engleski

Post-flood risks of inhalation exposure to Aspergillus section Flavi

Species assigned to Aspergillus section Flavi are food contaminants and may cause mycoses. Higher humidity may favour their occurrence in indoor environments and support the biosynthesis of aflatoxin B1 (AFB1), their toxic and cancerogenic metabolite. The aim of this study was to compare the frequencies of aflatoxin-producing and non-producing Aspergilli isolated from flood affected and control area in Croatia. Additionally, comet assay was employed to evaluate their genotoxic potential. Aspergilli of interest were isolated from air (N=60) and dust (N=60) samples collected during 2016 and 2017, two and three years after flood in Eastern Croatia. Identification of the isolates was based on morphology and the partial calmodulin sequences. Microextracts prepared from fungal cultures were analysed on AFB1 content by LC/MS. Genotoxicity of extracted Aspergilli was tested in human lung adenocarcinoma cell line A549 by alkaline comet- assay. Aspergilli (Flavi) dominated in the samples collected in flood-affected area (33/40) compared to the control area (3/40) and were more frequent in the airsamples (83%). AFB1 producing abilities were confirmed only for isolates from flood affected area (10/33). Genotoxic potential measured as tail intensity (% of DNA in comet tail) was slightly higher for AFB1-negative compared to AFB1-positive extract (0.57 ±0.94 and 0.14 ± 0.31, respectively). Flood may support the occurrence of Aspergilli from section Flavi in indoor environments. Inhalation of these mycoparticles may have a harmful effect on the respiratory system of the exposed people regardless of AFB1 presence. This work has been fully supported by Croatian Science Foundation under the project MycotoxA (IP-092014-5982).

Aspergillus section Flavi, aflatoxin B1, genotoxicity, flood

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