First Characterization and Description of Aspergillus Series Versicolores in French Bioaerosols

Abstract

Air quality can be altered by fungal contaminants suspended in the air, forming bioaerosols. Aspergilli section Nidulantes series Versicolores are recurrent in bioaerosols and are mainly responsible for allergies and asthma aggravation. Phylogenetic studies recently identified 12 new species within this series. This study is the first to identify species of Aspergillus series Versicolores in French bioaerosols and to characterize them macroscopically, microscopically and molecularly. Bioaerosols were collected in a cancer treatment center, in contaminated homes and in agricultural environments. A total of 93 isolates were cultured on selective media, observed by optical microscopy and identified by benA amplification before sequencing. The field data (temperature and relative humidity) were statistically tested to explore the ecology of these species. Eight species were identified from bioaerosols: Aspergillus creber and A. jensenii, which represent more than 80% of the isolates, and A. protuberus, A. puulaauensis, A. sydowii, A. tabacinus, A. amoenus and A. fructus. Aspergilli series Versicolores are distributed differently depending on the sampling site and climatic determinants. Aspergillus protuberus was found in bioaerosols collected under significantly lower relative humidity (p = 3.899 × 10−4). Characterization and repartition of these isolates belonging to the Versicolores series constitute an important step to better assess exposure to fungal bioaerosols.

Cellular Cytotoxicity and Oxidative Potential of Recurrent Molds of the Genus Aspergillus Series Versicolores

“…Aspergillus creber was the most common species in the bioaerosols (7 out of 11 isolates), which was consistent with data on fungal diversity in bioaerosols from the USA [17], Croatia [16], Italy [41], and our previous study [20] (France). Aspergillus amoenus, A. jensenii, and A. protuberus have also been found in bioaerosols in other studies [16,20]. However, the specific diversity here was quite low.…”

“…The cell survival measured after 24, 48, and 72 h of exposure did not show any significant difference with those measured for the negative control, except for the A549 cell line exposed to spore suspensions at 10 5 spores/mL of the Aspergillus jensenii species, considered as the most frequently found species of the series Versicolores in bioaerosols after A. creber [16,20].…”

“…DNA extraction was performed as described in our previous study [20] using a modified protocol of the Nucleospin™ Plant II kit (Macherey-Nagel, Duren, Germany). Fungal material was transferred to a 2 mL microcentrifuge tube with glass beads.…”

“…As mentioned in the introduction and in previous studies, the species of the series Versicolores showed a significant phenotypic polymorphism. This polymorphism was found at the microscopic level with the presence of spores of variable colors, and can be smooth, rough, or verrucous; and at the macroscopic level with a variety of textures and synthesis of pigments and exudates, even between isolates belonging to the same species [17,20,45].…”

“…This series currently includes 17 species, the majority of which have been discovered recently as a result of various phylogenetic studies [15][16][17][18]. These ubiquitous species are present in more than 70% of bioaerosols [19][20][21][22][23] and have been isolated from a wide variety of substrates (food, soil, air, sea water, plants, etc.) [21,22,[24][25][26][27].…”