CHARACTERIZATION OF AIRBORNE ASPERGILLUS SERIES VERSICOLORES COLLECTED IN FRENCH BIOAEROSOLS

Abstract

Indoor air quality and exposure to fungal bioaerosols is a major concern in Europe where people spend most of their time indoors. 30-50% of European homes have moisture problems facilitating mold growth, with significant health and economic consequences. Aspergilli series Versicolores are molds recurrently found in these homes which are known to cause allergies, aggravate asthma and produce sterigmatocystin, a potential human carcinogen. Recent phylogenetic studies highlighted new Versicolores species which led us to characterize fungal isolates of this section to better understand their repartition in French bioaerosols. Air samples were taken with a cyclonic biocollector indoor (hospital and mold-damaged homes) and outdoor (agricultural environment), temperature and relative humidity were recorded during sampling. Collection liquid was cultured on malt extract agar (MEA) medium supplemented with chloramphenicol (0.05%, w/v). Each colony was isolated and then purified on MEA. A total of 93 isolates belonging to the series Versicolores were characterized both macroscopically, microscopically and were also identified using molecular approach. We identified eight different species from bioaerosols: Aspergillus creber (n = 40), A. jensenii (n = 37), A. protuberus (n = 6), A. puulaauensis (n = 4), A. sydowii (n = 2), A. tabacinus (n = 2), A. fructus (n = 1), and A. amoenus (n = 1). The phylogenetic tree performed from the BenA sequences shows homologies between isolates of the same species recovered from bioaerosols collected in the same environment which confirms the interest of Bt2a/b primers set for the identification of species of the Versicolores series. This work constitutes the first characterization of Aspergilli of the series Versicolores from French bioaerosols.

Symptom Clusters