Species diversity and cytotoxic potency of airborne sterigmatocystin-producing Aspergilli from the section Versicolores

• Published in: The Science of the total environment 2016-08, Vol.562, p.296-304
• Main Authors: Despot, Daniela Jakšić, Kocsubé, Sandor, Bencsik, Ottó, Kecskeméti, Anita, Szekeres, András, Vágvölgyi, Csaba, Varga, Janos, Klarić, Maja Šegvić
• Format: Article
• Language: English
• Subjects: Air Microbiology; Airborne fungi; Aspergillus; Aspergillus - cytology; Aspergillus - physiology; Croatia; Cytotoxicity; Dust; Environmental Monitoring; Genetic Variation; Mycotoxin; Sterigmatocystin; Sterigmatocystin - analysis; Sterigmatocystin - toxicity; Versicolores
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2016.03.183

This study presents the distribution and species diversity of sterigmatocystin-producing Aspergilli from the section Versicolores in the indoor air of apartment-AP, basements-BS and grain mill-GM in Croatia, as well as the cytotoxic potency of isolates. The species comprised 0.7–20% of total airborne fungi detected in the AP, 11–55% in the BS, and 0–2% in the GM. Based on CaM sequences, seven species were identified; dominant were Aspergillus jensenii and Aspergillus creber, followed by Aspergillus protuberus, Aspergillus venenatus, Aspergillus tennesseensis, Aspergillus amoenus, Aspergillus griseoaurantiacus and three undescribed species. All of the identified species produced sterigmatocystin-STC (HPLC/UV-VIS); A. griseoaurantiacus (208.29μg/mL) and A. jensenii (1.192–133.63μg/mL) produced the highest levels, the lowest were detected in A. protuberus and A. tennesseensis (0.117–2.749μg/mL). Lower species diversity was obtained in the GM due to overgrowth with more propulsive fungi. Relatively high STC levels (0.06–2.35μg/g) detected in 52% of GM dust samples confirmed the presence of STC-producers, although this STC cannot be exclusively attributed to Aspergilli (Versicolores). STC and the majority of STC-producing Aspergilli were cytotoxic to human lung A549 cells (IC50 0.9–2.3μg/mL) and THP-1 macrophage-like cells (IC50 0.3–0.6μg/mL) in relatively low concentrations suggesting that humans can be at high risk during chronic exposure. [Display omitted] •Abundance and species diversity of indoor STC-producing Aspergillus (Versicolores)•Based on CaM sequences indoor air comprised seven species of Versicolores.•All isolates produced STC but with differences in production capacity.•High STC levels in grain mill dust indicated the contamination with STC-producers.•STC and Aspergilli are cytotoxic in concentrations that can be detected indoors.