engleski

Frequency of sterigmatocystin (stc)-producing dustborne aspergilli from flooded and unflooded houses in Croatia – employment of HPLC/DAD/MS method in STC exposure assessment.

STC is precursor of aflatoxin and also the end product in biosynthesis of Aspergilli from the section Versicolores. Mechanism of STC toxicity is transformation by CYP monooxygenases into epoxide, which forms DNA-adducts leading to hepatotoxicity and carcinogenicity. STC-producing Aspergilli are frequently airborne in damp dwellings and could be expected in dust contributing to STC intake by inhalation. The purpose of the study was to employ HPLC/DAD/MS method for STC analysis in STC-producing Aspergilli extracts in order to estimate health risk based on their STC-producing capacity and frequency in dust taken in winter and summer of the year 2016 from flooded and unflooded houses in Croatia. STC analysis was performed by HPLC-DAD-ESI/MS/MS gradient method: Symmetry C18 4.6x150 mm, 3.5 μm column ; mobile phase (methanol/water), flow rate 1.0 ml/min ; DAD 254 nm ; positive ionization mode. Aspergilli (Versicolores) were of similar frequency in control and flooded village (40–100 %) but the concentrations in dust were more than 10 times higher in flooded houses (4.5 x 105 CFU/g). STC production was confirmed for 6/6 control village isolates (6–30.2 mg/mg) in winter and 3/5 isolates in summer period (25.1–42.2 mg/mg). Isolates from the flooded area showed similar STCproducing abilities (3/3 isolates, 2.4–22.1 mg/mg in winter ; 9/13 isolates, 1.9–39.9 mg/mg in summer). Significantly higher concentrations of dustborne Aspergilli STC-producers in flooded houses suggest increased health risk due to expected STC content in inhalable dust. This work has been fully supported by Croatian Scientific Foundation under the project MycotoxA (IP-09-2014- 5982).

sterygmatocistin, aspergilli, HPLC-DAD-MS

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