysis with Chisquare as the measure of distance. Our research listed a total of 158 species of allergenic fungi belonging to 82 genera and 30 taxonomic orders. Most of the species (n = 122) elicited a Type I hypersensitivity reaction while 33 species had more than one hypersensitivity type (Types I-III-IV). The most common allergenic fungi belong to the genus Alternaria (41 species). Two fungal taxa commonly found in spoiled food, Penicillium (9 species) and Aspergillus (8 species), were also listed as allergenic. We did not find any strong correlation between allergenic reaction with the following spore traits: shape, texture, color, size, appendages, and with the type of spores, presence of mycotoxins, and the species lifestyle. However, spore length and width were positively associated with hypersensitivity reaction. Allergenic fungi with short and/or narrow spores can likely cause multiple types of hypersensitivity reactions while fungi with large and/or wide spores can induce either Type I or Type III hypersensitivity reaction. Our research study provides interesting insights into the role of fungal spore morphologies in human allergenicity.