Flat bottom cell culture plates

Aspergillus fumigatus (strain AF4215, MYA 1163; American Type Culture Collection) was grown on Sabouraud glucose agar plates (BD Bioscience, San Jose, CA, USA) for three days at 37 °C. Conidia were collected in Hanks’ balanced saline solution (Gibco) and filtered through a cell strainer. The estimation of the conidial number was performed microscopically in a Neubauer slide (LO–Laboroptik, Friedrichsdorf, Germany). Resting conidia were immediately used or were stored at 4 °C for a maximum of one week. A. fumigatus hyphae were prepared by seeding of resting conidia in flat-bottom cell culture plates (Nunc, Langenselbold, Germany) in Yeast Nitrogen Base (Sigma-Aldrich, Taufkirchen, Germany) medium for 17 h at 37 °C.

Two different strains each of A. fumigatus (strains AF4215, ATCC MYA 1163 and AF293), A. terreus (clinical isolates T9 and T90, provided by Cornelia Lass-Flörl, Medical University of Innsbruck, Innsbruck, Austria), A. niger complex (A. niger, clinical isolates BS and 715) and A. flavus (clinical isolates 253 and 467), and one strain of A. brasiliensis (strain ATCC 16404) were grown on Sabouraud glucose agar plates (BD Bioscience, San Jose, CA, USA) at 37 °C for 3 days. Conidia were harvested by gently scraping the surface of the plates, washed in Hanks’ balanced saline solution (Gibco, Paisley, UK) and filtered through sterile gauze. The number of the conidia was estimated in a Neubauer chamber (LO–Laboroptik, Friedrichsdorf, Germany). Resting conidia were used immediately for the experiments or stored at 4 °C for a maximum of one week. For the preparation of Aspergillus hyphae, resting conidia were plated in flat-bottom cell culture plates (Nunc, Langenselbold, Germany) and incubated in Yeast Nitrogen Base (YNB; Sigma-Aldrich, Taufkirchen, Germany) medium at 37 °C for 17 h to allow formation of hyphae.